Search results for "restriction"
showing 10 items of 527 documents
Vertical stratification of bacteria and archaea in sediments of a small boreal humic lake
2019
ABSTRACT Although sediments of small boreal humic lakes are important carbon stores and greenhouse gas sources, the composition and structuring mechanisms of their microbial communities have remained understudied. We analyzed the vertical profiles of microbial biomass indicators (PLFAs, DNA and RNA) and the bacterial and archaeal community composition (sequencing of 16S rRNA gene amplicons and qPCR of mcrA) in sediment cores collected from a typical small boreal lake. While microbial biomass decreased with sediment depth, viable microbes (RNA and PLFA) were present all through the profiles. The vertical stratification patterns of the bacterial and archaeal communities resembled those in mar…
Interventions to Slow Aging in Humans: Are We Ready?
2015
The workshop entitled 'Interventions to Slow Aging in Humans: Are We Ready?' was held in Erice, Italy, on October 8-13, 2013, to bring together leading experts in the biology and genetics of aging and obtain a consensus related to the discovery and development of safe interventions to slow aging and increase healthy lifespan in humans. There was consensus that there is sufficient evidence that aging interventions will delay and prevent disease onset for many chronic conditions of adult and old age. Essential pathways have been identified, and behavioral, dietary, and pharmacologic approaches have emerged. Although many gene targets and drugs were discussed and there was not complete consens…
Beliefs and Experiences of Individuals Following a Zero-Carb Diet
2021
The adoption of carbohydrate-restrictive diets to improve health is increasing in popularity, but there is a dearth of research on individuals who choose to severely restrict or entirely exclude carbohydrates. The present study investigated the beliefs and experiences of individuals following a diet that severely limits, or entirely excludes, dietary carbohydrates, colloquially known as a ‘zero-carb’ diet, for at least 6 months. Zero-carb dieters (n = 170) recruited via a social networking site completed an online qualitative survey prompting them to discuss their motives, rationale, and experiences of following a low-carb diet. Transcripts of participants’ responses were …
Anti-aging medicine: pitfalls and hopes
2009
Since the beginnings of time humans have searched for a fountain of youth. This has led to many extravagant claims which have been highly profitable for their proponents. This area has become known as anti-aging medicine and has deservedly been frowned upon by the medical establishment. On the other hand, in the last decades dramatic advances in our understanding of the aging process have come from studies in worms, flies and mice. This article reviews some of these advances and places the extravagant claims of anti-aging medicine in perspective. We conclude that a balanced diet of moderate proportions and exercise remain today the only proven fountain of youth. © 2009 Informa UK Ltd.
Flavobacterium columnare colony types: connection to adhesion and virulence?
2008
Four different colony morphologies were produced by Flavobacterium columnare strains on Shieh agar plate cultures: rhizoid and flat (type 1), non-rhizoid and hard (type 2), round and soft (type 3), and irregularly shaped and soft (type 4). Colonies produced on AO agar differed from these to some extent. The colony types formed on Shieh agar were studied according to molecular characteristics [Amplified Fragment Length Polymorphism (AFLP), Automated Ribosomal Intergenic Spacer Analysis (ARISA), and whole cell protein SDS-PAGE profiles], virulence on rainbow trout fingerlings, and adhesion on polystyrene and fish gills. There were no molecular differences between colony types within one strai…
Molecular community and population studies of arbuscular mycorrhizal fungi (Glomeromycota)
2014
The arbuscular mycorrhizal symbiosis, which appeared at the same time as land plants, 460 million years ago, is a mutualistic beneficial association between most land plants, including those cultivated, and arbuscular mycorrhizal fungi (AMF). AMF, from the Glomeromycota phylum, are widespread soil microorganisms needing a photosynthetic host to complete their life cycle (obligate symbionts). The great potential of plant mineral nutrition improvement and crop production increased during this symbiosis, make AMF an asset in the context of an increase in the demand of world food crop production. The control of that symbiosis by ecology engineering in order to improve ecosystem services, especi…
Perlecan Maintains the Integrity of Cartilage and Some Basement Membranes
1999
Perlecan is a heparan sulfate proteoglycan that is expressed in all basement membranes (BMs), in cartilage, and several other mesenchymal tissues during development. Perlecan binds growth factors and interacts with various extracellular matrix proteins and cell adhesion molecules. Homozygous mice with a null mutation in the perlecan gene exhibit normal formation of BMs. However, BMs deteriorate in regions with increased mechanical stress such as the contracting myocardium and the expanding brain vesicles showing that perlecan is crucial for maintaining BM integrity. As a consequence, small clefts are formed in the cardiac muscle leading to blood leakage into the pericardial cavity and an ar…
Functional incorporation of green fluorescent protein into hepatitis B virus envelope particles
2004
AbstractThe envelope of hepatitis B virus (HBV), containing the L, M, and S proteins, is essential for virus entry and maturation. For direct visualization of HBV, we determined whether envelope assembly could accommodate the green fluorescent protein (GFP). While the C-terminal addition of GFP to S trans-dominant negatively inhibited empty envelope particle secretion, the N-terminal GFP fusion to S (GFP.S) was co-integrated into the envelope, giving rise to fluorescent particles. Microscopy and topogenesis analyses demonstrated that the proper intracellular distribution and folding of GFP.S, required for particle export were rescued by interprotein interactions with wild-type S. Thereby, a…
Screening of hereditary spastic paraplegia patients for alterations at NIPA1 mutational hotspots.
2008
Item does not contain fulltext Mutations in NIPA1 cause hereditary spastic paraplegia type 6 (SPG6 HSP). Sequencing of the whole gene has revealed alterations of either of two nucleotides in eight of nine SPG6 HSP families reported to date. By analysing CpG methylation, we provide a mechanistic explanation for a mutational hotspot to underlie frequent alteration of one of these nucleotides. We also developed PCR RFLP assays to detect recurrent NIPA1 changes and screened 101 independent HSP patients, including 45 index patients of autosomal dominant HSP families. Our negative finding in this cohort for which several other causes of HSP had been excluded suggests NIPA1 alterations at mutation…
Loss of heterozygosity at the short arm of chromosome 3 in renal‐cell cancer correlates with the cytological tumour type
1993
A majority of renal-cell tumours retain heterozygosity at the short arm of chromosome 3. To investigate possible histopathological differences between tumours with and without such losses, we compared loss of heterozygosity data from 51 tumours with 1 histological and 2 different cytological classifications of renal-cell tumour. Using the cytological classification of Thoenes et al., we only found tumours with loss of heterozygosity in these authors' clear-cell category. Possibly, only these tumours arise by a mechanism of double loss of a tumour-suppressor gene on 3p, non-clear-cell renal tumours having a different genetic background. Alternatively, deletions may occur in all subtypes, in …