Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036572 (seizures)
 80,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nineteen patients with advanced cancer were entered into a phase I clinical trial of Tumor Necrosis Factor (TNF) which was designed to determine the pharmacokinetic profile, safety, and maximal tolerated dose (MTD) of the recombinant human cytokine in vivo. TNF was administered by continuous infusion for 24 hours followed by pharmacokinetics and a 120-hour infusion repeated every 3 weeks. The initial dose was 40 micrograms/m2 and was ultimately escalated to 200 micrograms/m2. A total of forty 5-day cycles were administered to 18 of these patients; and all were evaluable for toxicity. Toxicities in this trial included fever, chills, rigors, hypotension, headaches, seizures, lethargy, weight loss, and malaise. At all dose levels, but more significantly at the highest doses, hematological toxicities were observed and grade 3 neurotoxicity (headache and confusion), and hypotension were noted. Two patients expired during the study, and this was felt to be related to septic episodes. Because of these severe toxicities, 160 micrograms/m2 was defined as the MTD. At 160 micrograms/m2 peak serum levels occurred within 5-20 minutes of initiation and were not detectable 1 hour later. No anti-tumor responses were observed. No measurable plasma levels of TNF were observed with the administration of doses of 80 micrograms/m2. This dose level could be further studied in phase II studies alone and in combination with other agents, utilizing a continuous infusion schedule.
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PMID:A phase I pharmacokinetic study of recombinant human tumor necrosis factor administered by a 5-day continuous infusion. 142 28

Leukocyte activation is known to involve cell membrane potential changes. Phenobarbital, an anesthetic and anticonvulsant that can inhibit neuronal membrane depolarization, may also affect leukocyte activation. Measuring membrane potential, actin polymerization, chemotaxis, superoxide production, lymphocyte proliferation, intracellular calcium concentration, and cytokine production, we found that phenobarbital at a concentration of 15-30 micrograms/ml, which is considered a therapeutic serum level for controlling seizures, did not affect polymorphonuclear neutrophil (PMN) activation. At levels higher than 100 micrograms/ml, phenobarbital significantly suppressed formylmethionyl-leucyl-phenylalanine (fMLP)-induced chemotaxis. Concentrations greater than 300 micrograms/ml also inhibited phorbol myristate acetate-stimulated membrane potential change. In contrast, 30 micrograms/ml phenobarbital significantly inhibited lymphocyte proliferation stimulated by phytohemagglutinin (PHA) and pokeweed mitogen. This concentration of phenobarbital also suppressed the increase of intracellular free calcium induced by PHA. However, only a higher concentration of phenobarbital (300 micrograms/ml) was able to inhibit PHA-induced interleukin-2 (IL-2) production and suppress the proliferation of PHA-induced IL-2 receptor-bearing lymphocytes. These results suggest that concentrations of phenobarbital associated with anticonvulsive levels do not affect PMN activation but suppress lymphocyte activation, possibly by affecting intracellular signal transduction.
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PMID:Effects of phenobarbital on leukocyte activation: membrane potential, actin polymerization, chemotaxis, respiratory burst, cytokine production, and lymphocyte proliferation. 150 69

Interleukin-1 (IL-1), a cytokine involved in the acute phase reaction to injury and infection, has multiple effects in the central nervous system, including induction of fever and sleep and the release of several neuropeptides. We evaluated effects of IL-1 beta on inhibitory postsynaptic function at the gamma-aminobutyric acidA (GABAA) receptor. IL-1 (100 pg/ml to 10 ng/ml) augmented GABAA receptor function in cortical synaptic preparations. This effect of IL-1 was largely prevented by incubation with a specific IL-1 receptor antagonist. The related cytokines interleukin-6 and tumor necrosis factor did not augment GABA-dependent chloride transport. Similar enhancement of GABAA receptor function was observed in tissue prepared from mice previously injected intraperitoneally with IL-1 (1 microgram). Electrophysiological studies in cultured primary cortical neurons demonstrated that IL-1 enhanced the GABA-mediated increase in chloride permeability, whereas IL-1 alone produced no alterations in resting conductance. Behavioral studies indicated that IL-1 is similarly active in vivo; mice treated with IL-1 showed a decrease in open-field activity and an increase in the threshold for pentylenetetrazol-induced seizures. The interaction of IL-1 with GABAA receptors might account for the somnogenic and motor-depressant effects of this cytokine.
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PMID:Interleukin-1 augments gamma-aminobutyric acidA receptor function in brain. 184 88

