Harmful effects of malnutrition and possible sustainable solution

Malnutrition is a condition that results from eating a diet that does not supply a healthy amount of one or more nutrients. It is a condition characterized by lack of one or more essential nutrients from the diet or a surplus of some nutrients which affect the body negatively. Malnutrition consists of two types: undernutrition and overnutrition. Undernutrition involves the deficiency of macronutrients like protein or calories and micronutrients like iron, iodine and many more. Protein energy malnutrition is caused by the inadequate intake of protein and calories. It is further classified in three types, kwashiorkor, marasmus and marasmic kwashiorkor. Malnutrition mainly affects an individual’s immune system, lean body mass, cardio-respiratory functions, muscle functions. Malnutrition can be caused due to many factors including unavailability of food, poverty, higher food prices and many more. Strategies like biofortification and supplementation are used for the treatment of malnutrition.

Morphometric and Immunohistochemical Characteristics of the Adult Human Soft Palate Muscles

The soft palate is the only structure that reversibly separates the respiratory and gastrointestinal systems. Most species can eat and breathe at the same time. Humans cannot do this and malfunction of the soft palate may allow food to enter the lungs and cause fatal aspiration pneumonia. Speech is the most defining characteristic of humans and the soft palate, along with the larynx and tongue, plays the key roles. In addition, palatal muscles are involved in snoring and obstructive sleep apnea. Considering the significance of the soft palate, its function is insufficiently understood. The objectives of this study were to document morphometric and immunohistochemical characteristics of adult human soft palate muscles, including fiber size, the fiber type, and myosin heavy chain (MyHC) composition for better understanding muscle functions. In this study, 15 soft palates were obtained from human autopsies. The palatal muscles were separated, cryosectioned, and stained using histological and immunohistochemical techniques. The results showed that there was a fast type II predominance in the musculus uvulae and palatopharyngeus and a slow type I predominance in the levator veli palatine. Approximately equal proportions of type I and type II fibers existed in both the palatoglossus and tensor veli palatine. Soft palate muscles also contained hybrid fibers and some specialized myofibers expressing slow-tonic and embryonic MyHC isoforms. These findings would help better understand muscle functions.

Foreflipper and hindflipper muscle reconstructions of Cryptoclidus eurymerus in comparison to functional analogues: introduction of a myological mechanism for flipper twisting

Background Plesiosaurs, diapsid crown-group Sauropterygia, inhabited the oceans from the Late Triassic to the Late Cretaceous. Their most exceptional characteristic are four hydrofoil-like flippers. The question whether plesiosaurs employed their four flippers in underwater flight, rowing flight, or rowing has not been settled yet. Plesiosaur locomotory muscles have been reconstructed in the past, but neither the pelvic muscles nor the distal fore- and hindflipper musculature have been reconstructed entirely. Methods All plesiosaur locomotory muscles were reconstructed in order to find out whether it is possible to identify muscles that are necessary for underwater flight including those that enable flipper rotation and twisting. Flipper twisting has been proven by hydrodynamic studies to be necessary for efficient underwater flight. So, Cryptoclidus eurymerus fore- and hindflipper muscles and ligaments were reconstructed using the extant phylogenetic bracket (Testudines, Crocodylia, and Lepidosauria) and correlated with osteological features and checked for their functionality. Muscle functions were geometrically derived in relation to the glenoid and acetabulum position. Additionally, myology of functionally analogous Chelonioidea, Spheniscidae, Otariinae, and Cetacea is used to extract general myological adaptations of secondary aquatic tetrapods to inform the phylogenetically inferred muscle reconstructions. Results A total of 52 plesiosaur fore- and hindflipper muscles were reconstructed. Amongst these are flipper depressors, elevators, retractors, protractors, and rotators. These muscles enable a fore- and hindflipper downstroke and upstroke, the two sequences that represent an underwater flight flipper beat cycle. Additionally, other muscles were capable of twisting fore- and hindflippers along their length axis during down- and upstroke accordingly. A combination of these muscles that actively aid in flipper twisting and intermetacarpal/intermetatarsal and metacarpodigital/metatarsodigital ligament systems, that passively engage the successive digits, could have accomplished fore-and hindflipper length axis twisting in plesiosaurs that is essential for underwater flight. Furthermore, five muscles that could possibly actively adjust the flipper profiles for efficient underwater flight were found, too.

