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ID PMID Title PublicationDate abstract
15225593 Molecular imaging of the transcription factor NF-kappaB, a primary regulator of stress res 2004 Jul 13 A wide range of environmental stress and human disorders involves inappropriate regulation of NF-kappaB, including cancers and numerous inflammatory conditions. We have developed transgenic mice that express luciferase under the control of NF-kappaB, enabling real-time non-invasive imaging of NF-kappaB activity in intact animals. We show that, in the absence of stimulation, strong, intrinsic luminescence is evident in lymph nodes in the neck region, thymus, and Peyer's patches. Treating mice with stressors, such as TNF-alpha, IL-1alpha, or lipopolysaccharide (LPS) increases the luminescence in a tissue-specific manner, with the strongest activity observable in the skin, lungs, spleen, Peyer's patches, and the wall of the small intestine. Liver, kidney, heart, muscle, and adipose tissue exhibit less intense activities. Exposure of the skin to a low dose of UV-B radiation increases luminescence in the exposed areas. In ocular experiments, LPS- and TNF-alpha injected NF-kappaB-luciferase transgenic mice exhibit a 20-40-fold increase in lens NF-kappaB activity, similar to other LPS- and TNF-alpha-responsive organs. Peak NF-kappaB activity occurs 6h after injection of TNF-alpha and 12h after injection of LPS. Peak activities occur, respectively, 3 and 6h later than that in other tissues. Mice exposed to 360J/m(2) of UV-B exhibit a 16-fold increase in NF-kappaB activity 6h after exposure, characteristically similar to TNF-alpha-exposed mice. Thus, in NF-kappaB-luciferase transgenic mice, NF-kappaB activity also occurs in lens epithelial tissue and is activated when the intact mouse is exposed to classical stressors. Furthermore, as revealed by real-time non-invasive imaging, induction of chronic inflammation resembling rheumatoid arthritis produces strong NF-kappaB activity in the affected joints. Finally, we have used the model to demonstrate NF-kappaB regulation by manipulating the Vitamin A status in mice. NF-kappaB activity is elevated in mice fed a Vitamin A deficient (VAD) diet, and suppressed by surplus doses of retinoic acid (RA). We thus demonstrate the development and use of a versatile model for monitoring NF-kappaB activation both in tissue homogenates and in intact animals after the use of classical activators, during disease progression and after dietary intervention.
15096183 Conventional protein kinase C and atypical protein kinase Czeta differentially regulate ma 2004 May In chronic inflammatory diseases such as rheumatoid arthritis, joint macrophages/monocytes are the major source of pro- and anti-inflammatory cytokines. Little is understood regarding the signalling pathways which determine the production of the pro-inflammatory cytokine, tumour necrosis factor-alpha (TNF-alpha) and the anti-inflammatory cytokine, interleukin-10 (IL-10). Two pathways integral to macrophage function are the protein kinase C (PKC)- and the cAMP-dependent pathways. In this report, we have investigated the involvement of PKC and cAMP in the production of TNF-alpha and IL-10 by peripheral blood monocyte-derived macrophages. The utilization of the PKC inhibitors Go6983, Go6976 and RO-32-0432 demonstrated a role for conventional PKCs (alpha and beta) in the production of TNF-alpha in response to stimulation by lipopolysaccharide and phorbol 12-myristate 13-acetate (PMA)/ionomycin. PKC stimulation resulted in the downstream activation of the p42/44 mitogen-activated protein kinase (MAPK) pathway which differentially regulates TNF-alpha and IL-10. The addition of cAMP however, suppressed activation of this MAPK and TNF-alpha production. Cyclic-AMP augmented IL-10 production and cAMP response element binding protein activation upon stimulation by PMA/ionomycin. In addition, cAMP activated PKCzeta; inhibition of which, by a dominant negative adenovirus construct, selectively suppressed IL-10 production. These observations suggest that pro-inflammatory and anti-inflammatory cytokines are differentially regulated by PKC isoforms; TNF-alpha being dependent on conventional PKCs (alpha and beta) whereas IL-10 is regulated by the cAMP-regulated atypical PKCzeta.
