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Hitchcock I, Skrobanski H, Matter E, Munro E, Whalen J, Nolthenius JT, Crocker-Buque A, Harrington A, Vandenberghe D, Acaster S, Williams K. A qualitative study to explore the burden of disease in activated phosphoinositide 3-kinase delta syndrome (APDS). Orphanet J Rare Dis 2024; 19:203. [PMID: 38760658 PMCID: PMC11102230 DOI: 10.1186/s13023-024-03215-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 05/10/2024] [Indexed: 05/19/2024] Open
Abstract
BACKGROUND Activated phosphoinositide 3-kinase delta syndrome (APDS) is an ultra-rare primary immunodeficiency, with only 256 cases reported globally. This study aimed to explore the disease burden of APDS from the perspective of individuals with APDS and their caregivers. METHODS Qualitative interviews were conducted with healthcare providers (HCPs), individuals with APDS and caregivers, to explore the symptoms and health-related quality of life (HRQoL) impact of APDS. Some individuals and caregivers also completed a narrative account exercise. All interviews were audio recorded and transcribed. Data were analysed using thematic analysis and saturation was recorded. RESULTS Semi-structured qualitative interviews were conducted with healthcare providers (HCPs), individuals with APDS and caregivers. Individuals and caregivers had the option of completing a narrative account exercise. Six HCPs participated in an interview. Seven participants completed the narrative account exercise (N = 5 caregivers and N = 2 individuals with APDS) and 12 took part in an interview (N = 4 caregivers and N = 8 individuals with APDS). Themes identified from HCPs interviews included symptoms, clinical manifestations, HRQoL impacts and treatments/management of APDS. The narrative account exercise identified similar themes, but with the addition to the journey to diagnosis. These themes were explored during the individual/caregiver interviews. Reported clinical manifestations and symptoms of APDS included susceptibility to infections, lymphoproliferation, gastrointestinal (GI) disorders, fatigue, bodily pain, and breathing difficulties. HRQoL impacts of living with APDS included negative impacts to daily activities, including work, education and social and leisure activities, physical functioning, as well as emotional well-being, such as concern for the future, and interpersonal relationships. Impacts to caregiver HRQoL included negative impacts to physical health, work, emotional well-being, interpersonal relationships and family life and holidays. The management of APDS included the use of healthcare services and medications including immunoglobulin replacement therapy (IRT), rapamycin, prophylactic antibiotics, leniolisib, as well as medical procedures due to complications. CONCLUSIONS APDS has a high disease burden and there is an unmet need for licensed, more targeted treatments which modify disease progression. This study was the first to describe the day-to-day experience and HRQoL impact of APDS from the perspective of individuals living with the condition, caregivers and treating physicians.
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Cant AJ, Chandra A, Munro E, Rao VK, Lucas CL. PI3Kδ Pathway Dysregulation and Unique Features of Its Inhibition by Leniolisib in Activated PI3Kδ Syndrome and Beyond. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. IN PRACTICE 2024; 12:69-78. [PMID: 37777067 PMCID: PMC10872751 DOI: 10.1016/j.jaip.2023.09.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/30/2023] [Accepted: 09/11/2023] [Indexed: 10/02/2023]
Abstract
The phosphoinositide 3-kinase (PI3K) pathway regulates diverse cellular processes, with finely tuned PI3Kδ activity being crucial for immune cell development and function. Genetic hyperactivation of PI3Kδ causes the inborn error of immunity activated phosphoinositide 3-kinase δ syndrome (APDS). Several PI3Kδ inhibitors have been investigated as treatment options for APDS, but only leniolisib has shown both efficacy and tolerability. In contrast, severe immune-mediated adverse events such as colitis, neutropenia, and hepatotoxicity have been observed with other PI3Kδ inhibitors, particularly those indicated for hematological malignancies. We propose that leniolisib is distinguished from other PI3Kδ inhibitors due to its structure, specific inhibitory properties selectively targeting the δ isoform without overinhibition of the δ or γ isoforms, and the precise match between APDS mechanism of disease and drug mechanism of action.
