SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The neuropeptide alpha-melanocyte-stimulating hormone (alpha-MSH) has potent antipyretic and antiinflammatory properties. When administered systemically, the naturally occurring molecule and its COOH-terminal tripeptide sequence inhibit inflammation induced by peripherally applied irritants and intradermal injections of mediators of inflammation such as interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF alpha). We recently found that alpha-MSH can act solely within the brain to inhibit inflammation caused by a general irritant applied to the skin. This activity appears to be shared with salicylate drugs and the combined observations suggest the existence of descending neurogenic antiinflammatory signals capable of modulating inflammation in peripheral tissues. To improve our knowledge of the scope of this action of the peptide, alpha-MSH was injected into the cerebral ventricles (i.c.v.) of mice that had received intradermal injections in the ear of mediators of inflammation: IL-1 beta, IL-8, leukotriene B4, and platelet-activating factor. The centrally administered peptide inhibited the actions of all of these proinflammatory agents as determined from comparisons with measures of ear edema over time in control animals; this indicates that the central peptide can alter inflammation induced in the periphery by major mediators of inflammation. In tests confined to IL-1 beta, central administration of alpha-MSH(11-13) was also effective. These findings support the concept of a descending neurogenic antiinflammatory influence promoted by an action of alpha-MSH within the brain, an inhibitory influence that is not restricted to modulation of just one or a limited set of the mediators of inflammation.
John Hunter's A Treatise on the Blood, Inflammation and Gunshot Wounds was published in 1794. Throughout the nineteenth century this was considered the most important study of inflammation and has been widely quoted since. After a section on the nature of blood and the circulatory system, in which he describes the vascular supply in detail, he passes on to an extensive survey of inflammation. This is based mainly on his wide clinical experience, including that as a military surgeon. He, however, supplements this with a number of experiments, some of which are classic. He bases his observations on the four cardinal signs of Celsus (redness, heat, swelling and pain). Inflammation is then divided into three main groups: adhesive, suppurative and ulcerative. He discusses the nature of pus and the formation and treatment of abscesses. He describes his experiments on the transplantation of tissues under the general heading of adhesive inflammation. This, he states, underlies the union of wounds and thus the union of tissues after transplantation. Although unaware of the role of infecting organisms as a cause of inflammation, he makes observations on inflammation in smallpox, venereal infections and tuberculosis. He relates these to his observations on inflammatory aspects of wound healing. Lister was particularly influenced by Hunter's observations in the development of antisepsis. As well as the local effect of inflammation, Hunter was concerned with the constitutional effects such as fever.
The Working Group on Neurogenic Inflammation proposed 11 testable hypotheses in the three domains of neurogenic inflammation, perceptual and central integration, and nonneurogenic inflammation. The working group selected the term people reporting chemical sensitivity (PRCS) to identify the primary subject group. In the domain of neurogenic inflammation, testable hypotheses included: PRCS have an increased density of c-fiber neurons in symptomatic tissues; PRCS produce greater quantities of neuropeptides and prostanoids than nonsensitive subjects in response to exposure to low-level capsaicin or irritant chemicals; PRCS have an increased and prolonged response to exogenously administered c-fiber activators such as capsaicin; PRCS demonstrate augmentation of central autonomic reflexes following exposure to agents that produce c-fiber stimulation; PRCS have decreased quantities of neutral endopeptidase in their mucosa; exogenous neuropeptide challenge reproduces symptoms of PRCS. In the domain of perceptual and central integration, testable hypotheses included: PRCS have alterations in adaptation, habituation, cortical representation, perception, cognition, and hedonics compared to controls; the qualitative and quantitative interactions between trigeminal and olfactory systems are altered in PRCS; higher integration of sensory inputs is altered in PRCS. In the domain of nonneurogenic inflammation, testable hypotheses included: increased inflammation is present in PRCS in symptomatic tissues and is associated with a heightened neurosensory response; PRCS show an augmented inflammatory response to chemical exposure. The working group recommended that studies be initiated in these areas.
