1
|
Perretti M, Croxtall JD, Wheller SK, Goulding NJ, Hannon R, Flower RJ. Mobilizing lipocortin 1 in adherent human leukocytes downregulates their transmigration. Nat Med 1996; 2:1259-62. [PMID: 8898757 DOI: 10.1038/nm1196-1259] [Citation(s) in RCA: 182] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Polymorphonuclear leukocyte (PMN) migration into sites of inflammation is fundamental to the host defense response. Activation of endothelial cells and PMNs increases the expression or activation of adhesion molecules, culminating in rolling and subsequent adherence of these cells to the vascular wall. Further activation of adherent PMNs, possibly by endothelial cell ligands, leads, within a few minutes, to extravasation itself. This process is not clearly understood, but adhesion molecules or related proteins, as well as endogenous chemokines, may play an important role. The anti-inflammatory glucocorticoids delay extravasation, which implies that an inhibitory regulatory system exists. Resting PMNs contain abundant cytoplasmic lipocortin 1 (LC1, also called annexin I)', and the activity profile of this protein suggests that it could reduce PMN responsiveness. To investigate this we have assessed neutrophil transmigration both in vivo and in vitro and examined the content and subcellular distribution of LC1 in PMNs by fluorescence-activated cell-sorting (FACS) analysis, western blotting and confocal microscopy. We report that LC1 is mobilized and externalized following PMN adhesion to endothelial monolayers in vitro or to venular endothelium in vivo and that the end point of this process is a negative regulation of PMN transendothelial passage.
Collapse
|
|
29 |
182 |
2
|
Hannon R, Blumsohn A, Naylor K, Eastell R. Response of biochemical markers of bone turnover to hormone replacement therapy: impact of biological variability. J Bone Miner Res 1998; 13:1124-33. [PMID: 9661076 DOI: 10.1359/jbmr.1998.13.7.1124] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Biochemical markers of bone turnover may be useful to monitor patients taking hormone replacement therapy (HRT). The aim of this study was to assess the utility of markers in monitoring HRT by comparing the response of a large panel of markers to HRT with their within subject variability. We measured the response of markers to transdermal estradiol in 11 postmenopausal women over 24 weeks. We measured the within subject variability of markers in 11 untreated healthy postmenopausal women over the same period. The mean decrease in markers of bone formation after 24 weeks treatment ranged from 19% for procollagen type I C-terminal propeptide (PICP) to 40% for procollagen type I N-terminal propeptide (PINP). The mean decrease in markers of bone resorption ranged from 10% for tartrate-resistant acid phosphatase (TRAP) to 67% for C-terminal cross-linked telopeptide The least significant change (LSC at p < 0.05), calculated from the within subject variability in the untreated group, was used to define response. LSC for osteocalcin was 21%, bone alkaline phosphatase 28%, PICP 24%, PINP 21%, type I collagen telopeptide 28%, TRAP 17%, urinary calcium 90%, hydroxyproline 75%, total deoxypyridinoline 47%, free pyridinoline 36%, free deoxypyridinoline 26%, N-terminal cross-linked telopeptide 70%, and C-terminal cross-linked telopeptide 132%. The greatest number of responders after 24 weeks of treatment were found using PINP and osteocalcin (9 each), and free deoxypyridinoline (8 each) and total deoxypyridinoline (8 each) and total deoxypyridinoline (7 each). Lumbar spine bone mineral density defined four patients as responders. The ability to detect a response differs between markers and is not dependent on the magnitude of response to therapy.
Collapse
|
Comparative Study |
27 |
168 |
3
|
|
Review |
25 |
167 |
4
|
Ajuebor MN, Flower RJ, Hannon R, Christie M, Bowers K, Verity A, Perretti M. Endogenous monocyte chemoattractant protein-1 recruits monocytes in the zymosan peritonitis model. J Leukoc Biol 1998; 63:108-16. [PMID: 9469480 DOI: 10.1002/jlb.63.1.108] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The role of monocyte chemoattractant protein-1 (MCP-1) in the recruitment of blood-derived monocytes in a model of zymosan peritoneal inflammation was investigated. After zymosan injection (1 mg) a rapid influx of polymorphonuclear leukocytes (PMN) and monocytes into the peritoneal cavity associated with mouse MCP-1 (JE) gene activation and protein secretion in the exudates occurred. MCP-1 production (maximal at 4 h) preceded the accumulation of monocytes (F4/80-positive cells, maximally recovered between 16 and 24 h). Treatment of mice with a single injection of anti-mouse MCP-1 antibody inhibited 16-h monocyte accumulation by approximately 40%, however, a significant decrease in the number of PMN was also measured. Finally, intraperitoneal injection of murine recombinant MCP-1 (1 microg) produced a selective accumulation of monocytes (F4/80-positive cells) into the peritoneal cavity. In conclusion, we show the novel existence of a strict relationship between MCP-1 production and leukocyte accumulation in this model of acute inflammation.
