Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085584 (encephalopathy)
 18,178 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fourteen patients with Borrelia burgdorferi infection were investigated for possible abnormalities of tryptophan and neopterin metabolism. Four patients (2 were investigated before therapy, 2 when therapy had been already started) had acute Lyme neuroborreliosis, and 10 patients were investigated months to years after an acute infection. Increased concentrations of neopterin and of the tryptophan-degradation product, L-kynurenine, were detected in the cerebrospinal fluid of patients with acute Lyme neuroborreliosis; one patient presented with subnormal tryptophan. Similar but less marked changes were seen in the treated patients and in some of the patients with Lyme encephalopathy. No such abnormalities were seen in the serum of the patients. The data indicate a role of the immune system and particularly of endogenously formed cytokines, like interferon-gamma and tumour necrosis factor-alpha, effecting tryptophan and neopterin metabolism in patients with acute Lyme neuroborreliosis.
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PMID:Neopterin production and tryptophan degradation in acute Lyme neuroborreliosis versus late Lyme encephalopathy. 786 24

Human immunodeficiency virus infection leads to a deregulated production of a number of cytokines. Some of them (IL-1, IL-6, TNF-alpha, interferon-gamma) are produced in increased amounts in vivo, whereas the production of IL-2 is decreased. This latter abnormality plays a pivotal role in the establishment of the immunodeficiency. Some cytokines (IL-1, IL-6, TNF-alpha) stimulate the in vitro replication of HIV, whereas others (mainly the interferons) inhibit it. The effect of cytokines in vivo in the spreading of HIV remains, however, largely unknown. Cytokines may also be involved in the development of many clinical manifestations associated with HIV infection. IL-1, IL-6 and TNF-alpha may play a role in tissue damages associated with opportunistic infections, in HIV-related encephalopathy and in cachexia. Cytokines, mainly IL-6, IL-10 and IL-13, may stimulate the growth of malignant cells during Kaposi sarcoma or lymphomas. Better knowledge of the role of cytokines during HIV infection should allow new therapeutic approaches based on the use of either recombinant cytokines or specific antagonists, with the aim of limiting both HIV spreading and the clinical manifestations of this infection.
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PMID:Cytokines in HIV infection. 792 84

Human African trypanosomiasis (HAT) is caused by infestation with a flagellate protozoan, the trypanosome which is inoculated by the bite of the tsetse fly Glossina. The particular ecological conditions of parasites and vectors are such that the disease is only found in the intertropical regions of Africa. Although there are many species of trypanosomes, only two, belonging to the brucei group are likely to lead to HAT. These two species are quite similar morphologically but have different pathogenicity. Trypanosoma brucei gambiense found in West and Central Africa leads to a chronic form of the disease or sleeping sickness. T. b. rhodesiense leads to a more virulent and acute condition, although for each species of trypanosome there are strains of different virulence, which account, at least in part, for the interindividual variability in the clinical course. Immediately after penetration into the human organism, the trypanosome multiplies at the point of inoculation, producing a local inflammatory reaction. It then invades the whole organism, and the central nervous system (CNS). The involvement of the CNS leads to an irreversible demyelinating process ending by death without treatment. Apart from the initial stages, it is not easy to determine the phase of the disease that the patient is presenting. The parasite can escape the host immune response by varying the surface glycoprotein coat. Variable surface glycoproteins (VSG) are strongly antigenic and lead to great antibody response with immune lysis. But, some heterologous antigenic variants can survive to repopulate blood and other tissues. This mechanism of antigenic variation is under parasite genetic control. The trypanosome can release numerous pathogenic substances which cause alterations in cytokine/prostaglandin network. A 41-46 kDa molecule termed trypanosome-released lymphocyte trigerring factor may selectively activate CD8+ T cells to produce interferon-gamma which then activates macrophages but also promotes parasite growth. Activated macrophages release tumor necrosis factor alpha and nitric oxide (NO) which are trypanostatic static and other cytokines and prostanglandins. These macrophage relased substances enhance the immunosuppression and alter the blood brain barrier (BBB). So, trypanosomes and inflammatory cells can invade the CNS leading to a progressive meningoencephalitis with typical perivascular cuffings which explain neurological disorders and neuroendocrine alterations. The inflammatory cells (lymphocytes, astrocytes, glial cells) produce cytokines, NO and other mediators and enhance the CNS immunopathological process. The peri-ventricular regions, the tuberoinfundibula and thalamic-hypothalamic regions, are particulary involved. These disturbances lead to a progressively complete disruption of the normal sleep-waking cycle. Antibodies anti-CNS components (galactocerebrosides, neurofilaments, tryptophane) are also described in sera and cerebrospinal fluid (CSF) of HAT patients. Their presence may be due to cross reactions with comon epitopes between host and trypanosomes which can lead to a self-propagating autoimmune reaction, which accounts for the marked demyelination found in the late stage of the disease. The diagnosis of CNS involvement in not easy to establish in the early neurological phase in the absence of neurological signs and in absence of great chnages in CSF. This is an important problem because it is the basis to apply existing available drugs. pentamidine and suramin are effective only in early stages of the disease when CNS is not invaded. Melarsoprol is effective in all-stages: this is the drug of choice when CNS is involved. Unfortunaley, melarsoprol is toxic and, in 5% of treated patients, this drug can lead to arsenical encephalopathy which is often fatal. In the continuing search for new antitrypanosonal drugs, biochemical peculiarities of the trypanosome are used as drug garget, especially glycolysis, trypanothione, sensibil
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PMID:[Human African trypanosomiasis]. 895 90