Excessive local production of nitric oxide (NO) has been suggested to play a role in rodent models of airway inflammation and in pulmonary diseases such as asthma. However, even given the plethora of data available including gene expression data, pharmacological data, and gene deletion studies in animal models, it is still not clear which nitric-oxide synthase (NOS) isoform is involved in eosinophilic airway inflammation. In this rat study, the nonselective NOS inhibitor L-NAME (N(G)-nitro-L-arginine methyl ester), but not a selective inducible NOS (iNOS) inhibitor 1400W (N-3-(aminomethyl)benzyl)acetamidine), impacted on Sephadex-induced inflammation by significantly inhibiting lung edema, eosinophil infiltration, tumor necrosis factor alpha, interleukin-13, and eotaxin levels in the lung tissue. Furthermore, iNOS gene expression was not induced following Sephadex administration, which confirms that iNOS does not play a role in this model. To demonstrate that this phenomenon was not restricted to this model of asthma, L-NAME, but not 1400W, was shown to reduce eosinophilia in an antigen-induced model. However, in contrast to the Sephadex model, there was an induction of iNOS gene expression after antigen challenge. In a model of aerosolized lipopolysaccharide-induced inflammation, where iNOS gene expression is increased, 1400W inhibited the increased neutrophilia. These data suggest that the compound has been administered using an appropriate dosing regimen for iNOS inhibition in the rat lung. In conclusion, it appears that constitutive, not inducible, NOS isoforms are important in NO production in models of allergic inflammation, which questions whether there is a role for iNOS inhibitors as therapy for the treatment of asthma.
The marked diminution in the number of circulating eosinophils, which has been shown to occur during acute bacterial infections, is a distinctive aspect of eosinophil physiology and of the host response to acute infection. The mouse rendered eosinophilic by infection with trichinosis provides a suitable model for study of the eosinopenic response induced by acute inflammation. The alterations in eosinophil dynamics associated with acute inflammatory reactions in trichinous mice were studied with pneumococcal abscesses, with Escherichia coli pyelonephritis, with Coxsackie viral pancreatitis, and with acute subcutaneous inflammation due to turpentine. Each of these stimuli of acute inflammation markedly suppressed the eosinophilia of trichinosis. This suggests that the eosinopenia is a response to the acute inflammatory process rather than the response to a specific type of pathogen. These studies apply quantitative techniques to ascertain the effects of acute inflammation on eosinophil production in bone marrow and on distribution of eosinophils in the peripheral tissues. From these observations, it is apparent that the initial response to acute inflammation includes a rapid drop in numbers of circulating eosinophils, a rapid accumulation of eosinophils at the periphery of the inflammatory site, and an inhibition of egress of eosinophils from the bone marrow. With prolongation of the inflammatory process, inhibition of eosinopoiesis occurs.
Immune inflammation (II) arises on the basis of immunopathological mechanisms and acquires certain qualitative and quantitative features. It develops in a sensitized host following a specific immune response. Several kinds of II are to be distinguished differing from each other by the prevalence of disorders in cellular or humoral immunity, the pattern of the antigen, involvement in the response of immunoglobulins of different classes, complement components and a set of mediators. According to Sell's scheme, six immunopathological mechanisms are distinguished which underlie the development of early (like immediate type hypersensitivity) or late (like delayed type hypersensitivity) immune inflammation. Sometimes humoral and cellular mechanisms alternate in II which is reflected in the morphological picture of inflammation. This is illustrated by an example of the study of tissue inflammatory reactions in the synovial membrane in rheumatoid arthritis. Immune inflammation shows a trend to self-reproduction and continuous course with periods of remission and exacerbation of different durations. Timely recognition of immune inflammation is important both theoretically and practically.
Nuclear factor-kappaB (NF-kappaB) and glucocorticoid receptor-alpha (GR-alpha) have diametrically opposed functions in regulating inflammation. We investigated whether unresolving acute respiratory distress syndrome (ARDS) is associated with systemic inflammation- induced glucocorticoid resistance and whether prolonged methylprednisolone administration accelerates the suppression of systemic inflammatory indices and normalizes the sensitivity of the immune system to glucocorticoids. Patients enrolled into a randomized trial evaluating prolonged methylprednisolone administration in unresolving ARDS had serial plasma samples collected before and after randomization. In the plasma, we measured the concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukins (IL) IL-1beta and IL-6, adrenocorticotropic hormone (ACTH), and cortisol. The ability of patient plasma to influence the NF-kappaB and GR-signal transduction systems of normal peripheral blood leukocytes (PBL) was examined. Patients treated with methylprednisolone had progressive and sustained reductions of TNF-alpha, IL-1beta, IL-6, ACTH, and cortisol concentrations over time. Normal PBL exposed to plasma samples collected during methylprednisolone exhibited significant progressive increases in all aspects of GR-mediated activity and significant reductions in NF-kappaB DNA-binding and transcription of TNF-alpha and IL-1beta. These findings provide support for the presence of endogenous glucocorticoid inadequacy in the control of inflammation and systemic inflammation-induced peripheral glucocorticoid resistance in ARDS. Prolonged methylprednisolone administration accelerated the resolution of both systemic inflammation and peripheral acquired glucocorticoid resistance in ARDS.
