scholarly journals Not merely a protective packing organ? A review of fascia and its force transmission capacity

2018 ◽  
Vol 124 (1) ◽  
pp. 234-244 ◽  
Author(s):  
Jan Wilke ◽  
Robert Schleip ◽  
Can A. Yucesoy ◽  
Winfried Banzer
Keyword(s):  
Animal Studies ◽  
Biomechanical Properties ◽  
Force Transmission ◽  
Locomotor System ◽  
Myofascial Force Transmission ◽  
Transmitted Force ◽  
Muscle Fascia ◽  
The Central Nervous System

Recent research indicates that fascia is capable of changing its biomechanical properties. Moreover, as it links the skeletal muscles, forming a body-wide network of multidirectional myofascial continuity, the classical conception of muscles as independent actuators has been challenged. Hence, the present synthesis review aims to characterize the mechanical relevance of the connective tissue for the locomotor system. Results of cadaveric and animal studies suggest a clinically relevant myofascial force transmission to neighboring structures within one limb (e.g., between synergists) and in the course of muscle-fascia chains (e.g., between leg and trunk). Initial in vivo trials appear to underpin these findings, demonstrating the existence of nonlocal exercise effects. However, the factors influencing the amount of transmitted force (e.g., age and physical activity) remain controversial, as well as the role of the central nervous system within the context of the observed remote exercise effects.

scholarly journals New Evidence on the Role of D-Aspartate Metabolism in Regulating Brain and Endocrine System Physiology: From Preclinical Observations to Clinical Applications

2020 ◽  
Vol 21 (22) ◽  
pp. 8718
Author(s):  
Alessandro Usiello ◽  
Maria Maddalena Di Fiore ◽  
Arianna De Rosa ◽  
Sara Falvo ◽  
Francesco Errico ◽  
...  
Keyword(s):  
Animal Studies ◽  
Endocrine System ◽  
Postnatal Life ◽  
Functional Development ◽  
The Central Nervous System ◽  
High Concentrations ◽  
System Physiology ◽  
Metabolizing Enzyme

The endogenous amino acids serine and aspartate occur at high concentrations in free D-form in mammalian organs, including the central nervous system and endocrine glands. D-serine (D-Ser) is largely localized in the forebrain structures throughout pre and postnatal life. Pharmacologically, D-Ser plays a functional role by acting as an endogenous coagonist at N-methyl-D-aspartate receptors (NMDARs). Less is known about the role of free D-aspartate (D-Asp) in mammals. Notably, D-Asp has a specific temporal pattern of occurrence. In fact, free D-Asp is abundant during prenatal life and decreases greatly after birth in concomitance with the postnatal onset of D-Asp oxidase expression, which is the only enzyme known to control endogenous levels of this molecule. Conversely, in the endocrine system, D-Asp concentrations enhance after birth during its functional development, thereby suggesting an involvement of the amino acid in the regulation of hormone biosynthesis. The substantial binding affinity for the NMDAR glutamate site has led us to investigate the in vivo implications of D-Asp on NMDAR-mediated responses. Herein we review the physiological function of free D-Asp and of its metabolizing enzyme in regulating the functions of the brain and of the neuroendocrine system based on recent genetic and pharmacological human and animal studies.

Pre-Strained Epimuscular Connections Cause Muscular Myofascial Force Transmission to Affect Properties of Synergistic EHL and EDL Muscles of the Rat

2005 ◽  
Vol 127 (5) ◽  
pp. 819-828 ◽  
Author(s):  
Can A. Yucesoy ◽  
Guus C. Baan ◽  
Bart H. F. J. M. Koopman ◽  
Henk J. Grootenboer ◽  
Peter A. Huijing
Keyword(s):  
Muscle Length ◽  
Substantial Part ◽  
Force Transmission ◽  
Myofascial Force Transmission ◽  
Extensor Hallucis Longus ◽  
Edl Muscle ◽  
Force Difference ◽  
Force Characteristics

