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1.
BMC Health Serv Res ; 23(1): 1354, 2023 Dec 04.
Article in English | MEDLINE | ID: mdl-38049861

ABSTRACT

BACKGROUND: One in five children with an intellectual disability in the UK display behaviours that challenge. Despite associated impacts on the children themselves, their families, and services, little research has been published about how best to design, organise, and deliver health and care services to these children. The purpose of this study was to describe how services are structured and organised ("service models") in England for community-based health and care services for children with intellectual disability who display behaviours that challenge. METHODS: Survey data about services were collected from 161 eligible community-based services in England. Staff from 60 of these services were also interviewed. A combination of latent class and descriptive analysis, coupled with consultation with family carers and professionals was used to identify and describe groupings of similar services (i.e., "service models"). RESULTS: The latent class analysis, completed as a first step in the process, supported a distinction between specialist services and non-specialist services for children who display behaviours that challenge. Planned descriptive analyses incorporating additional study variables were undertaken to further refine the service models. Five service models were identified: Child and Adolescent Mental Health Services (CAMHS) (n = 69 services), Intellectual Disability CAMHS (n = 28 services), Children and Young People Disability services (n = 25 services), Specialist services for children who display behaviours that challenge (n = 27 services), and broader age range services for children and/or adolescents and adults (n= 12 services). CONCLUSIONS: Our analysis led to a typology of five service models for community health and care services for children with intellectual disabilities and behaviours that challenge in England. Identification of a typology of service models is a first step in building evidence about the best provision of services for children with intellectual disabilities who display behaviours that challenge. The methods used in the current study may be useful in research developing service typologies in other specialist fields of health and care. STUDY REGISTRATION: Trial Registration: Current Controlled Trials ISRCTN88920546, Date assigned 05/07/2022.


Subject(s)
Intellectual Disability , Adult , Adolescent , Humans , Child , Intellectual Disability/therapy , Intellectual Disability/psychology , Community Health Services , England , Caregivers/psychology , Surveys and Questionnaires
2.
Free Radic Biol Med ; 120: 246-254, 2018 05 20.
Article in English | MEDLINE | ID: mdl-29555590

ABSTRACT

The generation of 3-nitrotyrosine, within proteins, is a post-translational modification resulting from oxidative or nitrative stress. It has been suggested that this modification could be used as a biomarker for inflammatory diseases. Despite the superiority of mass spectrometry-based determinations of nitrotyrosine, in a high-throughput clinical setting the measurement of nitrotyrosine by an enzyme-linked immunosorbent assay (ELISA) is likely to be more cost-effective. ELISAs offer an alternative means to detect nitrotyrosine, but many commercially available ELISAs are insufficiently sensitive to detect nitrotyrosine in healthy human serum. Here, we report the development, validation and clinical application of a novel electrochemiluminescence-based ELISA for nitrotyrosine which provides superior sensitivity (e.g. a 50-fold increase in sensitivity compared with one of the tested commercial colorimetric ELISAs). This nitrotyrosine ELISA has the following characteristics: a lower limit of quantitation of 0.04 nM nitrated albumin equivalents; intra- and inter-assay coefficients of variation of 6.5% and 11.3%, respectively; a mean recovery of 106 ±â€¯3% and a mean linearity of 0.998 ±â€¯0.001. Far higher nitration levels were measured in normal human blood cell populations when compared to plasma. Mass spectrometry was used to validate the new ELISA method. The analysis of the same set of chemically modified albumin samples using the ELISA method and mass spectrometry showed good agreement for the relative levels of nitration present in each sample. The assay was applied to serum samples from patients undergoing elective surgery which induces the human inflammatory response. Matched samples were collected before and one day after surgery. An increase in nitration was detected following surgery (median (IQR): 0.59 (0.00-1.34) and 0.97 (0.00-1.70) nitrotyrosine (fmol of nitrated albumin equivalents/mg protein) for pre- and post-surgery respectively. The reported assay is suitable for nitrotyrosine determination in patient serum samples, and may also be applicable as a means to determine oxidative stress in primary and cultured cell populations.


