Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1762617 (weakness)
 37,932 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although they are considered as destructive agents, free radicals can sometimes become useful. Their presence is intimately coupled with the activity of certain hemal oxydases which insert an atom of oxygen into their substrate by a stereospecific radical mecanism. The cytochromes P450 and the enzymes of the eicosanoide metabolism are some examples. The free radicals can act as second cellular messengers, especially to modulate the metabolism of arachidonic acid and the prostaglandin tract or to infer a myorelaxation. They can even play the role of neurotransmitters such as azote monoxyde. The activation of phagocytes, which is an essential event in the inflammatory reaction, integrates these notions at several levels: in the mechanisms of bacterial death, in the spread of the inflammatory reaction and in the alteration of the extra-cellular matrix. The inflammatory reaction is initiated by interactions between vascular endothelium, platelets and leukocytes including signal exchanges, adhesion molecule expression and secretion of chimiotactic mediators. Activation of vascular endothelium is a key event in the initiation of the phenomenon. The cells intervening in the precocious inflammatory phase were tissular mastocytes and platelet-liberating mediators (histamine) and neutrophile cells responsible for vascular injuries induced by oxygen free radicals and nitric oxide. Reactive oxygen intermediates play a critical role, primarily to limit tissue damage and prevent or inhibit infection, secondary to enhancing and prolonging reaction. The monocytes and platelets liberate cytokines early, which appears to be important in activation and production of an inflammatory response. In fact, cytokines, especially TNF alpha and IL-1, induce synthesis and secretion endothelial adhesion molecules such as ICAM-1, VCAM-1 and E-selectin, which have been demonstrated to mediate leukocyte recruitment to sites of inflammation. The cytokines also activate the fibroblasts and endothelial cells that produce, among others, free radicals and other chimiotactic cytokines of which some (IL-8 and related) can induce neutrophil degranulation and stimulate oxidative stress and formation of free radicals. Furthermore, endothelial cells have been shown to make use of a broad repertoire of cytokines including IL-1, IL-6, IL-8, MCP-1 and gro/MGSA, which may be secreted during an inflammatory response and exercise pro-inflammatory functions. Under the influence of the inflammatory mediators, other enzymes are also activated. The inducible isoforms of cyclo-oxygenase (COX-2) and nitric oxide synthase (iNOS) play an important role in inflammatory reactions via the production respectively of prostaglandins and nitric oxide. The induction of cell adhesion molecules (ICAM-1, VCAM-1 and E-selectin), cytokines, acute phase proteins, growth factors, COX-2 and iNOS expression is mediated by the activation of transcriptional factors, especially the nuclear factor kappa B (NF-kappa B). The NF-kappa B system is essentially involved in immediate early expression of various immunoregulatory genes and has been demonstrated to represent an important regulatory system of endothelial activation. The target genes for NF-kappa B comprise a growing list of genes intrinsically linked to a coordinated inflammatory response. The NF-kappa B is a heterodimer composed of two subunits (p65 and p50). In non-stimulated cells, NF-kappa B resides in the cytoplasm as an inactive complex bound to its inhibitor, I kappa B. Upon stimulation with various agents including cytokines, mitogenes, viruses and reactive oxygen intermediates, I kappa B dissociates from the NF-kappa B-I kappa B complex and translocates to the nucleus, binding with high affinity to specific sites in the promoter regions of target genes and stimulating their transcription. In the case of any weakness of this anti-oxidizing defence or any over-production of radical species, a state of oxidative stress occurs. (ABSTRACT TRUNC
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PMID:[Free radicals and antioxidants: physiology, human pathology and therapeutic aspects (part II)]. 980 2

The contemporary presence of organomegaly, skin manifestations, polyneuropathy, endocrinopathy and monoclonal component characterises the POEMS syndrome, often associated with osteosclerotic myeloma and Castelman's disease and more frequent in the Japanese. Clinical manifestations seem to be related to the production of many interleukins, mainly IL-1, IL-6 and TNF. Several endocrinopathies have been described, the most frequent being diabetes. Only one previous case of hypoparathyroidism associated with the syndrome has been described in medical reviews. Polyneuropathy is often sensitivo-motory and skin disease accounts for Raynaud phenomenon, skin pigmentation, hypertricosis and others. We describe the case of a 74-year-old man who underwent clinical examination for weakness mainly in the legs. Clinical and instrumental data showed rhabdomyolysis due to hypoparathyroidism. The contemporary presence of a monoclonal band of light chains on proteic electrophoresis, organomegaly and distal leg neuropathy allowed us to make a diagnosis of POEMS syndrome.
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PMID:A man with worsening weakness. 1078 Jan 92

