Search PubMed⌕ Search

Biomedical subjects

P Price

Publications and source records attributed to P Price.

At least 55 records · Page 3Linked to original sources
PubMed2003

Expression of RANKL and OPG mRNA in periodontal disease: possible involvement in bone destruction.

Periodontitis is a complex, multifactorial process affected by bacterial plaque-components and host defense mechanisms. Inflammation of the periodontitium may lead the destruction of the underlying ligament and alveolar bone. Receptor activator of NF-kappaB ligand (RANKL), a novel TNF receptor-related protein is an important factor for osteoclast differentiation and activation. Given osteolysis by osteoclast has been demonstrated in periodontitis, we hypothesized that RANKL expression may be associated with bone destruction in periodontitis. We used semi-quantitative RT-PCR to compare the gene expression of RANKL and osteoprogerin (OPG), a decoy receptor of RANKL, between moderate and advanced periodontitis, and healthy subjects. The level of RANKL mRNA was highest in advanced periodontitis. In contrast, the level of OPG mRNA in both advanced and moderate periodontitis was lower than that in the healthy group. It appears that the ratio of RANKL to OPG mRNA in periodontitis has increased. To determine the localization of RANKL gene transcripts in gingival tissue at the cellular level, in situ hybridization was performed using digoxigenin-labeled specific riboprobes. RANKL mRNA was expressed in inflammatory cells, mainly lymphocyte and macrophages. In addition, proliferating epithelium in the vicinity of inflammatory cells expressed high levels of RANKL mRNA. In short, our data suggest that up regulation of RANKL mRNA in both inflammatory cells and epithelium may be associated with the activation of osteoclastic bone destruction in periodontitis.

Adult↗
PubMed2002

Phase II study to evaluate combining gemcitabine with flutamide in advanced pancreatic cancer patients.

A phase II study was undertaken to determine the safety of combining flutamide with gemcitabine, with response rate being the primary end point. Twenty-seven patients with histologically proven, previously untreated, unresectable pancreatic adenocarcinoma received gemcitabine, 1 g m(-2) intravenously on days 1, 8 and 15 of a 28 day cycle, and flutamide 250 mg given orally three times daily. Treatment was halted if there was unacceptable toxicity, or evidence of disease progression. Toxicity was documented every cycle. Tumour assessment was undertaken after cycles 2 and 4, and thereafter at least every additional four cycles. One hundred and seventeen cycles of treatment were administered, median four cycles per patient (range 1-18). Gemcitabine combined with flutamide was well tolerated, with most toxicities being recorded as grade 1 or 2 and only nine treatment cycles associated with grade 3 toxicity. The most frequent toxicity was myelosuppression. One case of transient jaundice was recorded. The commonest symptomatic toxicity was nausea and vomiting. The response rate was 15% (four partial responses), median survival 6 months and 22% of patients were alive at 1 year. These results suggest antitumour activity of the combination therapy to be equivalent to single agent gemcitabine.

Adult↗
PubMed2002

Use of radiolabelled choline as a pharmacodynamic marker for the signal transduction inhibitor geldanamycin.

There is an urgent need to develop non-invasive pharmacodynamic endpoints for the evaluation of new molecular therapeutics that inhibit signal transduction. We hypothesised that, when labelled appropriately, changes in choline kinetics could be used to assess geldanamycin pharmacodynamics, which involves inhibition of the HSP90 molecular chaperone-->Raf1-->Mitogenic Extracellular Kinase-->Extracellular Signal-Regulated Kinase 1 and 2 signal transduction pathway. Towards identifying a potential pharmacodynamic marker response, we have studied radiolabelled choline metabolism in HT29 human colon carcinoma cells following treatment with geldanamycin. We studied the effects of geldanamycin, on net cellular accumulation of (methyl-(14)C)choline and (methyl-(14)C)phosphocholine production. In parallel experiments, the effects of geldanamycin on extracellular signal-regulated kinase 1 and 2 phosphorylation and cell viability were also assessed. Additional validation studies were carried out with the mitogenic extracellular kinase inhibitor U0126 as a positive control; a cyclin-dependent kinase-2 inhibitor roscovitine and the phosphatidylinositol 3-kinase inhibitor LY294002 as negative controls. Hemicholinium-3, an inhibitor of choline transport and choline kinase activity was included as an additional control. In exponentially growing HT29 cells, geldanamycin inhibited extracellular signal-regulated kinase 1 and 2 phosphorylation in a concentration- and time-dependent manner. These changes were associated with a reduction in (methyl-(14)C)choline uptake, (methyl-(14)C) phosphocholine production and cell viability. Brief exposure to U0126, suppressed phosphocholine production to the same extent as Hemicholinium-3. In contrast to geldanamycin and U0126, which act upstream of extracellular signal-regulated kinase 1 and 2, roscovitine and LY294002 failed to suppress phosphocholine production. Our results suggest that when labelled with carbon-11 isotope, (methyl-(11)C)choline may be a useful pharmacodynamic marker for the non-invasive evaluation of geldanamycin analogues.