Three cases of long-standing intranasal cocaine abuse were associated with orbitopathy or optic neuropathy. All three cases were characterized by chronic sinusitis. Histopathologic examination of involved sinus and orbital tissues revealed chronic and acute nonspecific inflammation, with no evidence of unusual infections or of idiopathic midline destructive disease. In two of the cases, there was radiographic evidence of contiguous orbital inflammation associated with sinusitis. The inflammatory orbital process in these two cases was steroid responsive, but in one case recurrent inflammation occurred in response to steroid tapering. One patient suffered a complete loss of vision in the involved eye due to fulminant orbital inflammation and optic nerve dysfunction.
Experiments in rats suffering from primary acute adjuvant inflammation showed independent changes in serum acute phase protein concentration and macroscopic paw inflammation during antiinflammatory treatment: soybean trypsin inhibitor and horse-radish peroxidase caused antiinflammatory effects but simultaneously produced increased alpha 2 macroglobulin levels. On the other hand, cycloheximide significantly inhibited the increase of alpha 2 macroglobulin concentration in adjuvant inflammation, however, it had no antiinflammatory effect. All forms of treatment caused even some change in protein plasma levels of healthy rats which probably relates to an activation of cells producing interleukin-1, interleukin-6, and/or hepatocyte stimulating factor which trigger the synthesis of acute phase proteins in the liver. In inflamed rats, the snake venom batroxobin caused a significant decrease in the fibrinogen level whereas the paw swelling remained completely unaffected. Therefore, it seems to be doubtful whether acute phase proteins essentially contribute to the modulation of acute inflammatory reaction in primary rat adjuvant inflammation.
Activation of cutaneous sensory nerves induces vasodilatation and vascular permeability, i.e., neurogenic inflammation. We examined the histology and possible mast cell involvement in cutaneous neurogenic inflammation induced by electrical nerve stimulation (ENS). Three lines of evidence indicated that mast cells were not involved in rodent cutaneous neurogenic inflammation induced by electrical stimulation of the saphenous nerve. 1) Most mast cells (86.5% of all mast cells in the dorsal skin of the paw) were found in the deep dermis, whereas vessels developing increased vascular permeability after nerve stimulation (visualized with the supravital dye Monastral blue B, a macro-molecular tracer) were localized predominantly in the superficial dermis. By contrast, i.v. substance P, which also causes increased cutaneous vascular permeability, predominantly caused deeper vessels to leak. As analyzed by electron microscopy, the vessels that developed permeability in response to nerve stimulation, and were thereby stained with Monastral blue B, were found to be exclusively postcapillary venules. 2) Disodium cromoglycate (DSCG), a mast cell stabilizing compound, inhibited the cutaneous vascular permeability induced by intradermal injections of anti-IgE in a dose-dependent manner. By contrast, vascular permeability induced by ENS was not influenced by disodium cromoglycate treatment. 3) ENS and i.v. substance P both induced cutaneous vascular permeability in mast cell-deficient W/Wv mice, despite the fact that their skin contained only 4.7% of the mast cells present in their normal +/+ litter mates. The magnitude of ENS-induced vascular permeability responses in W/Wv mice were similar to control +/+ and BALB/c mice. This study supports our earlier observations suggesting that mast cell activation is not essential for the initial, vascular permeability phase of neurogenic inflammation in rodent skin.
Turpentine induced inflammation has been shown to elevate liver sialyl- and galactosyltransferase activities (Turchen, B., Jamieson, J.C., Huebner, E., and van Caeseele, L. (1977) Can. J. Zool. 55, 1567-1571; Lombart, C., Sturgess, J., and Schachter, H. (1980) Biochem. Biophys. Acta 629, 1-12). We now report that serum sialyl-, but not galactosyltransferase activities are significantly elevated in turpentine inflammation. A liver slice system is used to demonstrate that liver releases large amounts of sialyltransferase activity into medium after inflammation, whereas only a low level of galactosyltransferase activity is released. Studies with rat and human asialo-alpha 1-acid glycoprotein as acceptors, coupled with the use of lactose to confirm the nature of the linkages formed, showed that Gal beta 1 leads to 4GlcNAc alpha 2 leads to 6 sialyltransferase is released from liver in turpentine inflammation and is mainly responsible for the elevated sialyltransferase activity found in serum. The alpha 2 leads to 6 sialyltransferase is exhibiting the properties of a typical acute phase reactant.
