PubMed Health⌕ Search

Biomedical subjects

P Moss

Publications and source records attributed to P Moss.

At least 19 recordsLinked to original sources
PubMed2005

A distinct subset of chemokines dominates the mucosal chemokine response in inflammatory bowel disease.

BACKGROUND: Inflammatory bowel disease (IBD) is characterised by intense mucosal recruitment of activated leukocytes. Chemokines determine inflammatory leukocyte recruitment and retention. AIM: To compare expression of the entire chemokine family within colonic mucosa from IBD patients and uninflamed controls. METHODS: A microarray of cDNAs, representing every member of this superfamily and their cognate receptors, was hybridised with probes derived from colonoscopic biopsies. RESULTS: A distinct subset of chemokines, consisting of CXCLs 1-3 and 8 and CCL20, was upregulated in active colonic IBD, compared with uninflamed areas or tissue from controls. Increased expression of their cognate receptors, CXCR1, CXCR2 and CCR6, was confirmed by quantitative PCR and immunohistochemistry. An identical chemokine response was induced in Caco-2 cells by stimulation with interleukin (IL)-1beta, but not tumour necrosis factor-alpha (TNF-alpha). By contrast, IL-1beta and TNF-alpha were synergistic in an HT29 cell line and primary keratinocytes. CONCLUSIONS: IL-1beta and TNF-alpha appear to be the pivotal mediators of a previously unidentified coordinated epithelial chemokine response that dominates the mucosal chemokine environment in inflamed IBD tissue.

Caco-2 Cells↗
PubMed2005

Leptospirosis: a case report of a patient with pulmonary haemorrhage successfully managed with extra corporeal membrane oxygenation.

Leptospirosis is a zoonosis of worldwide significance. Pulmonary involvement is common but often mild and of little clinical significance. However, over the last two decades an increasing number of cases have been reported with pulmonary haemorrhage as a prominent feature [Carvalho CR, Bethlem EP. Pulmonary complications of leptospirosis. Clin Chest Med, 2002;23(2):469-78]. These cases are particularly challenging to treat as they often have resistant hypoxaemia despite maximal invasive mechanical ventilation. Consequently, there is a high mortality rate. Here, we present a case of severe leptospirosis complicated by massive pulmonary haemorrhage which was successfully managed by extra corporeal membrane oxygenation (ECMO).

Adult↗
PubMed2004

Investigation of systems to prevent diversion of opiate drugs in general practice in the UK.

BACKGROUND: Statutory regulations govern the procedures that must be followed by general practitioners (GPs) in the UK to minimise the risk of diversion of prescribed opiate drugs for illicit use. However, evidence presented at the trial of Harold Shipman, a GP convicted of murdering patients with diamorphine, suggests that the regulations and monitoring of GPs' prescribing are failing. AIM: To assess the policies followed by general practices in Leicestershire and Rutland with regard to the controlled drugs regulations. METHODS: A semi-structured interview was administered to a purposeful sample of lead GPs to explore how their practices applied the regulations. The controlled drugs registers and drug storage facilities in these practices were inspected. A questionnaire was sent to all the remaining practices to seek information about their application of the regulations, any concerns they had about the regulations, and any suggestions for improving them. RESULTS: Of the 142 general practices in Leicestershire, the lead GP in 14 took part in the interviews. Respondents expressed dissatisfaction with current policies including the design of controlled drug registers, and generally supported the reintroduction of an inspection scheme. Ninety (70.9%) of the 127 practices to whom the questionnaire was sent responded and, of these, 31 (34.4%) no longer held a supply of controlled drugs. Those that did hold controlled drugs indicated concern about the regulations, confusion about some aspects including the return and disposal of unused drugs, and a desire for advice and support in the implementation of the regulations. Forty two of the 59 respondents who held a supply of controlled drugs (71.2%) would welcome regular inspection. CONCLUSION: GPs are confused about the controlled drugs regulations and have little support in implementing them. The suspension of inspection schemes has reduced the amount of advice and support available to them and, in consequence, the regulations are interpreted differently in different practices. These findings are cause for concern about the risk of diversion of controlled drugs, and illustrate how patient safety systems can decay when they are not maintained.

Drug and Narcotic Control↗
PubMed2003

Cellular immune responses to influenza.