14724823 Autoreactivity to lipoate and a conjugated form of lipoate in primary biliary cirrhosis. 2003 Dec BACKGROUND & AIMS: Although considerable effort has been directed toward the mapping of peptide epitopes by autoantibodies, the role of nonprotein molecules has been less well studied. The immunodominant autoantigen in primary biliary cirrhosis (PBC), E2 components of pyruvate dehydrogenase complexes (PDC-E2), has a lipoate molecule bonded to the domain to which autoantibodies are directed. METHODS: We examined sera from patients with PBC (n = 105), primary sclerosing cholangitis (n = 70), and rheumatoid arthritis (n = 28) as well as healthy volunteers (n = 43) for reactivity against lipoic acid. The lipoic acid hapten specificity of the reactive antibodies in PBC sera was determined following incubation of aliquots of the sera with human serum albumin (HSA), lipoylated HSA (HSA-LA), PDC-E2, lipoylated PDC-E2, polyethylene glycol (PEG), lipoylated PEG, free lipoic acid, and synthetic molecular mimics of lipoic acid. RESULTS: Anti-lipoic acid specific antibodies were detected in 81% (79 of 97) of antimitochondrial antibody (AMA)-positive patients with PBC but not in controls. Two previously unreported specificities in AMA-positive sera that recognize free lipoic acid and a carrier-conjugated form of lipoic acid were also identified. CONCLUSIONS: We hypothesize that conjugated form(s) of native or xenobiotic lipoic acid mimics contribute to the initiation and perpetuation of autoimmunity by at first breaking self-tolerance and participating in subsequent determinant spreading. The variability in the immunoreactive carrier/lipoate conjugates provides an experimental framework on which potential mechanisms for the breakdown of self-tolerance following exposure to xenobiotics can be investigated. The data have implications for patients taking lipoic acid as a dietary supplement.
12880669 Various causes and clinical characteristics in vertigo in children with normal eardrums. 2003 Aug OBJECTIVE: The differential diagnosis of vertigo in children is extensive. Otitis media and middle ear effusion could be the most common causes of vertigo in children, but there are some problems in detecting the other causes for vertigo because they are one of most frequent diseases of childhood. The purpose of this study is to review the clinical characteristics and both the audiological and vestibular findings of vertigo in children with normal eardrums, who do not show otitis media or middle ear effusion, and to assist in making a differential diagnosis of vertigo. METHODS: The fifty five children (< 16 years old) with vertigo, who visited the Department of Otolaryngology, Ajou University Hospital, Suwon, South Korea between January 1995 and December 2001 were selected for this study. These excluded the patients with abnormal eardrums/tympanograms or those that did not perform questionnaires, audiological, or vestibular evaluations. They were retrospectively analyzed for clinical symptoms, vestibular functions, and differential diagnosis. RESULTS: The most common causes for vertigo in children were migraine in 17 (30.9%) and benign paroxysmal vertigo of childhood (BPVC) in 14 (25.5%). Other less frequent causes included four cases of trauma, two cases each of Meniere's disease, delayed endolymphatic hydrops, benign positional vertigo, and one case only for cerebellopontine angle tumor, seizure, acute vestibular neuritis, juvenile rheumatoid arthritis, leaving ten cases (18.2%) as unclassified. Abnormal findings were noted in 13 (23.6%) in pure tone audiogram, 3 (5.5%) in positioning test, 6 (10.9%) in bithermal caloric test, and 36 (65.5%) in rotation chair test. CONCLUSIONS: The vertigo in children with normal eardrums, who did not show otitis media or middle ear effusion, was most commonly caused by migraine and BPVC. These findings have shown to be very different from those with adult vertigo. The evaluation of vertigo in children requires a questionnaire for extensive and complete history taking, audiograms and vestibular function tests. And in selected cases, electroencephalography, hematological evaluation, imaging of the brain or temporal bone should be performed.
12730766 A technical and clinical evaluation of digital X-ray radiogrammetry. 2003 Jun Skeletal assessment by morphometry at peripheral sites (e.g. metacarpal index), although simple to perform and widely available, was limited by poor precision and technical aspects of radiogrammetry. Digital X-ray radiogrammetry (DXR) uses the principles of this long-established method but applies more sophisticated methodology to overcome these problems. The aims of this study were to (a) investigate the effects of radiographic technique on bone mineral density (BMD) measurement by DXR, (b) compare DXR to dual-energy X-ray absorptiometry (DXA) and single-energy X-ray absorptiometry (SXA) and (c) determine the applicability of DXR in identifying individuals who most appropriately might be referred for axial DXA. Different radiographers performing the radiograph do not adversely affect precision. Precision, unstandardised (CV%) and standardised (sCV%), is good with both double (DF)- and single (SF)-sided emulsion radiographic film, but better with SF (CV% 0.92 vs 1.12 DF; SCV% 1.76 vs 2.93 DF). Repeat analysis precision was determined on SF (CV% 0.24, sCV% 0.55). A significant ( p<0.001), systematic difference was found between BMD measured from DF and SF (mean difference 0.017 g/cm(2)). The overall percentage difference between the methods was 2.98% (range 0.18-5.78%). Correlations between DXR BMD and DXA were moderately good (r=0.56-0.77, p<0.001); with SXA of the forearm they were excellent (r=0.91, p<0.001). The sensitivity and specificity of DXR for detecting women with osteopaenia or osteoporosis (DXA T-score less than -1; World Health Organisation) was determined at the spine [area under curve (AUC)=0.82, standard error (SE)=0.04], femoral neck (AUC=0.84, SE=0.04) and total hip (AUC=0.84, SE=0.04). Based on femoral neck BMD for detection of osteopaenia, a DXR T-score threshold of -1.05 would be appropriate for detection of patients who might benefit most from axial DXA measurements. The DXR is quick and simple to use, having potential for application in a variety of settings as analysis can be performed in a central unit, with radiographs taken in sites over a wide geographical area. Retrospective analysis may also be performed, e.g. on radiographs taken to monitor rheumatoid arthritis. The technique may also provide a simple, widely available and relatively inexpensive method to assess patients at risk of osteopaenia or osteoporosis, and who most appropriately could be referred for axial DXA. This may be particularly relevant in those who suffer low-trauma fractures and attend accident and emergency or fracture clinics, where investigation for osteoporosis is often overlooked.
