The fin-to-limb transition is heralded as one of the most important events in vertebrate evolution. Over the last few decades our understanding of how limbs evolved has significantly increased; but, hypotheses for why limbs evolved are still rather open. Fishes that engage their fins to ‘walk' along substrate may provide some perspective. The charismatic frogfishes are often considered to have the most limb-like fins, yet we still know little about their underlying structure. Here we reconstruct the pectoral fin musculoskeletal anatomy of the scarlet frogfish to identify adaptations that support fin-assisted walking behaviours. The data are compared to three additional anglerfish species: the oval batfish, which represents an independent acquisition of fin-assisted walking; and two pelagic deep-sea swimmers, the triplewart seadevil and ghostly seadevil. Our results clearly show broad musculoskeletal differences between the pectoral fins of swimming and walking anglerfish species. The frogfish and batfish have longer and more robust fins; larger, differentiated muscles; and better developed joints, including a reverse ball-and-socket glenoid joint and mobile ‘wrist'. Further, the frogfish and batfish show finer-scale musculoskeletal differences that align with their specific locomotor ecologies. Within, we discuss the functional significance of these anatomical features in relation to walking, the recurring evolution of similar adaptations in other substrate locomoting fishes, as well as the selective pressures that may underlie the evolution of limbs.

β-Hydroxy-β-methylbutyrate (HMB) is a popular ergogenic aid used by human athletes and as a supplement to sport horses, because of its ability to aid muscle recovery, improve performance and body composition. Recent findings suggest that HMB may stimulate satellite cells and affect expressions of genes regulating skeletal muscle cell growth. Despite the scientific data showing benefits of HMB supplementation in horses, no previous study has explained the mechanism of action of HMB in this species. The aim of this study was to reveal the molecular background of HMB action on equine skeletal muscle by investigating the transcriptomic profile changes induced by HMB in equine satellite cells in vitro. Upon isolation from the semitendinosus muscle, equine satellite cells were cultured until the 2nd day of differentiation. Differentiating cells were incubated with HMB for 24 h. Total cellular RNA was isolated, amplified, labelled and hybridised to microarray slides. Microarray data validation was performed with real-time quantitative PCR. HMB induced differential expressions of 361 genes. Functional analysis revealed that the main biological processes influenced by HMB in equine satellite cells were related to muscle organ development, protein metabolism, energy homoeostasis and lipid metabolism. In conclusion, this study demonstrated for the first time that HMB has the potential to influence equine satellite cells by controlling global gene expression. Genes and biological processes targeted by HMB in equine satellite cells may support HMB utility in improving growth and regeneration of equine skeletal muscle; however, the overall role of HMB in horses remains equivocal and requires further proteomic, biochemical and pharmacokinetic studies.

Decrease in muscle mass and performance with ageing is one of the main factors of frailty in the elderly. Maintenance of muscle performance by involving in physical activities is essential to increase independence and quality of life among elderly. The use of natural compounds with ergogenic activity in old people would increase the effect of moderate exercises in the maintenance of physiological muscle capacity. Resveratrol (RSV), a polyphenol found in walnuts, berries and grapes, shows this ergogenic activity. By using young, mature and old mice as models, we have found that RSV improves muscle performance in mature and old animals but not in young animals. Without showing significant effect by itself, RSV primed the effect of exercise by increasing endurance, coordination and strength in old animals. This effect was accompanied by a higher protection against oxidative damage and an increase in mitochondrial mass. RSV increased catalase and superoxide dismutase protein levels in muscle and primed exercise to reverse the decrease in their activities during ageing. Furthermore, RSV increased the level of mitochondrial mass markers such as cytochrome C, mitochondrial transcription factor A and nuclear respiratory factor-1 in muscle in exercised animals. Our results indicate that RSV can be considered an ergogenic compound that helps maintain muscle performance during ageing and subsequently reduces frailty and increases muscle performance in old individuals practising moderate exercise.

Spasmodic dysphonia is a disabling voice condition caused by a chronic neurological disorder of central motor processing. Present therapy is directed at relief of symptoms rather than cure. Botulinum toxin type A injection into the thyroarytenoid muscle has become the pre-eminent approach for treatment of adductor spasmodic dysphonia. Botulinum toxin A injections can be performed in an out-patient setting under electromyographic guidance. We present our experience with 153 injections in 14 patients with adductor spasmodic dysphonia over a 10-year period. We demonstrate that the electromyography signal is a reliable prognostic indicator in terms of efficacy, and that patients' subjective opinion is a valid indicator of treatment success and future treatment strategy.