Subject(s)
Biomarkers/analysis , Enzyme-Linked Immunosorbent Assay/methods , Luminescent Measurements/methods , Oxidative Stress/physiology , Tyrosine/analogs & derivatives , Adult , Aged , Female , Humans , Male , Middle Aged , Tyrosine/analysis
3.
Oxid Med Cell Longev ; 2015: 496271, 2015.
Article in English | MEDLINE | ID: mdl-26113954

ABSTRACT

Advanced oxidation protein products (AOPP) are reportedly elevated in the plasma of patients with a number of diseases, including diabetes mellitus, that involve oxidative stress. However, the accurate measurement of AOPP in human plasma is hampered by the formation of a precipitate following the addition of potassium iodide and glacial acetic acid according to the published assay procedure. Here we describe a modification of the AOPP assay which eliminates interference by precipitation and provides a robust, reliable, and reproducible protocol for the measurement of iodide oxidising capacity in plasma samples (intra-assay CV 1.7-5.3%, interassay CV 5.3-10.5%). The improved method revealed a significant association of AOPP levels with age (p < 0.05) and hypertension (p = 0.01) in EDTA-anticoagulated plasma samples from 52 patients with diabetes and 38 nondiabetic control subjects, suggesting a possible link between plasma oxidising capacity and endothelial and/or vascular dysfunction. There was no significant difference between AOPP concentrations in diabetic (74.8 ± 7.2 µM chloramine T equivalents) and nondiabetic (75.5 ± 7.0 µM chloramine T equivalents) individuals.


Subject(s)
Advanced Oxidation Protein Products/blood , Diabetes Mellitus, Type 2/pathology , Oxidative Stress , Aged , Biomarkers/blood , Case-Control Studies , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/complications , Female , Humans , Hypertension/complications , Male , Middle Aged , Smoking
4.
Anesthesiology ; 119(6): 1284-95, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24126262

ABSTRACT

BACKGROUND: Although predictors of laryngeal mask airway failure in adults have been elucidated, there remains a paucity of data regarding laryngeal mask airway failure in children. METHODS: The authors performed a retrospective database review of all pediatric patients who received a laryngeal mask anesthetic at their institution from 2006 to 2010. Device brands were restricted to LMA Unique™ (Cardinal Health, Dublin, OH) and LMA Classic™ (LMA North America, San Diego, CA), and primary outcome was laryngeal mask failure, defined as any airway event requiring device removal and tracheal intubation. Potential risk factors were analyzed with both univariate and multivariate techniques and included medical history, physical examination, surgical, and anesthetic characteristics. RESULTS: Of the 11,910 anesthesia cases performed in the study, 102 cases (0.86%) experienced laryngeal mask failure. Common presenting features of laryngeal mask failures included leak (25%), obstruction (48%), and patient intolerance such as intractable coughing/bucking (11%). Failures occurred before incision in 57% of cases and after incision in 43%. Independent clinical associations included ear/nose/throat surgical procedure, nonoutpatient admission status, prolonged surgical duration, congenital/acquired airway abnormality, and patient transport. CONCLUSIONS: The findings of the study support the use of the LMA Unique™ and LMA Classic™ as reliable pediatric supraglottic airway devices, demonstrating relatively low failure rates. Predictors of laryngeal mask airway failure in the pediatric surgical population do not overlap with those in the adult population and should therefore be independently considered.