12692986 [Clinical significance of serum KL-6 and SP-D for the diagnosis and treatment of interstit 2003 Feb OBJECTIVE: To elucidate the clinical significance of serum KL-6 and SP-D for the diagnosis and treatment of interstitial lung disease in connective tissue disorders. METHODS: 139 patients with various connective tissue disorders were subjected for the study, which included 46 cases of rheumatoid arthritis, 43 cases of Sjögren's syndrome, 16 cases of SLE, 10 cases of systemic sclerosis, 9 cases of polymyositis/dermatomyositis, 6 cases of vasculitis syndrome, 5 cases of Behçet's disease and 4 cases of MCTD. Serum levels of KL-6 and SP-D were determined by enzyme-immunoassay. The sensitivity, specificity and accuracy of serum KL-6 and SP-D for the diagnosis of interstitial lung disease were compared with serum LDH. The relationship of serum KL-6 and SP-D levels with high resolution CT (HRCT) of the lung and Gallium scintigraphy findings was analyzed. In some cases, serum levels of the two markers were determined monthly in the course of the disease. RESULTS: When the serum levels of KL-6 and SP-D were measured simultaneously, the sensitivity to diagnose interstitial lung disease was 67.7%, the specificity was 98.1%, and the accuracy was 91.4%, while those of serum LDH were 45.2%, 88.9%, 79.1% respectively. In the patients with interstitial lung disease, those who had elevated serum levels of both KL-6 and SP-D showed parenchymal collapse opacity-dominant pattern in HRCT. On the other hand, the patients with interstitial lung disease who had normal levels of serum KL-6 and SP-D or had elevation either in KL-6 or SP-D levels showed ground glass opacity-dominant pattern in HRCT. There was no significant correlation between serum marker levels and Gallium scintigraphy findings. When serum KL-6 and SP-D were measured monthly, the levels of both markers changed more specifically and sensitively to the lung disease activity compared with serum LDH. CONCLUSIONS: Serum KL-6 and SP-D are more specific and useful markers for the diagnosis and evaluation of interstitial lung disease compared with serum LDH in connective tissue disorders.
12403202 Risk factors for anti-inflammatory-drug- or aspirin-induced gastrointestinal complications 2002 Oct STUDY DESIGN: Prospective, multicenter, observational research study. BACKGROUND: Minimal research exists that describes the potential for serious gastrointestinal complications in individuals receiving outpatient physical therapy care. OBJECTIVE: To identify the prevalence of risk factors for gastrointestinal complications induced by anti-inflammatory drugs or aspirin in individuals receiving outpatient physical therapy services. METHODS AND MEASURES: A self-administered questionnaire was used at 65 ambulatory physical therapy clinics to document past medical history, history of present illness, and medication use. Risk factors for anti-inflammatory-drug- or aspirin-induced gastrointestinal complications were identified and the proportion of patients reporting each factor was determined. RESULTS: A total of 2433 patients completed the survey. Of the 2311 evaluable patients included in the study, 78.6% reported over-the-counter or prescribed use of an anti-inflammatory drug or aspirin during the week prior to the survey. Forty-nine percent of the patients reported at least 1 risk factor for drug-induced gastrointestinal complications, while 12.9% reported 2 or more risk factors. The most frequently reported established risk factors among anti-inflammatory drug or aspirin users were (1) combination (dual) therapy (22.3% reported concomitant use of anti-inflammatory and aspirin therapy), (2) advanced age (15.7% were over the age of 61 years), (3) history of peptic ulcer disease (7.8% had a history of peptic ulcer disease), and (4) significant systemic illness (6.8% reported having rheumatoid arthritis or heart disease). A frequently encountered risk factor combination was advanced age with a history of peptic ulcer disease (12.7%). CONCLUSIONS: Patients seen at physical therapy ambulatory clinics present with multiple risk factors for anti-inflammatory-drug- or aspirin-induced gastrointestinal complications and provide a potential opportunity for risk reduction by clinicians working in this environment.