Lung lavage levels of angiotensin-converting enzyme (ACE)-like activity were increased in C57BL/6 mice with Bacille Calmette-Guérin (BCG)-induced chronic granulomatous pulmonary inflammation and splenomegaly. Contrariwise, ACE activity was not increased in lung lavage fluids of CBA mice that developed only minimal pulmonary inflammation in response to BCG. ACE-like activity correlated with the intensity of inflammation and Captopril, a specific competitive inhibitor of ACE activity, markedly suppressed the induction and maintenance of the BCG-induced inflammatory response in both lungs and spleen. It was necessary, however, to provide sustained treatment with large doses of Captopril in order to reduce the inflammatory response. After a single intraperitoneal injection of Captopril, ACE levels in lung lavage of BCG-injected mice were reduced but returned to preinjection levels or greater within 24 h. The highest dose of Captopril was more effective in reducing the lung fluid level of ACE in BCG-inflamed lungs. This suggests that sustained daily injections of Captopril were necessary to maintain reduced ACE levels. In vitro studies indicated that high concentrations of Captopril did not affect macrophage mobility or chemotactic activity for macrophages. Thus, ACE may act as a molecular mediator of BCG-induced granulomatous inflammation in the lung.
STUDY OBJECTIVES: To identify the characteristics of airway inflammation in persistent asthma and to examine the role of neutrophilic inflammation in noneosinophilic persistent asthma. METHODS: Nonsmoking adults (n = 56) with persistent asthma and healthy control subjects (n = 8) underwent hypertonic saline solution challenge and sputum induction. Selected sputum portions were dispersed with dithiothreitol and assayed for total cell count, cellular differential, supernatant eosinophil cationic protein (ECP), myeloperoxidase, and interleukin (IL)-8. RESULTS: We identified two distinct inflammatory patterns. Typical eosinophilic inflammation occurred in 41% of subjects, whereas the remainder exhibited noneosinophilic asthma (59%). Both neutrophil percentage and absolute neutrophil counts were increased in subjects with noneosinophilic asthma (64%, 283 x 10(6)/mL) compared to eosinophilic asthma (14%, 41 x 10(6)/mL) and control subjects (34%, 49 x 10(6)/mL; p = 0.0001). Myeloperoxidase was elevated in both noneosinophilic (280 ng/mL) and eosinophilic groups (254 ng/mL) compared with control subjects (82 ng/mL; p = 0.002). Sputum IL-8 levels were highest in subjects with noneosinophilic asthma (45 ng/mL) compared to eosinophilic asthma (9.6 ng/mL) and control subjects (3.5 ng/mL; p = 0.0001). Neutrophils correlated with IL-8 levels (r = 0.72). ECP was highest in subjects with eosinophilic asthma (2,685 ng/mL) compared with noneosinophilic asthma (1,081 ng/mL) and control subjects (110 ng/mL; p = 0.0001). CONCLUSION: Induced-sputum analysis in persistent asthma identifies two different inflammatory patterns. The most common pattern is noneosinophilic, associated with a neutrophil influx and activation, which may be mediated by IL-8 secretion. There is heterogeneity of airway inflammation in persistent asthma, which indicates differing mechanisms and may impact on treatment responses.
The effects of joint inflammation on bone marrow and periarticular bone were studied in mice using antigen-induced arthritis and zymosan-induced arthritis as models for an immune and a non-immune-mediated chronic inflammation. To allow for a comparison of the two types of arthritis care was taken to induce comparable degrees of inflammation as evaluated with 99mTechnetium uptake and histology. The antigen-induced arthritis caused a significant suppression of the mitotic activity in the bone marrow close to the inflammatory focus during the first days of arthritis. The zymosan-induced arthritis did not produce alterations of the bone marrow activity. Both types of arthritis were able to induce long-lasting and irreversible damage to cartilaginous and bony structures. Apposition of bone was observed in both types of arthritis although much earlier in the antigen-induced arthritis. The apposition of bone was found to emerge largely from the periosteum and not from the epiphyseal plates, as shown by 125I-deoxyuridine autoradiography. Qualitative and quantitative differences suggest that joint inflammation which is immunologically mediated, results in more severe (peri)articular tissue damage than a non-immunological arthritis.