Epworth Collection:
http://hdl.handle.net/11434/444
2024-03-28T10:46:16ZThe age-associated decrease in the amount of amplifiable full-length mitochondrial DNA in human skeletal muscle.
http://hdl.handle.net/11434/2008
Title: The age-associated decrease in the amount of amplifiable full-length mitochondrial DNA in human skeletal muscle.
Epworth Authors: Kovalenko, Sergey
Abstract: A variety of techniques have been applied to investigate the interrelationship between age-related atrophy of rat soleus muscle and other signs of muscle aging, such as changes in muscle fibre type composition, decrease in bioenergy capacity and accumulation of mitochondrial DNA (mtDNA) arrangements. Age-related atrophy of rat soleus muscle was shown to start at the age of about 28 months. It was accompanied by a decrease in the number of slow twitch muscle fibres (type I) and an increase in the proportion of muscle fibres co-expressing slow and fast myosins (type Ic and IIc fibres). Bioenergy capacity of the soleus muscle, assessed by the level of measurable cytochrome c oxidase (COX) activity, was found to be decreased both in the middle age and old rats compared to the young animals. Muscle atrophy was also accompanied by a decrease in the amount of full-lengthmitochondrial DNA (FL-mtDNA) amplifiable by the extra-long PCR (XL-PCR) and the increase in the number of mtDNA deletions. The results of the study show that the decline in the bioenergy capacity of the rat soleus occurs by the middle age. It is followed by the onset of the age-related muscle atrophy that is accompanied by both fibre type changes and functional mtDNA degradation.2002-01-01T00:00:00ZRelative risks and odds ratios: simple rules on when and how to use them.
http://hdl.handle.net/11434/1864
Title: Relative risks and odds ratios: simple rules on when and how to use them.
Epworth Authors: McKenzie, Dean; Thomas, Christopher
Abstract: AIM:
Relative risks and odds ratios are widely reported in the medical literature, but the latter can be very difficult to understand. We sought to further clarify these important indices.
METHODS:
We defined both relative risks and odds ratios, then looked at the types of study for which each statistic is suited. We illustrated calculation of relative risks and odds ratios through analysis of tabled data from a recent published longitudinal study, using a 2x2 table, bar charts and R, the open source statistical programming language. Simple rules for when and how to use relative risks and odds ratios are presented.
CONCLUSION:
Understanding the difference between relative risks and odds ratios and when and how to use them may aid clinical interpretation, dissemination and translation of research findings.2020-04-01T00:00:00ZGood clinical practice can and must include comparative effectiveness research.
http://hdl.handle.net/11434/1742
Title: Good clinical practice can and must include comparative effectiveness research.
Epworth Authors: Zeps, Nikolajs
Abstract: Key components of self‐improving healthcare systems are their ability to collect baseline data, identify opportunities for improvement, design and implement strategies for change, and measure the effectiveness and other outcomes of the intervention, in a ‘virtuous cycle’ of continuous improvement. Nowhere is this more clearly outlined than in the process of clinical trials of new interventions. The concept of development and implementation of new evidence is straightforward, but can be very difficult to achieve in practice. Cultural and infrastructural issues present significant barriers to achieving the ideal of continuous and consistent derivation of evidence to support changes in practice.2018-11-01T00:00:00ZRoundtable discussion. How best to ameliorate the normal increase in mitochondrial superoxide formation with advancing age.
http://hdl.handle.net/11434/1382
Title: Roundtable discussion. How best to ameliorate the normal increase in mitochondrial superoxide formation with advancing age.
Epworth Authors: Linnane, Anthony; Ernster, Lars; Nohl, Hans; Orrenius, Sten; Ozawa, T.; Ji, L. L.; Beckman, K.; Aiken, J. M.; Pepe, S.; Feuers, R. J.; Wei, Y. H.; Mori, A.; Barja, G.; Hipkiss, A. R.; Von Zglinicki, T.; Driver, C.; Goto, S.; Curtay, J. P.
Abstract: Aging is related to the rate of oxygen consumption. Over 90% of oxygen is used by the mitochondria; of this, 1 to 3% is diverted to superoxide radical formation. Although other sources of superoxide radicals (and H2O2) are present in the cell, their contribution should be small compared to that of the mitochondria.
Mitochondrial‐derived superoxide radicals can produce mitochondrial DNA changes. These changes are reflected in the synthesis of defected respiratory chain components that further increase the rate of superoxide radical formation and decrease the rate of ATP production. The decline in mitochondrial function with time is believed to contribute to the progressive increase in the chance of disease and death with increasing age. Thus, decreasing the rate of mitochondrial superoxide radical formation should be a significant focus of efforts to increase the span of healthy, useful life.
Today, mitochondrial superoxide radical production can be decreased by caloric restriction, and probably by nitrone and nitroso compounds‐if so, then also by nitroxides and hydroxylamines. Birds divert a smaller fraction of the O2 they use to the formation of superoxide radicals than do mammals; the same is true of the long‐lived white‐footed mouse compared to normal mice. Can means be found to do the same in humans? Another approach to the problem would be to search for compounds that can associate with electron‐rich areas of the respiratory chain‐possibly buckminsterfullerene and its derivatives (free radical sponges)‐so as to block access by O2 to these areas.
Denham Harman1998-11-01T00:00:00Z