Growth equations for skeletal muscle derived from the cytonuclear ratio and growth constraining supplementary functions

1999 ◽  
Vol 68 (1) ◽  
pp. 129-140 ◽  
Author(s):  
C. Z. Roux
Keyword(s):  
Muscle Mass ◽  
Whole Body ◽  
Muscle Fibres ◽  
Cell Nuclei ◽  
Cross Sectional ◽  
Body Protein ◽  
Mass Growth ◽  
Growth Constraints ◽  
The Difference ◽  
Almost All

AbstractFor purely hypertrophic muscle it is postulated that the growth rate in number of nuclei is proportional to the cytoplasmic mass per nucleus multiplied by a growth constraining supplementary function. Growth constraint depends on the distance from any one of the limit number of nuclei, the limit muscle mass or the limit cytoplasmic mass per nucleus. Furthermore, theory and evidence are presented for a power (allometric) relationship between total number of nuclei (n) and muscle mass (m) given by the equation n = gmh. Evidence points to two clusters of values for h, one in the vicinity of h = 2/3 and the other h = 1/2. Both may depend on a linear relationship between number of nuclei inside muscle fibre and fibre cross-sectional area. The difference between the two situations can be derived from basic assumptions on either local or systemic diffusion mediated control of the number or division of satellite cell nuclei, leading directly to values of h either equal to 2/3 or V2. For likely values of h and suitable choices of growth constraints, almost all well known growth functions in the literature are derived as potentially applicable to total number of nuclei, or muscle mass or their ratio. Muscle mass growth will show a sigmoidal form for h = 1. This explains sigmoidal growth in body mass as it is mostly dominated by muscle mass. A possible linear growth phase before maturity is explicable from the cessation of either length (h = 1) or nuclear (h = 0) growth in muscle fibres, while cytoplasmic growth continues to maturity. Furthermore, two rat examples indicate that whole body protein growth can be described by the equations derived for muscle mass growth.

Structure and electrical properties of eye muscles in cave- and surface-dwelling crayfishes

1980 ◽  
Vol 84 (1) ◽  
pp. 187-199
Author(s):  
D. Mellon ◽  
G. Lnenicka
Keyword(s):  
Input Resistance ◽  
Selective Advantage ◽  
Oculomotor System ◽  
Membrane Resistance ◽  
Muscle Fibres ◽  
Cross Sectional ◽  
Eye Muscles ◽  
Current Voltage ◽  
The Difference ◽  
Cave Dweller

The morphologies and passive electrical parameters of fibres in two eye muscles of a surface- and a cave-dwelling crayfish were compared. In the cave-dwelling form the muscles contained fewer fibres, of less diameter, and hence had a smaller cross-sectional area. Current-voltage relationships were similar in both species. Input resistance was higher in the cave-dweller, but the difference was not as great as would be expected on the basis of geometry alone. Accordingly, the specific membrane resistance of muscle fibres in the cave-dweller is 50–60% smaller than that in the surface-dweller. This may account partially for the observation that identified excitatory junctional potentials in muscles of cave- and surface dwellers have similar amplitudes. We conclude that a functional oculomotor system is maintained in cave-dwelling crayfish, and that this system confers some positive selective advantage.

scholarly journals Alternate Mediterranean diet score is positively associated with skeletal muscle mass index in middle-aged adults

2017 ◽  
Vol 117 (8) ◽  
pp. 1181-1188 ◽  
Author(s):  
Hui-yuan Tian ◽  
Rui Qiu ◽  
Li-peng Jing ◽  
Zhan-yong Chen ◽  
Geng-dong Chen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mediterranean Diet ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
General Information ◽  
Whole Body ◽  
Cross Sectional ◽  
Mediterranean Diet Score ◽  
Skeletal Muscle Mass Index ◽  
Diet Score