Benzoquinones↗
PubMed2002

Cancer Research UK procedures in manufacture and toxicology of radiotracers intended for pre-phase I positron emission tomography studies in cancer patients.

Radiolabelled compounds formulated for injection (radiopharmaceuticals), are increasingly being employed in drug development studies. These can be used in tracer amounts for either pharmacokinetic or pharmacodynamic studies. Such radiotracer studies can also be carried out early in man, even prior to conventional Phase I clinical testing. The aim of this document is to describe procedures for production and safety testing of oncology radiotracers developed for imaging by positron emission tomography in cancer patients. We propose strategies for overcoming the inability to produce compounds in sufficient quantities via the radiosynthetic routes for full chemical characterisation and toxicology testing including (i) independent confirmation as far as possible that the stable compound associated with the radiopharmaceutical is identical to the non-labelled compound, (ii) animal toxicity studies with > or = 10 times (typically 100 times) the intended tracer dose in humans scaled by body surface area, and (iii) patient monitoring during the radiotracer positron emission tomography clinical trial.

Animals↗
PubMed2002

The EORTC Laboratory Research Division. European Organisation for Research and Treatment of Cancer.

The Laboratory Research Division (LRD) of the EORTC currently consists of five Groups with expertise that includes pre-clinical drug development, all aspects of cancer pharmacology, clinically-relevant receptor and biomarker studies, functional imaging and contemporary pathology. The LRD provides a Europewide resource for cancer clinical trials with particular expertise in the evolving field of translational research. In the development of therapies designed to exploit the molecular and cellular pathology of cancer, it is essential that translational research is included at all stages and the EORTC, through the LRD, has access to such expertise. In addition to providing support for drug development and clinical trials, the LRD represents a unique forum for the development of contemporary translational research expertise, the establishment of quality standards and the education of young laboratory and clinical scientists embarking on careers in oncology.

Europe↗
PubMed2002

Common HLA-B8-DR3 haplotype in Northern India is different from that found in Europe.

The aim of this study was to determine whether a common diabetic haplotype, including human leukocyte antigen (HLA)-B8 and HLA-DR3, in Northern India is the same haplotype as the European HLA-B8-DR3 haplotype. DNA samples from Northern Indian subjects selected on the basis of HLA-B8 and HLA-DR3 were tested for microsatellite and single nucleotide polymorphism alleles throughout the major histocompatibility complex (MHC). It was found that the Indian samples represent a conserved haplotype in which all alleles were shared by Indian subjects with HLA-B8 and HLA-DR3, but were different to those that are characteristic of the European 8.1 ancestral haplotype. The Indian and European haplotypes share HLA-B*0801, HLA-DRB1*0301 and HLA-DQB1*02 but differ for subtypes of HLA-Cw*07 and HLA-DRB3 and all central MHC alleles tested. In contrast, Indian subjects selected on the basis of HLA-B58 ( 1-17) and HLA-DR3 shared the same alleles at other MHC loci as have been described in the common Chinese haplotype with HLA-B58/17 and HLA-DR3. A third haplotype, HLA-B50/21 and HLA-DR3, was also found to be highly conserved but shares little in common with the other two HLA-DR3-containing Indian haplotypes.

Diabetes Mellitus, Type 1↗
PubMed2002

Levels of IL-6 and soluble IL-6 receptor are increased in HIV patients with a history of immune restoration disease after HAART.

