Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inspiratory muscle weakness in patients with chronic obstructive pulmonary disease (COPD) is of major clinical relevance; maximum inspiratory pressure generation is an independent determinant of survival in severe COPD. Traditionally, inspiratory muscle weakness has been ascribed to hyperinflation-induced diaphragm shortening. However, more recently, invasive evaluation of diaphragm contractile function, structure, and biochemistry demonstrated that cellular and molecular alterations occur, of which several can be considered of pathologic nature. Although the fiber-type shift toward oxidative type I fibers in COPD diaphragm is regarded as beneficial, rendering the overloaded diaphragm more resistant to fatigue, the reduction of diaphragm fiber force generation in vitro likely contributes to diaphragm weakness. The reduced diaphragm force generation at single-fiber level is associated with loss of myosin content. Moreover, the diaphragm in COPD is exposed to oxidative stress and sarcomeric injury. The current Pulmonary Perspective postulates that the oxidative stress and sarcomeric injury activate proteolytic machinery, leading to contractile protein wasting and, consequently, loss of force-generating capacity of diaphragm fibers in patients with COPD. Interestingly, several of these presumed pathologic alterations are already present early in the course of the disease (GOLD I/II), although these patients do not appear to be limited in their daily-life activities. Therefore, investigating in vivo diaphragm function in mild to moderate COPD should be the focus of future research. Treatment of diaphragm dysfunction in COPD is complex because its etiology is unclear, but recent findings show promise for the use of proteasome inhibitors in syndromes associated with muscle wasting, such as the diaphragm in COPD.
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PMID:Diaphragm muscle fiber dysfunction in chronic obstructive pulmonary disease: toward a pathophysiological concept. 1741 28

Treatment for breast cancer patients includes surgical removal of the tumor followed by chemotherapy. Chemotherapy frequently results in difficult to manage symptoms that threaten compliance with the therapy. Symptoms include fatigue, declines in functional ability, muscle wasting, and a decreased quality of life. Preparing the body to tolerate a stressful event such as chemotherapy has been termed "prehabilitation". This case study determined the efficacy of introducing aerobic training 1 week prior to and continuing through 8 weeks of chemotherapy on fatigue and functional ability in a 42-year-old newly diagnosed breast cancer patient. The patient participated in a supervised and home-based walking program. Fatigue during daily activities and functional ability (12-minute walk, ascending and descending stairs, sit to stand, getting to and rising from the floor, 30-second bicep curl) were measured before and after exercise training. Results indicate that 5 of 7 functional measures demonstrated improvement, ranging from 23.4- 54.5%. In addition, fatigue while performing activities of daily living, as well as following the performance of the functional tasks, was reduced. The findings of this case study indicate that fatigue can be decreased and functional ability can be improved as a result of aerobic training initiated 1 week before and continued throughout chemotherapy. This case study presents a novel approach to introducing exercise prior to and continued during 8 weeks of chemotherapy in a way that may reduce the cumulative effects of this stressor.
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PMID:Effects of aerobic training prior to and during chemotherapy in a breast cancer patient: a case study. 1753 Sep 64

The post-polio syndrome (PPS) is an entity characterized for an episode of muscular weakness and/or abnormal muscular fatigue in individuals that had presented acute polio years before. We report the case of PPS in a patient, 40 years, that thirty-five years after had had paralytic poliomyelitis, developed new symptoms of fatigue, muscular atrophy, dyspnea, difficulties in deambulation and muscular and joint pain. The electromyographic findings revealed injuried neurons of the anterior horn of the marrow and reinnervation after muscular tests.
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PMID:Post-poliomyelitis syndrome: case report. 1766 30

Cancer cachexia is a debilitating and life-threatening syndrome characterised by anorexia, body weight loss, loss of adipose tissue and skeletal muscle, and accounts for > or = 20% of deaths in neoplastic patients. Cancer cachexia significantly impairs quality of life and response to antineoplastic therapies, increasing the morbidity and mortality of cancer patients. Muscle wasting is the most important phenotypic feature of cancer cachexia and the principle cause of function impairment, fatigue and respiratory complications, and is mainly related to a hyperactivation of muscle proteolytic pathways. Existing therapeutic strategies have proven to be only partially effective. In the last decade, the correction of anorexia, the inhibition of catabolic processes and the stimulation of anabolic pathways in muscle has been attempted pharmacologically, giving encouraging results in animal models and through preliminary clinical trials.
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PMID:Novel treatments for cancer cachexia. 1768 72