12393422 A critical role of placental growth factor in the induction of inflammation and edema form 2003 Jan 15 Angiogenesis is a prominent feature of a number of inflammatory human diseases, including rheumatoid arthritis, psoriasis, and cutaneous delayed-type hypersensitivity (DTH) reactions. Up-regulation of placental growth factor (PlGF), a member of the vascular endothelial growth factor (VEGF) family, has been found in several conditions associated with pathologic angiogenesis; however, its distinct role in the control of angiogenesis has remained unclear. To directly investigate the biologic function of PlGF in cutaneous inflammation and angiogenesis, DTH reactions were investigated in the ear skin of wild-type mice, of PlGF-deficient mice, and of transgenic mice with targeted overexpression of human PlGF-2 in epidermal keratinocytes, driven by a keratin 14 promoter expression construct. Chronic transgenic delivery of PlGF-2 to murine epidermis resulted in a significantly increased inflammatory response, associated with more pronounced vascular enlargement, edema, and inflammatory cell infiltration than seen in wild-type mice. Conversely, PlGF deficiency resulted in a diminished and abbreviated inflammatory response, together with a reduction of inflammatory angiogenesis and edema formation. VEGF expression was up-regulated at a comparable level in the inflamed skin of all genotypes. These findings reveal that placental growth factor plays a critical role in the control of cutaneous inflammation, and they suggest inhibition of PlGF bioactivity as a potential new approach for anti-inflammatory therapy.
12296294 Dietary modification of inflammation with lipids. 2002 Aug The n-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are found in high proportions in oily fish and fish oils. The n-3 PUFA are structurally and functionally distinct from the n-6 PUFA. Typically, human inflammatory cells contain high proportions of the n-6 PUFA arachidonic acid and low proportions of n-3 PUFA. The significance of this difference is that arachidonic acid is the precursor of 2-series prostaglandins and 4-series leukotrienes, which are highly-active mediators of inflammation. Feeding fish oil results in partial replacement of arachidonic acid in inflammatory cell membranes by EPA. This change leads to decreased production of arachidonic acid-derived mediators. This response alone is a potentially beneficial anti-inflammatory effect of n-3 PUFA. However, n-3 PUFA have a number of other effects which might occur downstream of altered eicosanoid production or might be independent of this activity. For example, animal and human studies have shown that dietary fish oil results in suppressed production of pro-inflammatory cytokines and can decrease adhesion molecule expression. These effects occur at the level of altered gene expression. This action might come about through antagonism of the effects of arachidonic acid-derived mediators or through more direct actions on the intracellular signalling pathways which lead to activation of transcription factors such as nuclear factor kappa B (NFB). Recent studies have shown that n-3 PUFA can down regulate the activity of the nuclear transcription factor NFB. Fish oil feeding has been shown to ameliorate the symptoms in some animal models of chronic inflammatory disease and to protect against the effects of endotoxin and similar inflammatory challenges. Clinical studies have reported that oral fish oil supplementation has beneficial effects in rheumatoid arthritis and among some patients with asthma, supporting the idea that the n-3 PUFA in fish oil are anti-inflammatory. There are indications that inclusion of n-3 PUFA in enteral and parenteral formulas might be beneficial to patients in intensive care or post-surgery.
12088274 Polyisoprenyl phosphates: natural antiinflammatory lipid signals. 2002 May Lipoxins (LX) and aspirin-triggered 15-epimer LX are leukocyte-derived eicosanoids generated during host defense that serve as down-regulatory signals. The specific intracellular events that govern cellular responses to inhibitory extracellular signals are of wide interest in order to understand pivotal intracellular events in diseases characterized by enhanced inflammatory responses, such as asthma, rheumatoid arthritis and atherosclerosis. We recently uncovered a novel role for polyisoprenyl phosphates, in particular presqualene diphosphate (PSDP), as natural down-regulatory signals in human neutrophils that directly inhibit phospholipase D and superoxide anion generation. Activation of LXA4 receptors (ALXR) reverses proinflammatory receptor-initiated decrements in PSDP and inhibits cellular responses. These findings represent evidence for a novel paradigm for lipid-protein interactions in the control of cellular responses, namely receptor-initiated degradation of repressor lipids that is subject to regulation by aspirin treatment via the actions of aspirin-triggered 15-epimer LX at the ALXR, and identify new templates for antiinflammatory drugs by design.