AbstractResearches have suggested Mediterranean diet might lower the risk of chronic diseases, but data on skeletal muscle mass (SMM) are limited. This community-based cross-sectional study examined the association between the alternate Mediterranean diet score (aMDS) and SMM in 2230 females and 1059 males aged 40–75 years in Guangzhou, China. General information and habitual dietary information were assessed in face-to-face interviews conducted during 2008–2010 and 3 years later. The aMDS was calculated by summing the dichotomous points for the items of higher intakes of whole grain, vegetables, fruits, legumes, nuts, fish and ratio of MUFA:SFA, lower red meat and moderate ethanol consumption. The SMM of the whole body, limbs, arms and legs were measured using dual-energy X-ray absorptiometry during 2011–2013. After adjusting for potential covariates, higher aMDS was positively associated with skeletal muscle mass index (SMI, SMM/height2, kg/m2) at all of the studied sites in males (all Ptrend<0·05). The multiple covariate-adjusted SMI means were 2·70 % (whole body), 2·65 % (limbs), 2·50 % (arms) and 2·70 % (legs) higher in the high (v. low) category aMDS in males (all P<0·05). In females, the corresponding values were 1·35 % (Ptrend=0·03), 1·05, 0·52 and 1·20 %, (Ptrend>0·05). Age-stratified analyses showed that the favourable associations tended to be more pronounced in the younger subjects aged less than the medians of 59·2 and 62·2 years in females and males (Pinteraction>0·10). In conclusion, the aMDS shows protective associations with SMM in Chinese adults, particularly in male and younger subjects.

scholarly journals Reference Values for Skeletal Muscle Mass – Current Concepts and Methodological Considerations

Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 755 ◽  
Author(s):  
Carina O. Walowski ◽  
Wiebke Braun ◽  
Michael J. Maisch ◽  
Björn Jensen ◽  
Sven Peine ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Reference Values ◽  
Skeletal Muscle Mass ◽  
Bioelectrical Impedance ◽  
Reference Population ◽  
Muscle Quality ◽  
Whole Body ◽  
Whole Body Imaging ◽  
Cross Sectional

Assessment of a low skeletal muscle mass (SM) is important for diagnosis of ageing and disease-associated sarcopenia and is hindered by heterogeneous methods and terminologies that lead to differences in diagnostic criteria among studies and even among consensus definitions. The aim of this review was to analyze and summarize previously published cut-offs for SM applied in clinical and research settings and to facilitate comparison of results between studies. Multiple published reference values for discrepant parameters of SM were identified from 64 studies and the underlying methodological assumptions and limitations are compared including different concepts for normalization of SM for body size and fat mass (FM). Single computed tomography or magnetic resonance imaging images and appendicular lean soft tissue by dual X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) are taken as a valid substitute of total SM because they show a high correlation with results from whole body imaging in cross-sectional and longitudinal analyses. However, the random error of these methods limits the applicability of these substitutes in the assessment of individual cases and together with the systematic error limits the accurate detection of changes in SM. Adverse effects of obesity on muscle quality and function may lead to an underestimation of sarcopenia in obesity and may justify normalization of SM for FM. In conclusion, results for SM can only be compared with reference values using the same method, BIA- or DXA-device and an appropriate reference population. Limitations of proxies for total SM as well as normalization of SM for FM are important content-related issues that need to be considered in longitudinal studies, populations with obesity or older subjects.

scholarly journals Japanese radio calisthenics prevents the reduction of skeletal muscle mass volume in people with type 2 diabetes

2020 ◽  
Vol 8 (1) ◽  
pp. e001027 ◽  
Author(s):  
Tomonori Kimura ◽  
Takuro Okamura ◽  
Keiko Iwai ◽  
Yoshitaka Hashimoto ◽  
Takafumi Senmaru ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Resistance Training ◽  
Muscle Mass ◽  
High Intensity ◽  
Skeletal Muscle Mass ◽  
Whole Body ◽  
Therapeutic Exercises ◽  
The Difference

ObjectiveReduction of muscle mass and strength is an important treatment target for patients with type 2 diabetes. Recent studies have reported that high-intensity resistance training improves physical function; however, all patients found it difficult to perform high-intensity resistance training. Radio calisthenics, considered as therapeutic exercises to promote health in Japan, are simple exercises that can be performed regardless of age and help move the muscles and joints of the whole body effectively according to the rhythm of radio. We investigated the efficacy of radio calisthenics for muscle mass in patients with type 2 diabetes in this retrospective cohort study.Research design and methodsA total of 42 hospitalized patients with type 2 diabetes were recruited. The skeletal muscle mass index (SMI, kg/m2) was calculated as appendicular muscle mass (kg) divided by height squared (m2). We defined the change of SMI as the difference of SMI between the beginning and end of hospitalization.ResultsAmong 42 patients, 15 (11 men and 4 women) performed radio calisthenics. Body weights of both radio calisthenics exercisers and non-exercisers decreased during hospitalization. The change of SMI was significantly lesser in radio calisthenics exercisers than in non-exercisers (7.1±1.4 to 7.1±1.3, –0.01±0.09 vs 6.8±1.1 to 6.5±1.2, –0.27±0.06 kg/m2, p=0.016). The proportion of decreased SMI was 85.2% (23/27 patients) in non-radio calisthenics exercisers, whereas that in radio calisthenics exercisers was 46.7% (7/15 patients).ConclusionsRadio calisthenics prevent the reduction of skeletal muscle mass. Thus, radio calisthenics can be considered effective for patients with type 2 diabetes.

