Relationship of Skeletal Muscle Atrophy to Functional Status: A Systematic Research Review

2000 ◽  
Vol 2 (2) ◽  
pp. 117-131 ◽  
Author(s):  
Kathleen Michael

In the realm of muscle atrophy research, many studies address minute details of molecular function but few examine the effects of atrophy in terms of mobility, strength, endurance, and performance of activities of daily living. The relationship between impairment and functional limitation is the focus of this research review. A wide array of studies constitute this area of inquiry, including investigations as diverse and widely disparate as molecular chemistry and space travel and populations as different as rats, healthy young men, and elderly women. Thirty-four studies were selected based on their fit with the Enabling-Disabling Model. Three paradigms of atrophy and function emerged. Adaptation reflects the plastic nature of muscle when placed under certain conditions, ranging from disuse to high-resistance exercise. Injury/loss describes damage to muscle tissue from ischemia, medications, or reloading or reperfusion trauma. Also in this category is the loss of muscle that is seen with aging. Integrity relates to the muscle’s tendency to protect itself and maintain structural adjacencies and cellular proportions. Based on the 3 muscle research paradigms, the relationship of muscle atrophy to function is portrayed as a bidirectional interaction wherein form and function have an influence on each other by way of physical changes, including those of adaptation, injury/loss, or integrity. A conceptual model is constructed to reflect this relationship.

2019 ◽  
Vol 11 (1-2) ◽  
pp. 106-129
Author(s):  
Sirkku Inkeri Ruokkeinen ◽  
Aino Liira

This article examines the relationship of material text (text of the document) and paratext in light of fourteenth to sixteenth century evidence. Despite the wealth of interest generated by paratexts and paratextuality in recent years, especially in the fields of literary studies, book history, and translation studies, theoretical approaches to paratexts and paratextuality remain scarce. The paratextual status of an element is typically determined by its function, in combination with its distance from the material text: elements within the codex which do not share space with the text are part of the paratext. Less studied, however, is the gray area of elements which are located within the codex and share the space with the text. We examine this border between text and paratext through an analysis of late medieval and early modern initials, typeface, script and notes. While the form and function of the element are a good starting point, we propose that gauging the optionality of the element, in relation to the abstract text of the work and the material text of the document, is a better indicator of its paratextual status. Optionality should therefore be taken into consideration as evidence of a type of contemporary paratextual understanding.


Author(s):  
David Blockley

‘Everything has structure’ considers the fundamental nature and role of structure and the relationship of structural engineering with other engineering disciplines and with architecture. Decision making is driven by the purpose of a man-made structure and how ‘fitness for purpose’ is realised. There is a need to understand how forces flow through a structure in order to ensure it meets its primary purpose of being strong and safe whilst at the same time meeting many other needs such as affordability, aesthetic, and regulatory and environmental criteria. The best structures are a harmony of architecture and engineering—where form and function are one and the flow of forces is logical.


1964 ◽  
Vol 96 (7) ◽  
pp. 991-1004 ◽  
Author(s):  
Margaret Rae MacKay

AbstractThe information to be obtained from thorough life-history studies is an extremely useful tool, perhaps especially so when ecology is being emphasized, as it is to-day, by the life-table and other mathematical approaches to the study of population processes. This information is desired by workers in many fields of entomology – by the biological and chemical control experts, the biomathematicians, the theorists and even the taxonomists. However, much of the knowledge that these workers require, for instance the fine distinctions of behaviour and environment, has been overlooked in most life-history studies, and I strongly suspect that one of the weaknesses of studies of this nature has been the failure to analyse the mode of living of an insect (or, in the case of Lepidoptera, of the immature forms) in relation to the anatomy on one hand and environmental circumstances on the other. To look for these relationships, I believe that one requires (a) the ability and perseverance to perceive detail as minute as that required for a taxonomic study, and (b) a considerable knowledge of the taxonomic detail that is to be obtained from basic morphological studies. Therefore, in this paper, attention is drawn to pertinent structural characters of lepidopterous larvae and their probable connection with the behaviour and microhabitats of the larvae, in the hope that some guidance may be offered to future students of life-histories, at least in Lepidoptera.


Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).


Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 807
Author(s):  
Silvia Ravalli ◽  
Concetta Federico ◽  
Giovanni Lauretta ◽  
Salvatore Saccone ◽  
Elisabetta Pricoco ◽  
...  

Skeletal muscle atrophy, resulting from states of hypokinesis or immobilization, leads to morphological, metabolic, and functional changes within the muscle tissue, a large variety of which are supported by the stromal cells populating the interstitium. Telocytes represent a recently discovered population of stromal cells, which has been increasingly identified in several human organs and appears to participate in sustaining cross-talk, promoting regenerative mechanisms and supporting differentiation of local stem cell niche. The aim of this morphologic study was to investigate the presence of Telocytes in the tibialis anterior muscle of healthy rats undergoing an endurance training protocol for either 4 weeks or 16 weeks compared to sedentary rats. Histomorphometric analysis of muscle fibers diameter revealed muscle atrophy in sedentary rats. Telocytes were identified by double-positive immunofluorescence staining for CD34/CD117 and CD34/vimentin. The results showed that Telocytes were significantly reduced in sedentary rats at 16 weeks, while rats subjected to regular exercise maintained a stable Telocytes population after 16 weeks. Understanding of the relationship between Telocytes and exercise offers new chances in the field of regenerative medicine, suggesting possible triggers for Telocytes in sarcopenia and other musculoskeletal disorders, promoting adapted physical activity and rehabilitation programmes in clinical practice.


Blood ◽  
1948 ◽  
Vol 3 (7) ◽  
pp. 729-754 ◽  
Author(s):  
WILLIAM N. VALENTINE ◽  
CHARLES G. CRADDOCK ◽  
JOHN S. LAWRENCE

Abstract The hormonal control through the hypophyseo-adrenal cortical system of lymphoid tissue structure and function is an important concept. We cannot at the present time regard that the concept is established fact. Final judgment must await additional work and the clarification of some of the inconsistencies which appear to exist. It seems reasonable that lymphoid tissue is one of the end organs of adrenal cortical hormone and that it may perhaps play a role in the response of the organism to stress. It seems quite clear that the sugar hormone of the adrenal cortex is capable of producing structural alterations in lymphoid tissue. Change in thoracic duct lymphocyte numbers as a result of augmentation in the amount of available adrenal cortical hormone is at present controversial. Experiments in this laboratory have failed to demonstrate it. The production of lymphopenia, at least in some species and possibly in man, by increasing available sugar hormone is supported by some evidence. The exact mechanism of production of lymphopenia is open to question, its relationship to changes in lymphoid tissue structure being one of inference. The converse situation—absolute lympocytosis resulting from deprivation of adrenal cortical hormone—is the subject of controversial reports. At best, it must be admitted that relatively slight alterations from the accepted normal range of lymphocyte values occur in the adrenal insufficient organism. Changes in plasma gamma globulins and antibody titers associated with changes in the amount of available cortical hormone are reported. It should be clarified whether such changes have necessarily resulted from lymphocyte dissolution or are related to other of the variegated actions of adrenal cortical hormone. The relationship of adrenal cortical hormone to lymphoid tissue and lymphocytes and the relationship of the latter to the response of the organism to stress must indeed be complex. It is reasonably well established that the life span of the lymphocyte is very short indeed1,58,22 and each lymphocyte presumably liberates its metabolically important contents within a few hours at the most. If stress continues for any period of time, as often it does, it is difficult to visualize the wisdom of interfering with the production of metabolically vital substances in order to secure the transient benefits of lymphoid tissue dissolution. It is also somewhat difficult to regard as proved that the various changes reported after hormone augmentation or deprivation necessarily represent the normal mechanism by which these factors are regulated and kept within physiologic limits. More investigations are required to answer such questions and to further elucidate the interrelationship of the adrenal cortex and lymphoid tissues.


