Skeletal Muscles: Insight into Embryonic Development, Satellite Cells, Histology, Ultrastructure, Innervation, Contraction and Relaxation, Causes, Pathophysiology, and Treatment of Volumetric Muscle I | Author : Azab Elsayed Azab | Abstract | Full Text | Abstract :Background: Skeletal muscles are attached to bone and are responsible for the axial and appendicular movement of the skeleton and for maintenance of body position and posture.
Objectives: The present review aimed to high light on embryonic development of skeletal muscles, histological and ultrastructure, innervation, contraction and relaxation, causes, pathophysiology, and treatment of volumetric muscle injury. The heterogeneity of the muscle fibers is the base of the flexibility which allows the same muscle to be used for various tasks from continuous low-intensity activity, to repeated submaximal contractions, and to fast and strong maximal contractions. The formation of skeletal muscle begins during the fourth week of embryonic development as specialized mesodermal cells, termed myoblasts. As growth of the muscle fibers continues, aggregation into bundles occurs, and by birth, myoblast activity has ceased. Satellite cells (SCs), have single nuclei and act as regenerative cells. Satellite cells are the resident stem cells of skeletal muscle; they are considered to be self-renewing and serve to generate a population of differentiation-competent myoblasts that will participate as needed in muscle growth, repair, and regeneration. Based on various structural and functional characteristics, skeletal muscle fibres are classified into three types: Type I fibres, Type II-B fibres, and type II-A fibres. Skeletal muscle fibres vary in colour depending on their content of myoglobin. Each myofibril exhibits a repeating pattern of cross-striations which is a product of the highly ordered arrangement of the contractile proteins within it. The parallel myofibrils are arranged with their cross-striations in the register, giving rise to the regular striations seen with light microscopy in longitudinal sections of skeletal muscle. Each skeletal muscle receives at least two types of nerve fibers: motor and sensory. Striated muscles and myotendinous junctions contain sensory receptors that are encapsulated proprioceptors. The process of contraction, usually triggered by neural impulses, obeys the all-or-none law. During muscle contraction, the thin filaments slide past the thick filaments, as proposed by Huxleys sliding filament theory. In response to a muscle injury, SCs are activated and start to proliferate; at this stage, they are often referred to as either myogenic precursor cells (MPC) or myoblasts. In vitro, evidence has been presented that satellite cells can be pushed towards the adipogenic and osteogenic lineages, but contamination of such cultures from non-myogenic cells is sometimes hard to dismiss as the underlying cause of this observed multipotency. There are, however, other populations of progenitors isolated from skeletal muscle, including endothelial cells and muscle-derived stem cells (MDSCs), blood-vessel-associated mesoangioblasts, muscle side-population cells, CD133+ve cells, myoendothelial cells, and pericytes. Volumetric muscle loss (VML) is defined as the traumatic or surgical loss of skeletal muscle with resultant functional impairment. It represents a challenging clinical problem for both military and civilian medicine. VML results in severe cosmetic deformities and debilitating functional loss. In response to damage, skeletal muscle goes through a well-defined series of events including; degeneration (1 to 3days), inflammation, and regeneration (3 to 4 weeks), fibrosis, and extracellular matrix remodeling (3 to 6 months).. Mammalian skeletal muscle has an impressive ability to regenerate itself in response to injury. During muscle tissue repair following damage, the degree of damage and the interactions between muscle and the infiltrating inflammatory cells appear to affect the successful outcome of the muscle repair process. The transplantation of stem cells into aberrant or injured tissue has long been a central goal of regenerative medicine and tissue engineering.