Collapse
|
|
27 |
157 |
5
|
Jones C, Badger SA, Hannon R. The role of carbohydrate drinks in pre-operative nutrition for elective colorectal surgery. Ann R Coll Surg Engl 2011; 93:504-7. [PMID: 22004631 DOI: 10.1308/147870811x13137608455136] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
INTRODUCTION Traditionally, patients have been fasted from midnight on the night before elective surgery. With the advent of the enhanced recovery programme for elective colorectal surgery, there has been a major change in established practice with patients able to continue with clear fluids up to two hours prior to surgery and solids up to six hours prior to surgery. It has been suggested that nutritional supplements in the immediate pre-operative period enhance post-operative recovery. The aim of this review was therefore critically to appraise the evidence available regarding the use of pre-operative carbohydrate (CHO) supplements for elective colorectal surgery. METHODS A literature search was performed using: PubMed, MEDLINE(®), Athens and Google Scholar. The following keywords were used: 'pre-operative', 'carbohydrate supplements', 'enhanced recovery' and 'colorectal surgery', singly or in combination. To ensure an up-to-date literature search, the search was restricted to the last ten years. To maximise the search, backward chaining of reference lists from retrieved papers was also undertaken. Only English language articles were included. CONCLUSIONS The use of CHO drinks pre-operatively in colorectal surgery is both safe and effective. There is no increased risk of aspiration and it results in a shorter hospital stay, a quicker return of bowel function and less loss of muscle mass. On the basis of this evidence, the use of pre-operative CHO drinks should be standard in elective colorectal patients. Further research is nevertheless required for those with diabetes mellitus.
Collapse
|
Review |
14 |
129 |
6
|
Alldridge LC, Harris HJ, Plevin R, Hannon R, Bryant CE. The annexin protein lipocortin 1 regulates the MAPK/ERK pathway. J Biol Chem 1999; 274:37620-8. [PMID: 10608817 DOI: 10.1074/jbc.274.53.37620] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Lipocortin 1 (annexin 1) is a calcium- and phospholipid-binding protein that modulates anti-inflammatory responses including those induced by lipopolysaccharide. To investigate the precise role of lipocortin 1 in regulating the lipopolysaccharide-induced signal transduction pathways, we generated stable RAW 264.7 macrophage cell lines expressing decreased and increased lipocortin 1 protein. Several RAW 264.7 clones with increased lipocortin 1 protein levels showed constitutive activation of the mitogen-activated protein kinase extracellular signal-regulated kinase, which was down-regulated following lipopolysaccharide treatment. Conversely, clones with decreased lipocortin 1 protein expression showed prolonged extracellular signal-regulated kinase activity, following lipopolysaccharide activation. Lipocortin 1 specifically regulates the components of the extracellular signal-regulated kinase pathway, since changes in lipocortin 1 protein expression had no affect on the related mitogen-activated protein kinases p38 and c-Jun N-terminal kinase. Lipocortin 1 modulated upstream components of the extracellular signal-regulated kinase pathway and associated with the adaptor protein growth factor binding protein. The downstream consequences of altered extracellular signal-regulated kinase activity were independent of the proinflammatory transcription factor nuclear factor kappa B. These data indicate that lipocortin 1 specifically regulates proximal signaling components of the extracellular signal-regulated kinase signal transduction pathway, resulting in the modulation of biochemical functions in RAW macrophages.