Cellular immune responses are believed to play an important role in controlling influenza infection. CD4+ and CD8+ T cell responses are well described and CD8+ immunity is of paramount importance in killing virally infected cells. In the past few years several novel techniques have been devised which allow quantification of antigen-specific cellular immune responses and these will be reviewed briefly. Influenza-specific cellular immunity is elicited following natural infection and several viral proteins have been identified as targets for cellular responses. Cellular immunity is detectable throughout life in most donors but there is clear evidence of impaired cellular immunity in the elderly, a population at particular risk of influenza infection. This finding must be viewed against the background of 'immune senescence' that is documented with aging. Cellular responses are able to provide heterosubtypic immunity to influenza viral antigens. As such the induction of cellular immune responses is a highly desirable aim of vaccination protocols. Induction of cellular immunity with conventional formalin-inactivated vaccine is poor although some improvement may be derived from novel forms of vaccine delivery such as the use of adjuvanted carriers. Nevertheless, a range of new vaccines is being developed which are more effective in priming cellular responses. Although there is relatively little detail on the nature of the cellular response induced by these agents, they hold out the promise of more effective and durable protection from influenza infection.

Adjuvants, Immunologic↗
PubMed2001

Developments in the treatment of post-transplant viral disease.

Stem cell transplantation is a potentially curative procedure for many types of haemopoietic malignancy but is associated with a period of intense immunosuppression which may last for 1 to 2 years. During this time new viral infections or reactivation of endogenous, latent virus can lead to a variety of clinical symptoms which, together, make a significant contribution to the morbidity and mortality of the procedure. Improvements in viral detection, prophylaxis and treatment of established disease are helping to minimize the clinical impact of viral disease, but a definitive solution to this problem must await improvements in our ability to reconstitute an effective immune system. Each of the viruses implicated in post-transplant disease has a unique relationship with the host immune system, and there is every hope that improvements in our understanding of viral immunology will be translated into more effective clinical control.

Herpesviridae Infections↗
PubMed2000

Influenza virus lung infection protects from respiratory syncytial virus-induced immunopathology.

The effect of infection history is ignored in most animal models of infectious disease. The attachment protein of respiratory syncytial virus (RSV) induces T helper cell type 2-driven pulmonary eosinophilia in mice similar to that seen in the failed infant vaccinations in the 1960s. We show that previous influenza virus infection of mice: (a) protects against weight loss, illness, and lung eosinophilia; (b) attenuates recruitment of inflammatory cells; and (c) reduces cytokine secretion caused by RSV attachment protein without affecting RSV clearance. This protective effect can be transferred via influenza-immune splenocytes to naive mice and is long lived. Previous immunity to lung infection clearly plays an important and underestimated role in subsequent vaccination and infection. The data have important implications for the timing of vaccinations in certain patient groups, and may contribute to variability in disease susceptibility observed in humans.

Animals↗
PubMed2000

Sequencing and expression analysis of the serine protease gene cluster located in chromosome 19q13 region.

The human kallikrein gene cluster, located in the chromosome band 19q13, contains several tissue-specific serine protease genes including the prostate-specific KLK2, KLK3 and prostase genes. To further characterize the gene cluster, we have mapped, sequenced, and analyzed the genomic sequence from the region. The results of EST database searches and GENSCAN gene prediction analysis reveal 13 serine protease genes and several pseudogenes in the region. Expression analysis by RT-PCR indicates that most of these protease genes are expressed only in a subset of the 35 different normal tissues that have been examined. Several protease genes expressed in skin show higher expression levels in psoriatic lesion samples than in non-lesional skin samples from the same patient. This suggests that the imbalance of a complex protease cascade in skin may contribute to the pathology of disease. The proteases, excluding the kallikrein genes, share approximately 40% of their sequences suggesting that the serine protease gene cluster on chromosome 19q13 arose from ancient gene duplications.

Amino Acid Sequence↗
PubMed2000

HLA class I-minor histocompatibility antigen tetramers select cytotoxic T cells with high avidity to the natural ligand.

INTRODUCTION: Cytotoxic T cells specific for the hematopoietic system-restricted minor histocompatibility antigens HA-1 and HA-2 are potential tools for the treatment of relapsed leukemia after minor histocompatibility antigen mismatched bone marrow transplantation. HA-1/HA-2-specific cytotoxic T cells with strong cytotoxic activity against HA-1/HA-2 positive target cells can be generated in vitro using HA-1 and HA-2 peptide-pulsed dendritic cells as antigen presenting cells. MATERIAL AND METHODS: We used HLA-A2 HA-1/HA-2 tetramers (HA-1(A2)/HA-2(A2) tetramers) to monitor the in vitro generation of HA-1- or HA-2-specific cytotoxic T cells. RESULTS: We show that the intensity of the tetramer-staining of the HA-1/HA-2-specific cytotoxic T cells strongly correlates with their capability to recognize mHag positive target cells. The bright tetramer-staining cytotoxic T cells lyse target cells expressing the natural ligand. The dim tetramer-staining cytotoxic T cells fail to lyse natural ligand positive target cells and lyse peptide-pulsed target cells only. The frequency of bright tetramer-staining, high avidity minor histocompatibility antigen-specific CTLs increases significantly upon appropriate antigen-specific restimulations. CONCLUSION: Our results demonstrate that HLA class I-minor histocompatibility antigen tetramers are useful tools for monitoring and selection of high avidity HA-1- and HA-2-specific cytotoxic T cells for adoptive immunotherapy.

