chronic injury
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Author(s):  
Ajith K. Subhash ◽  
Michael Davies ◽  
Andrew Gatto ◽  
Jacob M. Bogdanov ◽  
Rae Lan ◽  
...  

Abstract Purpose of Review Fibro-adipogenic progenitors were first characterized in 2010 and later found to contribute significantly to muscle regeneration and mediate degenerative changes in muscle following injury. These progenitors were also found to have an influence on the rotator cuff muscle’s response to chronic injury which is defined by fibrosis accompanied by massive fatty degeneration. The purpose of this review is to highlight progenitor cells, their contribution to fibro-adipogenesis in rotator cuff tissue, and the factors influencing fibro-adipogenesis in this tissue. Recent Findings Fibro-adipogenic progenitors are a key mediator of the fatty infiltration notably prevalent in rotator cuff injury. Relative to other muscle groups, the rotator cuff has relatively high rates of fibro-adipogenesis following massive chronic rotator cuff tears. This may be linked to the pre-injury density of fibro-adipogenic progenitors in muscle tissue affecting post-injury levels of fibro-adipogenesis. In addition, suprascapular nerve injury in rat models of rotator cuff tears has demonstrated worse, histologic, and biomechanical properties and lower healing rates of rotator cuff repairs. However, fatty infiltration in the rotator cuff following suprascapular nerve compression has been shown to be reversible following release of the nerve compression. Summary The fibro-adipogenic response to acute and chronic injury in rotator cuff tissue is determined by a complex array of factors including progenitor cell influence, transcriptional pathways, chronicity of the injury, anatomic location of injury, microenvironmental influences, and the severity of nerve involvement. Elucidating the complex interactions of these factors will provide potential targets for therapeutic intervention in vivo.


2022 ◽  
Author(s):  
Ghassan Maan Salim ◽  
Mohd Anwar Zawawi

Abstract Knee joint is an important part of human body. People with poor knee condition generally have limited physical movement, rendering to mental stress and agony. Knee pain can be categorized into three groups, known as acute injury, chronic injury and medical condition. Current technology to support the knee diagnosis and treatment procedures are limited to the use of manual goniometer, x-ray and magnetic resonance imaging (MRI). Alternative devices with continuous measurement capability for knee monitoring are minimum at this time, mainly due to the difficulties to cover the wide angle of the knee flexion. X-ray and MRI technologies are useful to have some insight on the knee problem, but they are not applicable for continuous monitoring. Aside from being expensive for general use of MRI, x-ray on the other hand can cause short-term side effects due to radiation exposure. The aim of this paper is to demonstrate the use of optical sensor integrated with mechanical gear system as a knee monitoring device. A plastic compartment, made by using 3D printer is used to place the sensor and the gear system. The design of the overall device allows direct attachment on a knee brace for easy placement on the knee. Based on current study, the proposed sensor has a range of motion between 0 deg. to 160 deg., 0.08 deg. resolution as well as support continuous monitoring of the knee. The sensor performance has been demonstrated for gait motion, ascending and descending stairs, sit-to-stand movement and maximum knee flexion applications.


2021 ◽  
pp. 56-59
Author(s):  
N. P. Makhlynets ◽  
Z. R. Ozhogan ◽  
M. V. Piuryk

Learning for children is a necessary stage in the development of personality, which helps the child to more easily acquire the necessary knowledge to further establish the individual. Оn the other hand it is a difficult stage in life of young people who lose the ability to communicate offline, especially during distance learning. It is difficult for children to adapt to the constant stay at home, to communicate with classmates and friends online, to adapt to the new rhythm of life and the dynamics of learning. Staying more than half of the time at the computer with a layer of psychological difficulties in the conditions of distance learning leads to constant stress and chronic stress. The modern educational system has changed so much in the last two years that the student must constantly adapt to new learning platforms and innovations. And the inability to clearly see and do laboratory classes in many subjects, self-study, even physical education classes leads to chronic stress. Stress is becoming an increasingly global problem, especially among children, because it negatively affects their lives and health, the progression of bad habits, and in turn, disorders of the dental system. Therefore, it is important to study the problem of social emotional chronic stress in the educational activities of students in terms of distance learning and its impact on the formation of disorders of the dental system. To reduce the impact of stressors, children use bad habits: sucking fingers, biting nails, pencils or pens, sitting in front of a monitor with his mouth open, despite a positive breath test (presence of nasal breathing), in the same position resting his head on his hands, causing chronic injury in this area. According to many studies, this may be the result of a person's adaptation to existing chronic stress. Our study was based on a quantitative study conducted among school-age patients who have bad habits (sucking a finger or other objects, breathing through their mouths, resting their heads on their hands while listening to an online lesson) through a secret questionnaire that collected information on the most stressful areas of life and distance learning under quarantine. The article presents the results of an anonymous survey of 60 patients, which includes periods of onset and progression of a chronic habit, the presence of various stressors, the reasons for poor performance. Our results of a secret survey indicate the state of chronic stress of students, their being in a state of social stress due to new living conditions, frequent changes between periods of live communication and distance learning, psychological problems in the family, emotional relief during the habit. Due to the fact that children live in conditions of chronic stress, they lose motivation to learn. They do not get pleasure from it, but in turn seek help in habits that, according to our patients, help reduce the impact of stress on quality of life and their own emotional state. The results of the study explain the formation of adaptive responses of the body to the stress factor (E. Gelgorn, W. Canon) and confirm the relationship between chronic bad habits in children under social stress.