12086484 Identification of potent and novel alpha4beta1 antagonists using in silico screening. 2002 Jul 4 The antigen alpha4beta1 (very late antigen-4, VLA-4) plays an important role in the migration of white blood cells to sites of inflammation. It has been implicated in the pathology of a variety of diseases including asthma, multiple sclerosis, and rheumatoid arthritis. We describe a series of potent inhibitors of alpha4beta1 that were discovered using computational screening for replacements of the peptide region of an existing tetrapeptide-based alpha4beta1 inhibitor (1; 4-[N'-(2-methylphenyl)ureido]phenylacetyl-Leu-Asp-Val) derived from fibronectin. The search query was constructed using a model of 1 that was based upon the X-ray conformation of the related integrin-binding region of vascular cell adhesion molecule-1 (VCAM-1). The 3D search query consisted of the N-terminal cap and the carboxyl side chain of 1 because, upon the basis of existing structure-activity data on this series, these were known to be critical for high-affinity binding to alpha4beta1. The computational screen identified 12 reagents from a virtual library of 8624 molecules as satisfying the model and our synthetic filters. All of the synthesized compounds tested inhibit alpha4beta1 association with VCAM-1, with the most potent compound having an IC(50) of 1 nM, comparable to the starting compound. Using CATALYST, a 3D QSAR was generated that rationalizes the variation in activities of these alpha4beta1 antagonists. The most potent compound was evaluated in a sheep model of asthma, and a 30 mg nebulized dose was able to inhibit early and late airway responses in allergic sheep following antigen challenge and prevented the development of nonspecific airway hyperresponsiveness to carbachol. Our results demonstrate that it is possible to rapidly identify nonpeptidic replacements of integrin peptide antagonists. This approach should be useful in identification of nonpeptidic alpha4beta1 inhibitors with improved pharmacokinetic properties relative to their peptidic counterparts.
20641743 (68)Ga-1,4,7,10-Tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-cyclo(Arg-Gly-Asp-D-P 2004 Integrins are a family of heterodimeric glycoproteins on cell surfaces that mediate diverse biological events involving cell–cell and cell–matrix interactions (1). Integrins consist of an α and a β subunit and are important for cell adhesion and signal transduction. The α(v)β(3) integrin is the most prominent receptor affecting tumor growth, tumor invasiveness, metastasis, tumor-induced angiogenesis, inflammation, osteoporosis, and rheumatoid arthritis (2-7). Expression of the α(v)β(3) integrin is strong on tumor cells and activated endothelial cells, whereas expression is weak on resting endothelial cells and most normal tissues. The α(v)β(3) antagonists are being studied as antitumor and antiangiogenic agents and the agonists are being studied as angiogenic agents for coronary angiogenesis (6, 8, 9). The peptide sequence Arg-Gly-Asp (RGD) has been identified as a recognition motif used by extracellular matrix proteins (vitronectin, fibrinogen, laminin, and collagen) to bind to a variety of integrins, including α(v)β(3). Various radiolabeled antagonists have been introduced for imaging of tumors and tumor angiogenesis (10). Most of the cyclic RGD peptides are composed of five amino acids. Various cyclic RGD peptides exhibit selective inhibition of binding to α(v)β(3) (50% inhibition concentration (IC(50)), 7–40 nM) but not to α(v)β(5) (IC(50), 600–4,000 nM) or α(IIb)β(3) (IC(50), 700–5,000 nM) integrins (11). Various radiolabeled cyclic RGD peptides and peptidominetics have been found to have high accumulation in tumors in mice (12, 13). Out of these developments [(18)F]Galacto-c(RGDfK) has been evaluated in a number of clinical studies for imaging of α(v)β(3) in cancer patients (14-19). Decristoforo et al. (20) reported the development of (68)Ga-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-cyclo(Arg-Gly-Asp-D-Phe-Lys) ((68)Ga-DOTA-c(RGDfK)) for positron emission tomography (PET) imaging of α(v)β(3) receptors in nude mice bearing melanoma tumors.
20641531 Cyclo(Arg-Gly-Asp-d-Tyr-Lys)-Cy5.5. 2004 Integrins are a family of cell surface heterodimeric glycoproteins that mediate diverse biological events involving cell-cell and cell-matrix interactions (1). They consist of an α and a β subunit. They are important for cell adhesion and signal transduction. The α(v)β(3) integrin is the most prominent receptor class affecting tumor growth, tumor invasiveness, metastasis, tumor-induced angiogenesis, inflammation, osteoporosis, and rheumatoid arthritis (2-7). The α(v)β(3) integrin is strongly expressed on tumor cells and activated endothelial cells. In contrast, expression of α(v)β(3) integrin is weak on resting endothelial cells and most normal tissues. The α(v)β(3) antagonists are being studied as anti-tumor and anti-angiogenic agents (4, 8, 9) and the agonists as angiogenic agents for coronary angiogenesis (10, 11). A tripeptide sequence consisting of Arg-Gly-Asp (RGD) is identified as a recognition motif used by extracellular matrix proteins (vitronectin, fibrinogen, laminin, and collagen) to bind to a variety of integrins including α(v)β(3). Various radiolabeled antagonists were introduced for imaging of tumors and tumor angiogenesis (12). Optical fluorescence imaging is increasingly used to obtain biological functions of specific targets (13, 14). However, the intrinsic fluorescence of biomolecules poses a problem when visible light (350-700 nm) absorbing fluorophores are used. Near-infrared (NIR) fluorescence (700-1000 nm) detection avoids the background fluorescence interference of natural biomolecules, providing a high contrast between target and background tissues. NIR fluorophores have wider dynamic range and minimal background as a result of reduced scattering compared with visible fluorescence detection. They also have high sensitivity, resulting from low infrared background, and high extinction coefficients, which provide high quantum yields. The NIR region is also compatible with solid-state optical components, such as diode lasers and silicon detectors. NIR fluorescence imaging is becoming a non-invasive alternative to radionuclide imaging. Cyclo(RGDyK) was conjugated with Cy5.5 to study in vivo biodistribution of the tracer in tumor-bearing mice. Cy5.5 is a NIR fluorescent dye with absorbance maximum at 675 nm and emission maximum at 694 nm with a high extinction coefficient of 250,000 (mol/L)(-1)cm(-1). RGD-Cy5.5 or c(RGDyK)-Cy5.5 was found to have a high and long-lasting accumulation in α(v)β(3)-positve U87MG human glioblastoma tumor cells in nude mice (15). The binding of RGD-Cy5.5 to the integrin receptor was found to be specific both in vitro and in vivo.