A diffuse macular erythroderma and subsequent desquamation after 1 to 2 weeks are two of the five major diagnostic criteria of toxic shock syndrome (TSS). We present the case of a 15-month-old girl with TSS, but without erythroderma or desquamation. She was admitted with high fever, shock, and multiorgan involvement. Minimal or no cutaneous signs were present. Initially the diagnosis of the syndrome of hemorrhagic shock and encephalopathy was made. After 7 days, a TSS toxin 1-producing strain of Staphylococcus aureus was cultured from an inguinal lymph node, where inflammation had already been noticed on admission. Moreover, the girl had no antibodies against this toxin. The serum cytokine profile during the acute phase of her illness showed high levels of tumor necrosis factor-alpha, interleukin-6 and interferon-gamma, as is seen during activation of the immune system by TSS toxin 1. Other possible causes for the patient's illness were excluded. We conclude that the patient had TSS without rash. Without the evidence implicating a TSS toxin 1-producing strain of S. aureus as the cause of her disease, a diagnosis of syndrome of hemorrhagic shock and encephalopathy would have been made. It is possible that some cases of syndrome of hemorrhagic shock and encephalopathy represent a variant of TSS in small children.
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PMID:Toxic shock syndrome without rash in a young child: link with syndrome of hemorrhagic shock and encephalopathy? 967 39

Human immunodeficiency virus (HIV)-1 infection is often complicated with neurologic disorders, but the pathogenesis of HIV-1 encephalopathy is incompletely understood. Tat (HIV-1 transactivator protein) is released from HIV-1-infected cells and has been detected in the sera and cerebrospinal fluid of HIV-1-infected patients. Tat, along with increased inflammatory cytokines such as interferon-gamma (IFN-gamma), have been implicated in the pathogenesis of HIV-1-associated blood-brain barrier dysfunction. The present study examined the effects of Tat and IFN-gamma on human brain microvascular endothelial cells (HBMECs), which constitute the blood-brain barrier. Tat produced cytotoxicity of HBMECs, but required IFN-gamma. IFN-gamma treatment of HBMECs up-regulates vascular endothelial growth factor receptor-2 (VEGFR2/KDR), which is known to be the receptor for Tat. Tat activated KDR in the presence of IFN-gamma, and Tat-mediated cytopathic changes involve its interaction with KDR and phosphatidylinositol 3-kinase (PI3K). Further understanding and characterization of Tat-HBMEC interactions should help us understand HIV-1 neuropathogenesis and develop strategies to prevent HIV-1 encephalopathy.
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PMID:Human immunodeficiency virus type 1 tat-mediated cytotoxicity of human brain microvascular endothelial cells. 1460 71

