| 1. |
- Diakidou, Amalia, et al.
(author)
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Characterization of the contents of ascending colon to which drugs are exposed after oral administration to healthy adults
- 2009
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In: Pharmaceutical research. - : Springer Science and Business Media LLC. - 0724-8741 .- 1573-904X. ; 26:9, s. 2141-2151
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Journal article (peer-reviewed)abstract
- PURPOSE: To characterize the contents of the ascending colon in healthy adults under fasting and fed state conditions, with a view to designing in vitro studies to explain/predict dosage form performance in the lower gut. METHODS: Twelve healthy adults participated in a two-phase crossover study. In Phase A, subjects were fasted (water allowed) overnight plus 5 h in the morning prior to colonoscopy (fasted state). In Phase B, subjects were fasted overnight, consumed a standard breakfast (960 kcal) in the morning, and were offered a light lunch 4.5 h later. In this phase, colonoscopy was performed 1 h after lunch (fed state). Volume, pH, and buffer capacity of colonic contents were measured immediately upon collection. After ultracentrifugation, the supernatant was further characterized. RESULTS: Free water content, pH, surface tension, and isobutyrate levels were lower in fed than in fasted subjects. On the other hand, buffer capacity, osmolality, acetate, butyrate, cholate, and chenodeoxycholate levels were higher in fed subjects. Carbohydrate content; protein content; and levels of long chain fatty acids, phosphatidylcholine, and cholesterol were not affected significantly by prandial state. CONCLUSION: Composition of fluids in the ascending colon is affected by feeding. This may affect the performance of products designed to deliver drug to the colon.
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| 2. |
- Goumas, Georgios, et al.
(author)
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ACTiCLOUD : Enabling the Next Generation of Cloud Applications
- 2017
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In: 2017 IEEE 37TH INTERNATIONAL CONFERENCE ON DISTRIBUTED COMPUTING SYSTEMS (ICDCS 2017). - : IEEE Computer Society. - 9781538617915 - 9781538617922 - 9781538617939 ; , s. 1836-1845
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Conference paper (peer-reviewed)abstract
- Despite their proliferation as a dominant computing paradigm, cloud computing systems lack effective mechanisms to manage their vast amounts of resources efficiently. Resources are stranded and fragmented, ultimately limiting cloud systems' applicability to large classes of critical applications that pose non-moderate resource demands. Eliminating current technological barriers of actual fluidity and scalability of cloud resources is essential to strengthen cloud computing's role as a critical cornerstone for the digital economy. ACTiCLOUD proposes a novel cloud architecture that breaks the existing scale-up and share-nothing barriers and enables the holistic management of physical resources both at the local cloud site and at distributed levels. Specifically, it makes advancements in the cloud resource management stacks by extending state-of-the-art hypervisor technology beyond the physical server boundary and localized cloud management system to provide a holistic resource management within a rack, within a site, and across distributed cloud sites. On top of this, ACTiCLOUD will adapt and optimize system libraries and runtimes (e.g., JVM) as well as ACTiCLOUD-native applications, which are extremely demanding, and critical classes of applications that currently face severe difficulties in matching their resource requirements to state-of-the-art cloud offerings.
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| 3. |
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| 4. |
- Karakostas, Vasileios, et al.
(author)
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Efficient Resource Management for Data Centers : The ACTiCLOUD Approach
- 2018
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In: 2018 International conference on embedded computer systems. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450364942 ; , s. 244-246
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Conference paper (peer-reviewed)abstract
- Despite their proliferation as a dominant computing paradigm, cloud computing systems lack effective mechanisms to manage their vast resources efficiently. Resources are stranded and fragmented, limiting cloud applicability only to classes of applications that pose moderate resource demands. In addition, the need for reduced cost through consolidation introduces performance interference, as multiple VMs are co-located on the same nodes. To avoid such issues, current providers follow a rather conservative approach regarding resource management that leads to significant underutilization. ACTiCLOUD is a three-year Horizon 2020 project that aims at creating a novel cloud architecture that breaks existing scale-up and share-nothing barriers and enables the holistic management of physical resources, at both local and distributed cloud site levels. This extended abstract provides a brief overview of the resource management part of ACTiCLOUD, focusing on the design principles and the components.
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| 5. |
- Vertzoni, Maria, et al.
(author)
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Characterization of the ascending colon fluids in ulcerative colitis
- 2010
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In: Pharmaceutical research. - : Springer Science and Business Media LLC. - 0724-8741 .- 1573-904X. ; 27:8, s. 1620-1626
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Journal article (peer-reviewed)abstract
- Purpose: To characterize the fluid composition in ascending colon of fasted adults with ulcerative colitis in relapse and in remission with a view to predicting variations on dosage form performance in the lower inflamed gut. Methods: Twelve patients participated in a two-phase, crossover study. Enrolment to the relapse phase (Phase A) and designation of the remission state for the second colonoscopy (Phase B) were based on Clinical Rachmilewicz Index values. Samples were analyzed for pH and buffer capacity immediately upon collection. After ultracentrifugation, osmolality, surface tension, soluble protein, soluble carbohydrates, and the levels of ten bile acids, seven short-chain fatty acids (SCFAs), three long-chain fatty acids, triglycerides, diglycerides, monoglycerides, phosphatidylcholine, and cholesterol were measured. Results: Total SCFAs are significantly decreased in relapse, but pH remains unaffected. Regardless of remission/relapse status, pH and isobutyric acid levels are lower than in healthy adults. Buffer capacity, osmolality, and soluble protein are higher than in healthy adults. Treatment with prednisolone increases the volume of intracolonic contents. Conclusion: Variations in fluid composition of the ascending colon with activity and severity of ulcerative colitis may have an impact on the performance of orally administered products that are targeted to release the therapeutic agent in the colon.
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| 6. |
- Vertzoni, Maria, et al.
(author)
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Degradation kinetics of metronidazole and olsalazine by bacteria in ascending colon and in feces of healthy adults
- 2011
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In: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 413:1-2, s. 81-86
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Journal article (peer-reviewed)abstract
- PURPOSE To compare the degradation kinetics of metronidazole and olsalazine by the bacteria of ascending colon and the bacteria of feces of healthy adults. METHODS Contents of the ascending colon of seven healthy adults were collected under conditions simulating the bioavailability/bioequivalence studies in the fasted and in the fed states on a crossover basis. Material from the contents of the ascending colon was prepared by ultracentrifuging and diluting the precipitate with a volume of normal saline equivalent to that of the supernatant. Fecal material was prepared from feces of three healthy adults collected at two occasions that were separated by at least 6 months. Ex vivo drug degradation kinetics were evaluated under anaerobic conditions. RESULTS Mean half-lives of metronidazole degradation in material from the contents of the ascending colon collected in the fasted state and in fecal material were 16.1 and 2.4 min, respectively (p<0.001). The corresponding numbers for olsalazine were 57.8 and 9.2 min, respectively (p<0.001). Both compounds were stable in material from the contents of ascending colon collected in the fed state. CONCLUSIONS Compared with data in fecal material, degradation of metronidazole and olsalazine in material from the contents of the ascending colon is significantly slower and it becomes non-significant during the arrival of fresh food remnants in the region.
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