20641803 (99m)Tc-Ethylenediaminediacetic acid/hydrazinonicotinic acid-cyclo(Arg-Gly-Asp-D-Try-Lys). 2004 Integrins are a family of heterodimeric glycoproteins on cell surfaces that mediate diverse biological events involving cell–cell and cell–matrix interactions (1). Integrins consist of an α and a β subunit and are important for cell adhesion and signal transduction. The α(v)β(3) integrin is the most prominent receptor affecting tumor growth, tumor invasiveness, metastasis, tumor-induced angiogenesis, inflammation, osteoporosis, and rheumatoid arthritis (2-7). Expression of the α(v)β(3) integrin is strong on tumor cells and activated endothelial cells, whereas expression is weak on resting endothelial cells and most normal tissues. Antagonists of α(v)β(3) are being studied as antitumor and antiangiogenic agents, and the agonists of α(v)β(3) are being studied as angiogenic agents for coronary angiogenesis (6, 8, 9). A tripeptide sequence consisting of Arg-Gly-Asp (RGD) has been identified as a recognition motif used by extracellular matrix proteins (vitronectin, fibrinogen, laminin, and collagen) to bind to a variety of integrins, including α(v)β(3). Various radiolabeled antagonists have been introduced for imaging of tumors and tumor angiogenesis (10). Most cyclic RGD peptides are composed of five amino acids. Haubner et al. (11) reported that various cyclic RGD peptides exhibit selective inhibition of binding to α(v)β(3) (inhibition concentration (IC(50)), 7–40 nM) but not to integrins α(v)β(5) (IC(50), 600–4,000 nM) or α(IIb)β(3) (IC(50), 700–5,000 nM). Various radiolabeled cyclic RGD peptides have been found to have high accumulation in tumors in nude mice (12). Hydrazinonicotinic acid (HYNIC) is a coupling agent for (99m)Tc labeling of peptides that can achieve high specific activities without affecting the receptor-binding ability of the amino acid sequence. Decristoforo et al. (13) reported the success of radiolabeling cyclo(Arg-Gly-Asp-D-Tyr-Lys) (c(RGDyK)) by conjugation of HYNIC to the ε amino group of Lys with ethylenediaminediacetic acid (EDDA) and tris(hydroxymethyl)-methylglycine (tricine) as coligand. The (99m)Tc-EDDA/HYNIC-c(RGDyK) peptide showed high tumor accumulation in nude mice bearing M21 human melanoma tumors and A549 human lung carcinoma tumors.