The well established and characterized animal model for the human demyelinating autoimmune disease multiple sclerosis (MS) is known as experimental autoimmune encephalomyelitis (EAE). EAE is clinically characterized by focal areas of inflammation and demyelination and an infiltrate composed of large numbers of lymphocytes and macrophages, often found in a perivascular localization but also throughout the central nervous system (CNS). Active immunization of mice with several different protein components of myelin, including myelin basic protein (MBP), proteolipid protein (PLP) and myelin oligodendrocyte glycoprotein (MOG), are capable of eliciting an immune response resulting in the quintessential symptoms of EAE: ascending paralysis involving the tail and then the limbs. Depending on the mouse strain and myelin antigen utilized, the disease course can be acute or chronic relapsing, characterized by a rapid onset of hind limb weakness that commonly progresses to paralysis, followed by spontaneous remission starting 7-10 days after the initial appearance of symptoms. EAE can also be induced passively by the adoptive transfer of in vitro activated CD4+ T cell clones or lines, typically of the Th1 phenotype, into irradiated susceptible recipients. The mechanisms involved in the cellular pathogenesis leading to paralysis and demyelination have been extensively studied and are primarily mediated by CD4+ T cells of the Th1 phenotype, with specificity for myelin antigens. Following activation, Th1 CD4 T cells produce in abundance the inflammatory cytokines TNF-alpha, IFN-gamma and lymphotoxin alpha (LT-alpha, also know as TNF-beta). IFN-gamma production is highly correlated with encephalitogenicity and may contribute to disease by up-regulation of adhesion molecules on endothelial cells, facilitating migration of lymphocytes into the CNS; by induction of major histocompatibility complex (MHC) class I and MHC class II molecules on astrocytes, microglial cells and brain endothelium, facilitating antigen (Ag) presentation in the CNS; and by activation of macrophages, leading to production of nitric oxide, a potent cytotoxic molecule. TNF-alpha and LT-alpha are both members of the TNF family of molecules and cause cell death by apoptosis following interaction with their counter-receptors, the TNFR1 and TNFR2, leading to a cascade of proteolytic events culminating in the blebbing of the cytoplasmic membrane, nuclear condensation and DNA fragmentation. Consequently, the production of TNF-alpha and LT-alpha by Th1 clones has been correlated with encephalitogenic potential and antibodies (Abs) to both prevents EAE upon transfer of encephalitogenic clones. Even though substantial evidence exists for the role of inflammatory cytokines in the pathogenesis of EAE, other mechanisms of myelin destruction are thought to exist. To date, many reports have implicated a role for the cell death-inducing ligand pair Fas and Fas-ligand (FasL).
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PMID:Evidence that Fas and FasL contribute to the pathogenesis of experimental autoimmune encephalomyelitis. 1114 Apr 65

Little is known concerning factors associated with the outcome of juvenile dermatomyositis (JDM), which can be variable and lethal. Previous work has documented that the association of DQA1*0501 with JDM is higher than in control groups and that the first symptoms (rash and weakness) of JDM appear to follow evidence of an infectious process--most frequently upper respiratory in nature. Preliminary data show that a long period of symptoms being left untreated before starting therapy and the TNF alpha-308A allele are associated with prolonged JDM symptoms requiring > or = 36 months of immunosuppressive therapy. A short duration of untreated disease is associated with a relative increase in CD8(+) T cells and CD56(+) natural killer (NK) cells in the untreated JDM muscle biopsy compared with a longer duration of untreated disease. The TNF alpha-308A allele is overrepresented in white children with JDM. In addition, it is associated with pathologic calcifications, increased production of TNF alpha by peripheral blood mononuclear cells in vitro and JDM muscle fibers in vivo, and occlusion of capillaries, which may be mediated in part by elevated circulating levels of thrombospondin-1, a potent anti-angiogenic factor. We speculate that DQA1*0501 is associated with JDM susceptibility to an infectious process, eliciting and activating NK cells early in the disease course. We conclude that the TNF alpha-308A allele indicates directly (or is a surrogate marker of) children with JDM who produce higher concentrations of TNF alpha in response to this undefined inflammatory stimulus, as well as increased concentrations of TSP-1 with resultant small vessel occlusion, contributing to subsequent disease chronicity.
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PMID:Juvenile dermatomyositis: the association of the TNF alpha-308A allele and disease chronicity. 1156 68