Many patients with chronic obstructive pulmonary disease (COPD) suffer from exercise intolerance. In about 40% of the patients exercise capacity is limited by alterations in skeletal muscle rather than pulmonary problems. Indeed, COPD is often associated with muscle wasting and a slow-to-fast shift in fiber type composition resulting in weakness and an earlier onset of muscle fatigue, respectively. Clearly, limiting muscle wasting during COPD benefits the patient by improving the quality of life and also the chance of survival. To successfully combat muscle wasting and remodeling during COPD a clear understanding of the causes and mechanisms is needed. Disuse, hypoxemia, malnutrition, oxidative stress and systemic inflammation may all cause muscle atrophy. Particularly when systemic inflammation is elevated muscle wasting becomes a serious complication. The muscle wasting may at least partly be due to an increased activity of the ubiquitin proteasome pathway and apoptosis. However, it might well be that an impaired regenerative potential of the muscle rather than the increased protein degradation is the crucial factor in the loss of muscle mass during COPD with a high degree of systemic inflammation. Finally, we briefly discuss the various treatments and rehabilitation strategies available to control muscle wasting and fatigue in patients with COPD.
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PMID:Factors contributing to muscle wasting and dysfunction in COPD patients. 1822 67

Although hormone therapy is widely used in the management of prostate cancer, the optimal timing of its initiation remains a matter of debate. Many studies of the last decades have reported a small but significant survival benefit and a clear delay in the development of clinical symptoms after early initiation of therapy. Patients who have localized or locally advanced prostate cancer and are not suitable for curative options like radical prostatectomy or radiotherapy can best be managed by hormone therapy alone, which has already been recognized as the optimal treatment for metastatic disease. On the other hand, long-term hormone treatment will expose the patient to the risk of substantial adverse effects, including muscle wasting, chronic fatigue and osteoporosis. Prognostic and quality-of-life factors also have an impact on the treatment decision, particularly in patients most likely to profit from an extension of the remaining life span. Based on available evidence, early hormone therapy may be recommended for men with poorly differentiated tumors or advanced disease and for those infrequently seen by their physicians. This management can prevent prostate cancer from migrating to the bones, where treatment becomes extremely difficult and cure or even longterm control of the disease is an exception.
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PMID:Hormone therapy for prostate cancer - immediate initiation. 1854 85

Muscular atrophy due to denervation can be substantially reversed by direct electrical stimulation. Some muscle properties are, however, resistant to change. Using a rabbit model of established denervation atrophy, we investigated whether the extent of restoration would vary with the stimulation protocol. Five patterns, delivering 24,000-480,000 impulses/day, were applied for 6 or 10 weeks. The wet weight, cross-sectional area, tetanic tension, shortening velocity, and power of denervated muscles subjected to stimulation all increased significantly. The fibers were larger and more closely packed and there was no evidence of necrosis. There was a small increase in excitability. Isometric twitch kinetics remained slow and fatigue resistance did not improve. The actual pattern of stimulation had no influence on any of these findings. The results, interpreted in the context of ultrastructural changes and an ongoing clinical study, reaffirm the clinical value of introducing stimulation during the initial non-degenerative phase. They indicate that there would be little therapeutic benefit in adopting regimes more energetically demanding than those in current use, and that the focus should now shift to protocols that represent the least intrusion into activities of daily living.
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PMID:Therapeutic stimulation of denervated muscles: the influence of pattern. 1856 23

