Abstract：
:We present evidence of feed-forward loop relationships and positive association between physical activity and performance levels, which are components of frailty, using measures from 431 high functioning women initially aged 70-79 years followed over 7 visits. Physical activity levels were assessed using a questionnaire. Grip strength was measured using a handheld dynamometer and usual walking speed was measured over 4-m. The results suggest that a reduction in physical activity would not only degrade physical performance, but it would further reduce physical activity through declines in physical performance. As both physical activity and physical performance impact frailty, improvement of physical activity could help reduce frailty directly as well as indirectly via improved physical performance. Our findings support a priori hypothesis that feed-forward loops are present in the phenotype of frailty, which is due to dysregulated energetics. A methodologically broader implication is that we introduce modeling and analysis of feed-forward loop data here. The feed-forward loop, as we define it, is different from the concept of feedback loops used in biochemical systems. Generalizing our model of two-variable feed-forward loop, three, four or multivariable feed-forward loop can be applied to other biological systems.
journal_name
Mech Ageing Devjournal_title
Mechanisms of ageing and developmentauthors
RoyChoudhury A,Dam TT,Varadhan R,Xue QL,Fried LPdoi
10.1016/j.mad.2014.08.001subject
Has Abstractpub_date
2014-11-01 00:00:00pages
5-11eissn
0047-6374issn
1872-6216pii
S0047-6374(14)00055-4journal_volume
141-142pub_type
临床试验,杂志文章abstract：:In this paper, we approach the problem of attempting to understand senescence by understanding the complexity and hierarchical structure of mammalian organisms. To do this, we make use of some concepts from abstract relational biology; in particular, graph theory. We subsequently utilize these concepts to develop the ...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(84)90056-3
更新日期：1984-10-31 00:00:00
abstract：:The present review focuses on the effect of aging on flow-mediated outward remodeling (FMR) via alterations in estrogen metabolism, oxidative stress and inflammation. In ischemic disorders, the ability of the vasculature to adapt or remodel determines the quality of the recovery. FMR, which has a key role in revascula...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2020.111416
更新日期：2020-12-14 00:00:00
abstract：:This cross-sectional study was conducted among a rural elderly population of 725 individuals aged over 60 years from Eastern India to assess the association of multiple chronic diseases with frailty and dependence. Multimorbidity, frailty, and dependence were assessed using prevalidated tools. Regression models were u...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2020.111384
更新日期：2020-12-01 00:00:00
abstract：:Confluent late passage WI-38 human diploid fibroblast cultures grown in the presence or absence of hydrocortisone for fifteen population doublings were measured cytochemically for DNA, nuclear RNA, basic nuclear protein and acidic nuclear protein content during a 12-hour interval following a medium-change stimulation....
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(81)90059-2
更新日期：1981-11-01 00:00:00
abstract：:A subset of 43 [35S]methionine labeled mitochondrial proteins, identified on two dimensional electrophoresis gels of whole body extracts of adult Drosophila, were compared between two age groups. These flies, which except for their spermatocytes consist entirely of postmitotic cells, were 6 days old and 38 days old, w...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(86)90105-3
更新日期：1986-03-01 00:00:00
abstract：:Quantitative measurements of glycogen in aging bruchids showed there was a considerable decrease (> 50%) with age except on the fifth day when an increase was observed, followed by a decrease on the sixth day. The variations in glycogen content with age suggests that glycogen serves as one of the energy sources respon...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(80)90082-2
更新日期：1980-01-01 00:00:00