Changes in ultrasound measures of muscle area (UtM) during lactation in different breeds and parities and with different feeding levels were examined. Random regressions were fitted to repeated measures of UtM in order to study changes in variance components of UtM during lactation. Correlations between measures taken in different stages of lactation and in different parities were also calculated. The shape of UtM curves during lactation appeared to be fairly consistent for all breeds and parities. The lowest point of all curves coincided with the expected nadir of body reserves during lactation. With lower-than-normal feeding level, the drop of UtM after calving was deeper and the overall level was lower. A major proportion of the variance in UtM was found to be determined by additive genetic variation. In all three breeds studied, repeatability and heritability estimates were high and fairly consistent during lactation and between parities. The very high genetic correlations between measures taken in different periods of lactation suggested that muscle growth and recovery are controlled by the same gene complex throughout lactation.

Our results suggest that UtM, if used jointly with other body measures such as body condition score, could be a useful indicator of tissue mobilization and deposition in the lactating cow, especially during the early stage of lactation.

It is well known that in advanced cervical metastatic disease of head and neck squamous cell carcinoma, the incidence of distant metastasis is high. A case of distant metastasis to the scapular muscles from an uncontrolled cervical metastasis of laryngeal carcinoma is presented. Other unusual metastatic sites are reviewed and the possible mechanism of the spread is discussed.

Potential measures of muscularity derived from X-ray computer tomography (CT) were assessed using data for 160 sheep (50 Suffolk males, 50 Suffolk females, 40 Texel males and 20 Charollais males). One-fifth of the lambs within each breed and sex were slaughtered at each of 14, 18 or 22 weeks of age and two-fifths slaughtered at 26 weeks. All lambs were CT scanned prior to slaughter with longitudinal and cross-sectional scans taken at three positions along the body [5th lumbar vertebra (LV5), mid-shaft of the femur (FEM) and ischium (ISC)]. After slaughter, linear measurements of side length (SL) and M. longissimus thoracis et lumborum (LTL) width (A) and depth (B) (12/ 13th thoracic vertebra) were taken on the left side of the carcass. The side was dissected and femur length (FL), the weight of three muscles surrounding the femur (M3) and the total muscle weight in the side (TM) were recorded. Five muscularity measures were calculated for the carcass. Two for the LTL muscle (A/SL, B/SL), one for the hind leg (√M3/FL3) and one for the whole carcass (√TM/SL3).

Correlations between spine length measured on the CT longitudinal scans and side length measured on the carcass were high (> 0·62), while correlations between measurements of LTL width and depth on the carcass with those on the LV5 scan were moderate (> 0·41). CT measures of muscularity were derived using linear measurements taken on CT scans together with a prediction of total muscle weight using CT tissue areas. Correlations between CT measures and dissection measures of LTL and whole carcass muscularity were moderate to high (0·33–0·54). Correlations between the dissection measure and four CT measures of hind leg muscularity were higher (0·48-0·60). These results clearly show that good in vivo measures of muscularity can be obtained for sheep by using measurements that can be taken on CT scans. This will be a useful tool for selection programmes aiming to improve sheep carcass shape, particularly those already using CT scanning to increase rates of genetic improvement in lean tissue growth.

The aim of the present study was to investigate the effects of photoperiod and feeding level on lipid metabolism in ovine perirenal and subcutaneous adipose tissues (AT) and in skeletal and cardiac muscles. Twenty dry non-pregnant ovariectomised ewes were divided into two groups and subjected to either 8 h or 16 h light/d, and underfed at 22 % energy requirements for 7 d. Half of the ewes in each group were slaughtered and the remaining ewes were refed at 190 % energy requirements for 14 d, until slaughtering. Refeeding increased (2.6–4.3-fold) malic enzyme (ME), fatty acid synthase (FAS), glucose-6-phosphate dehydrogenase (G6PDH) and glycerol-3-phosphate dehydrogenase (G3PDH) activities in subcutaneous AT as well as lipoprotein lipase (LPL) activity in perirenal (3.5-fold) and subcutaneous (10-fold) AT and to a lesser extent (1.4-fold) in the skeletal longissimus thoracis and cardiac muscles. Moreover, variations of LPL mRNA level followed variations of LPL activity: refeeding increased perirenal AT- and cardiac muscle-mRNA levels (7.4- and 2-fold respectively). The main finding of this study is that, for a given level of food intake, long days (compared with short days) increased the LPL activity in the longissimus thoracis muscle and, in refed ewes, the activities of LPL and ME in subcutaneous AT. Furthermore, long days increased LPL mRNA level in cardiac muscle and perirenal AT. Thus, our results show that there are direct effects of photoperiod on sheep AT lipogenic potential, as well as on muscle LPL activity, which are not caused by changes in nutrient availability.