21204315 Microbubbles conjugated with knottin 2.5D. 2004 Ultrasound is the most widely used imaging modality in clinical medicine (1) and its role in noninvasive molecular imaging with ligand-carrying microbubbles is expanding (2). Microbubbles are comprised of spherical cavities filled by a gas encapsulated in a shell. The shells are made of phospholipids, surfactant, denatured human serum albumin, or synthetic polymer. Ligands and antibodies can be incorporated into the shell surface of microbubbles. Microbubbles are usually 1–8 μm in diameter. They provide a strongly reflective interface and resonate to ultrasound waves. They are used as ultrasound contrast agents in imaging of inflammation, angiogenesis, intravascular thrombus, and tumors (3-5). They are also potentially used for drug and gene delivery (6). Integrins are a family of heterodimeric glycoproteins on cell surfaces that mediate diverse biological events involving cell–cell and cell–matrix interactions (7). Integrins consist of an α and a β subunit and are important for cell adhesion and signal transduction. The α(v)β(3) integrin is the most prominent receptor affecting tumor growth, tumor invasiveness, metastasis, tumor-induced angiogenesis, inflammation, osteoporosis, and rheumatoid arthritis (8-13). Expression of the α(v)β(3) integrin is strong on tumor cells and activated endothelial cells, whereas expression is weak on resting endothelial cells and most normal tissues. The α(v)β(3) antagonists are being studied as antitumor and antiangiogenic agents, and the agonists are being studied as angiogenic agents for coronary angiogenesis (12, 14, 15). The peptide sequence Arg-Gly-Asp (RGD) has been identified as a recognition motif used by extracellular matrix proteins (e.g., vitronectin, fibrinogen, laminin, and collagen) to bind to a variety of integrins, including α(v)β(3). Various radiolabeled antagonists have been introduced for imaging of tumors and tumor angiogenesis (16). Microbubbles conjugated to either peptides or antibodies against integrins, cell adhesion molecules, and VEGF receptors have previously been studied for the noninvasive assessment and imaging of tumor angiogenesis (17-20). Cystine knot peptides (knottins) share a common disulfide-bonded framework and a triple-stranded β-sheet fold (21). The integrin-binding RGD motif was grafted into a knottin from trypsin inhibitor II of the squash plant (Ecballium elaterium). Knottin 2.5D (with three disulfide bonds; GCPQGRGDWAPTSCSQDSDCLAGCVCGPNGFCG-NH(2)) was identified from a series of genetically engineered knottin peptides to have nanomolar binding to the α(v)β(3), α(v)β(5), and α(5)β(1) integrin receptors (22, 23). Willmann et al. (24) studied ultrasonic imaging of tumor vasculature using microbubbles conjugated with knottin 2.5D (MB(Knottin)) in mice bearing human tumor xenografts.
15542543 Properties and expression of human tartrate-resistant acid phosphatase isoform 5a by monoc 2005 Feb Human serum tartrate-resistant acid phosphatase exists as two enzyme isoforms (TRACP 5a and 5b), derived by differential, post-translational processing of a common gene product. Serum TRACP 5b is from bone-resorbing osteoclasts (OC) and becomes elevated in diseases of increased bone resorption. TRACP 5a is secreted by macrophages (MPhi) and dendritic cells (DC) and is increased in many patients with rheumatoid arthritis. Our purpose was to fully characterize the properties of human TRACP isoforms and to produce an antibody specific to TRACP 5a for use as a biomarker in chronic inflammatory diseases. Partially purified, natural serum TRACP isoforms and recombinant TRACP 5a (rTRACP 5a) were compared with respect to specific activity and subunit structure and presence of sialic acid. Mice were immunized with rTRACP 5a, and resulting hybridomas were screened for monoclonal antibody to serum TRACP 5a. One antibody, 220, was tested for its epitope specificity and use in various immunological techniques. rTRACP 5a had properties identical to serum TRACP 5a. Antibody 220 was specific for the trypsin-sensitive epitope in the loop peptide, present only in TRACP 5a. Antibody 220 was effective for specific immunoprecipitation, immunoassay, and immunoblot of TRACP 5a. Intact TRACP was present in MPhi, DC, and OC. TRACP 5a was the predominant isoform secreted by MPhi and DC, whereas TRACP 5b was the predominant isoform secreted by OC. TRACP isoforms 5a and 5b may have different functions inside and outside of monocyte-derived cells. Antibody 220 is an important resource for studies of the biosynthetic relationship among TRACP isoforms and of the significance of serum TRACP 5a as a marker in diseases of bone metabolism and inflammation.
15242197 Staphylococcus aureus nasal carriage in a student community: prevalence, clonal relationsh 2004 Jun OBJECTIVE: To evaluate the prevalence and risk factors of nasal Staphylococcus aureus (SA) in the community. DESIGN: Cross-sectional study. SETTING: Wake Forest University, Winston-Salem, North Carolina. PARTICIPANTS: Four hundred fifty students were screened for nasal SA carriage during the fall of 2000, 2001, and 2002. METHODS: Students were screened by nose swabs. A self-administered questionnaire collected information on demographics and medical history. Antibiotic testing and PFGE were performed on isolates. Risk factors were determined by logistic regression analysis. RESULTS: Of 450 volunteers, 131 (29%) were SA carriers. Antibiotic resistance was high for azithromycin (26%) and low for ciprofloxacin (1%), tetracycline (5%), mupirocin (1%), and methicillin (2%). PFGE patterns were not associated with carriage. Age, male gender, white race, medical student, allergen injection therapy, chronic sinusitis, rheumatoid arthritis, hospitalization for 6 months or less, and use of antibiotics were associated with carrier status by univariate analysis. Stepwise multivariate logistic regression led to a best fitting model with older age (OR, 1.04; CI95, 1.005-1.079), male gender (OR, 1.50; CI95, 0.982-2.296), and chronic sinusitis (OR, 2.71; CI95, 0.897-8.195) as risk factors. Antibiotic use (< 4 weeks) (OR, 0.41; CI95, 0.152-1.095) and allergen injection therapy (OR, 0.41; CI95, 0.133-1.238) were protective. Analyses of carriers revealed candidate factors for persistent carriage to be nasal SA colonization rate and male gender. Factors for azithromycin resistance were non-medical students and antibiotic use in the past 6 months. CONCLUSION: Older male volunteers suffering from chronic sinusitis and not taking antibiotics were at higher risk for carrying SA.