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Eggleston M, Godat T, Munro E, Alonso MA, Shi H, Bhattacharya M. Ray transfer matrix for a spiral phase plate. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2013; 30:2526-2530. [PMID: 24323013 DOI: 10.1364/josaa.30.002526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a ray transfer matrix for a spiral phase plate. Using this matrix we determine the stability of an optical resonator made of two spiral phase plates and trace stable ray orbits in the resonator. Our results should be relevant to laser physics, optical micromanipulation, quantum information, and optomechanics.
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McGregor D, Rajagopalan S, Munro E. Upper Limb Ischaemia in a Young Female. Eur J Vasc Endovasc Surg 2012. [DOI: 10.1016/j.ejvs.2012.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Munro E, Arber S. 4204 POSTER The Role of the Family in Influencing Women's Decision-making About Taking Part in Breast Cancer Clinical Trials. Eur J Cancer 2011. [DOI: 10.1016/s0959-8049(11)71370-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Wright K, Munro E, del Carmen M, Goodman AK. Prognosis and comorbidities in stage III and IV endometrial cancer. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e16553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e16553 Background: While endometrial cancer may be associated with many comorbid conditions, none have been characterized as changing overall prognosis. The aim of this study was to identify medical conditions or laboratory values, that may serve as prognostic factors in stage III and IV endometrial cancer. Methods: A retrospective chart review identified 112 women with stage III or IV endometrial cancer between years 1993–1998. Information about medical comorbidities and presenting lab values were collected using electronic medical records. Progression free survival (PFS) and overall survival (OS) were analyzed using the Kaplan-Meier survival method and the log rank test. Results: The average age was 64.9 yrs. 79 women (70.5%) had stage III disease and 33 women (29.5%) had stage IV disease. For those with a baseline creatinine <1.2 (n = 91), the PFS and OS were not significantly different from those with a baseline creatinine ≥1.2 (n = 17; p = 0.554 and p = 0.487, respectively). There was a non-significant trend toward worse PFS for the 41 patients with hypertension (HTN) compared to the 62 without (48.0 and 61.2 months, p = 0.191). The overall survival was significantly worse for those with HTN (38.7 months vs. 56.0 months p = 0.046). For those with known coronary artery disease, no significant difference in PFS or OS was found (p = 0.792 and p = 0.312 respectively). Those with diabetes (n = 15) did not have a significantly different PFS compared to those who did not (n = 88; p = 0.728). The OS was worse at 20.1 months for those with diabetes compared to 54.3 months for those without (p = 0.001). Baseline albumin had a significant effect on both PFS and OS. Those with an albumin <3.5 (n = 54) had a PFS of 46.2 months compared to 94.0 months for those with an albumin ≥3.5 (n = 23; p = 0.007), and the OS for those with low albumin was 44.8 months compared to 83.4 months for those with the higher albumin (p = 0.005). Conclusions: These results suggest that past medical history and some baseline laboratory values may be important in considering prognosis. In particular, patients with a history of HTN or diabetes have a worse overall survival. Those with a baseline albumin of <3.5 have a worse PFS and OS. No significant financial relationships to disclose.
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Marques AIC, Munro E, Welsh EM. Migrating foreign body in the parotid duct of a boxer dog. Vet Rec 2008; 163:691-692. [PMID: 19060320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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Corbett M, Xiong Y, Boyne JR, Wright DJ, Munro E, Price C. IQGAP and mitotic exit network (MEN) proteins are required for cytokinesis and re-polarization of the actin cytoskeleton in the budding yeast, Saccharomyces cerevisiae. Eur J Cell Biol 2006; 85:1201-15. [PMID: 17005296 DOI: 10.1016/j.ejcb.2006.08.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 08/04/2006] [Accepted: 08/04/2006] [Indexed: 11/21/2022] Open
Abstract
In budding yeast the final stages of the cell division cycle, cytokinesis and cell separation, are distinct events that require to be coupled, both together and with mitotic exit. Here we demonstrate that mutations in genes of the mitotic exit network (MEN) prevent cell separation and are synthetically lethal in combination with both cytokinesis and septation defective mutations. Analysis of the synthetic lethal phenotypes reveals that Iqg1p functions in combination with the MEN components, Tem1p, Cdc15p Dbf20p and Dbf2p to govern the re-polarization of the actin cytoskeleton to either side of the bud neck. In addition phosphorylation of the conserved PCH protein, Hof1p, is dependent upon these activities and requires actin ring assembly. Recruitment of Dbf2p to the bud neck is dependent upon actin ring assembly and correlates with Hof1p phosphorylation. Failure to phosphorylate Hof1p results in the increased stability of the protein and its persistence at the bud neck. These data establish a mechanistic dependency of cell separation upon an intermediate step requiring actomyosin ring assembly.
