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81.
Stephanie K Tanamas Anita E Wluka Jean-Pierre Pelletier Johanne Martel-Pelletier François Abram Yuanyuan Wang Flavia M Cicuttini 《Arthritis research & therapy》2010,12(2):R58
Introduction
To examine the natural history of subchondral bone cysts and to determine whether knee cartilage loss and risk of joint replacement is higher in knees with cysts, compared with those with bone marrow lesions (BMLs) only or those with neither BMLs nor cysts. 相似文献82.
Eoin Gunnigle Paul McCay Matthew Fuszard Catherine H. Botting Florence Abram Vincent O'Flaherty 《Applied and environmental microbiology》2013,79(14):4210-4219
Low-temperature anaerobic digestion (LTAD) technology is underpinned by a diverse microbial community. The methanogenic archaea represent a key functional group in these consortia, undertaking CO2 reduction as well as acetate and methylated C1 metabolism with subsequent biogas (40 to 60% CH4 and 30 to 50% CO2) formation. However, the cold adaptation strategies, which allow methanogens to function efficiently in LTAD, remain unclear. Here, a pure-culture proteomic approach was employed to study the functional characteristics of Methanosarcina barkeri (optimum growth temperature, 37°C), which has been detected in LTAD bioreactors. Two experimental approaches were undertaken. The first approach aimed to characterize a low-temperature shock response (LTSR) of M. barkeri DSMZ 800T grown at 37°C with a temperature drop to 15°C, while the second experimental approach aimed to examine the low-temperature adaptation strategies (LTAS) of the same strain when it was grown at 15°C. The latter experiment employed cell viability and growth measurements (optical density at 600 nm [OD600]), which directly compared M. barkeri cells grown at 15°C with those grown at 37°C. During the LTSR experiment, a total of 127 proteins were detected in 37°C and 15°C samples, with 20 proteins differentially expressed with respect to temperature, while in the LTAS experiment 39% of proteins identified were differentially expressed between phases of growth. Functional categories included methanogenesis, cellular information processing, and chaperones. By applying a polyphasic approach (proteomics and growth studies), insights into the low-temperature adaptation capacity of this mesophilically characterized methanogen were obtained which suggest that the metabolically diverse Methanosarcinaceae could be functionally relevant for LTAD systems. 相似文献
83.
Corinne F Maurice Sarah CL Knowles Joshua Ladau Katherine S Pollard Andy Fenton Amy B Pedersen Peter J Turnbaugh 《The ISME journal》2015,9(11):2423-2434
Recent studies have provided an unprecedented view of the microbial communities colonizing captive mice; yet the host and environmental factors that shape the rodent gut microbiota in their natural habitat remain largely unexplored. Here, we present results from a 2-year 16 S ribosomal RNA gene sequencing-based survey of wild wood mice (Apodemus sylvaticus) in two nearby woodlands. Similar to other mammals, wild mice were colonized by 10 bacterial phyla and dominated by the Firmicutes, Bacteroidetes and Proteobacteria. Within the Firmicutes, the Lactobacillus genus was most abundant. Putative bacterial pathogens were widespread and often abundant members of the wild mouse gut microbiota. Among a suite of extrinsic (environmental) and intrinsic (host-related) factors examined, seasonal changes dominated in driving qualitative and quantitative differences in the gut microbiota. In both years examined, we observed a strong seasonal shift in gut microbial community structure, potentially due to the transition from an insect- to a seed-based diet. This involved decreased levels of Lactobacillus, and increased levels of Alistipes (Bacteroidetes phylum) and Helicobacter. We also detected more subtle but statistically significant associations between the gut microbiota and biogeography, sex, reproductive status and co-colonization with enteric nematodes. These results suggest that environmental factors have a major role in shaping temporal variations in microbial community structure within natural populations. 相似文献
84.
Bram Vivijs Pieter Moons Abram Aertsen Chris W. Michiels 《Applied and environmental microbiology》2014,80(19):6054-6061
Some members of the family Enterobacteriaceae ferment sugars via the mixed-acid fermentation pathway. This yields large amounts of acids, causing strong and sometimes even lethal acidification of the environment. Other family members employ the 2,3-butanediol fermentation pathway, which generates comparatively less acidic and more neutral end products, such as acetoin and 2,3-butanediol. In this work, we equipped Escherichia coli MG1655 with the budAB operon, encoding the acetoin pathway, from Serratia plymuthica RVH1 and investigated how this affected the ability of E. coli to cope with acid stress during growth. Acetoin fermentation prevented lethal medium acidification by E. coli in lysogeny broth (LB) supplemented with glucose. It also supported growth and higher stationary-phase cell densities in acidified LB broth with glucose (pH 4.10 to 4.50) and in tomato juice (pH 4.40 to 5.00) and reduced the minimal pH at which growth could be initiated. On the other hand, the acetoin-producing strain was outcompeted by the nonproducer in a mixed-culture experiment at low pH, suggesting a fitness cost associated with acetoin production. Finally, we showed that acetoin production profoundly changes the appearance of E. coli on several diagnostic culture media. Natural E. coli strains that have laterally acquired budAB genes may therefore have escaped detection thus far. This study demonstrates the potential importance of acetoin fermentation in the ecology of E. coli in the food chain and contributes to a better understanding of the microbiological stability and safety of acidic foods. 相似文献
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88.