Collapse
|
|
26 |
114 |
7
|
Hannon R, Evans T, Felsenfeld G, Gould H. Structure and promoter activity of the gene for the erythroid transcription factor GATA-1. Proc Natl Acad Sci U S A 1991; 88:3004-8. [PMID: 2014222 PMCID: PMC51372 DOI: 10.1073/pnas.88.8.3004] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have cloned the gene for the chicken erythroid transcription factor GATA-1 (formerly Eryf1, NF-E1, or GF-1). The gene is composed of six exons, two of which encode the two finger domains of the protein. Transcription of GATA-1 in chicken embryonic erythroid cells initiates from multiple sites clustered approximately 200 base pairs upstream from the start of protein-coding sequence. A number of sequence motifs for known DNA-binding proteins are found to be protected in DNase I-footprinting experiments by either erythroid or brain nuclear extracts or by both. Notably, a cluster of three GATA-1 sites is protected by the erythroid extract, as well as by purified GATA-1. We find that the upstream region of the gene functions as a powerful promoter when transfected into embryonic erythroid cells. In primary chicken embryo fibroblasts the promoter exhibits lower activity, which is increased when the cells are cotransfected with a second plasmid expressing the GATA-1 cDNA. The results suggest that GATA-1 protein plays an autoregulatory role in its own expression.
Collapse
|
research-article |
34 |
104 |
8
|
Sharif MA, Soong CV, Lau LL, Corvan R, Lee B, Hannon RJ. Endovenous laser treatment for long saphenous vein incompetence. Br J Surg 2006; 93:831-5. [PMID: 16673353 DOI: 10.1002/bjs.5351] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Endovenous laser treatment is a percutaneous technique used for the treatment of long saphenous vein (LSV) incompetence. This paper presents the results of an uncontrolled case series undertaken to assess the feasibility, safety and efficacy of this technique. METHODS Some 145 incompetent LSVs in 136 patients with saphenofemoral reflux were treated with endovenous laser. The data were evaluated prospectively. Assessment was carried out at 1 week, 3 and 12 months for LSV occlusion and symptomatic relief. RESULTS Primary procedural success was achieved in 124 (85.5 per cent) of 145 LSVs. Reasons for primary failure included failed cannulation, failure to pass the guidewire and patient discomfort. At 3 months' follow-up, 105 (89.7 per cent) of 117 veins were totally and nine (7.7 per cent) were partially occluded. At 12 months, 63 (76 per cent) of 83 veins were totally and 15 (18 per cent) were partially occluded. At this stage 73 (88 per cent) of 83 patients remained satisfied, but 26 (31 per cent) had residual or recurrent varicosities. Of these, only five required further treatment. Complications included saphenous nerve injury in one patient and superficial skin burns in a second. CONCLUSION Endovenous laser treatment for LSV reflux is safe and can be carried out under local anaesthesia in an outpatient setting with good patient satisfaction and low complication rates.
Collapse
|
Research Support, Non-U.S. Gov't |
19 |
60 |
9
|
Abstract
Alendronate is an antiresorptive therapy for osteoporosis and results in a decrease in bone turnover. To choose the optimal measurement for monitoring this therapy, the size of the change needs to be compared with the variability of the measurement. We studied 26 women with postmenopausal osteoporosis (bone mineral density [BMD] T score < -2.5), who were randomized in a 2:1 ratio to receive alendronate (10 mg/day) and calcium carbonate (500 mg/day) or calcium carbonate alone for 6 months. We measured serum markers of bone formation (osteocalcin [OC], bone isoform of alkaline phosphatase [BAP], and collagen type I C-terminal propeptide [CICP]) and urinary markers of bone resorption (cross-linked N-telopeptide [NTx], free deoxypyridinoline [iFDpd], and free pyridinolines). All subjects had two measurements 1 week apart at baseline to calculate the short-term variability. Biochemical measurements were then made at 4, 8, 12, 24, and 25 weeks. Measurements of bone mass were made by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and proximal femur twice at baseline and then at 24 and 25 weeks. The mean difference in change in BMD and markers between both groups at the end of the study that were significant were (short-term variability in brackets): DXA total hip 4.3% (2.5%), NTX 49% (10%), iFDpd 22% (12%), OC 28% (13%), BAP 31% (13%), and CICP 31% (11%). Five of the six markers showed significant responses to alendronate therapy, but they differed in the relationship between size of response and variability. These biochemical markers performed better than DXA for monitoring alendronate therapy over 6 months.