Antigen Presentation↗
PubMed1999

T cell responses to D-penicillamine in drug-induced myasthenia gravis: recognition of modified DR1:peptide complexes.

The anti-rheumatoid drug D-penicillamine (D-pen) has a reactive sulfhydryl group capable of modifying self antigens, and can provoke typical autoantibody-mediated myasthenia gravis (MG), especially in DR1+ individuals. We have selected T cell clones from one such patient that were highly specific for D-pen but not its L-isomer or D-cysteine. Moreover, they were restricted to HLA-DR1, had a Th1 phenotype and used TCR V alpha4.1, V beta6.1. They responded well to blood mononuclear cells prepulsed with D-pen either in the absence of serum or after chloroquine treatment, but not to autologous D-pen-pulsed B cell lines. Thus, D-pen may directly couple to distinctive peptides resident in surface DR1 molecules on circulating macrophages or dendritic cells.

Aged↗
PubMed1999

Molecular cloning and characterization of prostase, an androgen-regulated serine protease with prostate-restricted expression.

The identification of genes with selective expression in specific organs or cell types provides an entry point for understanding biological processes that occur uniquely within a particular tissue. Using a subtraction approach designed to identify genes preferentially expressed in specific tissues, we have identified prostase, a human serine protease with prostate-restricted expression. The prostase cDNA encodes a putative 254-aa polypeptide with a conserved serine protease catalytic triad and an amino-terminal pre-propeptide sequence, indicating a potential secretory function. The genomic sequence comprises five exons and four introns and contains multiple copies of a chromosome 19q-specific minisatellite repeat. Northern analysis indicates that prostase mRNA is expressed in hormonally responsive normal and neoplastic prostate epithelial tissues, but not in prostate stromal constituents. Prostase shares 35% amino acid identity with prostate-specific antigen (PSA) and 78% identity with the porcine enamel matrix serine proteinase 1, an enzyme involved in enamel matrix degradation and with a putative role in the disruption of intercellular junctions. Radiation-hybrid-panel mapping localized prostase to chromosome 19q13, a region containing several other serine proteases, including protease M, pancreatic/renal kallikrein hK1, and the prostate-specific kallikreins hK2 and hK3 (PSA). The sequence homology between prostase and other well-characterized serine proteases suggests several potential functional roles for the prostase protein that include the degradation of extracellular matrix and the activation of PSA and other proteases.

Amino Acid Sequence↗
PubMed1999

New ultraviolet signal actuated switching valve for the measurement of low level impurities by liquid chromatography/mass spectrometry.

A new ultraviolet (UV) signal actuated switching valve for diverting the main matrix compound to waste, preventing it entering the ion source of the mass spectrometer is described. Sensitivity for trace impurities eluting after the drug substance cimetidine or related compounds could be enhanced by a factor of 4-5. The increase in sensitivity was dependent on the type of ion source which interfaced the mass spectrometer. The benefit of the switching valve was greater with a line of sight type source than with an orthogonal one. The detection limit for a trace compound in a matrix compound was improved by up to a factor of 10 with the line of sight type source but only by a factor of 5 with the orthogonal source.

Cimetidine↗
PubMed1999

Early-onset myasthenia gravis: a recurring T-cell epitope in the adult-specific acetylcholine receptor epsilon subunit presented by the susceptibility allele HLA-DR52a.

