Reduced Satellite Cell Numbers and Myogenic Capacity in Aging Can Be Alleviated by Endurance Exercise

Background: Muscle regeneration depends on satellite cells, myogenic stem cells that reside on the myofiber surface. Reduced numbers and/or decreased myogenic aptitude of these cells may impede proper maintenance and contribute to the age-associated decline in muscle mass and repair capacity. Endurance exercise was shown to improve muscle performance; however, the direct impact on satellite cells in aging was not yet thoroughly determined. Here, we focused on characterizing the effect of moderate-intensity endurance exercise on satellite cell, as possible means to attenuate adverse effects of aging. Young and old rats of both genders underwent 13 weeks of treadmill-running or remained sedentary. Methodology: Gastrocnemius muscles were assessed for the effect of age, gender and exercise on satellite-cell numbers and myogenic capacity. Satellite cells were identified in freshly isolated myofibers based on Pax7 immunostaining (i.e., exvivo). The capacity of individual myofiber-associated cells to produce myogenic progeny was determined in clonal assays (in-vitro). We show an age-associated decrease in satellite-cell numbers and in the percent of myogenic clones in old sedentary rats. Upon exercise, there was an increase in myofibers that contain higher numbers of satellite cells in both young and old rats, and an increase in the percent of myogenic clones derived from old rats. Changes at the satellite cell level in old rats were accompanied with positive effects on the lean-to-fat Gast muscle composition and on spontaneous locomotion levels. The significance of these data is that they suggest that the endurance exercise-mediated boost in bot

Student perceptions of veterinary anatomy practical classes: a longitudinal study

Using cadaveric material to teach veterinary students poses many challenges. However, little research exists on the contribution of this traditional approach to student learning. This longitudinal study aimed to investigate student perceptions of cadaver-based anatomy classes in a vertically integrated veterinary curriculum at the University of Nottingham's School of Veterinary Medicine and Science. Likert-scale statements and free-text boxes were used in a questionnaire distributed to second-year veterinary students (response rate 59%, 61/103). The same questionnaire was subsequently distributed to the same cohort 2 years later, in the students' fourth year of study (response rate 68%, 67/98). Students agreed that cadaver-based activities aid their learning, and they particularly value opportunities to develop practical skills while learning anatomy. There are few changes in perception as undergraduates progress to clinical years of teaching. Students perceive anatomy to be important, and feel that their learning has prepared them for clinical placements. This study emphasizes the importance of using cadaveric materials effectively in anatomy teaching and, in particular, using clinical skills training to enhance the anatomy curriculum

The effects of dissection-room experiences and related coping strategies among Hungarian medical students

Background: Students get their first experiences of dissecting human cadavers in the practical classes of anatomy and pathology courses, core components of medical education. These experiences form an important part of the process of becoming a doctor, but bring with them a special set of problems. Methods: Quantitative, national survey (n = 733) among medical students, measured reactions to dissection experiences and used a new measuring instrument to determine the possible factors of coping. Results: Fifty per cent of students stated that the dissection experience does not affect them . Negative effects were significantly more frequently reported by women and students in clinical training (years 3,4,5,6). The predominant factor in the various coping strategies for dissection practicals is cognitive coping (rationalisation, intellectualisation). Physical and emotional coping strategies followed, with similar mean scores. Marked gender differences also showed up in the application of coping strategies: there was a clear dominance of emotional-based coping among women. Among female students, there was a characteristic decrease in the physical repulsion factor in reactions to dissection in the later stages of study. Conclusions: The experience of dissection had an emotional impact on about half of the students. In general, students considered these experiences to be an important part of becoming a doctor. Our study found that students chiefly employed cognitive coping strategies to deal with their experiences. Dissection-room sessions are important for learning emotional as well as technical skills. Successful coping is achieved not by repressing emotions but by accepting and understanding the negative emotions caused by the experience and developing effective strategies to deal with them. Medical training could make better use of the learning potential of these experiences

Balance and its Clinical Assessment in Older Adults - A Review

BACKGROUND: Human beings rely on multiple systems to maintain their balance as they perform their activities of daily living. These systems may be undermined functionally by both disease and the normal aging process. Balance impairment is associated with increased fall risk. PURPOSE: This paper examines the dynamic formulation of balance as activity and reviews the biological mechanisms for its control. A "minimal-technology" scheme for its clinical evaluation in the ambulatory care setting is proposed. METHODS: The PubMed, Scopus and CINAHL databases were searched for relevant articles using the following terms in combination with balance: aging, impairment, control mechanisms, clinical assessment. Only articles which describe test procedures, their psychometrics and rely exclusively on equipment found in a regular physician office were reviewed. RESULTS: Human bipedal stance and gait are inherently low in stability. Accordingly, an elaborate sensory apparatus comprising visual, vestibular and proprioceptive elements, constantly monitors the position and movement of the body in its environment and sends signals to the central nervous system. The sensory inputs are processed and motor commands are generated. In response to efferent signals, the musculoskeletal system moves the body as is necessary to maintain or regain balance. The combination of senescent decline in organ function and the higher prevalence of diseases of the balance control systems in older adults predisposes this population subset to balance impairment. Older adults with balance impairment are likely to present with "dizziness". The history should concentrate on the first experience, with an attempt made to categorize it as a Drachman type. Since the symptomatology is often vague, several of the recommended physical tests are provocative maneuvers aimed at reproducing the patient's complaint. Well-validated questionnaires are available for evaluating the impact of "dizziness" on various domains of patient's lives, including their fear of falling. Aspects of a good history and physical examination not otherwise addressed to balance function, such as medications review and cognitive assessment, also yield information that contributes to a better understanding of the patient's complaint. Ordinal scales, which are aggregates of functional performance tests, enable detailed quantitative assessments of balance activity. CONCLUSION: The integrity of balance function is essential for activities of daily living efficacy. Its deterioration with aging and disease places older adults at increased risk of falls and dependency. Balance can be effectively evaluated in the ambulatory care setting, using a combination of scalar questionnaires, dedicated history-taking and physical tests that do not require sophisticated instrumentation.http://deepblue.lib.umich.edu/bitstream/2027.42/193094/2/nihms754637.pdfPublished versio