Collapse
|
Clinical Trial |
26 |
50 |
10
|
Hannon R, Bateman E, Allan J, Harborne N, Gould H. Control of RNA polymerase binding to chromatin by variations in linker histone composition. J Mol Biol 1984; 180:131-49. [PMID: 6392565 DOI: 10.1016/0022-2836(84)90434-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We have measured the frequency of initiation sites in chromatin for RNA polymerase in vitro as a function of the composition of linker histones (H1 and its analogues). In linker histone-depleted chromatin, RNA chain initiation appears to be restricted to the exposed linker DNA. On titration with purified linker histones, initiation is further restricted to an extent determined by the amount and type of linker histone, and the source of depleted chromatin. The extent of repression is correlated with the capacity of linker histones to induce the formation of higher-order structure in the complex. The results suggest that the effects of linker histones are mediated through the higher-order structure of chromatin, which prevents access of polymerase to the linker DNA. Accordingly, we find that structures imposed by the linker histones after polymerase binding are not inhibitory. Microscopy reveals that the higher-order structure in partially condensed chromatin is discontinuous, with solenoidal units spaced by sections of unravelled nucleosomes. Since salt stimulation of linker histone exchange does not result in derepression of linkers in our assay, we conclude that the distribution of higher-order units in chromatin is static and that the linker histones exchange between high-affinity sites in established units. We have previously shown that the globin gene is selectively unfolded in tissues that express the gene. The present results suggest that the transcriptional activity of specific genes is maintained by differential linker histone binding within chromatin.
Collapse
|
|
41 |
45 |
11
|
Peel NF, Barrington NA, Blumsohn A, Colwell A, Hannon R, Eastell R. Bone mineral density and bone turnover in spinal osteoarthrosis. Ann Rheum Dis 1995; 54:867-71. [PMID: 7492234 PMCID: PMC1010035 DOI: 10.1136/ard.54.11.867] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVES To determine whether there was a generalised increase in bone mineral density (BMD) in spinal osteoarthrosis (OA), and to determine the mechanism of this possible protection against osteoporosis as assessed by biochemical markers of bone turnover. METHODS We studied 375 women (ages 50 to 85) from a population based group. Spinal OA was defined from radiographs as the presence of degenerative changes affecting intervertebral or facet joints. BMD of the lumbar spine (LS), femoral neck (FN) and total body (TB) was measured by dual energy x ray absorptiometry (Lunar DPX). Bone turnover rates were estimated from measurement of biochemical markers of bone formation and resorption (urine deoxypyridinoline (Dpyr) and serum bone specific alkaline phosphatase (BAP)). RESULTS BMD at each site was greater in the women with spinal OA (mean increase in LS-BMD 7.9%, 95% confidence interval (CI) 1.0 to 15.1; TB-BMD 8.4%, 95% CI 1.9 to 9.7; FN-BMD 6.4%, 95% CI 0.3 to 12.6). Twenty four hour urinary excretion of Dpyr, corrected for TB bone mineral content, and serum BAP were 19% lower in the women with spinal OA (95% CI for Dpyr 4.3 to 31.9%; for BAP 6.3 to 32.0%). CONCLUSIONS Spinal OA is associated with a generalised increase in BMD and a decreased rate of bone turnover. This suggests that the protective effect of spinal OA against osteoporosis may be mediated by decreased bone turnover.
Collapse
|
Comparative Study |
30 |
43 |
12
|
Lau LL, Halliday MI, Lee B, Hannon RJ, Gardiner KR, Soong CV. Intestinal manipulation during elective aortic aneurysm surgery leads to portal endotoxaemia and mucosal barrier dysfunction. Eur J Vasc Endovasc Surg 2000; 19:619-24. [PMID: 10873730 DOI: 10.1053/ejvs.2000.1063] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES to investigate the effect of intestinal manipulation on intestinal permeability and endotoxaemia during elective abdominal aortic aneurysm (AAA) surgery. DESIGN prospective randomised controlled study. PATIENTS AND METHODS fourteen patients undergoing elective infrarenal AAA repair were randomised into either the transperitoneal (n=7) or extraperitoneal approach (n=7). Intestinal permeability was measured preoperatively (PO), and at day 1 (D1) and day 3 (D3) after surgery using the lactulose/mannitol absorption test. Portal and systemic blood samples were taken before clamping, at completion of proximal and distal anastomoses and immediately before abdominal wound closure, for endotoxin measurement using the chromogenic limulus amoebocyte lysate assay. RESULTS intestinal permeability was significantly increased at D1 (0.107+/-0.04 (mean+/-S.E.M.)) in the transperitoneal group compared to the PO level (0.020+/-0.004, p<0.05) and to the extraperitoneal group at D1 (0.020+/-0.004, p<0.05) which showed no change in comparison with the PO level. No correlation was seen between increased intestinal permeability and aortic clamp time, operation time, amount of blood lost or transfused. However, a significantly higher concentration of portal endotoxin was detected intraoperatively in the transperitoneal group of patients in comparison to the extraperitoneal group (p<0.05). There was a significant positive correlation between portal endotoxaemia and intestinal permeability (r(s)=0.955 p=0.001). CONCLUSION an increase in intestinal permeability and a greater degree of portal endotoxaemia are observed during transperitoneal approach to the aorta. This suggests that intestinal manipulation may impair gut mucosal barrier function and contribute to the systemic inflammatory response seen in AAA surgery.