15067094 Thalidomide induces apoptosis in human monocytes by using a cytochrome c-dependent pathway 2004 Apr 15 Thalidomide has been shown to be an effective treatment in various immunologic diseases such as Crohn's disease and rheumatoid arthritis. Its major effect is thought to be mediated by the inhibition of TNF-alpha, but the exact mechanism of action is still uncertain. Recent observations could demonstrate that the induction of monocyte apoptosis is a common feature of a variety of anti-inflammatory agents. Therefore, we investigated the role of thalidomide on monocyte apoptosis. Treatment with thalidomide resulted in apoptosis of human peripheral blood monocytes in a time- and dose-dependent manner as demonstrated by annexin V staining. Monocyte apoptosis required the activation of caspases, as combined stimulation by thalidomide together with the broad caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone markedly prevented monocyte cell death. Apoptosis was triggered by a CD95/CD95 ligand, TNF-RI, and TRAIL-R1 independent pathway with an inhibition of AKT-1 kinase and consecutive mitochondrial release of cytochrome c, followed by the proteolytic activation of initiator caspase-9 and effector caspase-3. Our data suggest that thalidomide-induced monocyte apoptosis is at least partially mediated by a mitochondrial signaling pathway and might contribute to the complex immunomodulatory properties of the drug.
15034939 Interleukin (IL)-17 enhances tumor necrosis factor-alpha-stimulated IL-6 synthesis via p38 2004 Apr 1 Inflammatory cytokines are well known to play crucial roles in the pathogenesis of rheumatoid arthritis. Among them, interleukin (IL)-17 is a cytokine that is mainly synthesized by activated T cells and its receptors are present in osteoblasts. The synthesis of IL-6, known to stimulate osteoclastic bone resorption, is reportedly responded to bone resorptive agents such as tumor necrosis factor-alpha (TNF-alpha) in osteoblasts. It has been reported that IL-17 enhances TNF-alpha-stimulated IL-6 synthesis in osteoblast-like MC3T3-E1 cells. We previously showed that sphingosine 1-phosphate (S1-P) mediates TNF-alpha-stimulated IL-6 synthesis in these cells. In the present study, we investigated the mechanism of IL-17 underlying enhancement of IL-6 synthesis in MC3T3-E1 cells. IL-17 induced phosphorylation of p38 mitogen-activated protein (MAP) kinase. SB203580 and PD169316, specific inhibitors of p38 MAP kinase, significantly reduced the enhancement by IL-17 of TNF-alpha-stimulated IL-6 synthesis. IL-17 also amplified S1-P-stimulated IL-6 synthesis, and the amplification by IL-17 was suppressed by SB203580. Anisomycin, an activator of p38 MAP kinase, which alone had no effect on IL-6 level, enhanced the IL-6 synthesis stimulated by TNF-alpha. SB203580 and PD169316 inhibited the amplification by anisomycin of the TNF-alpha-induced IL-6 synthesis. Taken together, our results strongly suggest that IL-17 enhances TNF-alpha-stimulated IL-6 synthesis via p38 MAP kinase activation in osteoblasts.
15031635 Gold sodium thiomalate and chloroquine inhibit cytokine production in monocytic THP-1 cell 2003 Nov Gold sodium thiomalate (GST), chloroquine (CQ), and methotrexate have been widely used in the therapy of rheumatoid arthritis and other inflammatory conditions. Using the human monocytic cell line THP-1 we have analyzed effects of these drugs on cytokine production and intracellular signaling. GST and CQ were equally effective in reducing lipopolysaccharide (LPS)-induced IL-1 beta release while CQ was a more effective inhibitor of TNF-alpha production than GST. Methotrexate did not affect production of these cytokines. CQ reduced IL-1 beta mRNA expression and strongly inhibited phosphorylation of mitogen-activated protein kinase (MAPK) p38, and to a lesser extent c-Jun N-terminal kinase and extracellular signal-regulated kinase 1/2. In contrast, GST did not affect cytokine mRNA expression or MAPK activation. However, GST selectively inhibited the activity of the interleukin-1 converting enzyme (ICE)/caspase-1. These data demonstrate that CQ inhibits IL-1 beta release from monocytes by interfering with pretranscriptional signaling and TNF-alpha release by posttranslational events whereas GST downregulates IL-1 beta secretion by interfering with posttranslational IL-1 beta processing.