Open Heart ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. e000831 ◽  
Author(s):  
Melissa Suzanne Burroughs Peña ◽  
Katrina Swett ◽  
Robert C Kaplan ◽  
Krista Perreira ◽  
Martha Daviglus ◽  
...  

ObjectiveTo describe the relationship of household secondhand smoke (SHS) exposure and cardiac structure and function.MethodsParticipants (n=1069; 68 % female; age 45–74 years) without history of tobacco use, coronary artery disease or severe valvular disease were included. Past childhood (starting at age <13 years), adolescent/adult and current exposure to household SHS was assessed. Survey linear regression analyses were used to model the relationship of SHS exposure and echocardiographic measures of cardiac structure and function, adjusting for covariates (age, sex, study site, alcohol use, physical activity and education).ResultsSHS exposure in childhood only was associated with reduced E/A velocity ratio (β=−0.06 (SE 0.02), p=0.008). SHS exposure in adolescence/adult only was associated with increased left ventricular ejection fraction (LVEF) (1.2 (0.6), p=0.04), left atrial volume index (1.7 (0.8), p=0.04) and decreased isovolumic relaxation time (−0.003 (0.002), p=0.03). SHS exposure in childhood and adolescence/adult was associated with worse left ventricular global longitudinal strain (LVGLS) (two-chamber) (0.8 (0.4), p= 0.049). Compared with individuals who do not live with a tobacco smoker, individuals who currently live with at least one tobacco smoker had reduced LVEF (−1.4 (0.6), p=0.02), LVGLS (average) (0.9 (0.40), p=0.03), medial E′ velocity (−0.5 (0.2), p=0.01), E/A ratio (−0.09 (0.03), p=0.003) and right ventricular fractional area change (−0.02 (0.01), p=0.01) with increased isovolumic relaxation time (0.006 (0.003), p=0.04).ConclusionsPast and current household exposure to SHS was associated with abnormalities in cardiac systolic and diastolic function. Reducing household SHS exposure may be an opportunity for cardiac dysfunction prevention to reduce the risk of future clinical heart failure.


2019 ◽  
Vol 8 (9) ◽  
pp. 214-225
Author(s):  
Nongmeikapam Premika Devi

The present study examines the relationship of depression and the neuropsychologicalfunction of attention, planning and auditory verbal learning and memory among individualswith HIV/AIDS. 200 subjects who were HIV/AIDS positive (100 males and 100 females) andwere within age range of 20 to 50 years and minimum education level of 8th standard weretaken. The result indicates that Depression slows down the performance of attention; alsodepression most likely decreases the function of auditory verbal learning and memory


Perichoresis ◽  
2015 ◽  
Vol 13 (1) ◽  
pp. 75-97
Author(s):  
Laura Verner

Abstract An integral method of keeping a non-conforming community functioning is the construction and up keep of networks, as this web of connections provided security and protection with other non-conformists against the persecuting authorities. The non-conforming Catholic community of Elizabethan England (1558-1603) established various networks within England and abroad. This article is based on research that examines the network of Catholics in the Elizabethan Midlands in order to understand both its effectiveness and the relationship of the local and extended Catholic community with one another. The construction, function and result of these networks will be surveyed over several categories of networks, such as local, underground, clerical and exile. Members of the Midland Catholic community travelled to others areas of the British Isles and Europe to gather spiritual and material support for their faith, sent their children abroad for religious education, and resettled abroad creating in this wake a larger and complex international network. The main objective of this exercise is to show the dynamic and function of the network, and understand the impact it had at the local level for Midland Catholics.


Author(s):  
Мархат Увайсовна Яхьяева

В статье предпринята попытка соотношения таких юридических категорий, как «уголовное преследование» и «функция обвинения». Проводится компаративный анализ обвинения и подозрения как неотъемлемых элементов деятельности органов, осуществляющих уголовное преследование. The article attempts to correlate such legal categories as “criminal prosecution” and “function of accusation”. A comparative analysis of charges and suspicions as integral elements of the activities of bodies carrying out criminal prosecution is carried out.


Sign in / Sign up

Export Citation Format

Share Document