Five dogs euthanatized because of refractory seizures were found to have hematopoietic elements in the interstitium of the choroid plexus at the level of the fourth ventricle. None of the dogs had significant hematologic or cerebrospinal fluid abnormalities. The extramedullary hematopoiesis was confined to the central nervous system and consisted of megakaryocytes, immature granulocytes, and rubricytes in two dogs and of one predominant cell population in each of the other three dogs. These findings are unique, and factors possibly contributing to the formation of a hematopoietic inductive microenvironment in the choroid plexus are cytokine-neurokine homologies, locally altered vascular supply, and aberrant functioning of bone marrow-derived central nervous system macrophages.
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PMID:Extramedullary hematopoiesis in the choroid plexus of five dogs. 748 23

A number of important neurological diseases, including HIV-1 encephalitis, Alzheimer's disease, and brain trauma, are associated with increased cerebral expression of the multifunctional cytokine transforming growth factor-beta 1 (TGF-beta 1). To determine whether overexpression of TGF-beta 1 within the central nervous system (CNS) can contribute to the development of neuropathological alterations, a bioactive form of TGF-beta 1 was expressed in astrocytes of transgenic mice. Transgenic mice with high levels of cerebral TGF-beta 1 expression developed a severe communicating hydrocephalus, seizures, motor incoordination, and early runting. While unmanipulated heterozygous transgenic mice from a low expressor line showed no such alterations, increasing TGF-beta 1 expression in this line by injury-induced astroglial activation or generation of homozygous offspring did result in the abnormal phenotype. Notably, astroglial overexpression of TGF-beta 1 consistently induced a strong upmodulation of the extracellular matrix proteins laminin and fibronectin in the CNS, particularly in the vicinity of TGF-beta 1-expressing perivascular astrocytes, but was not associated with obvious CNS infiltration by hematogenous cells. While low levels of extracellular matrix protein expression may assist in CNS wound repair and regeneration, excessive extracellular matrix deposition could result in the development of hydrocephalus. As an effective inducer of extracellular matrix components, TGF-beta 1 may also contribute to the development of other neuropathological alterations, eg, the formation of amyloid plaques in Alzheimer's disease.
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PMID:Increased central nervous system production of extracellular matrix components and development of hydrocephalus in transgenic mice overexpressing transforming growth factor-beta 1. 760 85

Cytokines are thought to be important mediators in physiologic and pathophysiologic processes affecting the central nervous system (CNS). To explore this hypothesis, transgenic mice were generated in which the cytokine interleukin 6 (IL-6), under the regulatory control of the glial fibrillary acidic protein gene promoter, was overexpressed in the CNS. A number of transgenic founder mice and their offspring exhibited a neurologic syndrome the severity of which correlated with the levels of cerebral IL-6 expression. Transgenic mice with high levels of IL-6 expression developed severe neurologic disease characterized by runting, tremor, ataxia, and seizure. Neuropathologic manifestations included neuro-degeneration, astrocytosis, angiogenesis, and induction of acute-phase-protein production. These findings indicate that cytokines such as IL-6 can have a direct pathogenic role in inflammatory, infectious, and neurodegenerative CNS diseases.
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PMID:Neurologic disease induced in transgenic mice by cerebral overexpression of interleukin 6. 769 79

In a controlled, randomized trial, the authors investigated the effects of reconstituted human high-density lipoprotein (R-HDL) on survival, endotoxemia, cytokine production and pathophysiologic and metabolic events in an animal model of gram-negative septic shock. At 0.5, 8 and 16 hr after implantation of a clot infected with Escherichia coli, canines received intravenous R-HDL (n = 13), control lipid (n = 7) or human serum albumin (HSA, n = 7) divided into three doses (0.3, 0.1 and 0.1 g/kg, respectively) at an hourly rate of 0.1 g/kg. All animals were treated with antibiotics and fluids. Animals treated with R-HDL had lower levels of circulating endotoxin and tumor necrosis factor and a smaller decrease in white blood cell counts than did animals treated with lipids and HSA (all P < .05). The survival times of lipid- and HSA-treated animals were similar (P = .3) and were significantly greater than those of R-HDL-treated animals (P = .02). During the first 6 hr after clot implantation, R-HDL-treated animals had significantly greater abnormalities in liver function test findings compared with lipid- and HSA-treated animals (all P < .05). For the first 24 hr, R-HDL-treated animals had significant increases in HDL levels; however, there were no significant relationships between these levels and the constituents of HDL (apolipoprotein AI and phosphatidylcholine) or liver function abnormalities and survival times (all r < .2, P > .3). In normal animals, administration of R-HDL (in similar doses) caused transient elevation of liver enzymes; in animals given sterile clot i.p., R-HDL caused seizures.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Therapeutic trial of reconstituted human high-density lipoprotein in a canine model of gram-negative septic shock. 785 73