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Collins AR, Dusinská M, Horváthová E, Munro E, Savio M, Stĕtina R. Inter-individual differences in repair of DNA base oxidation, measured in vitro with the comet assay. Mutagenesis 2001; 16:297-301. [PMID: 11420396 DOI: 10.1093/mutage/16.4.297] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
There is a need for a reliable, robust and sensitive assay for DNA repair, suitable for use with human lymphocyte samples in molecular epidemiological investigations. The comet assay (single cell alkaline gel electrophoresis) has been modified to measure the ability of a simple subcellular extract of lymphocytes to carry out the initial step of repair, i.e. incision, on a DNA substrate carrying specific lesions--namely, oxidized bases introduced by visible light in the presence of photosensitizer. The cell extract is free of non-specific nuclease activity, incising DNA only if the DNA has been treated with photosensitizer and light. The activity varies between individuals, but consistency is seen between samples from each individual taken on occasions several months apart. The lack of activity of extract from Ogg1(-) mouse cells (deficient in the glycosylase that excises 8-oxoguanine) in this assay confirms that the activity measured is predominantly excision repair of oxidized bases. This new DNA repair assay is simple, rapid and requires only small quantities of lymphocyte extract (obtainable from 10 ml blood).
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Hill PB, Auxilia ST, Munro E, Genovese L, Silkstone MA, Kirby B. Resolution of skin lesions and long-term survival in a dog with superficial necrolytic dermatitis and liver cirrhosis. J Small Anim Pract 2000; 41:519-23. [PMID: 11105793 DOI: 10.1111/j.1748-5827.2000.tb03976.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A nine-year-old, neutered female Shetland sheepdog was presented with crusted, ulcerative skin lesions affecting the footpads, commissures of the lips and the lateral canthi of the eyes. Histopathological examination of skin biopsies revealed changes consistent with superficial necrolytic dermatitis and biochemical analysis demonstrated elevated liver enzymes. Abdominal radiography revealed a small liver which, on ultrasonography, appeared diffusely mottled and showed changes suggestive of periportal fibrosis. On exploratory laparotomy, the pancreas appeared normal, but the liver was small and had multiple nodules throughout the parenchyma. This appearance was confirmed as cirrhosis on histopathological examination. The dog was placed on a hepatic support diet and treated with colchicine, essential fatty acid supplementation and raw egg yolks. After four weeks, the skin lesions had resolved and the dog remained free of clinical signs over a 22-month follow-up period.
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Welsh EM, Kirby BM, Simpson JW, Munro E. Surgical management of perineal paraprostatic cysts in three dogs. J Small Anim Pract 2000; 41:358-61. [PMID: 11002939 DOI: 10.1111/j.1748-5827.2000.tb03220.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
BACKGROUND Improved risk assessment has been stressed as the way to reduce homicides by people with mental illness. The feasibility of predicting rare events needs examining. AIMS To examine the findings of public inquiries into homicides by people with mental illness to see if they support the claim that better risk assessment would have averted the tragedy. METHOD Analysis was made of the findings of the public inquiries between 1988 and 1997 in relation to the predictability and preventability of the homicides. RESULTS Of the homicides considered by the inquiry panels, 27.5% were judged to have been predictable, 65% preventable and 60% of the patients had a long-term history containing violence or substantial risk factors for violence. CONCLUSIONS Improved risk assessment has only a limited role in reducing homicides. More deaths could be prevented by improved mental health care irrespective of the risk of violence. If services become biased towards those assessed as high risk, then ethical concerns arise about the care of both violent and non-violent patients.