Dermatomyositis and polymyositis are the two major idiopathic inflammatory myopathies. The Bohan and Peter's criteria are still useful despite the probably different pathogenesis of the two myopathies. Cutaneous manifestations of dermatomyositis include heliotrope rash and Gottron's papules. The heliotrope rash, with or without edema, in a distribution involving periorbital skin is very suggestive of the diagnosis. Papules may be found overlying the "kneedle" of the hand or the elbows, knees, feet. Periungueal erythema with telangiectasis were characteristic but not pathognomonic. Scalp involvement is common. Skin lesions of dermatomyositis may precede the development of the myopathy and may persist after the control of the myositis. Some patients have an amyopathic dermatomyositis with normal muscle-enzyme, magnetic resonance scan and muscle biopsy. Muscle disease affects the proximal muscles, is generally symmetrical and symptoms are fatigue, weakness and sometimes myalgia. Proximal dysphagia reflects an involvement of striated muscle of the pharynx or proximal esophagus. Camptocormia reflects a severe involvement of paravertebral muscle. Other systemic features may be seen: pulmonary involvement (mostly interstitial pneumonitis and hypoventilation), arthralgias or arthritis, cardiac involvement, vasculatis and calcinosis particularly in children or adolescents with dermatomyositis. Malignant disease is associated with idiopathic inflammatory myopathies with a frequency of approximatively 10 to 15% in dermatomyositis and 5 to 10% in polymyositis and is strongly correlated with age, more than 50% of the patient over 65 years old were found to have a cancer. In the absence of malignant disease, the mainstay therapy for dermatomyositis and polymyositis is systemic corticosteroids (mostly 1mg/kg). In the lake of response or high dose dependance, intravenous immunoglobulins or immunosuppressive drugs like methotrexate or azathioprine may be discuss. Cyclophosphamide show some effectiveness in interstitial pneumonitis. Cyclosporin might be effective in children, less in adults. The efficacy of tacrolimus, mycophenolate mofetil, leflunomide and anti-TNF therapy need some prospective studies to determine if there are of value in idiopathic inflammatory myositis.
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PMID:[Dermatomyositis and polymyositis: clinical aspects and treatment]. 1196 87

Premature rupture of the fetal membranes is a major cause of preterm birth and its associated infant morbidity and mortality. Recently, it has become clear that rupture of the fetal membranes, term or preterm, is not merely the result of the stretch and shear forces of uterine contractions, but is, in significant part, the consequence of a programmed weakening process. Work in the rat model has demonstrated that collagen remodeling, with activation of matrix metalloproteinases (MMPs), and apoptosis increase markedly in the amnion at end-gestation, suggesting that these processes are involved in fetal membrane weakening. We have developed fetal membrane strength testing equipment and a systematic tissue sampling methodology that has allowed us to demonstrate that term, non-labored, fetal membranes have a zone of weakness overlying the cervix, which contains biochemical markers of both collagen remodeling and apoptosis. These findings provide strong support for the concept of programmed fetal membrane weakening prior to labor. Our model has also been used to establish the physical properties of individual fetal membrane components (amnion, chorion), determine the sequence of events during the fetal membrane rupture process, and demonstrate that treatment of fetal membranes with TNF or IL-1beta, in vitro, induces weakness and the identical biochemical markers of collagen remodeling and apoptosis seen in the physiological weak zone. The ability to simultaneously correlate macroscopic physical properties with histological and biochemical fetal membrane characteristics, presents a unique perspective on the physiology of fetal membrane rupture.
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PMID:The physiology of fetal membrane rupture: insight gained from the determination of physical properties. 1651 62

Tumor-induced skeletal muscle wasting (SMW) contributes to the fatigue and weakness experienced by persons with cancer cachexia. Tumor necrosis factor-alpha (TNFa) and cyclooxygenase (COX) activity have been implicated in SMW in some animal models of cancer cachexia. We report that indomethacin, a nonspecific inhibitor of COX, and NS398, a specific inhibitor of COX2, preserved muscle mass and reduced type 1 TNF receptors in muscles of mice bearing the Lewis lung carcinoma, but not in mice bearing the B16 melanoma. These data suggest that tumor-induced SMW can occur via a COX2-independent pathway. The COX2-dependent pathway may involve reducing the catabolic effects of TNFa in muscle. Further study is needed to understand the relationship between COX and SMW, and whether patients with cancer cachexia might benefit from COX inhibitors.
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PMID:Inhibitors of COX activity preserve muscle mass in mice bearing the Lewis lung carcinoma, but not the B16 melanoma. 1653 83