Cancers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 5719
Author(s):  
Albert Gibert-Ramos ◽  
David Sanfeliu-Redondo ◽  
Peio Aristu-Zabalza ◽  
Ana Martínez-Alcocer ◽  
Jordi Gracia-Sancho ◽  
...  

The liver sinusoids are a unique type of microvascular beds. The specialized phenotype of sinusoidal cells is essential for their communication, and for the function of all hepatic cell types, including hepatocytes. Liver sinusoidal endothelial cells (LSECs) conform the inner layer of the sinusoids, which is permeable due to the fenestrae across the cytoplasm; hepatic stellate cells (HSCs) surround LSECs, regulate the vascular tone, and synthetize the extracellular matrix, and Kupffer cells (KCs) are the liver-resident macrophages. Upon injury, the harmonic equilibrium in sinusoidal communication is disrupted, leading to phenotypic alterations that may affect the function of the whole liver if the damage persists. Understanding how the specialized sinusoidal cells work in coordination with each other in healthy livers and chronic liver disease is of the utmost importance for the discovery of new therapeutic targets and the design of novel pharmacological strategies. In this manuscript, we summarize the current knowledge on the role of sinusoidal cells and their communication both in health and chronic liver diseases, and their potential pharmacologic modulation. Finally, we discuss how alterations occurring during chronic injury may contribute to the development of hepatocellular carcinoma, which is usually developed in the background of chronic liver disease.


Author(s):  
Kyung Jin Lee ◽  
Cheon Ho Song ◽  
Jin Soo Kim ◽  
Sung Hoon Koh ◽  
Dong Chul Lee ◽  
...  

Purpose: The indications for surgery in patients with acute closed sagittal band injuries are still undecided. The purpose of this study is to classify the types of injuries based on intraoperative findings of patients who underwent surgery for sagittal injury, and to present treatment plans and surgical methods.Methods: Twenty-five patients who had undergone surgical exploration for closed sagittal band injury between January 2011 and December 2020 were included in the study, comprising of 17 patients with acute injury within 3 weeks, four patients with chronic injury, and four patients who underwent surgery because symptoms did not improve during conservative treatment were included. Patients with laceration, fracture, and rheumatoid arthritis were excluded. Results: Sagittal band injury was classified into two groups: superficial sagittal band (SSB) injury and proper sagittal band (PSB) injury. SSB injury was observed in 75.0% of spontaneous rupture cases and PSB injury was observed in 66.7% of traumatic rupture cases. SSB injury was observed in 83.3% of Rayan and Murray classification type II cases and PSB injury was observed in 61.5% of type III cases (p=0.041). All four patients who failed conservative treatment and underwent surgery had PSB injuries.Conclusion: We successfully corrected the sagittal band injury with extensor digitorum communis tendon instability through surgical treatment. Sagittal band injury can be classified into two types depending on the anatomical injury pattern; SSB and PSB injuries. Surgical method and treatment plan can be chosen based on this.


Author(s):  
Tzu-Ting Chiu ◽  
Kun-Ze Lee

Cervical spinal cord injury typically results in respiratory impairments. Clinical and animal studies have demonstrated that respiratory function can spontaneously and partially recover over time after injury. However, it remains unclear whether respiratory recovery is associated with alterations in metabolism. The present study was designed to comprehensively examine ventilation and metabolism in a rat model of spinal cord injury. Adult male rats received sham (i.e., laminectomy) or unilateral mid-cervical contusion injury (height of impact rod: 6.25 or 12.5 mm). Breathing patterns and whole-body metabolism (O2 consumption and CO2 production) were measured using a whole-body plethysmography system conjugated with flow controllers and gas analyzer at the acute (1 day post-injury), subchronic (2 weeks post-injury), and chronic (8 weeks post-injury) injury stages. The results demonstrated that mid-cervical contusion caused a significant reduction in the tidal volume. Although the tidal volume of contused animals can gradually recover, it remains lower than that of uninjured animals at the chronic injury stage. While O2 consumption and CO2 production were similar between uninjured and contused animals at the acute injury stage, these two metabolic parameters were significantly reduced in contused animals at the subchronic to chronic injury stages. Additionally, the relationships between ventilation, metabolism, and body temperature were altered by cervical spinal cord injury. These results suggest that cervical spinal cord injury causes a complicated reconfiguration of ventilation and metabolism that may enable injured animals to maintain a suitable homeostasis for adapting to the pathophysiological consequences of injury.