Subject(s)
Laryngeal Masks/adverse effects , Adolescent , Age Factors , Airway Obstruction/epidemiology , Airway Obstruction/etiology , Anesthesia , Child , Child, Preschool , Data Interpretation, Statistical , Databases, Factual , Equipment Failure , Female , Forecasting , Humans , Infant , Infant, Newborn , Male , Multivariate Analysis , Perioperative Period , Respiratory Tract Diseases/congenital , Retrospective Studies , Risk Factors , Treatment Outcome
5.
Free Radic Biol Med ; 50(1): 93-101, 2011 Jan 01.
Article in English | MEDLINE | ID: mdl-20837134

ABSTRACT

Apoptosis of neutrophils and their subsequent phagocytosis is critical to the successful resolution of inflammation. During inflammation, activated inflammatory cells generate reactive oxygen and nitrogen species, including nitric oxide (NO) and superoxide anion (O(2)(•-)), which rapidly combine to generate peroxynitrite (ONOO(-)). NO and ONOO(-) are proapoptotic in human neutrophils. This study examines the effects of NO and ONOO(-) on caspase activation and mitochondrial permeability in human neutrophils and determines the ability of these species to evoke apoptosis in human monocyte-derived macrophages (MDMs). NO or ONOO(-) release from donor compounds was characterized by electrochemistry and electron paramagnetic resonance. Neutrophils and MDMs isolated from the peripheral blood of healthy volunteers were exposed to NO or ONOO(-) before analysis of apoptosis by caspase activation, mitochondrial permeability, and annexin V binding. Both NO and ONOO(-) induced apoptosis via rapid activation of caspases 2 and 3 in neutrophils. In contrast, only ONOO(-) promoted apoptosis in MDMs, whereas a variety of NO donors were ineffective at inducing apoptosis in this cell type. We propose that human macrophages are refractory to NO-stimulated apoptosis in order that they persist long enough within the inflammatory focus to phagocytose apoptotic neutrophils, thereby ensuring successful resolution of inflammation.


Subject(s)
Apoptosis/drug effects , Drug Resistance , Inflammation/pathology , Macrophages/drug effects , Neutrophils/drug effects , Nitric Oxide/pharmacology , Caspases/metabolism , Cells, Cultured , Drug Resistance/immunology , Drug Resistance/physiology , Electrochemistry , Evoked Potentials/drug effects , Evoked Potentials/physiology , Humans , Inflammation/immunology , Macrophages/immunology , Macrophages/pathology , Mitochondria/drug effects , Mitochondria/metabolism , Neutrophils/immunology , Neutrophils/pathology , Nitric Oxide Donors/pharmacology , Permeability/drug effects , Peroxynitrous Acid/pharmacology
6.
J Neurosci ; 30(10): 3782-92, 2010 Mar 10.
Article in English | MEDLINE | ID: mdl-20220013

ABSTRACT

Death receptor 3 is a proinflammatory member of the immunomodulatory tumor necrosis factor receptor superfamily, which has been implicated in several inflammatory diseases such as arthritis and inflammatory bowel disease. Intriguingly however, constitutive DR3 expression has been detected in the brains of mice, rats, and humans, although its neurological function remains unknown. By mapping the normal brain expression pattern of DR3, we found that DR3 is expressed specifically by cells of the neuron lineage in a developmentally regulated and region-specific pattern. Behavioral studies on DR3-deficient (DR3(ko)) mice showed that constitutive neuronal DR3 expression was required for stable motor control function in the aging adult. DR3(ko) mice progressively developed behavioral defects characterized by altered gait, dyskinesia, and hyperactivity, which were associated with elevated dopamine and lower serotonin levels in the striatum. Importantly, retrograde tracing showed that absence of DR3 expression led to the loss of corticostriatal innervation without significant neuronal loss in aged DR3(ko) mice. These studies indicate that DR3 plays a key nonredundant role in the retention of normal motor control function during aging in mice and implicate DR3 in progressive neurological disease.