Background: Myofascial force transmission occurs between muscles (intermuscular myofascial force transmission) and from muscles to surrounding nonmuscular structures such as neurovascular tracts and bone (extramuscular myofascial force transmission). The purpose was to investigate the mechanical role of the epimuscular connections (the integral system of inter- and extramuscular connections) as well as the isolated role of extramuscular connections on myofascial force transmission and to test the hypothesis, if such connections are prestrained. Method of approach: Length-force characteristics of extensor hallucis longus (EHL) muscle of the rat were measured in two conditions: (I) with the neighboring EDL muscle and epimuscular connections of the muscles intact: EDL was kept at a constant muscle tendon complex length. (II) After removing EDL, leaving EHL with intact extramuscular connections exclusively. Results: (I) Epimuscular connections of the tested muscles proved to be prestrained significantly. (1) Passive EHL force was nonzero for all isometric EHL lengths including very low lengths, increasing with length to approximately 13% of optimum force at high length. (2) Significant proximodistal EDL force differences were found at all EHL lengths: Initially, proximal EDL force =1.18±0.11N, where as distal EDL force =1.50±0.08N (mean ± SE). EHL lengthening decreased the proximo-distal EDL force difference significantly (by 18.4%) but the dominance of EDL distal force remained. This shows that EHL lengthening reduces the prestrain on epimuscular connections via intermuscular connections; however; the prestrain on the extramuscular connections of EDL remains effective. (II) Removing EDL muscle affected EHL forces significantly. (1) Passive EHL forces decreased at all muscle lengths by approximately 17%. However, EHL passive force was still nonzero for the entire isometric EHL length range, indicating pre-strain of extramuscular connections of EHL. This indicates that a substantial part of the effects originates solely from the extramuscular connections of EHL. However, a role for intermuscular connections between EHL and EDL, when present, cannot be excluded. (2) Total EHL forces included significant shape changes in the length-force curve (e.g., optimal EHL force decreased significantly by 6%) showing that due to myofascial force transmission muscle length-force characteristics are not specific properties of individual muscles. Conclusions: The pre-strain in the epimuscular connections of EDL and EHL indicate that these myofascial pathways are sufficiently stiff to transmit force even after small changes in relative position of a muscle with respect to its neighboring muscular and nonmuscular tissues. This suggests the likelihood of such effects also in vivo.

scholarly journals Subinhibitory Antimicrobial Concentrations: A Review of In Vitro and In Vivo Data

1992 ◽  
Vol 3 (4) ◽  
pp. 193-201 ◽  
Author(s):  
George G Zhanel ◽  
Daryl J Hoban ◽  
Godfrey KM Harding
Keyword(s):  
Antimicrobial Activity ◽  
Animal Studies ◽  
Molecular Level ◽  
Bacterial Virulence ◽  
Antibacterial Effects ◽  
Wide Range ◽  
Immune Defences

Antimicrobial activity is not an ‘all or none’ effect. An increase in the rate and extent of antimicrobial action is usually observed over a wide range of antimicrobial concentrations. Subinhibitory antimicrobial concentrations are well known to produce significant antibacterial effects, and various antimicrobials at subinhibitory concentrations have been reported to inhibit the rate of bacterial growth. Bacterial virulence may be increased or decreased by subinhibitory antimicrobial concentrations by changes in the ability of bacteria to adhere to epithelial cells or by alterations in bacterial susceptibility to host immune defences. Animal studies performed in rats, hamsters and rabbits demonstrate decreased bacterial adherence, reduced infectivity and increased survival of animals treated with subinhibitory antimicrobial concentrations compared to untreated controls. The major future role of investigation of subinhibitory antimicrobial concentrations will be to define more fully, at a molecular level, how antimicrobials exert their antibacterial effects.