abstract：:Caenorhabiditis elegans males live longer than hermaphrodites when cultured individually. Since hermaphrodites contain a pair of X chromosomes (XX) and males are XO (there is no Y chromosome in C. elegans), we questioned whether chromosomal differences per se might impact life span. The use of mutations in the sex-det...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2007.06.001
更新日期：2007-07-01 00:00:00
abstract：:The ascidian Ciona intestinalis has a short life span and powerful regeneration capacities. The regeneration of the oral siphon (OS) involves wound healing, blastema formation, cell proliferation, and replacement of 8 oral pigment organs (OPO), the latter via differentiation and migration of stem/precursor cells from ...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2012.08.003
更新日期：2012-09-01 00:00:00
abstract：:This study aimed to assess platelets as a possible model for screening the accumulation of mitochondrial DNA mutations, particularly during normal ageing. For this purpose we isolated platelets from young and old donors selected by lack of systemic and haematological diseases. We studied the accumulation of a particul...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(97)00181-4
更新日期：1998-04-01 00:00:00
abstract：:In this paper, some of the key findings of the last decade will briefly be surveyed and, where possible, be related to two separate computer simulation models which have been designed to determine the validity of certain widely accepted dogmas and to define the limits and restrictions imposed by attrition of or ambigu...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(80)90103-7
更新日期：1980-09-01 00:00:00
abstract：:To investigate age-related changes in gene expression in WI-38 cells, we isolated RNA from young and senescent, quiescent cultures and made subtracted cDNA libraries. Density-arrested cells were incubated in serum-free MCDB-104 for 3 days. RNA was then isolated and subtracted cDNA libraries were made in the phagemid v...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(92)90039-g
更新日期：1992-09-01 00:00:00
abstract：:The intralobular distribution of three lysosomal enzymes, acid phosphatase, N-acetyl-beta-D-glucosaminidase, and beta-D-glucuronidase, was investigated in hepatocytes of 3-, 12-, 24-, and 36-month-old rats. The distribution pattern changed with age. In young rats, the activity was higher in the peripheral area than in...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(83)90109-4
更新日期：1983-06-01 00:00:00
abstract：:In the lung of Rana perezi no differences as a function of age have been found for any of the five major antioxidant enzymes, reduced (GSH), oxidized (GSSG) or glutathione ratio (GSSG/GSH), oxygen consumption (VO2) and for in vivo or in vitro stimulated tissue peroxidation. This frog shows a moderate rate of oxygen co...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(90)90089-x
更新日期：1990-12-01 00:00:00
abstract：:There is now strong evidence implicating the generation of reactive oxygen species (ROS) and the corresponding response to oxidative stress as key factors in the pathogenesis of several human diseases including cancer, atherosclerosis, and neurodegenerative disorders, and in ageing. The carcinogenicity of oxidative st...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章,评审
doi：10.1016/j.mad.2006.01.021
更新日期：2006-05-01 00:00:00
abstract：:Detailed structural, mutational, and biochemical analyses of human FEN1/DNA complexes have revealed the mechanism for recognition of 5' flaps formed during lagging strand replication and DNA repair. FEN1 processes 5' flaps through a previously unknown, but structurally elegant double-stranded (ds) recognition/single s...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章,评审
doi：10.1016/j.mad.2011.11.009
更新日期：2012-04-01 00:00:00
abstract：:Certain anatomic and functional parameters of the eye change with increasing chronological age. They may, therefore, serve as potential biomarkers of ageing. We investigated associations between four such ocular parameters (lens density, retinal vessel calibre, corneal endothelial cells and retinal nerve fibre layer t...