Transgenic mice expressing the cytokine interleukin-6 exhibit distinctive hippocampal interneuron pathology and behavioral seizures. Electroencephalographic recordings from these mice revealed anomalous hippocampal paroxysmal discharges and suppressed theta rhythm. Analysis of hippocampal field responses evoked by monosynaptic afferent stimulation revealed a site-specific increase in recurrent inhibition in the dentate gyrus. In addition, the cholinergic component of septohippocampal conditioning of dentate-evoked activity was absent in the transgenic mice. These results indicate that overexpression of interleukin-6 selectively disrupts cholinergic transmission by inducing a functional pathophysiology of hippocampal cholinoceptive target neurons.
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PMID:Site-specific hippocampal pathophysiology due to cerebral overexpression of interleukin-6 in transgenic mice. 795 12

We studied the production of tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) 2 and 7 days following status epilepticus (SE), induced in rats by intra-amygdala injection of kainate. At day 2 the release of both cytokines by hippocampal slices prepared from epileptic animals was increased compared to controls, whereas at day 7 only TNF alpha secretion was enhanced. Since SE-induced neuronal damage is probably due to excitotoxicity, we investigated the effects of agonists of glutamate receptors on TNF alpha release in organotypic hippocampal cultures. A correlation was found between the damage intensity and the release of TNF alpha, suggesting production of this cytokine by macrophagic microglia. We propose a role for TNF alpha and IL-6 in the adaptive phenomena which follow severe limbic seizures.
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PMID:Release of TNF alpha in the rat hippocampus following epileptic seizures and excitotoxic neuronal damage. 881 15

The murine monoclonal antibody muromonab CD3 (OKT3) is directed against the CD3 antigen on peripheral human T cells and effectively blocks all T cell function. Prophylaxis with muromonab CD3 (5mg intravenously once daily for 10 to 14 days) as induction therapy together with corticosteroids, azathioprine and delayed cyclosporin (sequential therapy) optimises early graft function by delaying the potentially nephrotoxic and hepatotoxic effects of cyclosporin until graft function is established. Although clinical data are limited (by inconsistencies in trial design and trial size), prophylactic muromonab CD3-based sequential therapy is significantly more effective than standard triple therapy in the prophylaxis of allograft rejection in renal and hepatic, but not cardiac, transplant recipients. Benefits are particularly notable in patients with delayed graft function. No significant between-treatment differences in patient survival have been observed. The overall efficacy of muromonab CD3- and polyclonal-based prophylactic regimens appears to be similar, although results vary between investigators and confirmation is needed. An anti-interleukin-2 monoclonal antibody-based prophylactic regimen improved graft and patient survival compared with muromonab CD3-based prophylaxis in hepatic transplant recipients. Antimuromonab CD3 antibodies may develop; however, muromonab CD3 may be successfully reused in patients with low titres. Preliminary pharmacoeconomic data suggest that mean drug costs are greater with quadruple immunosuppressive regimens containing muromonab CD3, antithymocyte globulin (ATG) or antilymphocyte globulin (ALG) than with triple therapy. Drug costs with prophylactic muromonab CD3-based regimens were similar or greater than those with polyclonal-based protocols. The first doses of muromonab CD3 are associated with the 'cytokine-release syndrome'. More severe first-dose events include aseptic meningitis, intragraft thromboses, seizures and potentially fatal pulmonary oedema. The incidence and/or severity of cytomegalovirus infection with prophylactic muromonab CD3 based immunosuppression is similar to or greater than that with triple therapy and ATG- or ALG-based regimens. However, the risk of infection and also the observed increase in lymphoproliferative disorders appears to be related to the degree of immunosuppression rather than to the drug itself Thus, sequential muromonab CD3-based therapy is more effective than standard triple therapy (in renal and hepatic transplant recipients) and appears to be similar to that of polyclonal-based regimens in the prophylaxis of transplant rejection. Although the routine use of prophylactic muromonab CD3 in low-risk patients with primary graft function does not appear to be justified, prophylactic muromonab CD3-based therapy has a role in patients at high risk of rejection.
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PMID:Muromonab CD3: a reappraisal of its pharmacology and use as prophylaxis of solid organ transplant rejection. 886 51


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