It is well known that an acute encephalopathy occasionally follows prolonged febrile seizures. We measured the concentrations of interferon-gamma, tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, IL-10, and soluble TNF receptor 1 (sTNFR1) in serum and CSF during the acute stage in 13 children with acute encephalopathy following prolonged febrile seizures (AEPFS) and 23 with prolonged febrile seizures without encephalopathy (PFS) to investigate the pathogenesis of AEPFS. Serum IL-6, IL-10, sTNFR1, and CSF IL-6 levels were significantly higher in AEPFS and PFS compared with control subjects. CSF IL-6 levels in AEPFS were significantly higher than those in PFS, but not serum IL-6, IL-10, or sTNFR1. The CSF IL-6 levels were significantly higher than the serum levels in AEPFS, but not PFS. The serum levels of sTNFR1 and IL-10 were significantly higher than those in the CSF in AEPFS and PFS. The serum IL-10 and sTNFR1 levels in patients who did not experience a second seizure were significantly higher than those in patients who experienced a second seizure, which was characterized by clusters of complex partial seizures several days after the initial prolonged febrile seizure. Our results suggest that serum IL-6, IL-10, TNF-alpha, and CSF IL-6 are part of the regulatory system of cytokines in AEPFS.
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PMID:Serum and CSF levels of cytokines in acute encephalopathy following prolonged febrile seizures. 1759 22

Enterohemorrhagic Escherichia coli (EHEC) induces hemorrhagic colitis and hemolytic uremic syndrome (HUS). Morbidity and mortality are increased in HUS patients with neurologic complications. To determine the pathogenesis of the central nervous system (CNS) involvement in HUS by EHEC, we determined the serum concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), soluble TNF receptor 1 (sTNFR1), IL-10, interferon-gamma (IFN-gamma), IL-2, IL-4, soluble E-selectin (sE-selectin), matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) during the acute stage in children with HUS with or without CNS involvement. Serum concentrations of IL-6, IL-10, sTNFR1, sE-selectin, MMP-9, and TIMP-1, but not TNF-alpha, IFN-gamma, IL-2, or IL-4, were significantly higher in patients with HUS with encephalopathy compared with controls. Serum IL-6, sTNFR1 and TIMP-1 concentrations were significantly higher in patients with HUS with encephalopathy compared with those with HUS without encephalopathy (P=0.031, P=0.005, and P=0.007, respectively) and those with acute colitis without HUS (P=0.011, P<0.001, and P=0.005, respectively). There were no significant differences in hemoglobin, platelet counts, leukocyte counts, or serum concentrations of IL-10, sE-selectin, MMP-9, aspartate aminotransferase, lactate dehydrogenase, blood urea nitrogen, creatinine, or C-reactive protein between the HUS patients with and without encephalopathy. Our preliminary study suggests that serum IL-6, sTNFR1 and TIMP-1 levels, particularly sTNFR1 and TIMP-1, are important for predicting neurological complications in patients with HUS.
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PMID:Soluble tumor necrosis factor receptor 1 and tissue inhibitor of metalloproteinase-1 in hemolytic uremic syndrome with encephalopathy. 1841 Sep 71

Human herpesvirus-6 (HHV-6) is a causative agent of exanthema subitum. The immunological pathogenesis of acute encephalopathy associated with HHV-6 infection is still unclear. We measured the concentrations of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, IL-10, and soluble TNF receptor 1 (sTNFR1) in serum and cerebrospinal fluid (CSF) during the acute stage in 15 infants with acute encephalopathy and 12 with febrile seizures associated with HHV-6 infection. The serum IL-6, IL-10, sTNFR1, CSF IL-6, and sTNFR1 levels of infants with encephalopathy who had neurological sequelae (n=9) were significantly higher than those with febrile seizures (p=0.011, 0.043, 0.002, 0.029, and 0.005, respectively). In acute encephalopathy, serum IL-6, sTNFR1, and CSF IL-6 levels in infants with neurological sequelae were significantly higher than those without (n=6) neurological sequelae (p=0.043, 0.026, and 0.029, respectively), and serum IFN-gamma, IL-6, IL-10, and sTNFR1 levels were significantly higher than those in the CSF (p=0.037, 0.037, 0.001, and 0.021, respectively). There were no significant differences in serum or CSF cytokine levels between infants who were positive for HHV-6 DNA in the CSF (n=6) compared to those who were negative (n=9). We suggest that cytokines mediate the pathogenesis of acute encephalopathy associated with HHV-6 infection, and that the elevated levels of serum IL-6, sTNFR1, and CSF IL-6 are important for predicting neurological sequelae.
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PMID:Serum and cerebrospinal fluid levels of cytokines in acute encephalopathy associated with human herpesvirus-6 infection. 1911 98

