Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | PubMed Central |
|---|---|
| Author | Cavenee, Webster K. Johnston, Dean George, Melnykovych |
| Abstract | Depression of the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase [mevalonate:NADP+ oxidoreductase (CoA-acylating); EC 1.1.1.34] was elicited by the removal of serum from the growth medium of HeLa S3G cells with a concomitant expected increase in cellular sterol biosynthesis; if dexamethasone (9α-fluoro-11β,17α,21-trihydroxy-16α-methyl-1, 4-pregnadiene-3,20-dione) was present in the serumless medium, there was an augmentation of HMG-CoA reductase activity but a suppression of sterol biosynthesis. When human serum, human low density lipoprotein, or calf serum was present in the medium, there was a reduction of both the enzyme activity and sterol biosynthesis, but the presence of dexamethasone resulted in an increase in HMG-CoA reductase activity as compared to the controls containing human serum, low density lipoprotein, or calf serum alone. In contrast, either low density lipoprotein or whole serum supplementation eliminated the differences in acetate incorporation into sterols between glucocorticoid-treated and untreated cells. Human high density lipoproteins had little effect on the enzyme activity and abolished the difference in sterol biosynthesis only at relatively high concentrations. Addition of low density lipoproteins to cells after preincubation in serumless medium elicited the same rate of decay of HMG-CoA reductase (t 1/2 3.8-4.2 hr) regardless of the presence of glucocorticoids in the medium, but there was an exaggerated lag before the onset of suppression in the hormone-treated cells. If free cholesterol was present in the medium, the dexamethasone augmentation of HMG-CoA reductase was maintained, but the addition of either 7-ketocholesterol or 25-hydroxycholesterol abolished the difference between glucocorticoid-treated and control cells. These observations suggest that, under certain physiological conditions, HMG-CoA reductase activity no longer accurately reflects cellular sterol biosynthesis. |
| Starting Page | 2103 |
| File Format | |
| ISSN | 10916490 |
| e-ISSN | 10916490 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Issue Number | 5 |
| Volume Number | 75 |
| Language | English |
| Publisher Date | 1978-05-01 |
| Access Restriction | Open |
| Subject Keyword | Research in Higher Education |
| Content Type | Text |
| Resource Type | Article |
| Subject | Multidisciplinary |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|