This little - heralded, meticulous investigation into
the effects of ablation of the telomerase catalytic subunit in mice with human - like telomeres provides us with strong reassurance that, should it prove to be the preferred approach for implementing the OncoSENS strategy, the effects of knocking out TERT would be limited to those dictated by the loss of telomere - lengthening per se, and would not lead to an unintentional loss of some essential but hitherto - unknown phsyiological function.
On the other hand, there are many other tissues — notably, the kidney and articular cartilage — where p16Ink4a - expressing senescent cells appear to be a contributing factor to human and murine degenerative aging, but which were not evaluated in treated or control mice in this study, and it would be of interest to see
the effects of ablation of p16Ink4a - positive senescent cells.
Not exact matches
«Our study suggests that in patients with heart failure and atrial fibrillation, catheter
ablation is an effective alternative treatment that can help patients avoid or discontinue this drug to reduce the risk
of these long - term side
effects.»
In
effect, this UAV survey across the
ablation zone
of the ice sheet perfectly bridges the gap between people on the ground studying what's under their feet in just one part
of the ice sheet, and the satellite data that shows what's going on across the entire ice sheet.
Ablation of kappa - opioid receptors from brain dopamine neurons has anxiolytic - like
effects and enhances cocaine - induced plasticity.
Emory neuropsychologist Dan Drane, who probes the
effects of epilepsy surgery on memory and language abilities, had identified Olds as a good example
of how the more precise stereotactic laser
ablation procedure pioneered by Gross can preserve those cognitive functions, in contrast to an open resection.
To impute aging phenotypes directly to p16Ink4a - expressing senescent cells, van Deursen and colleagues with expertise in the aging and senescence
of the relevant tissues developed and tested the
effects of a pharmacologically - inducible system for the
ablation of p16Ink4a - expressing cells.
It should be noted, however, that while a study on senescent cell
ablation in genetically normal mice would provide at least some evidence on the
effect of senescent cells (and their
ablation) on promoting cancer, even such a study would likely show less
effect than could be anticipated in a large mammal model, since even normally - aging mice rarely suffer metastatic disease to the extent
of aging humans, as sheer primary tumor volume is generally sufficient to be fatal to mice.
(6) Following this initial test
of abrogating the early, age - related rise in p16Ink4a - expressing cell burden, the investigators probed the
effects of leaving BubR1H / H; INK - ATTAC to undergo 5 months
of rapid «premature aging» (and thus, to the attendant accumulation
of high levels
of p16Ink4a - positive cells and onset
of «early - aging» phenotypes), and only then inducing
ablation of senescent cells with the INK - ATTAC drug - activated system (see Figure 2 (g) below).
Whole - body Induced Cell Turnover (WICT) consists
of the qualitative and quantitative coordination
of targeted cell
ablation with exogenous cell administration so as to
effect the replacement
of a patient's entire set
of endogenous cells with exogenous cells (
of the same quantity and cell type as the ablated endogenous cells they are replacing) derived from human pluripotent stem cells and directionally differentiated in vitro prior to their administration.
For confirmation, we exploited the flexibility
of our system, enabling tamoxifen inducible conditional gene
ablation while controlling for genetic background and tamoxifen
effects.
Specifically, the metabolic
effects of musculoskeletal loading in the current experiments resemble the partial restoration
of insulin sensitivity reported in leptin - deficient mice following myostatin
ablation (55, 56).
In this estimate, only 4.2 mm per month
of liquid water equivalent are due to the mass added by enhanced precipitation; the vast majority
of the
effect (72 mm per month
of decreased
ablation) is due to the
effect of precipitation on reflectivity.
Detailed studies
of the energy balance and
ablation of the Zongo and Chacaltaya glaciers support the importance
of air temperature increase, and identify the increase in downward infrared radiation as the main way that the
effect of the warmer air is communicated to the glacier surface [Wagnon et al. 1999; Francou et al, 2003].
As the authors point out, even if the whole story comes down to precipitation changes which favor
ablation, the persistence
of these conditions throughout the 20th century still might be an indirect
effect of global warming, via the remote
effect of sea surface temperature on atmospheric circulation.
This underscores the fact that
ablation (via the reflectivity
effect) depends on the seasonal distribution
of snowfall.
Concerning this
effect, one should note that the measured
ablation differed by a factor
of two between the two years studied, even though annual mean snowfall was similar in both years.
Ludicrous as it may sound to you, a rigorous system model
of the
effect upon surface temperatures from albedo changes due to snow / ice
ablation will not have any feedback loop whatsoever back to the fundamental input
of insolation.
The warming could, under certain circumstances, increase the sublimation, but the
effect of this on
ablation is generally small, because
of the high energy required for sublimation.