The effects of ovariectomy on bone mineral density, geometrical, and biomechanical characteristics in the rabbit femur

2010 ◽  
Vol 23 (01) ◽  
pp. 31-36 ◽  
Author(s):  
M. E. Kara ◽  
F. Sevil
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Animal Studies ◽  
Biomechanical Properties ◽  
Mineral Density ◽  
Cross Sectional ◽  
Tomographic Images ◽  
Three Point Bending ◽  
Rabbit Femur

SummaryThe aim of the study was to evaluate the bone mineral density, as well as the biomechanic and morphometric changes in the femur of ovariectomised rabbits.Twenty-four six-month-old New Zealand rabbits were randomly divided into an ovariectomy (n = 12) and a sham (n = 12) group. Six rabbits in each group were euthanatized at eight and 16 weeks after surgery, and the femora were resected. The morphometric data were obtained from tomographic images. Periosteal and endosteal diameters and cortical thickness were measured. Total cross-sectional, cortical and medullary areas were also measured. The bone mineral content, the bone area and the bone mineral density were measured from the proximal, distal and mid-shaft of the femur as well as the total femur by dual energy X-ray absorptiometry. Employing the three-point bending method, the ultimate force, stiffness and work-to-failure were measured. The mechanical data were normalised to obtain intrinsic biomechanical properties such as ultimate stress, elastic modulus, and toughness, all of which are independent of size and shape.The results indicated that the femur was both larger and weaker 16 weeks after surgery in the ovariectomised group. Results also suggest that the rabbit might be a useful animal model for investigation of diseases related to oestrogen loss such as human postmenopausal osteoporosis. However, additional studies with advanced techniques at several time points via in vivo animal studies, and precision and predictability analyses should be designed to standardise the rabbit as a model for osteoporosis.

scholarly journals A neuroprotective role for microglia in prion diseases

2016 ◽  
Vol 213 (6) ◽  
pp. 1047-1059 ◽  
Author(s):  
Caihong Zhu ◽  
Uli S. Herrmann ◽  
Jeppe Falsig ◽  
Irina Abakumova ◽  
Mario Nuvolone ◽  
...  
Keyword(s):  
Prion Diseases ◽  
Protective Role ◽  
Proteinase K ◽  
Immune Effector ◽  
Effector Cells ◽  
The Central Nervous System ◽  
Cultured Slices ◽  
Simplex Virus

Microglial activation is a hallmark of most neurodegenerative disorders, and is particularly conspicuous in prion diseases. However, the role of microglia, which function as both primary immune effector cells and professional phagocytes in the central nervous system, remains contentious in the context of neurodegeneration. Here, we evaluated the effect of microglial depletion/deficiency on prion pathogenesis. We found that ganciclovir-mediated microglial ablation on tga20/CD11b-thymidine kinase of Herpes simplex virus (HSVTK) cerebellar organotypic cultured slices markedly aggravated prion-induced neurotoxicity. A similar deterioration of disease was recapitulated in in vivo microglial depletion in prion-infected tga20/CD11b-HSVTK mice. Additionally, deficiency of microglia in interleukin 34 knockout (IL34−/−) mice again resulted in significantly augmented proteinase K–resistant prion protein deposition and accelerated prion disease progression. These results provide unambiguous evidence for a general protective role of microglia in prion pathogenesis.

Relationship of Motor Mechanisms to Gastroparesis Symptoms: Towards Individualized Treatment

2021 ◽  
Author(s):  
Michael Camilleri
Keyword(s):  
Animal Studies ◽  
Gastrointestinal Symptoms ◽  
Feedback Regulation ◽  
Individualized Treatment ◽  
Control Mechanisms ◽  
Gastric Accommodation ◽  
Billroth I ◽  
Gastric Sensitivity