Whole Body Protein Turnover in Chronically Undernourished Individuals

1994 ◽  
Vol 86 (4) ◽  
pp. 441-446 ◽  
Author(s):  
M. J. Soares ◽  
L. S. Piers ◽  
P. S. Shetty ◽  
A. A. Jackson ◽  
J. C. Waterlow
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Metabolic Rate ◽  
Muscle Mass ◽  
Basal Metabolic Rate ◽  
Normal Weight ◽  
Fat Free Mass ◽  
Whole Body ◽  
Body Protein ◽  
Chronic Undernutrition

1. Two groups of adult men were studied in Bangalore, India, under identical conditions: the ‘normal weight’ subjects (mean body mass index 20.8 kg/m2) were medical students of the institute with access to habitual energy and protein intakes ad libitum. The other group, designated ‘undernourished’, were labourers on daily wages (mean body mass index 16.7 kg/m2). 2. In an earlier study we obtained lower absolute values for both basal metabolic rate and protein synthesis in the undernourished subjects; however, when the data were expressed on a body weight or fat-free mass basis, a trend towards higher rates of protein synthesis, as well as higher basal metabolic rate, was evident. The suggestion was made that such results reflected the relatively higher energy intakes per kg body weight of the undernourished subjects on the day of study. The objective of the present study was therefore to control for the dietary intake during the measurement of whole body protein turnover. 3. In the present study dietary intakes were equated on a body weight basis; however, expressed per kg fat-free mass, the normal weight subjects had received marginally higher intakes of energy and protein. The results, however, were similar to those of the previous study. In absolute terms, basal metabolic rate, protein synthesis and breakdown were lower in the undernourished subjects. When expressed per kg body weight or per kg fat-free mass, the undernourished subjects had higher basal metabolic rates than the well-nourished subjects, whereas no differences were seen in the rate of protein synthesis or breakdown. 4. Estimates of muscle mass, based on creatinine excretion, indicated that the undernourished subjects had a higher proportion of non-muscle to muscle mass. Nitrogen flux (Q) was determined from 15N abundance in two end products, urea (Qu) and ammonia (Qa). The ratio Qu/Qa was increased in the undernourished subjects and was significantly correlated with the ratio of non-muscle to muscle mass (r = 0.81; P < 0.005). These results fit in with our earlier suggestion of a greater proportion of non-muscle (visceral) mass in undernourished subjects. 5. The present data suggest that there are no changes in the rate of protein synthesis or breakdown in chronic undernutrition when results are expressed, conventionally, per kg fat-free mass. It can be theoretically shown, however, that there could be a 15% reduction in the rate of turnover of the visceral tissues in chronic undernutrition. This, together with the reduced urinary nitrogen excretion, would contribute to nitrogen economy in these individuals.

scholarly journals Insulin-like Growth Factor 1 and Adiponectin and Associations with Muscle Deficits, Disease Characteristics, and Treatments in Rheumatoid Arthritis

2015 ◽  
Vol 42 (11) ◽  
pp. 2038-2045 ◽  
Author(s):  
Joshua F. Baker ◽  
Joan Marie Von Feldt ◽  
Sogol Mostoufi-Moab ◽  
Woojin Kim ◽  
Elena Taratuta ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Growth Factor ◽  
Disease Activity ◽  
Muscle Mass ◽  
Quantitative Computed Tomography ◽  
Whole Body ◽  
Insulin Like Growth Factor ◽  
Cross Sectional ◽  
Muscle Density ◽  
Age And Sex