Subject(s)
Aging/physiology , Cerebral Cortex/metabolism , Corpus Striatum/metabolism , Motor Skills/physiology , Receptors, Tumor Necrosis Factor, Member 25/physiology , Aging/genetics , Animals , Cell Communication/genetics , Cell Communication/physiology , Cerebral Cortex/growth & development , Cerebral Cortex/physiology , Corpus Striatum/growth & development , Corpus Striatum/physiology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Neurotransmitter Agents/deficiency , Neurotransmitter Agents/genetics , Neurotransmitter Agents/physiology , Receptors, Tumor Necrosis Factor, Member 25/deficiency , Receptors, Tumor Necrosis Factor, Member 25/genetics
7.
Chem Res Toxicol ; 22(4): 717-25, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19338340

ABSTRACT

2,3-dimethoxy-1,4-naphthoquinone (CAS-RN 6959-96-3) (DMNQ) and 2-methyl-1,4-naphthoquinone (CAS-RN 58-27-5) (MNQ:menadione) are effective one electron redox cycling chemicals in vitro. In addition, in vitro MNQ forms a thioether conjugate with glutathione by nucleophilic attack at the third carbon. In contrast, here we demonstrate that in vivo the major metabolic route is directly to the dihydronaphthoquinone for both DMNQ and MNQ followed by conjugation to mono- and di-glucuronides and sulfate. Analysis of urine and bile showed that glutathione conjugation of MNQ was only a very minor route of metabolism. DMNQ was distributed to all tissues including the brain, and MNQ was much less widely distributed. For DMNQ tissue half-life, in particular for the heart, was considerably longer than the plasma half-life. For both DMNQ and MNQ, urine 8-oxo-7,8-dihydro-2'-deoxyguanosine and liver transcriptomic analysis failed to show any evidence of redox stress. Oxidized glutathione (GSSG) in liver increased significantly at the 10 min postdosing time point only. Metabonomic analysis 96 h after DMNQ administration indicated decreased liver glucose and increased lactate and creatine suggesting an impairment of oxidative metabolism. We conclude that in vivo DMNQ and MNQ are primarily two electron reduced to the dihydronaphthoquinones and undergo little one electron redox cycling. For DMNQ, disruption of cellular oxidative metabolism may be a primary mechanism of toxicity rather than redox stress.


Subject(s)
Liver/metabolism , Naphthoquinones/pharmacokinetics , Vitamin K 3/pharmacokinetics , Animals , Chromatography, Liquid , Creatinine/urine , Electrons , Liver/drug effects , Male , Metabolomics , Mice , Mice, Inbred C57BL , Naphthoquinones/administration & dosage , Naphthoquinones/metabolism , Oxidative Stress , Tandem Mass Spectrometry , Tissue Distribution , Transcription, Genetic , Vitamin K 3/administration & dosage , Vitamin K 3/metabolism
8.
Curr Opin Drug Discov Devel ; 12(1): 72-80, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19152215

ABSTRACT

Genomics encompasses a range of powerful technologies that can be applied at all levels of gene expression, from transcription to mRNA translation. Collectively, these technologies have great potential for improving drug discovery, both target and molecule recognition, and development. In this article we review the current and potential future status of established and novel genomic methods within drug discovery.


Subject(s)
Drug Design , Drug Industry/methods , Drug-Related Side Effects and Adverse Reactions , Genomics/methods , Toxicology/methods , Gene Expression Profiling , Oligonucleotide Array Sequence Analysis
9.
Attach Hum Dev ; 10(2): 143-63, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18773316

ABSTRACT

This study assessed attachment security in adults with high-functioning autism spectrum disorders, using the Adult Attachment Interview (AAI; George, Kaplan, & Main, 1996). Of 20 participants, three were classified as securely attached, the same proportion as would be expected in a general clinical sample. Participants' AAIs were less coherent and lower in reflective function than those of controls, who were matched for attachment status and mood disorder. A parallel interview suggested that some aspects of participants' responses were influenced by their general discourse style, while other AAI scale scores appeared to reflect their state of mind with respect to attachment more specifically. There was little evidence that attachment security was related to IQ, autistic symptomatology or theory of mind. This study suggests that adults with autism can engage with the AAI and produce scoreable narratives of their attachment experiences, and a minority demonstrate secure attachment.


