Band Of Skeletal Muscle Research Articles

Myofascial trigger points in subjects with non-specific neck pain

Background: In recent years, non-specific neck pain has become a frequent complaint due to poor head postures. It is characterized by Myofascial Trigger Points (MTrPs) in palpable taut bands of skeletal muscle that refer pain to a distance, and that can cause distant motor and autonomic effects.
 Objective. The aim of the study was to assess the prevalence of active and latent MTrPs in subjects suffering from non-specific neck pain in two hospitals, Sri Lanka.
 Method: This cross- sectional descriptive study was carried out among 31 patients with non-specific neck pain, presented to the department of physiotherapy, Teaching Hospital Peradeniya and National Hospital, Kandy, Sri Lanka. Participants were referred by a physician for non-specific neck pain and MTrPs were determined by a physiotherapist. MTrPs diagnosis criteria were the presence of a palpable taut band in a skeletal muscle; presence of a hyper-sensible tender spot in the taut band; local twitch response; reproduction of the referred pain pattern in response to compression; and spontaneous presence of the typical referred pain pattern and/or patient recognition.
 Results. The prevalence of MTrPs among patients with non-specific neck pain was 100%. Each of the 31 patients exhibited at least two MTrPs in the analyzed muscles. The mean number of MTrPs on each patient was 4.71± 2.036. MTrPs of the upper trapezius muscles were the most prevalent, in 96.8% of the participants. MTrPs in the suboccipital muscles, sternocleidomastoid, levator scapulae reached a prevalence of 58.1%, 45.2%, 35.5% respectively. 76.74% of total number of MTrPs in all analyzed muscles were active MTrPs.
 Conclusions. MTrP is a common source of pain in subjects presenting non-specific neck pain. Our study determined the presence of both active and latent MTrPs in this population with a higher prevalence of active MTrPs compared to latent MTrPs in all individual muscles.

Living Machines

This article provides an insight into National Science Foundation (NSF) funded research and development of biological machines. The goal of these research projects is to build living, multicellular machines that sense, move, and solve real-world health problems. One of the Emergent Behaviors of Integrated Cellular Systems (EBICS) group has developed a biobot that walks. Inspired by the structure of human joints, this walker has two short, stubby legs connected by a bridge. The skeleton is constructed from a soft Jell-O-like 3D-printed skeleton called hydrogel, and surrounded by a band of skeletal muscle. The group genetically engineered the cells to produce a protein called channel rhodopsin, a sensory photorecepter that enables the muscle to contract in response to blue light. This provides an easy on–off switch to activate the muscle spurring the bot to move its legs and walk. As biologists understand better how tissues develop, bioengineers will be able to reverse-engineer development to better program cells to self-assemble to create biological machines. Plans for future bots include different cell types and many more functionalities.

Expression of SERPINA3s in cattle: focus on bovSERPINA3-7 reveals specific involvement in skeletal muscle.

α1-Antichymotrypsin is encoded by the unique SERPINA3 gene in humans, while it is encoded by a cluster of eight closely related genes in cattle. BovSERPINA3 proteins present a high degree of similarity and significant divergences in the reactive centre loop (RCL) domains which are responsible for the antiprotease activity. In this study, we analysed their expression patterns in a range of cattle tissues. Even if their expression is ubiquitous, we showed that the expression levels of each serpin vary in different tissues of 15-month-old Charolais bulls. Our results led us to focus on bovSERPINA3-7, one of the two most divergent members of the bovSERPINA3 family. Expression analyses showed that bovSERPINA3-7 protein presents different tissue-specific patterns with diverse degrees of N-glycosylation. Using a specific antibody raised against bovSERPINA3-7, Western blot analysis revealed a specific 96 kDa band in skeletal muscle. BovSERPINA3-7 immunoprecipitation and mass spectrometry revealed that this 96 kDa band corresponds to a complex of bovSERPINA3-7 and creatine kinase M-type. Finally, we reported that the bovSERPINA3-7 protein is present in slow-twitch skeletal myofibres. Precisely, bovSERPINA3-7 specifically colocalized with myomesin at the M-band region of sarcomeres where it could interact with other components such as creatine kinase M-type. This study opens new prospects on the bovSERPINA3-7 function in skeletal muscle and promotes opportunities for further understanding of the physiological role(s) of serpins.

TRIGGER POINT INJECTIONS IN MYOFASCIAL PAIN SYNDROME AND FIBROMYLAGIA : ARE WE SERVING OUR PATIENTS WELL?

(13%), subscapularis (10%), trapeze (24%), dorsal (12%), lumbar (21%), gluteus and sacral region (5%), other (10%). Background and aims Myofascial syndrome is a disorder characterized by the presence of myofascial trigger points (MTrPs) which result in a symptomatic pain response. Trigger points are discrete, focal, hyperirritable spots located in a taut band of skeletal muscle. They produce pain locally and in a referred pattern and often accompany chronic musculo- skeletal disorders. Palpation of a hypersensitive bundle or nodule of muscle fiber of harder than normal consis - tency is the physical finding typically associated with a trigger point. Palpation of the trigger point will elicit pain directly over the affected area and/or cause radiation of pain toward a zone of reference and a local twitch response. 1 After failure to respond to first line treatments trigger point injections are suggested for active trigger points. However, some authors contest their efficacy. 2 The objective of this study was to quantify the pain relief provided by MTrPs injections.