Objective.Rheumatoid arthritis (RA) is associated with low muscle mass and density. The objective of our study was to evaluate associations between 2 serum biomarkers [insulin-like growth factor 1 (IGF-1) and adiponectin] and skeletal muscle in RA.Methods.Whole-body dual energy X-ray absorptiometry measures of the appendicular lean mass index (ALMI; kg/m2) and total fat mass index (kg/m2), as well as the peripheral quantitative computed tomography measures of the lower leg muscle and fat cross-sectional area (CSA; cm2) and muscle density (an index of fat infiltration) were obtained from 50 participants with RA, ages 18–70 years. Multivariable linear regression analyses evaluated associations between body composition and levels of adiponectin and IGF-1, adjusted for age, sex, and adiposity.Results.Greater age was associated with higher adiponectin (p = 0.06) and lower IGF-1 (p = 0.004). Eight subjects had IGF-1 levels below the reference range for their age and sex. These subjects had significantly lower ALMI and muscle CSA in multivariable models. Lower IGF-1 levels were associated with greater clinical disease activity and severity, as well as low ALMI, muscle CSA, and muscle density (defined as 1 SD below normative mean). After adjusting for age and sex, greater adiponectin levels were associated with lower BMI (p = 0.02) as well as lower ALMI, and lower muscle CSA, independent of adiposity (p < 0.05). Only greater Health Assessment Questionnaire scores were significantly associated with lower adiponectin levels.Conclusion.Low IGF-1 and greater adiponectin levels are associated with lower muscle mass in RA. Lower IGF-1 levels were seen in subjects with greater disease activity and severity.

scholarly journals Heart size and mean muscle fibre cross-sectional area related to birth weight in pigs

2008 ◽  
Vol 16 (3) ◽  
pp. 259 ◽  
Author(s):  
M. RUUSUNEN ◽  
E. PUOLANNE ◽  
K. PARTANEN
Keyword(s):  
Birth Weight ◽  
Growth Performance ◽  
Muscle Mass ◽  
Carcass Composition ◽  
Cross Sectional Area ◽  
Heart Weight ◽  
Longissimus Dorsi ◽  
Muscle Fibres ◽  
Sectional Area ◽  
Cross Sectional

One of the aims in domestic pig breeding has been to increase the size of litters resulting in variation in birth weight of piglets. Pig breeding has also resulted in increased body muscle mass. Muscles with the same size can consist either of large number of thin muscle fibres or small number of thick muscle fibres. Larger body muscle content means that in living animal the heart must pump blood to larger muscle mass than earlier. Our interest in this study was to investigate the relationship between the pig’s birth weight and (i) growth performance and carcass composition, (ii) the size of organs, and (iii) the mean muscle fibre cross-sectional area at slaughter. The study consisted of twenty pigs slaughtered at the age of 165±2 days. The day after the slaughter, the carcass composition was determined by dissecting the chilled carcass into lean, fat, bones, and skin and organs were weighed. The average cross sectional area of muscle fibres was determined from three fast-twitch muscles longissimus dorsi, semimembranosus, gluteus superficialis, and two slow-twitch muscles infraspinatus and masseter. The birth weight of pigs ranged from 0.9 to 2.2 kg. We found no clear relationships between the birth weight and the pig’s growth performance from birth to slaughter. When the birth weight increased the heart weight at slaughter increased as well (P < 0.01). The heart weight was higher in those pigs with high carcass weight (P < 0.05) and with the high weight of total muscle mass in the carcass (P < 0.001). The cross sectional area of muscle fibres in M. longissimus dorsi (P < 0.05), M. semimembranosus (P < 0.10), and M. gluteus superficialis (P < 0.05) was larger in those pigs with low birth weight compared to those found in pigs with high birth weight.;

scholarly journals Morbidity of different treatment modalities in advanced Carcinoma larynx

2015 ◽  
Vol 20 (2) ◽  
pp. 66-74
Author(s):  
Md Sirajul Islam Mahfuz ◽  
Belayat Hossain Siddiquee ◽  
A Allam Choudhury ◽  
Shaikh Muniruddin Ahmad
Keyword(s):  
Cross Sectional Study ◽  
Treatment Modalities ◽  
Glottic Carcinoma ◽  
Neck Node ◽  
Cross Sectional ◽  
Advanced Carcinoma ◽  
Carcinoma Larynx ◽  
Neck Node Metastasis ◽  
The Difference ◽  
Almost All