Abram SR Alexander BT Bennett WA Granger JP 《American journal of physiology. Regulatory, integrative and comparative physiology》2001,281(5):R1390-R1393
Renal plasma flow (RPF) and glomerular filtration rate (GFR) are markedly increased during pregnancy. We recently reported that the renal hemodynamic changes observed during pregnancy in rats are associated with enhanced renal protein expression of neuronal nitric oxide synthase (nNOS). The purpose of this study was to determine the role of nNOS in mediating renal hemodynamic changes observed during pregnancy. To achieve this goal, we examined the effects of the nNOS inhibitor 7-nitroindazole (7-NI) on kidney function in normal conscious, chronically instrumented virgin (n = 6) and pregnant rats (n = 9) at day 16 of gestation. Infusion of 7-NI had no effect on RPF (4.7 +/- 0.7 vs. 4.8 +/- 0.9 ml/min), GFR (2.2 +/- 0.2 vs. 2.5 +/- 0.4 ml/min), or mean arterial pressure (MAP; 127 +/- 7 vs. 129 +/- 10 mmHg) in virgin rats. In contrast, 7-NI infused into pregnant rats decreased RPF (8.9 +/- 1.6 vs. 6.5 +/- 1.4 ml/min) and GFR (4.4 +/- 0.7 vs. 3.3 +/- 0.7 ml/min) while having no effect on MAP (123 +/- 4 vs. 123 +/- 3 mmHg). In summary, inhibition of nNOS in pregnant rats at midgestation results in significant decreases in RPF and GFR. nNOS inhibition in virgin rats had no effect on renal hemodynamics. These data suggest that nNOS may play a role in mediating the renal hemodynamic changes that occur during pregnancy. 相似文献
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90.
Camille Roubille Johanne Martel-Pelletier Jean-Pierre Raynauld Fran?ois Abram Marc Dorais Philippe Delorme Jean-Pierre Pelletier 《Arthritis research & therapy》2015,17(1)
IntroductionTo evaluate the impact of meniscal extrusion (Ext) on knee osteoarthritis (OA) structural progression and on response to strontium ranelate (SrRan) treatment at 36 months in patients with (+) or without (-) Ext, in association (+) or not (-) with bone marrow lesions (BML) in the medial compartment using X-rays (JSW) and qMRI.MethodsPatients from the qMRI substudy of the SEKOIA trial (SrRan 1 g/day, n = 113; SrRan 2 g/day, n = 105; placebo, n = 112) were stratified based on whether meniscal extrusion and/or BML were present or not in the medial compartment.ResultsIn the placebo group, Ext+ patients (n = 26) had more JSW loss (p = 0.002) and cartilage volume loss in the global knee (p = 0.034) and plateau (p = 0.005), and medial compartment (p = 0.0005) than Ext- patients (n = 86). Ext-BML+ patients (n = 18) demonstrated more JSW loss (p = 0.003) and cartilage volume loss in the global (p = 0.020) and medial femur (p = 0.055) than Ext-BML- (n = 68). Compared to Ext+ BML- (n = 14), Ext+ BML+ patients (n = 12) had more cartilage volume loss in the global femur (p = 0.028), with no change in JSW. The JSW loss (p = 0.0004) and cartilage volume loss (global knee, p = 0.033, medial compartment, p = 0.0005) were greater when Ext and BML were simultaneously present in the medial compartment. SrRan 2 g/day treatment demonstrated a reduction in OA knee structural progression with qMRI, but not with JSW, in which less cartilage volume loss was found in the plateaus (p = 0.007) in Ext+ patients (n = 15), and in the medial plateau (p = 0.046) in patients in whom both Ext and BML were co-localized.ConclusionThe findings of this study are novel and could have an impact on future strategies regarding clinical trials. Indeed, data first argue for a combined, cumulative effect of meniscal extrusion and bone marrow lesions on cartilage loss and, secondly, they showed that SrRan may have protective effects in OA patients with meniscal extrusion as well as when both meniscal extrusion and BML are co-localized. 相似文献