No immunodominant T-cell epitopes have yet been reported in the human acetylcholine receptor (AChR), the target of the pathogenic autoantibodies in myasthenia gravis (MG). We have selected and characterized T cells from MG patients by restimulation in culture with recombinant human AChR to alpha, gamma and epsilon subunits; the gamma and epsilon distinguish the fetal and adult AChR isoforms, respectively. We obtained clones specific for the epsilon, rather than the alpha or gamma, subunit in 3 of the first 4 early-onset MG cases tested. They all responded to peptide epsilon201-219 and to low concentrations of adult but not fetal AChR. Moreover, although using different T-cell receptor genes, they were all restricted to HLA-DR52a (DRB3*0101), a member of the strongly predisposing HLA-A1-B8-DR3 haplotype. This apparently immunodominant epsilon201-219 epitope (plus DR52a) was also recognized by clones from an elderly patient whose MG had recently been provoked by the drug D-penicillamine. In all 4 cases, however, the serum antibodies reacted better with fetal than adult AChR and may thus be end products of determinant spreading initiated by adult AChR-specific T cell responses. Furthermore, as these T cells had a pathogenic Th1 phenotype, with the potential to induce complement-activating antibodies, they should be important targets for selective immunotherapy.

Amino Acid Sequence↗
PubMed1999

Tetrameric HLA class I-minor histocompatibility antigen peptide complexes demonstrate minor histocompatibility antigen-specific cytotoxic T lymphocytes in patients with graft-versus-host disease.

Graft-versus-host disease (GvHD) is a chief complication of allogeneic bone marrow transplantation. In HLA-identical bone marrow transplantation, GvHD may be induced by disparities in minor histocompatibility antigens (mHags) between the donor and the recipient, with the antigen being present in the recipient and not in the donor. Cytotoxic T lymphocytes (CTLs) specific for mHags of the recipients can be isolated from the blood of recipients with severe GvHD (ref. 3). A retrospective study demonstrated an association between mismatch for mHags HA-1, -2, -4 and -5 and the occurrence of GvHD in adult recipients of bone marrow from HLA genotypically identical donors. Tetrameric HLA-peptide complexes have been used to visualize and quantitate antigen-specific CTLs in HIV-infected individuals and during Epstein-Barr virus and lymphocytic choriomeningitis virus infections. Here we show the direct ex vivo visualization of mHag-specific CTLs during GvHD using tetrameric HLA-class and I-mHag HA-1 and HY peptide complexes. In the peripheral blood of 17 HA-1 or HY mismatched marrow recipients, HA-1- and HY-specific CTLs were detected as early as 14 days after bone marrow transplantation. The tetrameric complexes demonstrated a significant increase in HA-1- and HY-specific CTLs during acute and chronic GvHD, which decreased after successful GvHD treatment. HLA class I-mHag peptide tetramers may serve as clinical tools for the diagnosis and monitoring of GvHD patients.

Adult↗
PubMed1999

Decay kinetics of human immunodeficiency virus-specific effector cytotoxic T lymphocytes after combination antiretroviral therapy.

Little is known of the changes in human immunodeficiency virus type 1 (HIV-1)-specific effector cytotoxic T lymphocytes (CTL) after potent antiretroviral therapy. Using HLA/peptide tetrameric complexes, we show that after starting treatment, there are early rapid fluctuations in the HIV-1-specific CTL response which last 1 to 2 weeks. These fluctuations are followed by an exponential decay (median half-life, 45 days) of HIV-1-specific CTL which continues while viremia remains undetectable. These data have implications for the immunological control of drug-resistant virus.

ADP-ribosyl Cyclase↗
PubMed1998

A pathogenetic role for the thymoma in myasthenia gravis. Autosensitization of IL-4- producing T cell clones recognizing extracellular acetylcholine receptor epitopes presented by minority class II isotypes.

Myasthenia gravis (MG) is caused by helper T cell-dependent autoantibodies against the muscle acetylcholine receptor (AChR). Thymic epithelial tumors (thymomas) occur in 10% of MG patients, but their autoimmunizing potential is unclear. They express mRNAs encoding AChR alpha and epsilon subunits, and might aberrantly select or sensitize developing thymocytes or recirculating peripheral T cells against AChR epitopes. Alternatively, there could be defective self-tolerance induction in the abundant maturing thymocytes that they usually generate. For the first time, we have isolated and characterized AChR-specific T cell clones from two MG thymomas. They recognize extracellular epitopes (alpha75-90 and alpha149-158) which are processed very efficiently from muscle AChR. Both clones express CD4 and CD8alpha, and have a Th-0 cytokine profile, producing IL-4 as well as IFN-gamma. They are restricted to HLA-DP14 and DR52a; expression of these minority isotypes was strong on professional antigen-presenting cells in the donors' tumors, although it is generally weak in the periphery. The two clones' T cell receptor beta chains are different, but their alpha chain sequences are very similar. These resemblances, and the striking contrasts with T cells previously cloned from non-thymoma patients, show that thymomas generate and actively induce specific T cells rather than merely failing to tolerize them against self antigens.

Amino Acid Sequence↗