Protein Characterization of Na +-Independent System L Amino Acid Transporter 3 in Mice : A Potential Role in Supply of Branched-Chain Amino Acids under Nutrient Starvation

We recently cloned the human Na(+)-independent system L neutral amino acid transporter LAT3. The aim of the present study was to characterize the molecular nature of mouse LAT3 at the protein level. Isolated mouse LAT3 showed 83% identity to human LAT3. Xenopus oocytes injected with mouse LAT3 cRNA showed the same functional property as human LAT3. Reverse transcriptase-polymerase chain reaction revealed apparent transcripts of mouse LAT3 in the liver, skeletal muscle, and pancreas, an expression pattern identical to that found in humans. Antibody generated against mouse LAT3 detected both approximately 58-kd and 48-kd bands in the sample from liver and only a 48-kd band in skeletal muscle and pancreas. Immunohistochemical study showed its clear localization in the plasma membrane of liver and skeletal muscle, whereas it was only detectable in the endoplasmic reticulum and in crystalline inclusions in pancreatic acinar cells. Starvation induced up-regulation of mouse LAT3 protein and mRNA in both liver and skeletal muscle but not in pancreas. These results suggest that LAT3 may indeed function as an amino acid transporter, transporting branched-chain amino acids from liver and skeletal muscle to the bloodstream and thereby participating in the regulatory system of interorgan amino acid nutrition.

Reproductive morphology of Brittanichthys axelrodi (Teleostei: Characidae), a miniature inseminating fish from South America

Light and electron microscopy were used to investigate the morphology of reproductive characters in a characid fish, Brittanichthys axelrodi. Spermatozoa were found in ovaries of females, thereby confirming insemination in this species. Bony hooks can be found on the fourth unbranched ray and branched rays 1-4 of the anal fin and the unique sigmoidally-curved ray of the caudal fin in mature males. Testes have three distinct regions: an anterior spermatogenic region, an aspermatogenic middle region lined with a simple squamous epithelium and used for storage of mature spermatozoa, and a posterior region of coiled chambers lined with a high simple cuboidal epithelium. The most posterior region appears to be instrumental in the formation and storage of spermatozeugmata, unencapsulated sperm packets. Thus far, this tripartite testis morphology is unique among characids. The mature spermatozoon has an elongate nucleus ( approximately 5 microm in length). A striated rootlet originates at the anterior end of the distal centriole and continues to the anterior tip of the cell. The striated rootlet wraps around the entire ventral area of the anterior part of the nucleus and appears to continue around the anterior tip of the nucleus and down the dorsal side as electron-dense material. Several large, spherical mitochondria ( approximately 0.6 microm in diameter) with lamellar cristae overlap the posterior end of the nucleus and continue beyond together with the cytoplasmic collar that contains the flagellum which lacks axonemal fins. Each spermatozeugma is lanceolate in shape when sectioned mid-sagitally, with the core staining positively for mucopolysaccharides. In both sexes, the gonopore opens posterior to the anus, with the urinary pore having a separate opening posterior to the gonopore. Bands of skeletal muscle were found in the area of the male gonopore. These morphological features are likely linked to the reproductive mode of insemination, a trait that is so far as known, relatively rare among teleost fishes, but is proving increasingly frequent among certain groups of characid fishes.

Identifying and Injecting Myofascial Trigger Points

Myofascial pain syndrome is characterized by the presence of discreet, hypersensitive nodules known as trigger points. A myofascial trigger point is a hyperirritable locus within a taut band of skeletal muscle, located in the muscle and/or fascia (1). They are palpable within muscles as cord-like bands within a sharply circumscribed area of extreme tenderness. Trigger points are found most commonly in muscles involved in postural support.

Effects of Epinephrine Infusion on Expression of Calpastatin in Porcine Cardiac and Skeletal Muscle

β-Adrenergic agonists induce muscle hypertrophy in mammalian species and alter the extractable activity of calpain proteinase and its specific endogenous inhibitor calpastatin. The effects on skeletal and cardiac muscle calpastatin of continuously infusing a group of pigs for 7 days with the physiological agonist epinephrine (0.15 μg/kg/min) were examined and compared with a placebo group. Basal levels of extractable calpastatin activity were higher in cardiac than skeletal muscle and epinephrine infusion increased the extractable activity in both muscle types (P < 0.05). An anti-recombinant porcine calpastatin antiserum detected a 135-kDa band and a 145/135-kDa doublet on Western blots of skeletal and cardiac extracts, respectively. Epinephrine infusion increased the 135-kDa band in skeletal muscle (P < 0.05), while the ratio of 145/135 kDa in cardiac muscle was decreased (P < 0.05). From Northern blots, the patterns of calpastatin mRNA species were similar in the two muscle types, two major transcripts at 5.8 and 3.2 kb in cardiac muscle, with equivalent bands in skeletal muscle of 5.4 and 2.8 kb. A faint 7.9-kb band was also detected in skeletal muscle. Epinephrine infusion had no effect on skeletal calpastatin mRNA but tended to increase the 5.8-kb mRNA in cardiac muscle (P = 0.053). These data indicate a differential response of the two muscle types to mildly elevated plasma epinephrine concentration and the response to elevated epinephrine may be at the translational or posttranslational level. Therefore, this type of stimulus appears to be less effective at perturbing calpastatin gene transcription than certain orally administered synthetic β-adrenergic agonists.