Subject(s)
Asperger Syndrome/psychology , Object Attachment , Adult , Female , Humans , Interviews as Topic , Male , Middle Aged , United Kingdom , Young Adult
10.
Toxicology ; 246(1): 34-9, 2008 Apr 03.
Article in English | MEDLINE | ID: mdl-18289762

ABSTRACT

microRNAs (miRNAs) are a large family of small regulatory RNA molecules found in all multicellular organisms. Since their discovery in 2001, there has been impressive progress in miRNA research, and a great deal is now known about the biosynthesis of miRNAs and their regulatory role in translation. It is becoming increasingly clear that miRNAs have fundamental roles to play in cellular responses to xenobiotic stress, the development of pathophysiological changes and other toxicological phenomenon such as susceptibility and resistance. Furthermore, the expression of miRNAs, like many of the genes important in toxicology, can be regulated by xenobiotics and DNA methylation. In this article we review the present understanding of the miRNA field with particular reference to toxicology. We also give an insight into our current projects within this exciting area and highlight some of the new challenges that now face miRNA research.


Subject(s)
Gene Regulatory Networks/physiology , MicroRNAs/physiology , Protein Biosynthesis/physiology , Toxicology/trends , Animals , MicroRNAs/biosynthesis , MicroRNAs/genetics
11.
Biochem Pharmacol ; 74(7): 1039-49, 2007 Oct 01.
Article in English | MEDLINE | ID: mdl-17681284

ABSTRACT

Apoptosis may be regulated by oxidants such as peroxynitrite (ONOO(-)). The tumour suppressor, p53, has been reported to play a crucial role in apoptosis induced by oxidants, therefore we assessed the ability of a ONOO(-) donor, GEA 3162, to activate caspases and induce mitochondrial permeability in a p53-deficient murine bone marrow cell line, Jaws II. Furthermore, these cells were stably transfected with Bcl-2, in order to investigate the impact of this survival protein on ONOO(-)-induced apoptosis. GEA 3162 activated caspases and induced loss of mitochondrial membrane potential in Jaws II cells. In particular, caspases 3 and 2 were activated, alongside minor activation of caspases 8 and 9, and apoptosis was partially dependent upon p38 MAP kinase activation, with little or no role for JNK. Overexpression of Bcl-2 abolished activation of all caspases and reduced the change in mitochondrial membrane potential. Thus, we have demonstrated that the ONOO(-) donor, GEA 3162, induces apoptosis in Jaws II murine myeloid cells despite lacking functional p53, via a pathway that principally involves caspases 2 and 3 and mitochondrial changes. This is blocked by overexpression of Bcl-2 via a mechanism that does not appear to merely reflect stabilisation of the mitochondrial membrane.


Subject(s)
Apoptosis/drug effects , Bone Marrow Cells/drug effects , Nitric Oxide Donors/pharmacology , Proto-Oncogene Proteins c-bcl-2/metabolism , Triazoles/pharmacology , Animals , Bone Marrow Cells/cytology , Bone Marrow Cells/metabolism , Caspases/metabolism , Cell Line , Cell Survival , Dose-Response Relationship, Drug , Enzyme Activation , Mice , Mitochondria/drug effects , Mitochondria/metabolism , Mitogen-Activated Protein Kinases/metabolism , Tumor Suppressor Protein p53/metabolism
12.
Methods Mol Biol ; 412: 177-200, 2007.
Article in English | MEDLINE | ID: mdl-18453112