Following a classical paper by Dr. Keith A. Kelly published in this journal, and over the past 40 years, there has been increased understanding of the functions of different regions of the stomach, specifically the fundus, antrum, and pylorus. Several of the important physiological principles were based on in vivo animal studies that led to the appreciation of regional function and control mechanisms. These include the roles of the extrinsic parasympathetic vagal innervation, the gastric enteric nervous system and electrical syncytium consisting of pacemaker cells and smooth muscle cells, and duodenogastric reflexes providing feedback regulation following the arrival of food and hydrogen ions stimulating the release of hormones and vagal afferent mechanisms that inhibit gastric motility and stimulate pyloric contractility. Further insights on the role of regional motor functions in gastric emptying were obtained from observations in patients following diverse gastric surgeries or bariatric procedures, including fundoplication, Billroth I and sleeve gastrectomy, and sleeve gastroplasty. Antropyloroduodenal manometry as well as measurements of pyloric diameter and distensibility index provided important assessments of the role of antral hypomotility and pylorospasm, and these constitute specific targets for individualized treatment of patients with gastroparesis. Moreover, in patients with upper gastrointestinal symptoms suggestive of gastroparesis, the availability of measurements of gastric accommodation as well as pharmacological agents to reduced gastric sensitivity or enhance gastric accommodation provide additional specific targets for individualized treatment. It is anticipated that, in the future, such physiological measurements will be applied in patients to optimize choice of therapy, possibly including identifying the best candidate for pyloric interventions.

scholarly journals Intranasal Borna Disease Virus (BoDV-1) Infection: Insights into Initial Steps and Potential Contagiosity

2019 ◽  
Vol 20 (6) ◽  
pp. 1318 ◽  
Author(s):  
Alexandra Kupke ◽  
Sabrina Becker ◽  
Konstantin Wewetzer ◽  
Barbara Ahlemeyer ◽  
Markus Eickmann ◽  
...  
Keyword(s):  
Viral Infections ◽  
Cell Types ◽  
Nerve Fibers ◽  
Olfactory Pathway ◽  
Adult Rats ◽  
The Central Nervous System ◽  
Receptor Neurons

Mammalian Bornavirus (BoDV-1) typically causes a fatal neurologic disorder in horses and sheep, and was recently shown to cause fatal encephalitis in humans with and without transplant reception. It has been suggested that BoDV-1 enters the central nervous system (CNS) via the olfactory pathway. However, (I) susceptible cell types that replicate the virus for successful spread, and (II) the role of olfactory ensheathing cells (OECs), remained unclear. To address this, we studied the intranasal infection of adult rats with BoDV-1 in vivo and in vitro, using olfactory mucosal (OM) cell cultures and the cultures of purified OECs. Strikingly, in vitro and in vivo, viral antigen and mRNA were present from four days post infection (dpi) onwards in the olfactory receptor neurons (ORNs), but also in all other cell types of the OM, and constantly in the OECs. In contrast, in vivo, BoDV-1 genomic RNA was only detectable in adult and juvenile ORNs, nerve fibers, and in OECs from 7 dpi on. In vitro, the rate of infection of OECs was significantly higher than that of the OM cells, pointing to a crucial role of OECs for infection via the olfactory pathway. Thus, this study provides important insights into the transmission of neurotropic viral infections with a zoonotic potential.

scholarly journals Protective Effects of Dietary Antioxidants against Vanadium-Induced Toxicity: A Review

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Iwona Zwolak
Keyword(s):  
Oxidative Stress ◽  
Animal Studies ◽  
Toxic Metal ◽  
Protective Effects ◽  
Dietary Antioxidants ◽  
Vanadium Toxicity ◽  
Preventive Effects

Vanadium (V) in its inorganic forms is a toxic metal and a potent environmental and occupational pollutant and has been reported to induce toxic effects in animals and people. In vivo and in vitro data show that high levels of reactive oxygen species are often implicated in vanadium deleterious effects. Since many dietary (exogenous) antioxidants are known to upregulate the intrinsic antioxidant system and ameliorate oxidative stress-related disorders, this review evaluates their effectiveness in the treatment of vanadium-induced toxicity. Collected data, mostly from animal studies, suggest that dietary antioxidants including ascorbic acid, vitamin E, polyphenols, phytosterols, and extracts from medicinal plants can bring a beneficial effect in vanadium toxicity. These findings show potential preventive effects of dietary antioxidants on vanadium-induced oxidative stress, DNA damage, neurotoxicity, testicular toxicity, and kidney damage. The relevant mechanistic insights of these events are discussed. In summary, the results of studies on the role of dietary antioxidants in vanadium toxicology appear encouraging enough to merit further investigations.

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