Myasthenia gravis (MG) is a chronic neuromuscular disease which leads to varying degrees of weakness in the skeletal muscles. Some of the symptoms of the disorder include weakness of the eye muscles, difficulty in swallowing and slurred speech. When only the muscles of the eyes are affected, the illness is termed ocular myasthenia, which is often characterized by abrupt onset of diplopia and ptosis of the eyelid. In most patients with ocular-onset MG, there is a progression to involvement of other muscle groups within the first two years (generalized myasthenia). In the case reported here, a 39-year-old male of Ecuadorian descent complained of difficulty seeing, double vision, dizziness, unsteady gait, difficulty maintaining balance and fatigue for the previous two days. Neurological examination was remarkable for total external ophthalmoplegia. There was no external bulbar muscle paralysis, motor weakness, muscle wasting, sensory deficits or sphincter dysfunction. His laboratory workup was significant for elevated acetylcholine receptor antibody. He was diagnosed with ocular MG after differential diagnoses were ruled out based on the onset and presentation of symptoms, the patient's age and a normal magnetic resonance imaging exam. No signs of generalized myasthenia were detected. His symptoms improved dramatically after treatment with Acetyl cholinesterase (AchE) inhibitors and steroids, regaining much of his ocular mobility and ability to walk without gait imbalance. At follow-up visits, the patient remained healthy with no evidence development of other myasthenic signs. This case is atypical since ocular MG does not normally occur in the absence of other myasthenic forms.
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PMID:An atypical course of myasthenia gravis. 1860 52

Although surgery techniques improved over the years, the clinical results of peripheral nerve repair remain unsatisfactory. In the present study, we compare the results of a collagen nerve guide conduit to the standard clinical procedure of nerve autografting to promote repair of transected peripheral nerves. We assessed behavioral and functional sensori-motor recovery in a rat model of peroneal nerve transection. A 1cm segment of the peroneal nerve innervating the Tibialis anterior muscle was removed and immediately replaced by a new biodegradable nerve guide fabricated from highly purified type I+III collagens derived from porcine skin. Four groups of animals were included: control animals (C, n=12), transected animals grafted with either an autologous nerve graft (Gold Standard; GS, n=12) or a collagen tube filled with an acellular skeletal muscle matrix (Tube-Muscle; TM, n=12) or an empty collagen tube (Collagen-Tube; CT, n=12). We observed that 1) the locomotor recovery pattern, analyzed with kinetic parameters and peroneal functional index, was superior in the GS and CT groups; 2) a muscle contraction was obtained in all groups after stimulation of the proximal nerve but the mechanical muscle properties (twitch and tetanus threshold) parameters indicated a fast to slow fiber transition in all operated groups; 3) the muscular atrophy was greater in animals from TM group; 4) the metabosensitive afferent responses to electrically induced fatigue and to two chemical agents (KCl and lactic acid) was altered in GS, CT and TM groups; 5) the empty collagen tube supported motor axonal regeneration. Altogether, these data indicate that motor axonal regeneration and locomotor recovery can be obtained with the insertion of the collagen tube RevolNerv. Future studies may include engineered conduits that mimic as closely as possible the internal organization of uninjured nerve.
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PMID:Functional recovery after peripheral nerve injury and implantation of a collagen guide. 1892 5

Muscle homeostasis involves de novo myogenesis, as observed in conditions of acute or chronic muscle damage. Tumor Necrosis Factor (TNF) triggers skeletal muscle wasting in several pathological conditions and inhibits muscle regeneration. We show that intramuscular treatment with the myogenic factor Arg(8)-vasopressin (AVP) enhanced skeletal muscle regeneration and rescued the inhibitory effects of TNF on muscle regeneration. The functional analysis of regenerating muscle performance following TNF or AVP treatments revealed that these factors exerted opposite effects on muscle function. Principal component analysis showed that TNF and AVP mainly affect muscle tetanic force and fatigue. Importantly, AVP counteracted the effects of TNF on muscle function when delivered in combination with the latter. Muscle regeneration is, at least in part, regulated by caspase activation, and AVP abrogated TNF-dependent caspase activation. The contrasting effects of AVP and TNF in vivo are recapitulated in myogenic cell cultures, which express both PW1, a caspase activator, and Hsp70, a caspase inhibitor. We identified PW1 as a potential Hsp70 partner by screening for proteins interacting with PW1. Hsp70 and PW1 co-immunoprecipitated and co-localized in muscle cells. In vivo Hsp70 protein level was upregulated by AVP, and Hsp70 overexpression counteracted the TNF block of muscle regeneration. Our results show that AVP counteracts the effects of TNF through cross-talk at the Hsp70 level. Therefore, muscle regeneration, both in the absence and in the presence of cytokines may be enhanced by increasing Hsp70 expression.
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PMID:Modulation of caspase activity regulates skeletal muscle regeneration and function in response to vasopressin and tumor necrosis factor. 1944 Mar 8


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