ABSTRACT

Neutrophil-derived granule enzymes, oxidants, and mediators have been implicated in the pathogenesis of a variety of inflammatory diseases. Neutrophil apoptosis is associated with the loss of expression of adhesion molecules and greatly reduced responsiveness to external stimuli, so that these cells become functionally isolated from their environment. In contrast with necrosis, apoptosis is associated with preservation of plasma membrane integrity, so that release of harmful neutrophil contents is limited, and the inert neutrophils are phagocytosed by local macrophages. Furthermore, phagocytosis of apoptotic neutrophils by human macrophages in vitro suppresses release of macrophage-derived pro-inflammatory mediators. In this way, by downregulating neutrophil functions and triggering "silent" clearance by phagocytes, apoptosis provides a mechanism for the safe disposal of potentially destructive inflammatory cells. Many of the molecular events involved in the apoptosis pathway have been identified and several complementary methods may be employed to identify and quantitate neutrophil apoptosis. This chapter will discuss analysis of neutrophil morphology, DNA fragmentation, membrane changes, mitochondrial alterations, caspase activation, and phagocytosis of apoptotic neutrophils by macrophages.


Subject(s)
Apoptosis , Neutrophils/physiology , Apoptosis/physiology , Blotting, Western , Caspases/metabolism , Cell Membrane/physiology , Centrifugation/instrumentation , Centrifugation/methods , DNA Fragmentation , Electrophoresis, Agar Gel , Fluorometry/methods , Humans , Microscopy, Polarization/methods , Mitochondria/metabolism , Neutrophils/metabolism , Permeability , Phagocytosis/physiology , Reagent Kits, Diagnostic , Staining and Labeling/methods
13.
Curr Drug Targets Inflamm Allergy ; 4(4): 447-54, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16101521

ABSTRACT

The accumulation of neutrophils during inflammation is essential for the destruction and removal of invading microorganisms. However, for resolution of inflammation to occur, neutrophils must also be removed from the inflammatory site since these cells are capable of releasing tissue toxic molecules. Neutrophil removal has been shown to occur via apoptosis and phagocyte clearance of apoptotic cells. Therefore, manipulation of these processes is likely to be a key therapeutic strategy in the management of inflammatory disease. In this review, we examine mediators of neutrophil survival and apoptosis and the signalling pathways that regulate the balance between life and death in these cells.


Subject(s)
Apoptosis/physiology , Cell Movement/drug effects , Inflammation/pathology , Neutrophils/physiology , Animals , Apoptosis/drug effects , Humans , Neutrophils/drug effects , Neutrophils/pathology , Signal Transduction/drug effects , Signal Transduction/physiology
14.
Mem Inst Oswaldo Cruz ; 100 Suppl 1: 67-71, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15962101

ABSTRACT

The ubiquitous free radical, nitric oxide (NO), plays an important role in many biological processes including the regulation of the inflammatory response. Alterations in NO synthesis by endogenous systems likely influence inflammatory processes occurring in a wide range of diseases including many in the cardiovascular system (e.g. atherosclerosis). Progression of inflammatory conditions depends not only upon the recruitment and activation of inflammatory cells but also upon their subsequent removal from the inflammatory milieu. Apoptosis, or programmed cell death, is a fundamental process regulating inflammatory cell survival and is critically involved in ensuring the successful resolution of an inflammatory response. Apoptosis results in shutdown of secretory pathways and renders effete, but potentially highly histotoxic, cells instantly recognisable for non-inflammatory clearance by phagocytes (e.g., macrophages). However, dysregulation of apoptosis and phagocytic clearance mechanisms can have drastic consequences for development and resolution of inflammatory processes. In this review we highlight the complexities of NO-mediated regulation of inflammatory cell apoptosis and clearance by phagocytes and discuss the molecular mechanisms controlling these NO mediated effects. We believe that manipulation of pathways involving NO may have previously unrecognised therapeutic potential for limiting or resolving inflammatory and cardiovascular disease.