What Are Good Muscle Endpoints for Translational Studies?

What Are Good Muscle Endpoints for Translational Studies? Jörn Rittweger()1,2 1Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany 2Department of Pediatrics and Adolescent Medicine, University of Cologne, Cologne, Germany © The Author Abstract Muscles matter to our health because of their size, their involvement in energy metabolism and their relevance for locomotion. Adequate selection of good endpoints is crucial for successfully designing translational studies. At least eight different muscle functions matter to health, namely the mechanical functions of exerting force, velocity, power, elastic storage and braking power, the two metabolic functions of substrate uptake (e.g. carbohydrates, lipids and amino acids) and substrate provision (e.g. lactate and amino acids) and secretory functions. However, specific endpoint tests have been validated for muscle force and power only. Walking speed and grip strength demonstrate good predictive value for hard clinical endpoints, such as disability, loss of autonomy and death. Vertical jump power also has good ecological validity and construct validity, and it depicts excellent test-retest reliability, which is an important advantage with regard to the study of power. Assessment of muscle mass, e.g. by magnetic resonance imaging, dual energy X-ray absorptiometry or bioelectrical impedance, should be considered as an important secondary endpoint to enhance construct validity. Further secondary endpoints should be included wherever they are likely to enhance the plausibility of the study outcome and assessment of test-retest reliability at baseline is always recommended. Well-established methods exist for three relevant muscular endpoints, namely power, strength and muscle mass, and these endpoints lend themselves to utilization in clinical studies. However, such validated methods lack a number of additional muscle functions that are scientifically only emerging. This applies foremost to the metabolic function of muscles but also to its role in storage and dissipation of mechanical energy.

Comparison between velocity‐specific exercise and isometric exercise on neck muscle functions and performance: a randomised clinical trial

Background Evidence has shown that velocity-specific exercise results in additional benefits for peripheral joint muscles by promoting their functions, however, its effects on spinal muscles are yet to be investigated. This study aimed to examine the feasibility and effects of velocity-specific exercise compared to isometric exercise on cervical muscle functions and performance in healthy individuals. Methods Thirty healthy adults were randomised to practise either the velocity-specific exercise (VSE, n = 15) or isometric exercise (IE, n = 15) for 6 weeks. Functions and performance of the cervical extensors and flexors were assessed pre- and post-program, by analyzing the peak torque and electromyography during the isokinetic testing, and cross-sectional area of the deep cervical muscles at rest. The self-reported level of difficulty and post-exercise soreness during the exercise were recorded to evaluate the feasibility and safety of the two exercise programs. Results Both VSE and IE exercises resulted in significant improvement of the muscle functions and performance while there were no between-group differences at reassessment of the (a) cross-sectional area of longus colli and semispinalis capitis; (b) EMG amplitude in sternocleidomastoid and cervical erector spinae, and (c) peak torque values. Further analysis revealed that degree of correlation between extension torque and EMG amplitude of cervical erector spinae increased in both groups. However, significant correlation was found only in VSE group post-program. There were no significant differences for the level of difficulty and post-exercise soreness found between two groups. Conclusions Both velocity-specific and isometric exercises significantly promoted cervical muscle functions and performance. The present study confirms that velocity-specific exercise can be practised safely and it also contributes to a greater enhancement in neuromuscular efficiency of the cervical extensors. These findings indicate that the velocity-specific exercise can be considered as a safe alternative for training of the cervical muscles. Further study is recommended to examine its benefit and application for promoting the muscle functions and recovery in symptomatic individuals.