Collapse
|
Clinical Trial |
25 |
40 |
13
|
Makar R, Reid J, Pherwani AD, Johnston LC, Hannon RJ, Lee B, Soong CV. Aorto-enteric fistula following endovascular repair of abdominal aortic aneurysm. Eur J Vasc Endovasc Surg 2000; 20:588-90. [PMID: 11136600 DOI: 10.1053/ejvs.2000.1247] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
Case Reports |
25 |
38 |
14
|
Arya N, Makar RR, Lau LL, Loan W, Lee B, Hannon RJ, Soong CV. An intention-to-treat by endovascular repair policy may reduce overall mortality in ruptured abdominal aortic aneurysm. J Vasc Surg 2006; 44:467-71. [PMID: 16950418 DOI: 10.1016/j.jvs.2006.05.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2006] [Accepted: 05/07/2006] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The use of endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm (AAA) has been restricted to a small number of specialized units on a selected group of patients. The aim of this study is to assess if the overall mortality in these patients with ruptured AAA may be reduced in a unit where all patients with ruptured AAA are considered first for EVAR. METHODS During a 24-month period beginning in July 2002, 51 patients admitted with ruptured AAA were considered for EVAR as the treatment of choice and comprised the study group. EVAR was performed in 17 patients. Open repair was performed in 34 patients: 13 patients had hemodynamic instability and 16 patients had an unsuitable aortic neck anatomy. The study group was compared with a historical control group of 41 patients with ruptured AAA who were treated by open repair from July 2000 to June 2002. RESULTS Mortality rate was 39% in the study group compared with 59% in the control group (P = .065). The duration of stay in the intensive care unit was significantly lower in the study group than in the control group (P = .01), although the total in-hospital stay was similar (17 days vs 14 days, P = .83). Within the study group, EVAR patients had a mortality rate of 24% compared with 47% in the open group (P = .14). CONCLUSION Although the number of patients was small, offering EVAR to as many patients as possible with ruptured AAA has resulted in a 20% reduction in mortality, albeit statistically insignificant. However, it is in the unstable patients that EVAR will need to improve survival before it may be hailed to supersede the conventional approach.
Collapse
|
|
19 |
37 |
15
|
Chen G, Kamal M, Hannon R, Warner TD. Regulation of cyclo-oxygenase gene expression in rat smooth muscle cells by catalase. Biochem Pharmacol 1998; 55:1621-31. [PMID: 9633998 DOI: 10.1016/s0006-2952(98)00021-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have studied, in detail, the effect of catalase, one of the naturally occurring antioxidant enzymes, on the expression of cyclo-oxygenase (COX) mRNA and protein in rat aortic smooth muscle cells (RASMC). The activity of COX enzyme within the cells was also determined. Catalase either alone or in combination with interleukin-1beta (IL-1beta) enhanced mRNA and protein expression for cyclo-oxygenase 2 (COX-2) in a concentration-dependent manner. However, it did not affect the expression of mRNA or protein for cyclo-oxygenase 1 (COX-1). The expression of mRNA for COX-2 induced by catalase was blocked completely by actinomycin D (ACT) or cycloheximide (CHX). In comparison, expression of mRNA for COX-2 stimulated by IL-1beta was inhibited by actinomycin D, but not by cycloheximide. This suggests that induction of the synthesis of mRNA for COX-2 by catalase and IL-1beta involves different mechanisms. In particular, the induction of mRNA for COX-2 by catalase requires on-going protein and RNA synthesis, but the induction following exposure to IL-1beta does not. The increase in expression of mRNA for COX-2 induced by catalase may be related to the ability of catalase to stimulate cyclic AMP response element (CRE) and NF-IL6 transcription factors, but not nuclear factor kappa B (NF-kappaB), for electrophoretic mobility shift assays (EMSA) showed that catalase enhanced nuclear factor binding to cyclic AMP response element and NF-IL6 but not to NF-kappaB. Catalase exerted a biphasic effect on prostaglandin synthesis. At low concentrations it enhanced prostaglandin production, but at high concentrations it tended to inhibit it. These findings suggest that catalase has differential and multiple effects on COX expression and activity in rat aortic smooth muscle cells.