Objectives: To evaluate morbidity of different modalities of treatment in advanced carcinoma larynx (stage III and IV). Methods: It was a cross sectional study conducted among selected 70 patients of advanced carcinoma larynx treated by different modalities of treatment from April 2009 to April 2010 in different tertiary hospitals in Dhaka. Results:The age of the patients ranged from 30 to 79 years (mean ± SD = 54±10.94), maximum age incidence 5th decade. Almost all were male, habituated in betel nut and leaves chewing and smoking. Mostly (60%) from poor socioeconomic group. 70% cases were supraglottic and 30% cases were glottic carcinoma. Nature of lesion was exophytic 71.43% and ulcerative 28.57%. 22.86% had neck node metastasis. Histopathologically 60% were moderately differentiated and grade II squamous cell carcinoma (SCC). In the total laryngectomy patient pharyngocuteneous fistula (30%), wound infection (10%), haematoma (10%), stomal recurrence (10%), stenosis is tracheostomy (10%), recurrent chest infection (10%) and pharyngeal stenosis (10%) were the morbidities. Mucositis or painful erythematous reaction in larynx and pharynx (95%), periconditis (2.5%), dryness of mouth and throat (100%), loss of test (100%), subcutaneous fibrosis (32.5%), nausea vomiting, skin rashes and alopecia (100%) were the morbidities of chemoradiotherapy and radiotherapy. After analysis the major and minor morbidities of different, modalities of treatment there was no significant (p > 0.05) difference among those modalities. Conclusion: The difference between the morbidity of single modality and combined modalities had not significant. So the combined modalities approach may be advocated for the treatment of advanced carcinoma larynx where required. DOI: http://dx.doi.org/10.3329/bjo.v20i2.22021 Bangladesh J Otorhinolaryngol; October 2014; 20(2): 66-74

scholarly journals Contraceptive User’s Profile

2016 ◽  
Author(s):  
Eka R Gunardi
Keyword(s):  
Obstet Gynecol ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Contraceptive Methods ◽  
Cross Sectional ◽  
Study Population ◽  
The Mean ◽  
The Difference ◽  
Almost All ◽  
The Cost

Objective: To obtain informations regarding the profile of contraceptive users in Raden Saleh Clinic, Jakarta. Method: A cross-sectional study was conducted in June 2012, at Raden Saleh Clinic, Jakarta. The study population was the patient who came to Raden Saleh Clinic from 2008 until 2011. Results: The mean age of the contraception users was 34.06 and the mean of their husband’s age was 38.91 years old. Most of the patients were graduated from senior high school (43.2%) and university (37.9%). More than half of the patients (55.2%) were not working and more than a half of their husband (53.2%) were private employee. Almost all (92.6%) of the patient were married. Most of the patient (38.8%) came with no prior contraception. After consultation, all patients had chosen their preferred contraceptive methods, namely IUD (61.4%), injectable contraception (20.9%), pill (13.7%), sterilization (3.4%), and implant (0.6%). Conclusion: Family planning reduces maternal mortality and the best method is different for each patient because of the difference in their own condition and the consideration of the cost and benefit. [Indones J Obstet Gynecol 2013; 1-4:179-82] Keywords: contraception, contraceptive users profile

Relation between plasma and tissue parameters of leucine metabolism in fed and starved rats

1986 ◽  
Vol 250 (6) ◽  
pp. E615-E621 ◽  
Author(s):  
J. A. Vazquez ◽  
H. S. Paul ◽  
S. A. Adibi
Keyword(s):  
Continuous Infusion ◽  
Total Protein ◽  
Specific Activity ◽  
Whole Body ◽  
Leucine Incorporation ◽  
Body Protein ◽  
Leucine Metabolism ◽  
Leucine Oxidation ◽  
The Difference ◽  
Plasma Leucine

By use of a primed continuous infusion of [1-14C]leucine, we investigated parameters of leucine metabolism in plasma, expired air, and tissues of fed and 48-h starved rats. The ratios of muscle to plasma specific activity of alpha-ketoisocaproate (KIC) in fed and starved rats were not significantly different from 1. The ratio of muscle to plasma specific activity of leucine was also not significantly different from 1 in fed rats, but was significantly lower than 1 in starved rats. The rate of leucine oxidation was 28-34% higher when calculation was based on plasma KIC rather than leucine specific activity. However, starvation significantly increased the rate of leucine oxidation with either specific activity. The rates of leucine incorporation into whole-body protein, calculated as the difference between plasma leucine turnover and oxidation, were unaffected by starvation, but the incorporations into total protein measured directly were significantly decreased in liver and muscle. We conclude that leucine or KIC specific activity in muscle is better predicted by plasma KIC than leucine specific activity, and the difference between rates of plasma leucine turnover and oxidation does not appear to be a valid measurement of leucine incorporation into whole-body protein.

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