Conclusion: It can be concluded that the formation of skeletal muscle begins during the fourth week of embryonic development as specialized mesodermal cells, termed myoblasts, by birth myoblast activity has ceased. Satellite cells are considered to be self-renewing, and serve to generate a population of differentiation-competent myoblasts. Skeletal muscle fibres are classified into three types. The process of contraction, usually triggered by neural impulses, obeys the all-or-none law. VML results in severe cosmetic deformities and debilitating functional loss. Mammalian skeletal muscle has an impressive ability to regenerate itself in response to injury. The transplantation of stem cells into aberrant or injured tissue has long been a central goal of regenerative medicine and tissue engineering. |
| Effect of Coronavirus Infection on Fasting Blood Glucose, Kidney Function, and Electrolytes in COVID-19 Patients in the Zawia Region, Western Libya | Author : Azab Elsayed Azab | Abstract | Full Text | Abstract :Background: Coronavirus disease 19 (COVID-19) is a pandemic infectious disease caused by the novel coronavirus. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). It is an aggressive virus that spread worldwide and is a systemic disease involving multiple systems, including respiratory, cardiovascular, gastrointestinal, hematopoietic, neurological, immune, and urinogenital systems.
Objectives: The present study aimed to evaluate the alteration in fasting blood glucose, serum urea, creatinine, Na+, K+, and Cl- levels among COVID-19 patients in the Zawia region, Western Libya.
Materials and Methods: 416 confirmed COVID-19 patients hospitalized in the Isolation Centre located in Zawia city, Libya. From the 1st May 2020 to the 30th March 2021, were enrolled in this prospective study. Covid-19 patients were defined as positive cases after the detection of SARS-CoV-2 RNA in oro-nasopharyngeal swab samples. Demographic data were extracted from electronic medical records and patient files. Also, 30 healthy individuals without any chronic disease or respiratory symptoms were recruited for the control group. Blood samples were collected via vein puncture for estimating biochemical parameters (fasting blood glucose, serum urea, creatinine, Na+, K+, and Cl- concentrations). The statistical significance of differences between groups was evaluated with the Mann- Whitney (U test). Associations between different parameters were evaluated with the Spearmans test.
Results: The results showed that coronavirus infection induced a significant increase in fasting blood glucose, serum urea, and creatinine concentrations. Infections also induced a decrease in serum sodium ion concentration, compared with healthy individuals. Seventy-six percent of corona virus-infected patients had hyperglycemia. Similarly, high levels of serum urea, creatinine, Cl-, Na+, and K+ were found in 40.9%, 39.9%, 27.9%, 8.9% and 6.5% of patients, respectively. Hyponatraemia, hypokalaemia, and hypochloremia were found in 35.5%, 13.7%, and 12.9% of patients. There were recorded a significant positive association between fasting blood glucose and serum urea, creatinine, and K+ concentration, between serum urea concentration and serum creatinine, K+, and Cl- concentrations, between serum creatinine and K+, and Cl- concentrations, and between serum Na+ and Cl- concentration, and a significant negative association between fasting blood glucose and serum Na+ and Cl- concentrations and between serum K+ and Na+ concentrations.