Collapse
MESH Headings
- Animals
- Catalase/pharmacology
- Cells, Cultured
- DNA/metabolism
- Gene Expression Regulation, Enzymologic/drug effects
- Interleukin-1/pharmacology
- Kinetics
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Prostaglandin-Endoperoxide Synthases/genetics
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Rats
- Transcription Factors/metabolism
Collapse
|
|
27 |
33 |
16
|
Abstract
Facilitated diffusion accounts for the rapid rate of association of many bacterial DNA binding proteins with specific DNA sequences in vitro. In this mechanism the proteins bind at random to non-specific sites on the DAN and diffuse (by 'sliding' or 'hopping') along the DNA chain until they arrive at their specific functional sites. We have investigated whether such a mechanism can operate in chromatin by using a bacterial DNA binding protein, Escherichia coli RNA polymerase, that depends on linear diffusion to locate initiation sites on DNA. We have measured the competition between chromatin and its free DNA for the formation of initiation complexes. Only the short linker segments exposed by the removal of histone H1 are available for interaction with the polymerase, but the sparsely distributed promoter sites on the linker DNA of such a polynucleosome chain are located at the same rate as those on DNA. We conclude that the polymerase is free to migrate between the separate linker DNA segments of a polynucleosome chain to reach a promoter site. This chain thus permits the 'hopping' of proteins between neighboring linker segments in their search for a target site on the accessible DNA.
Collapse
|
|
39 |
31 |
17
|
Hannon R, Bader A. A comparison of frontal pole, anterior median and caudate nucleus lesions in the rat. Physiol Behav 1974; 13:513-21. [PMID: 4445271 DOI: 10.1016/0031-9384(74)90282-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
Comparative Study |
51 |
28 |
18
|
Hannon R, Day CL, Butler AM, Larson AJ, Casey M. Alcohol consumption and cognitive functioning in college students. JOURNAL OF STUDIES ON ALCOHOL 1983; 44:283-98. [PMID: 6645513 DOI: 10.15288/jsa.1983.44.283] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Decreased cognitive performance was significantly correlated with increased quantity of alcohol per occasion and with total lifetime consumption in both women and men college students tested while sober. In men, however, increased performance on some tasks was also significantly correlated with increased frequency of drinking.
Collapse
|
|
42 |
28 |
19
|
Hannon RJ, Wolfe JH, Mansfield AO. Aortic prosthetic infection: 50 patients treated by radical or local surgery. Br J Surg 1996; 83:654-8. [PMID: 8689212 DOI: 10.1002/bjs.1800830522] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Fifty patients with aortic prosthetic infection were managed in a period of 10 years from 1983 to 1993. Twenty-five patients had recurrent sepsis after local surgery (group 1) and 22 of these eventually required radical surgery. Twenty-five patients had radical graft excision as the first procedure (group 2). Group 1 contained an excess of patients with local groin symptoms (11 in group 1 versus five in group 2, P = 0.03) and in this group fewer radiological techniques were used to document the extent of graft infection. The perioperative mortality rate was similar in both groups (seven in group 1 versus five in group 2). The number of amputations was also similar (five in group 1 versus four in group 2). The triad of occlusive disease, aortobifemoral bypass and groin symptoms was associated with eight of nine amputations. While the authors would consider using local techniques if the anastomosis was intact, the graft remained patent and infection appeared to be confined to the groin, this combination is uncommon and radical graft excision remains the preferred treatment.
