Skeletal muscle is a post-mitotic tissue maintained by repair and regeneration through a population of stem cell-like satellite cells. Following muscle injury, satellite cell proliferation is ...mediated by local signals ensuring sufficient progeny for tissue repair. Age-related changes in satellite cells as well as to the local and systemic environment potentially impact on the capacity of satellite cells to generate sufficient progeny in an ageing organism resulting in diminished regeneration. 'Rejuvenation' of satellite cell progeny and regenerative capacity by environmental stimuli effectors suggest that a subset of age-dependent satellite cell changes may be reversible. Epigenetic regulation of satellite stem cells that include DNA methylation and histone modifications which regulate gene expression are potential mechanisms for such reversible changes and have been shown to control organismal longevity. The area of health and ageing that is likely to benefit soonest from advances in the biology of adult stem cells is the emerging field of regenerative medicine. Further studies are needed to elucidate the mechanisms by which epigenetic modifications regulate satellite stem cell function and will require an increased understanding of stem-cell biology, the environment of the aged tissue and the interaction between the two.
Skeletal muscle is a post-mitotic tissue maintained by repair and regeneration through a population of stem
cell-like satellite cells. Following muscle injury, satellite cell proliferation is ...mediated by local signals ensuring sufficient
progeny for tissue repair. Age-related changes in satellite cells as well as to the local and systemic environment potentially
impact on the capacity of satellite cells to generate sufficient progeny in an ageing organism resulting in diminished
regeneration. 'Rejuvenation' of satellite cell progeny and regenerative capacity by environmental stimuli effectors suggest
that a subset of age-dependent satellite cell changes may be reversible. Epigenetic regulation of satellite stem cells that include
DNA methylation and histone modifications which regulate gene expression are potential mechanisms for such reversible
changes and have been shown to control organismal longevity. The area of health and ageing that is likely to
benefit soonest from advances in the biology of adult stem cells is the emerging field of regenerative medicine. Further
studies are needed to elucidate the mechanisms by which epigenetic modifications regulate satellite stem cell function and
will require an increased understanding of stem-cell biology, the environment of the aged tissue and the interaction between
the two.
Laryngeal mask airway is a non invasive supraglottic device which has led to a radical change in the management of modern general anaesthesia. Propofol as a single agent is unsatisfactory and to ...overcome problems associated with LMA insertions. In the present study, we evaluated the haemodynamic changes and laryngeal mask airway insertion conditions comparing ketamine and opioids as adjuncts to propofol.
90 patients were randomly divided into 3 groups of 30 each. In Group PK-ketamine 0.5mg kg(-1), in Group PF-fentanyl 1ug kg(-1) and in Group PB - butorphanol 20ug kg(-1) was given intravenously immediately before induction with propofol 2.5 mg kg(-1). Jaw relaxation was assessed according to Young's criteria and the overall conditions according to modified Scheme of Lund and Stovener.
The mean total dose of propofol required in Group PK was 160.37 ± 15.75mg, in Group PF 156.22 ± 17.18 mg and in Group PB 140.08 ± 18.97 mg. The incidence of absolute jaw relaxation was highest in Group PB (93.33%) patients, intermediate in Group PF (53.33%) patients and lowest in Group PK i.e. 36.66% patients. Excellent insertion conditions were observed in 12 (40%) patients in Group PK and 13 (43.33%) patients in Group PF and in 26 (86.67%) patients in Group PB. Group PK showed more rise in systolic and diastolic blood pressure and heart rate post LMA insertion as compared to Group PF and Group PB.
It is concluded that addition of butorphanol to propofol for LMA insertion provided absolute jaw relaxation and excellent insertion conditions with stable haemodynamics Side effects like coughing, gagging, lacrimation and laryngospasm were lower as compared to the other two groups.
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