Conclusion: It can be concluded that coronavirus infections induced increases in fasting blood glucose, serum urea, and creatinine, and a decrease in Na+ concentrations. There was a significant association between different parameters. These biochemical changes may help the clinicians to understand COVID-19 better and provide more clinical treatment options and prevent the serious complications of the disease. Thus, clinicians should pay special attention to fasting blood glucose, kidney function and electrolyte status of COVID-19 patients. Changes in fasting blood glucose, kidney function, and electrolyte levels can be a good indicator of disease progression. |
| Nonuse of Forest Residues is Impermissible Overlook for the Country with Limited Natural Resources | Author : Tamaz Patarkalashvili | Abstract | Full Text | Abstract :In human history forests always satisfied different needs of people like: food, energy, medicine plants, wood materials, fodder. From 20th century wood energy gradually was substituted by fossil fuel. But wood still remained irreplaceable resource for construction, furniture, paper industry. At the same time many new wood products have been developed from wood and agriculture residues, so called engineered wood, like: plywood, chipboards, fiberboards, MDF, etc. Bio-economy today uses biomass for manufacturing bio-based chemicals, plastics, pharmaceutical products as well as, residues for generating bio-energy. Nowadays, when the fossil fuel age declines due to its exhaustible character biomass regains a new importance. Biomass currently is the dominating renewable energy source for multiple use. Gradual substitution of fossil fuel by renewable energies instigates rapid growth of all renewable energy carriers like wind, solar, hydro, geo-thermal and bio-energy. It is the best strategy against climate change too. |
| Menstrual Blood Mesenchymal Stem Cells: Boon in Therapeutics | Author : PD Gupta | Abstract | Full Text | Abstract :Stem cell therapy gained momentum for the past three decades in therapeutics. Alternative strategies are indispensable for the treatment of many diseases in the present scenario due to side effects of synthetic chemicals as drugs. Mesenchymal cells of different origin have been in use with good results, though ethical issues and limited availability is a drawback. Novel menstrual blood mesenchymal stems cells prove to be a wealth out of waste is a boon in therapeutics. In this review we bring a bird’s eye view of different diseases treated with menstrual blood mesenchymal stem cells with positive results. Evolution in the use of these cells more and more will be a big relief to many who suffer with side effects of drugs. |
| Ameliorating Effects of Fenugreek Seeds Powder against Hematotoxicity Induced by Aluminum Chloride in Male Rabbits | Author : Azab Elsayed Azab | Abstract | Full Text | Abstract :Background: Humans are exposed to aluminum from the mouth, nose and epidermal route inducing toxic effects. Accumulation of aluminum has been associated with a variety of pathologies such as anemia, osteodystrophy, joint diseases, muscular weakness, and Alzheimer’s diseases Fenugreek extracts have been shown to be neutralizing of free radicals and enhancing antioxidant status.
Objectives: The present study aimed to evaluate the ameliorative effects of fenugreek seeds against hematotoxicity induced by Aluminum chloride in male rabbits.
Materials and Methods: This study included twenty-four adult male rabbits, which were divided into 4 groups, 6 rabbits for each. Group I (control group): Animals were provided with tap water and fed with a normal diet for 30 days. Group II (Fenugreek seeds powder group): Fenugreek seeds powder was given to rabbits in food at a dose of 10 g per kilogram of diet weight/kg of body weight/day for 30 Days. Group III (Aluminum chloride (ALCl3) group): Rabbits were treated orally with 150 mg/kg BW of AlCl3/day for 30 consecutive days. Group IV (Aluminum chloride/fenugreek co-administered group): Fenugreek seeds flour was added at a rate of 10 g per kilogram of diet weight, and rabbits were treated orally with 150 mg/kg BW of AlCl3/day for 30 consecutive days. At the end of the experiment and 24 hours after the last dose, all animals were anesthetized with ether and blood samples were collected by heart puncture.
Results: The results of the study showed that the treatment of male rabbits with aluminum chloride resulted in a significant decrease (P<0.01) in RBCs count, hemoglobin concentration, hematocrit value, MCV, MCH, and MCHC as compared to the control group. While there was a significant increase (P<0.01) in WBCs count, lymphocytes, and monocytes percentages and a significant decrease in granulocyte percentage when compared with the control group. Co-administration of fenugreek seeds powder and AlCl3 significantly improved all haematological parameters.
Conclusion: The results showed that the administration of rabbits with aluminum chloride caused a hematotoxicity, and co-administration of fenugreek seeds powder with AlCl3 alleviate the hematotoxicity induced by AlCl3. The use of fenugreek seeds powder by humans can be considered beneficial in the alleviation of hematotoxicity. It is recommended that humans exposed to AlCl3 should be advised to take fenugreek seeds powder as a rich source of antioxidants to prevent hematotoxicity induced by AlCl3. Further studies are necessary to elucidate the exact mechanism of the anti-hematotoxic effect of Fenugreek seeds powder and the potential usefulness of fenugreek seeds powder as a protective agent against AlCl3 induced hematotoxicity in clinical trials. |
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