journal_title：Mechanisms of ageing and development
pub_type： 临床试验,杂志文章,多中心研究
doi：10.1016/j.mad.2013.05.002
更新日期：2013-07-01 00:00:00
abstract：BACKGROUND:The proportion of European elderly is expected to increase to 30% in 2060. Combining dietary components may modulate many processes involved in ageing. So, it is likely that a healthful diet approach might have greater favourable impact on age-related decline than individual dietary components. This paper de...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章,随机对照试验
doi：10.1016/j.mad.2013.10.002
更新日期：2013-11-01 00:00:00
abstract：:Population studies have demonstrated that telomere length (TL) displays great diversity among different populations. Previously described controversial findings associated longevity with specific mitochondrial DNA haplogroups (hgs) (e.g., J and U). These observations may be influenced by population diversity, geograph...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2015.01.002
更新日期：2015-01-01 00:00:00
abstract：:The present study investigated whether age-related changes in the production of Th1 and Th2 cytokines by human T cells might be linked to altered frequencies of naive (CD45RA+) and memory (CD45RO+) T cell subsets. T cells from healthy elderly humans (n = 32) stimulated with anti-CD3epsilon monoclonal antibody OKT3 plu...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(99)00030-5
更新日期：1999-08-30 00:00:00
abstract：:This paper is the second one in a series of two papers hypothesizing and testing systemic grounds of reproductive life history in the female fruit fly. In the first paper, we analyzed mechanisms of individual fecundity scheduling and have drawn the following conclusions. Individual fecundity in female flies is endowed...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2003.10.007
更新日期：2004-01-01 00:00:00
abstract：:Considerable amount of data has accumulated during the past few years showing several changes in gene expression as a function of age. However, the basic mechanism of aging still remains poorly understood. In this review, we have mainly analysed the data pertaining to the hypothesis that aging is associated with genet...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章,评审
doi：10.1016/0047-6374(93)90015-j
更新日期：1993-01-01 00:00:00
abstract：:The responses of the left and right ventricles (LV and RV) to physical conditioning in cold (25 degrees C) and thermoneutral temperatures (35 degrees C), with special reference to lactate dehydrogenase (LDH) and its isoenzyme profile, were studied in the 2-month (young)- and 12-month (middle-aged)-old rats. Moderate h...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(99)00004-4
更新日期：1999-04-01 00:00:00
abstract：:Extrachromosomal circular DNA complexes from peripheral blood lymphocytes from inbred mice of accelerated senescence, were detected by mica-press-adsorption method. In senescence-resistant series (SAM-R), polydisperse circular DNAs were observed at 7 weeks of age and a restricted size class of small circular forms of ...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(85)90051-x
更新日期：1985-01-01 00:00:00
abstract：BACKGROUND:It seems to be clear that hepatic age-related HMG-CoA reductase total activation is connected to a rise of reactive oxygen species (ROS). However, the mechanism by which ROS achieve this effect is unknown. Thus, in this work, we have performed a study of HMG-CoAR by analyzing the enzymes involved in its shor...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2007.10.001
更新日期：2007-11-01 00:00:00
abstract：:During adult life, the thymus involutes and thymic output of mature T cells drastically declines. The molecular events underlying this process are not well understood. Here, we present evidence of the importance of miRNAs in regulating T cell differentiation in the aged. miRNAs are a wide-ranging regulatory element in...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/j.mad.2010.09.008
更新日期：2010-11-01 00:00:00
abstract：:Aging and HIV disease show certain immunological similarities. In both situations, control over viral infection is diminished, and there is an increase in certain types of cancer. The immune cell type responsible for controlling viral infections and cancer is the so-called CD8 or cytotoxic T cell. In elderly persons a...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章,评审
doi：10.1016/j.mad.2003.11.003
更新日期：2004-02-01 00:00:00
abstract：:This investigation represents the largest study so far published on human DNA damage and aging. The subject of this investigation is damage, determined as DNA alterations which give rise to complete molecular breaks in the course of treatment of purified DNA solutions with single-strand-specific nucleases. The DNA is ...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(87)90055-8
更新日期：1987-11-01 00:00:00
abstract：:Pituitary adenomas were the most common grossly visible naturally occurring neoplasms found in over 27% of rats surviving beyond 17 months of age. Twenty-three pituitary adenomas, fixed in buffered neutral formalin and embedded in paraffin, were tested for the presence of prolactin (PRL), growth hormone (GH) and thyro...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/0047-6374(82)90065-3
更新日期：1982-10-01 00:00:00
abstract：:Expression of dystrophin and the dystrophin-related protein utrophin has been studied in the human fetal brain both in vivo and in vitro. Results showed that both these proteins were developmentally regulated, even if their expression followed a different pattern. Utrophin was found since very early stages of developm...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(01)00360-8
更新日期：2002-03-15 00:00:00
abstract：:Telomeres are supposed to play a role in cellular aging and might contribute to the genetic background of human aging and longevity. During the past few years telomere length has been measured in various human tissues. However, very little is known about the individual telomere loss in different tissues from the same ...
journal_title：Mechanisms of ageing and development
pub_type： 杂志文章
doi：10.1016/s0047-6374(00)00173-1
更新日期：2000-11-15 00:00:00