Author(s):  
David Chadow ◽  
Giovanni J. Soletti ◽  
Mario Gaudino

The use of the Radial Artery (RA) as a conduit in coronary artery bypass grafting (CABG) has been steadily increasing since the early 1990’s and based on the most recent data may well become the standard of care for patients with multi-vessel coronary artery disease (CAD) requiring multiple arterial grafts. The TRA approach for cardiac catherization has also increased steadily in use by interventional cardiologists owing to its reduction in bleeding and vascular complications when compared with the femoral approach and is now considered the preferred arterial access. However, prior use of transradial access (TRA) for cardiac catherization is a contra-indication for the use of the RA for CABG because of high rates of structural damage to the vascular wall and potential for graft failure. In this issue of the Journal of Cardiac Surgery Clarke et al. examine the RA of two patients who had TRA for coronary angiography 8 and 12 years prior and note that both patients had chronic injury with dissection and obstruction of the lumen secondary to fibrosis suggesting that TRA causes long-term and irreversible damage rendering them unsuitable as conduits for CABG.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yuan-hui Li ◽  
Shuang Shen ◽  
Tong Shao ◽  
Meng-ting Jin ◽  
Dong-dong Fan ◽  
...  

AbstractMesenchymal stem cell (MSC) therapy has become a promising treatment for liver fibrosis due to its predominant immunomodulatory performance in hepatic stellate cell inhibition and fibrosis resolution. However, the cellular and molecular mechanisms underlying these processes remain limited. In the present study, we provide insights into the functional role of bone marrow-derived MSCs (BM-MSCs) in alleviating liver fibrosis by targeting intrahepatic Ly6Chi and Ly6Clo macrophage subsets in a mouse model. Upon chronic injury, the Ly6Chi subset was significantly increased in the inflamed liver. Transplantation of BM-MSCs markedly promoted a phenotypic switch from pro-fibrotic Ly6Chi subset to restorative Ly6Clo subpopulation by secreting paracrine cytokines IL-4 and IL-10 from the BM-MSCs. The Ly6Chi/Ly6Clo subset switch significantly blocked the source of fibrogenic TGF-β, PDGF, TNF-α, and IL-1β cytokines from Ly6Chi macrophages. Unexpectedly, BM-MSCs experienced severe apoptosis and produced substantial apoptotic bodies in the fibrotic liver during the 72 h period of transplantation. Most apoptotic bodies were engulfed by Ly6Clo macrophages, and this engulfment robustly triggered MMP12 expression for fibrosis resolution through the PtdSer-MerTK-ERK signaling pathway. This paper is the first to show previously unrecognized dual regulatory functions of BM-MSCs in attenuating hepatic fibrosis by promoting Ly6Chi/Ly6Clo subset conversion and Ly6Clo macrophage restoration through secreting antifibrogenic-cytokines and activating the apoptotic pathway.


Physiology ◽  
2021 ◽  
Vol 36 (5) ◽  
pp. 272-291 ◽  
Author(s):  
Dylan R. Addis ◽  
Saurabh Aggarwal ◽  
Ahmed Lazrak ◽  
Tamas Jilling ◽  
Sadis Matalon

The halogens chlorine (Cl2) and bromine (Br2) are highly reactive oxidizing elements with widespread industrial applications and a history of development and use as chemical weapons. When inhaled, depending on the dose and duration of exposure, they cause acute and chronic injury to both the lungs and systemic organs that may result in the development of chronic changes (such as fibrosis) and death from cardiopulmonary failure. A number of conditions, such as viral infections, coexposure to other toxic gases, and pregnancy increase susceptibility to halogens significantly. Herein we review their danger to public health, their mechanisms of action, and the development of pharmacological agents that when administered post-exposure decrease morbidity and mortality.


Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1014
Author(s):  
Yufei Yan ◽  
Jiefei Zeng ◽  
Linhao Xing ◽  
Changyong Li

Hepatic fibrosis is characterized by the pathological accumulation of extracellular matrix (ECM) in the liver resulting from the persistent liver injury and wound-healing reaction induced by various insults. Although hepatic fibrosis is considered reversible after eliminating the cause of injury, chronic injury left unchecked can progress to cirrhosis and liver cancer. A better understanding of the cellular and molecular mechanisms controlling the fibrotic response is needed to develop novel clinical strategies. It is well documented that activated hepatic stellate cells (HSCs) is the most principal cellular players promoting synthesis and deposition of ECM components. In the current review, we discuss pathways of HSC activation, emphasizing emerging extra- and intra-cellular signals that drive this important cellular response to hepatic fibrosis. A number of cell types and external stimuli converge upon HSCs to promote their activation, including hepatocytes, liver sinusoidal endothelial cells, macrophages, cytokines, altered ECM, hepatitis viral infection, enteric dysbiosis, lipid metabolism disorder, exosomes, microRNAs, alcohol, drugs and parasites. We also discuss the emerging signaling pathways and intracellular events that individually or synergistically drive HSC activation, including TGFβ/Smad, Notch, Wnt/β-catenin, Hedgehog and Hippo signaling pathways. These findings will provide novel potential therapeutic targets to arrest or reverse fibrosis and cirrhosis.


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