OBJECTIVES: We have previously described immune restoration diseases (IRD) associated with asymptomatic opportunistic infections presenting in immunodeficient HIV patients responding to highly active antiretroviral therapy (HAART). Here we address the question of whether patients with a history of IRD exhibit persistent immune activation, shown by elevated levels of interleukin-(IL)-6 and soluble IL-6 receptor (sIL-6R). METHODS: Peripheral blood mononuclear cells (PBMCs) and plasma were collected from HIV patients with nadir CD4 T cell counts of < 80/microL and who had achieved immune reconstitution after HAART with (n=14) or without (n=15) experiencing IRD, severely immunodeficient (SID) patients with < 80 CD4 T cells/microL (n=8) and HIV seronegative controls (n=15). PBMC production and plasma levels of IL-6, sIL-6R and interferon (IFN)-gamma (PBMC only) were measured by enzyme linked immunosorbent assay (ELISA). Intracellular flow cytometry was used to determine the predominant cellular source of IL-6 in HIV patients and controls. RESULTS: Unstimulated PBMC from IRD patients produced significantly higher amounts of IL-6 and sIL-6R than non-IRD patients and HIV seronegative controls. The sIL-6R concentration was also significantly higher in supernatants from mitogen-stimulated PBMC from IRD patients compared to non-IRD patients. The production of IFN-gamma did not differ between IRD and non-IRD patients. IRD patients had significantly higher plasma levels of IL-6 compared to non-IRD patients, SID patients and controls. Monocytes were the predominant source of IL-6 in both HIV patients and controls. CONCLUSIONS: Patients with a history of IRD after HAART have elevated levels of IL-6 and sIL-6R.

Adult↗
PubMed2002

Interleukin-1 gene polymorphism disease activity and bone mineral metabolism in rheumatoid arthritis.

OBJECTIVE: To determine whether interleukin-1 alpha and 1 beta gene polymorphism is associated with rheumatoid arthritis disease activity and bone mineral metabolism, and whether there is any relationship between IL-1 beta and rheumatoid arthritis (RA) motif gene. METHODS: IL-1 gene polymorphisms were analyzed in 65 RA patients who met American College of Radiology (ACR) criteria and 60 controls. From genomic DNA, 2 polymorphisms in each gene for IL1 alpha-889 and IL-1 beta + 3953 were typed by PCR-RFLP and HLA-DRB1 allele typing was also undertaken by PCR-SSOP. Some clinical and laboratory parameters were collected. The allelic frequencies and carriage rates were compared between RA patients and controls and between patients with active and quiescent disease. Comparison was also made between IL-1 polymorphism and parameters of bone mineral metabolism and between patients with the HLA-DRB1 RA motif plus IL-1 beta 2 and patients without the two alleles. Fisher test and the analysis of variance was used to analyze the data. RESULTS: There was no significant difference in the frequency and carriage rate of IL-1 alpha polymorphisms between RA patients and the controls. The beta 2/2 genotype of IL-1 beta was more common in female RA patients compared with controls (P = 0.001). A lower carriage rate of IL-1 beta 2 occurred in male RA patients (P = 0.001). A higher carriage rate of IL-1 alpha 2 is associated with a higher ESR (P = 0.008), HAQ score (P = 0.03), and vit-D3 (P < 0.001), but conversely a lower SJC (p = 0.002), a lower RF (P = 0.002) and a lower BMD at the lumbar spine (P = 0.001). A higher frequency of IL-1 alpha 1 is associated with a lower CRP value (P = 0.009). An increased IL-1 beta 2 carriage is associated with active rheumatoid disease as indicated by a higher CRP (P < 0.001), ESR (P < 0.001) and pain score (P = 0.001) and a higher BMD at the lumbar spine (P = 0.007), lower vit-D3 and. Udpd/Crea level The presence of the HLA DRB1 RA motif and IL-1 beta allele 2 at same time did not contribute to disease activity. CONCLUSION: Polymorphisms of the IL-beta gene may affect the RA occurrence. Carriage of IL-1 beta 2 polymorphisms is associated with more active disease in RA and the presence of both the IL-1 alpha 2 and the IL-1 beta 1 allele in RA influences bone resorption.

Alleles↗
PubMed2001

Measuring changes in human tumour vasculature in response to therapy using functional imaging techniques.

Antiangiogenic and antivascular agents provide new approaches to treating tumours. These may avoid many of the problems experienced with current approaches such as inherent and acquired resistance to treatment. Tumours do not grow beyond 1-2 mm(3) in size without the development of new vessels (Folkman, 1971). Such neo-vascularization (angiogenesis) allows tumour cells to increase their nutrient supply, survive and proliferate despite the new vessels often having structural and functional differences compared to normal tissue vasculature. Treatments targeted at tumour vasculature have produced impressive results in animal models (Lindsay et al, 1996; Watson et al, 1996; O'Reilly, 1997; Horsman et al, 1998). These therapies are now entering clinical trials. However, the successful introduction of these therapies into clinical practice will require the development of reliable ways to assess angiogenesis and its modification or inhibition in vivo. Here we discuss some of the emerging imaging techniques that may be useful.

Diagnostic Imaging↗
PubMed2001

Plasma bioavailable interleukin-6 is elevated in human immunodeficiency virus-infected patients who experience herpesvirus-associated immune restoration disease after start of highly active antiretroviral therapy.