Recently, the number of reports of encephalitis/encephalopathy associated with influenza virus has increased. In addition, the use of a non-steroidal anti-inflammatory drug, diclofenac sodium (DCF), is associated with a significant increase in the mortality rate of influenza-associated encephalopathy. Activated astrocytes are a source of nitric oxide (NO), which is largely produced by inducible NO synthase (iNOS) in response to proinflammatory cytokines. Therefore, we investigated whether DCF enhances nitric oxide production in astrocytes stimulated with proinflammatory cytokines. We stimulated cultured rat astrocytes with three cytokines, interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma, and then treated the astrocytes with DCF or acetaminophen (N-acetyl-p-aminophenol: APAP). iNOS and NO production in astrocyte cultures were induced by proinflammatory cytokines. The addition of DCF augmented NO production, but the addition of APAP did not. NF-kappaB inhibitors SN50 and MG132 inhibited iNOS gene expression in cytokine-stimulated astrocytes with or without DCF. Similarly, NF-kappaB p65 Stealth small interfering RNA suppressed iNOS gene expression in cytokine-stimulated astrocytes with or without DCF. LDH activity and DAPI staining showed that DCF induces cell damage in cytokine-stimulated astrocytes. An iNOS inhibitor, L-NMMA, inhibited the cytokine- and DCF-induced cell damage. In conclusion, this study demonstrates that iNOS and NO are induced in astrocyte cultures by proinflammatory cytokines. Addition of DCF further augments NO production. This effect is mediated via NF-kappaB signaling and leads to cell damage. The enhancement of DCF on NO production may explain the significant increase in the mortality rate of influenza-associated encephalopathy in patients treated with DCF.
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PMID:Diclofenac enhances proinflammatory cytokine-induced nitric oxide production through NF-kappaB signaling in cultured astrocytes. 1939 75

Previous reports suggested that brain-derived proinflammatory cytokines are involved in the pathogenesis of hepatic encephalopathy (HE) and brain edema in acute liver failure (ALF). To further address this issue, expression of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) mRNAs were measured in the brains of mice with acute liver failure resulting from exposure to azoxymethane. In addition, time to severe encephalopathy (coma) was assessed in mice lacking genes coding for interferon-gamma, the tumor necrosis factor receptor-1 or the interleukin-1 type 1 receptor. Interleukin-1beta, tumor necrosis factor-alpha and interferon-gamma expression were quantified using RT-PCR. Significant increases in interleukin-1beta and tumor necrosis factor-alpha mRNA were observed in the frontal cortex of azoxymethane-treated wild-type mice at coma stages of encephalopathy. Interferon-gamma, however, could not be detected in the brains of these animals. Onset of severe encephalopathy (coma) and brain edema in ALF mice were significantly delayed in interleukin-1 type 1 receptor or tumor necrosis factor receptor-1 knockout mice. Deletion of the interferon-gamma gene, on the other hand, had no significative effect on the neurological status or brain water content of acute liver failure mice. These results demonstrate that toxic liver injury resulting from exposure to azoxymethane is associated with selective induction of proinflammatory cytokines in the brain and that deletion of tumor necrosis factor receptor-1 or interlukin-1 type 1 receptor delays the onset of coma and brain edema in this model of acute liver failure. These findings further support a role for selective brain-derived cytokines in the pathogenesis of the cerebral complications in acute liver failure and suggest that anti-inflammatory strategies could be beneficial in their prevention.
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PMID:IL-1 or TNF receptor gene deletion delays onset of encephalopathy and attenuates brain edema in experimental acute liver failure. 1993 38


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