Subject(s)
Apoptosis/physiology , Arteriosclerosis/physiopathology , Inflammation/physiopathology , Nitric Oxide/physiology , Arteriosclerosis/etiology , Homeostasis/physiology , Humans , Inflammation/etiology
15.
Mem. Inst. Oswaldo Cruz ; 100(supl.1): 67-71, Mar. 2005. ilus
Article in English | LILACS | ID: lil-402178

ABSTRACT

The ubiquitous free radical, nitric oxide (NO), plays an important role in many biological processes including the regulation of the inflammatory response. Alterations in NO synthesis by endogenous systems likely influence inflammatory processes occurring in a wide range of diseases including many in the cardiovascular system (e.g. atherosclerosis). Progression of inflammatory conditions depends not only upon the recruitment and activation of inflammatory cells but also upon their subsequent removal from the inflammatory milieu. Apoptosis, or programmed cell death, is a fundamental process regulating inflammatory cell survival and is critically involved in ensuring the successful resolution of an inflammatory response. Apoptosis results in shutdown of secretory pathways and renders effete, but potentially highly histotoxic, cells instantly recognisable for non-inflammatory clearance by phagocytes (e.g., macrophages). However, dysregulation of apoptosis and phagocytic clearance mechanisms can have drastic consequences for development and resolution of inflammatory processes. In this review we highlight the complexities of NO-mediated regulation of inflammatory cell apoptosis and clearance by phagocytes and discuss the molecular mechanisms controlling these NO mediated effects. We believe that manipulation of pathways involving NO may have previously unrecognised therapeutic potential for limiting or resolving inflammatory and cardiovascular disease.


Subject(s)
Humans , Apoptosis/physiology , Arteriosclerosis/physiopathology , Inflammation/physiopathology , Nitric Oxide/physiology , Arteriosclerosis/etiology , Homeostasis/physiology , Inflammation/etiology
16.
Br J Pharmacol ; 143(1): 179-85, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15289284

ABSTRACT

1. GEA 3162 (1,2,3,4,-oxatriazolium, 5-amino-3-(3,4-dichlorophenyl)-chloride), has powerful effects on neutrophil function and apoptosis, but the underlying mechanisms are unclear, particularly with respect to the possible roles of nitric oxide (NO) and/or peroxynitrite (ONOO(-)). 2. Our hypothesis was that GEA 3162 is a generator of ONOO(-) and that its biological effects on neutrophil apoptosis differ from those of a conventional NO donor. The effects of GEA 3162 were compared to those of the established ONOO(-) donor, 3-morpholinosydnonimine (SIN-1), and the NO donor, diethylamine diazeniumdiolate (DEA/NO) in neutrophils from healthy volunteers. Electrochemical detection and electron paramagnetic resonance were used to define the NO-related species generated from these agents. 3. GEA 3162 and SIN-1 influence neutrophil apoptosis differently from DEA/NO. All three compounds induced morphological neutrophil apoptosis. However, both GEA 3162 and SIN-1 paradoxically inhibited internucleosomal DNA fragmentation, whereas DEA/NO induced fragmentation compared to control. 4. In contrast to DEA/NO, generation of free NO was not detectable in solutions of GEA 3162 or SIN-1 (100 microm). However, Cu/Zn superoxide dismutase (SOD; 50-750 U ml(-1)) unmasked NO generated from these compounds in a concentration-dependent manner. GEA 3162 and SIN-1 oxidised the O(2)(-)- and ONOO(-)-sensitive dye, dihydrorhodamine 123 (DHR 123; 1 microm), suggesting that ONOO(-) released from these compounds is responsible for oxidation of DHR 123. 5. We conclude that GEA 3162 is an ONOO(-) donor with pro-apoptotic properties that more closely resemble SIN-1 than the NO donor, DEA/NO. Moreover, unlike NO, ONOO(-) induces apoptosis in neutrophils via a mechanism that does not require DNA fragmentation.


Subject(s)
Apoptosis/drug effects , Molsidomine/analogs & derivatives , Neutrophils/drug effects , Nitric Oxide Donors/pharmacology , Peroxynitrous Acid/pharmacology , Superoxides/metabolism , Triazoles/metabolism , Triazoles/pharmacology , Cell Separation , Electrochemistry , Electron Spin Resonance Spectroscopy , Fluorescent Dyes , Humans , In Vitro Techniques , Molsidomine/pharmacology , Nitric Oxide/metabolism , Rhodamines
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