This study compared plasma bioavailable interleukin (IL)-6 levels in 3 groups: human immunodeficiency virus (HIV)-infected patients who had a human herpesvirus (HHV)-associated immune restoration disease (IRD) during highly active antiretroviral therapy (HAART); patients who experienced an IRD initiated by Mycobacterium avium complex, hepatitis C virus, or human papillomavirus; and control patients who had uneventful immune reconstitution. Total IL-6, soluble IL-6 receptor (sIL-6R), and soluble gp130 were measured by ELISA, and levels of free IL-6 and sIL-6/IL-6R complex were modeled mathematically. Persons who had an HHV-associated IRD had increased plasma bioavailable IL-6 before HAART, compared with patients who experienced a non-HHV-associated IRD and with control patients, and their plasma bioavailable IL-6 increased progressively over 3-4 years of treatment. Increased IL-6 production may be a feature of HAART-induced restoration of immune responses to HHV infections and may have long-term immunopathologic consequences.

Antiretroviral Therapy, Highly Active↗
PubMed2001

Percentage of CD3+CD4-CD8-gammadeltaTCR- T cells is increased HIV disease.

HIV patients given highly active antiretroviral therapy (HAART) experience a rapid rise in alphabetaT cell numbers, but changes in gammadeltaT cell populations have not been described. Here we investigate the effects of immune reconstitution and immune restoration diseases (IRDs) on expression of a pan-gammadeltaT cell receptor (TCR) marker on double-negative (CD3(+)CD4(-)CD8(-)) T cells and T cells expressing CD4 or CD8. IRDs are inflammatory disorders associated with preexisting infections in patients who have achieved immune reconstitution after HAART. Proportions of CD3(+)CD4(-)CD8(-) T cells and total gammadeltaT cells were not affected by CD4(+) T cell counts, HAART, or a history of IRD, but levels of CD4(-)CD8(-)gammadeltaTCR(-) T cells were higher in patients with <15% CD4(+) T cells.

Adult↗
PubMed2001

MHC haplotypes affect the expression of opportunistic infections in HIV patients.

This study explores whether MHC genes affect manifestations of opportunistic infections in HIV patients not treated with highly active antiretroviral therapy (HAART) and immunopathologic responses to pre-existing infections in patients who achieved immune reconstitution following HAART (i.e., "immune restoration diseases" or IRD). HLA-B27 and B17 were relatively rare in all HIV patients, but no HLA-B alleles significantly affected cytomegalovirus (CMV) or Mycobacterium avium complex (MAC) disease in patients who had not received HAART. However coexpression of alleles previously defined as the 44.1 ancestral haplotype (HLA-A2, -B44, and -DR4) was more common in the MAC and CMV patients. After HAART, HLA-B44 and (HLA-A2, -B44, -DR4) were found in 66% and 33%, respectively, of patients who experienced an IRD manifested as CMV retinitis and/or encephalomyelitis. This was confirmed by examination of microsatellite alleles, where the C1_2_5 locus in the class I region was most concordant with the 44.1 haplotype in the patients. HLA-B44 was not associated with IRD initiated by Mycobacterium sp, cutaneous VZV or HSV, or HCV infections, suggesting distinct pathologic mechanisms are responsible. CMV retinitis/encephalomyelitis IRD patients had marginally lower pretreatment CD4 T-cell counts, but indices of immune reconstitution were similar in all groups and independent of HLA-B44.

AIDS-Related Opportunistic Infections↗
PubMed2001

Localization of central MHC genes influencing type I diabetes.

The contribution of MHC class II haplotypes to susceptibility to type I diabetes has been clearly established, and interest has now focused on the effects of additional genes in the MHC region. We have investigated the central MHC alleles on 8.1 ancestral haplotype (HLA-A1, B8, DR3, DQ2), as it is well conserved in Caucasian populations. The HLA-DR3-DQ2 genotype is a recognized risk factor for type I diabetes. Single nucleotide polymorphisms and microsatellites in the MHC were used to map segments of the 8.1 ancestral haplotype carried by type I diabetic and control subjects expressing either HLA-B8 or DR3, but not both these markers. In this way we controlled for the diabetogenic effect of carriage of DR3. Alleles of the 8.1 ancestral haplotype between TNFA-308/D6STNFa and HLA-B were carried with significantly greater frequency in B8(-), DR3(+) type I diabetic patients compared with B8(-), DR3(+) controls. This interval was marked by a BAT1 gene polymorphism and a MIB microsatellite allele.

Alleles↗