Collapse
|
|
29 |
28 |
20
|
Edrees WK, Lau LL, Young IS, Smye MG, Gardiner KR, Lee B, Hannon RJ, Soong CV. The effect of lower limb ischaemia-reperfusion on intestinal permeability and the systemic inflammatory response. Eur J Vasc Endovasc Surg 2003; 25:330-5. [PMID: 12651171 DOI: 10.1053/ejvs.2002.1848] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES a relationship has been demonstrated between increased intestinal permeability, endotoxaemia and the development of the systemic inflammatory response syndrome (SIRS) after aortic surgery. The aim of this study was to evaluate whether isolated lower limb ischaemia-reperfusion (I/R) injury affects intestinal mucosal barrier function and cytokine release. PATIENTS AND METHODS four groups of patients were investigated, group I, patients with critical limb ischaemia (CLI) undergoing infra-inguinal bypass surgery (n=18); group II, patients with intermittent claudication (IC) undergoing infra-inguinal bypass surgery (n=14); group III, patients with CLI unsuitable for arterial reconstruction, undergoing major amputation (n=12); and group IV, patients undergoing carotid endarterectomy for symptomatic carotid stenosis (n=13). Intestinal permeability, endotoxaemia and urinary soluble tumour necrosis factor receptors were assessed (p55TNF-R). RESULTS an increase in intestinal permeability was observed on the 3rd postoperative day only in CLI group. This was found to correlate with arterial clamp time. Patients who had a femoro-distal bypass had significantly higher intestinal permeability compared to those who had femoro-popliteal bypass. Endotoxaemia was not detected in any of the groups. Postoperative urinary p55TNF-R concentrations were significantly higher in CLI group compared to the other groups. These did not correlate with the increased intestinal permeability. CONCLUSIONS our results support the hypothesis that revascularisation of critically ischaemia limbs leads to intestinal mucosal barrier dysfunction and cytokine release. They also suggest that the magnitude of the inflammatory response following I/R injury is related to the degree of initial ischaemia.
Collapse
|
|
22 |
27 |
21
|
Melkebeke P, Vandepitte J, Hannon R, Fevery J. Huge hepatomegaly, jaundice and portal hypertension due to amyloidosis of the liver. Digestion 1980; 20:351-7. [PMID: 7390060 DOI: 10.1159/000198459] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A 3 years evolution with amyloid involvement, primarily of the liver, in a patient is described. This led to intrahepatic cholestasis and to portal hypertension with esophageal varices.
Collapse
|
Case Reports |
45 |
22 |
22
|
Minie M, Clark D, Trainor C, Evans T, Reitman M, Hannon R, Gould H, Felsenfeld G. Developmental regulation of globin gene expression. JOURNAL OF CELL SCIENCE. SUPPLEMENT 1992; 16:15-20. [PMID: 1297648 DOI: 10.1242/jcs.1992.supplement_16.3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have used the globin family of genes in chicken to study developmental regulation of gene expression, both at the level of individual interaction of trans-acting factors with local promoters and enhancers, and at the level of chromatin structure. Regulation of all members of the alpha- and beta-globin clusters is affected by the erythroid regulatory factor GATA-1. Separate mechanisms exist for regulation of individual members of the family. As an example, we describe the control mechanisms that play a role in the expression of the rho-globin gene, which is expressed only in primitive lineage erythroid cells. In addressing the involvement of chromatin structure in gene activation, we have examined the role of locus control elements, and also considered the way in which RNA polymerase molecules might accommodate to the presence of nucleosomes on transcribed genes.