We propose that the pathogenesis of obesity-induced osteoarthritis may be explained by the metabolic changes in the striated muscle induced by the interaction of insulin resistance and systemic inflammation in obese individuals with metabolic syndrome being osteoarthritis the latest consequence by the physiological changes seen in the metabolic syndrome. Increased levels of TH1 cytokines are produced by activated macrophages in the presence of an acute or chronic infectious disease and suppress the sensitivity of insulin receptors on the membrane of muscle cell and adipocytes. Both cells are activated by inflammatory cytokines and contribute to enhance acute inflammation and to maintain a state of chronic, low-grade inflammation in apparently healthy obese individuals. The increased number of macrophage in the adipose tissue of obese individuals acts as an amplifier of inflammation. Patients with osteoarthritis and metabolic syndrome frequently are complaining about hotness and recurrent edema of feet and hands. It is probable that hyperinsulinemia in the presence of insulin resistance and inflammation, induce vasodilation through the TNF mediated-iNOS overexpression. Patients with metabolic syndrome express clinically the consequence of a poor uptake, storage and energy expenditure by the muscle and any other insulin dependent tissue and the consequence of high insulin plasma levels are vasodilation and increased protein synthesis. The fatigue and muscle weakness induced by insulin resistance and inflammation in obese patients with metabolic syndrome increase the frequency and the intensity of traumatic events of peripheral or axial joints that result in stretch and breaking of tenoperiosteal junction and abrasive damage of cartilage and therefore in these patients with metabolic syndrome and pro-inflammatory state the reparative process of cartilage and periarticular tissues would be severely modified by the growth factor activity in presence of high levels of insulin.
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PMID:The relationship between the metabolic syndrome and energy-utilization deficit in the pathogenesis of obesity-induced osteoarthritis. 1736 54

Polymyositis (PM), dermatomyositis (DM) and sporadic inclusion body myositis (s-IBM) are severe inflammatory muscle disorders of unknown cause, which may present life-threatening complications. Prognosis and response to medications may be predicted not only from the clinical and pathologic diagnostic group into which a patient belongs, but also from the patient's myositis-specific antibody status, extraskeletal muscle involvement, and the interval between onset of muscle weakness, and the start of the treatment. Corticosteroids remain the mainstay of treatment in PM and DM. In patients refractory or intolerant to corticosteroids, another therapy, often an immunosuppressive agent, or intravenous immunoglobulin (IVIg), is added. IVIg seems the treatment of choice in severe myositis with dysphagia. New molecules, anti-TNF and monoclonal antibodies anti-CD20 justifies randomised trial and long term follow up.
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PMID:[Current therapy for polymyositis and dermatomyositis]. 1892 83

The recombinant human IgG1 monoclonal antibody specific for human TNF-a adalimumab (Humira) has been recently introduced for the treatment of moderate/severe psoriasis. Neurological diseases have been rarely described as adverse events of anti-TNF agents. A case of acute respiratory failure due to diaphragmatic weakness following adalimumab therapy for psoriasis is described. A 65-year-old female patient presented with jaundice followed 2 days later by severe dyspnea and tachypnea which worsened when patient was lying flat, 1 week after the fourth dose of adalimumab. Isoniazid and vitamin B6 were co-administered with adalimumab. A symmetric elevation of diaphragms was shown on radiography and fluoroscopy. A pulmonary restrictive defect with a prominent decline of forced vital capacity (FVC) when the patient was on supine position was recorded. In the absence of specific limb electrophysiological abnormalities, acute bilateral symmetric phrenic neuropathy was diagnosed. The patient was a borderline candidate for mechanical ventilation for 3 weeks. Conservative treatment with oxygen was administered and both respiratory and liver disorder resolved 4 weeks following admission. A causal relationship of phrenal neuropathy with adalimumab is herein discussed.
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PMID:Acute bilateral phrenic neuropathy following treatment with adalimumab. 1966 17


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