Our study aimed to show whether it is useful to preserve the stapedial muscle during the surgical treatment of otosclerosis. The study was carried out on 67 patients with tympanoscopic evidence of otosclerosis. In group A (34 patients) the stapedial muscle was intra-operatively preserved as follows: the stapedial suprastructure with preserved muscle tendon was transpositioned onto the longer arm of the incus and secured with a wire loop. The mean uncomfortable level for sounds was measured after surgery and the results of group A patients were compared with those obtained in group B (33 patients, who underwent standard surgery). One month after surgery, in group A patients, the cochleostapedial reflex was evoked in 21 patients (61.8 per cent) and two months later in 32 patients (94.1 per cent). One month after operation, in group A patients the mean uncomfortable level was 108.8 dB, while three months later it increased to 114.1 dB. In group B, the relevant values were 97.8 dB one month after surgery, and 98.0.dB three months later. Our presumption that stapedial muscle preservation is necessary has been proved by the fact that the patients with the preserved muscle had a higher noise discomfort threshold.

Haemorrhages in the muscles of broiler chickens are major quality defects which occur in all types of muscles and muscle parts. They are closely related to muscle injury and can be the result of trauma, strenuous muscle activity, exposure to extreme environmental conditions, restraining and electrical stunning. In this review the different types of haemorrhages are classified. A brief introduction on muscle morphology and blood supply is given to discuss the mechanisms that may cause haemorrhages and a survey of these mechanisms is presented. Some of the mechanisms, together with factors likely to affect the susceptibility of chickens to haemorrhages, are discussed in relation to rearing, transport, slaughter and processing of broiler chickens.

The relationship between an ordinal (Likert) and a continuous (visual analog) measure of pain was investigated in 400 long-distance runners experiencing delayed-onset muscle soreness. Subjects completed a 100-mm visual analog scale (VAS) and a 7-point Likert scale twice a day for 5 days, starting at 9:00 PM on the evening of the run. The relationship between scales was modeled by calculating the median VAS for each Likert score and the modal Likert score for each point on the VAS. Standardized means were calculated by dividing the total of 5 day scores by the standard error of 5 day scores for all subjects. The relationship between scales was approximately linear, but VAS scores recorded concurrently with each Likert score varied enormously. VAS responses for a Likert score of zero were lower than expected, apparently because subjects chose zero only if they were completely free of soreness. The standardized mean of the Likert scale was higher (34.1 [SD 20] versus 30.4 [SD20] p <<< .0001), suggesting greater responsiveness. The Likert scale can be recommended as a method of measuring muscle soreness, but researchers should not anchor the lowest score to zero pain.

For 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.

Distribution of tissue weight in the musculature and skeleton was studied in ram, wether and ewe Omani sheep raised under an intensive management system and slaughtered over the range 18 to 38 kg live weight. Ram lambs had higher muscle weight in the forequarters than wether and ewe lambs whereas the latter ‘sexes’ had heavier hindquarters and slightly more muscle in the muscle groups of proximal hind- and forelimbs and those surrounding the spinal column. Some of the neck region muscles, e.g. m. splenius and m. longissimus capitis et atlantis, were more developed in ram than in wether and ewe lambs. The proportions in the side muscle weight of some muscles (mainly in the hindquarter) decreased with increased slaughter weight whereas others (mainly in forequarter) increased, with the majority of the muscles showing no significant slaughter weight effects. The magnitude of change in proportions of individual muscles with increased slaughter weight was small and unlikely to have a commercial impact on meat production from Omani sheep.

As a proportion of total carcass bone, the axial skeleton and the hindlimb decreased with increased slaughter weight whereas the forelimb did not show a significant change. Ram lambs had heavier individual bones than wether and ewe lambs and higher proportions of the axial skeleton and lower proportions of the hindlimb than wethers at 28 kg live weight. There were few differences between the various ‘sexes’ in length, width or circumference of bones. Except for the 12th rib, individual bones, in all sexes, grew at a rate lower than empty body weight.

It is suggested that future improvement of Omani sheep should take into consideration the high proportion of bone in the carcass of these animals as well as the relatively higher proportion of bone in the limbs than in the axial skeleton.