Collapse
|
Review |
33 |
19 |
23
|
Sharif MA, Lau LL, Lee B, Hannon RJ, Soong CV. Role of endovenous laser treatment in the management of chronic venous insufficiency. Ann Vasc Surg 2007; 21:551-5. [PMID: 17823037 DOI: 10.1016/j.avsg.2007.07.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2006] [Revised: 04/26/2007] [Accepted: 07/16/2007] [Indexed: 10/21/2022]
Abstract
Endovenous laser therapy (EVLT) is a recognized option in the treatment of uncomplicated varicose veins. This uncontrolled case series evaluates its effectiveness in the management of chronic venous insufficiency. Patients with a history of active or healed ulcers were selected for EVLT. The procedure was carried out in an outpatient setting over a period of 12 months. Assessment was carried out for evidence of ulcer healing and recurrence, long saphenous vein occlusion, and patient satisfaction at 3, 12, and 22 months. Results are expressed as means with range. EVLT was used to treat 23 limbs in 20 patients with a median age of 59 years (range 32-76) including 12 females and eight males. All patients had evidence of chronic venous insufficiency, graded at C5 or greater on the CEAP classification (C5 16, C6 7). Patients with long saphenous vein insufficiency were included, whereas those with either deep or combined deep and superficial venous incompetence were excluded. The cumulative 3-, 12-, and 22-month healing rates were 87% (20/23), 100% (23/23), and 95% (21/22), respectively. The only patient having a recurrence of ulcers at 22 months' follow-up (CEAP 6) had mid-calf perforator incompetence with recanalized long saphenous vein. Duplex scan demonstrated long saphenous vein occlusion in 100% (23/23), 96% (22/23), and 91% (20/22) at 3, 12, and 22 months, respectively. In all, 84% (16/19) of patients were satisfied with the results of treatment without any major procedure-related complication. These results demonstrate that EVLT, carried out in an outpatient setting, is effective in the treatment and prevention of chronic venous ulcers, with good patient satisfaction and no major complication.
Collapse
|
Research Support, Non-U.S. Gov't |
18 |
18 |
24
|
Badger SA, O'Donnell ME, Sharif MA, Boyd CS, Hannon RJ, Lau LL, Lee B, Soong CV. Risk Factors for Abdominal Aortic Aneurysm and the Influence of Social Deprivation. Angiology 2008; 59:559-66. [DOI: 10.1177/0003319708321586] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Introduction: the objective of this abdominal aortic aneurysm (AAA) screening study was to determine attendance and disease prevalence patterns in Northern Ireland and the role of deprivation and other risk factors. Patients and methods: patients from primary care practices from Belfast, Lisburn, and Saintfield were screened. Past medical history and deprivation details were determined. Results: 2264 men from Belfast, 1104 men in Lisburn, and 284 in Saintfield were invited to attend. Overall, 1659 (45.3%) men attended, with 40.6% from Belfast, 55.0% from Lisburn, and 45.8% from Saintfield ( P < .0001). Ninety-two (5.5%) new AAAs were diagnosed, with 6.5%, 3.8%, and 6.2% in the 3 areas ( P = .055). As deprivation decreased, attendance increased and prevalence decreased. Smoking, peripheral arterial disease, number of medications prescribed, and geographical origin were independent risk factors for AAAs. Conclusion: aneurysm prevalence is influenced by geographical origin and deprivation, which should, therefore, be important factors in health care planning and screening provision.
Collapse
|
|
17 |
16 |
25
|
Reid JA, Wolsley C, Lau LL, Hannon RJ, Lee B, Young IS, Soong CV. The Effect of Pravastatin on Intima Media Thickness of the Carotid Artery in Patients with Normal Cholesterol. Eur J Vasc Endovasc Surg 2005; 30:464-8. [PMID: 16099694 DOI: 10.1016/j.ejvs.2005.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2004] [Accepted: 05/09/2005] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Carotid intima media thickness (IMT) is a good indicator of the severity of atherosclerotic disease. Statins have been found to reduce carotid IMT in patients with hypercholesterolaemia. The aim of this study was to investigate if pravastatin is effective in reducing IMT in normocholesterolaemic patients with carotid artery disease. METHODS Patients with carotid artery stenosis and normal cholesterol levels who were not on a statin, were recruited. Patients were randomised to receive pravastatin or placebo daily. Serum concentration of cholesterol and IMT of common carotid arteries were measured before randomisation and at 3 monthly intervals thereafter, for 9 months. IMT was analysed to give the mean of a standardised 2 cm of the common carotid artery (CCA). Results are expressed as median (IQR) and comparison made using the Wilcoxon signed ranks test. RESULTS Fifty-four patients were examined. Twenty-eight patients were randomised to active treatment. There was no difference in demographic details and co-morbid states between the two groups. A significant reduction in cholesterol concentration was observed from 3 months in patients randomised to the pravastatin group [5.14(4.72-5.88) vs. 4.11(3.44-5.33), p < 0.05], while there was also a significant decrease in combined IMT form 6 months [1.53(1.36-1.87) vs. 1.41 (1.33-1.78), p < 0.05]. CONCLUSIONS The results demonstrate that pravastatin reduces intima media thickness of the common carotid artery in normocholesterolaemic patients with moderate carotid stenosis.
Collapse
|
|
20 |
15 |