The Z band in skeletal muscle in rigor exhibits the activated lattice form

The Z band of skeletal muscle is a tetragonal array of interdigitating thin filaments from adjacent sarcomeres held together by cross connecting filaments. Two visually unique forms of the Z band (small square, ss, and basketweave, bw) can be observed by TEM of cross sections. The ss form is found in relaxed muscle and the bw is found in maximally activated muscle. The average Z spacing in the bw form is 20% largerthan in the ss form. There is a correlation between active tension and the form of the Z band. This correlation suggests that cross bridge binding in the A band is directly related to the form of the Z band. In rigor, the cross bridges are completely bound; therefore, we predicted that the Z band would exhibit the bw form. To test this hypothesis we compared unstimulated muscle to glycerinated muscle in rigor.

Z band dynamics as a function of sarcomere length and the contractile state of muscle.

The Z band in skeletal muscle has two distinct structural states--a relaxed (small square or ss) form and a maximally activated (basket weave or bw) form. We have examined by electron microscopy and optical diffraction Z lattice forms and dimensions and A band spacings in relaxed, tetanized, stretched, and stretched-and-tetanized rat soleus muscle. We have tested the independent contributions of passive load, active tension, and sarcomere length to Z band state. As the A band spacing decreased with increasing load and increasing sarcomere length in the untetanized muscles, the Z lattice remained in the ss form and the Z spacing changed only slightly. Computer-enhanced images from digitized electron micrographs showed that the ss Z lattice resisted deformation regardless of load or method of stretching. In contrast, when the muscle was tetanized at sarcomere lengths of up to 2.7 microns, the Z lattice assumed the bw form and the Z spacing was increased by 20%. Regardless of lattice form, Z spacing did not vary significantly with sarcomere length. Images from freeze-substituted preparations showed both lattice forms comparable to those in images from glutaraldehyde-fixed muscles. Thus, Z band state appears to be a function of the presence (or absence) of active tension. Our previous three-dimensional model is compatible with these observations and with the sub-structures revealed by computer-enhanced images of both lattice forms.

Methanol-acetic anhydride: an efficient blocking agent for electron microscope cytochemistry. Its application to mouse testis and other tissues.

A mixture of absolute methanol and acetic anhydride (MA) (5:1, v/v; 24 h at 25 degrees C) which is known to methylate and acetylate--respectively--free carboxyl and amino groups in proteins, was tested for its effectiveness as a blocking agent in glutaraldehyde-fixed mouse testis and skeletal muscle. In young spermatids the staining of the acrosome with either uranyl acetate (UA) or ethanolic phosphotungstic acid (PTA) was completely prevented by prior treatment with MA. Esterification of carboxyl groups with 0.1 N HCl in methanol (24 h at 30 degrees C) eliminated the UA staining without affecting that due to PTA. It is concluded that--COOH groups are responsible for UA binding and that acetylation (of amino groups) prevented PTA binding. MA also abolishes the strong affinity of PTA to the lateral elements of the synaptonemal complex in meiotic chromosomes, the axoneme and fibrous sheath of the spermatid tail and the Z band in skeletal muscle. Reactivity was diminished in nucleoli and remained unaffected in chromatin, the outer coarse fibers of the flagellum and collagen fibrils. Different functional groups may participate in PTA staining. The ultrastructure was well preserved in all cases.

Immunochemial studies on myosin

Abstract 1. 1. Immunofluorescent methods have been used to detect myosin in the A bands of skeletal muscle, not only in intraspecific systems (immunizing antigen and stained muscle from the same species), but in interspecific systems (immunizing antigen and stained muscle from different species) as well. 2. 2. Two recent observations suggested that the interspecific staining reactions might be spurious: myosins purified by several procedures have been shown to contain antigenically active contaminants; and positive intraspecific reactions between anti-skeletal muscle myosin and cardiac myosin do not occur in rigorously purified systems. 3. 3. The test the possibility that interspecific reactions might be due to the presence of antigenically active contaminants, rabbit and chicken skeletal muscle myosins of various degrees of purity and their antisera were evaluated by gel-diffusion procedures. The cross reactions observed ranged from marked to absent depending upon the relative purity of the systems, thus demonstrating that adequately purified chicken and rabbit skeletal muscle myosins are completely dissimilar from one another by immunochemical criteria.