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von Dassow G, Munro E. Modularity in animal development and evolution: elements of a conceptual framework for EvoDevo. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1999; 285:307-25. [PMID: 10578108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
For at least a century biologists have been talking, mostly in a black-box sense, about developmental mechanisms. Only recently have biologists succeeded broadly in fishing out the contents of these black boxes. Unfortunately the view from inside the black box is almost as obscure as that from without, and developmental biologists increasingly confront the need to synthesize known facts about developmental phenomena into mechanistic descriptions of complex systems. To evolutionary biologists, the emerging understanding of developmental mechanisms is an opportunity to understand the origins of variation not just in the selective milieu but also in the variability of the developmental process, the substrate for morphological change. Ultimately, evolutionary developmental biology (EvoDevo) expects to articulate how the diversity of organic form results from adaptive variation in development. This ambition demands a shift in the way biologists describe causality, and the central problem of EvoDevo is to understand how the architecture of development confers evolvability. We argue in this essay that it makes little sense to think of this question in terms of individual gene function or isolated morphometrics, but rather in terms of higher-order modules such as gene networks and homologous characters. We outline the conceptual challenges raised by this shift in perspective, then present a selection of case studies we believe to be paradigmatic for how biologists think about modularity in development and evolution. J. Exp. Zool. (Mol. Dev. Evol.) 285:307-325, 1999.
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Abstract
OBJECTIVE Repeated public inquiries into child abuse tragedies in Britain demonstrate the level of public concern about the services designed to protect children. These inquiries identify faults in professionals' practice but the similarities in their findings indicate that they are having insufficient impact on improving practice. This study is based on the hypothesis that the recurrent errors may be explicable as examples of the typical errors of human reasoning identified by psychological research. METHODS The sample comprised all child abuse inquiry reports published in Britain between 1973 and 1994 (45 in total). Using a content analysis and a framework derived from psychological research on reasoning, a study was made of the reasoning of the professionals involved and the findings of the inquiries. RESULTS It was found that professionals based assessments of risk on a narrow range of evidence. It was biased towards the information readily available to them, overlooking significant data known to other professionals. The range was also biased towards the more memorable data, that is, towards evidence that was vivid, concrete, arousing emotion and either the first or last information received. The evidence was also often faulty, due, in the main, to biased or dishonest reporting or errors in communication. A critical attitude to evidence was found to correlate with whether or not the new information supported the existing view of the family. A major problem was that professionals were slow to revise their judgements despite a mounting body of evidence against them. CONCLUSIONS Errors in professional reasoning in child protection work are not random but predictable on the basis of research on how people intuitively simplify reasoning processes in making complex judgements. These errors can be reduced if people are aware of them and strive consciously to avoid them. Aids to reasoning need to be developed that recognize the central role of intuitive reasoning but offer methods for checking intuitive judgements more rigorously and systematically.
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Meyer-Franke A, Wilkinson GA, Kruttgen A, Hu M, Munro E, Hanson MG, Reichardt LF, Barres BA. Depolarization and cAMP elevation rapidly recruit TrkB to the plasma membrane of CNS neurons. Neuron 1998; 21:681-93. [PMID: 9808456 PMCID: PMC2693071 DOI: 10.1016/s0896-6273(00)80586-3] [Citation(s) in RCA: 431] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Here, we describe a novel mechanism for the rapid regulation of surface levels of the neurotrophin receptor TrkB. Unlike nodose ganglion neurons, both retinal ganglion cells (RGCs) and spinal motor neurons (SMNs) in culture display only low levels of surface TrkB, though high levels are present intracellularly. Within minutes of depolarization or cAMP elevation, surface TrkB levels increase by nearly 4-fold, and this increase is not blocked by cycloheximide. These findings suggest that activity and cAMP elevation rapidly recruit TrkB to the plasma membrane by translocation from intracellular stores. We propose that a fundamental difference between peripheral nervous system (PNS) and central nervous system (CNS) neurons is the activity dependence of CNS neurons for responsiveness to their peptide trophic factors and that differences in membrane compartmentalization of the receptors underlie this difference.
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Munro E. Changing the response of professionals to child abuse. Br J Gen Pract 1998; 48:1609-11. [PMID: 9830191 PMCID: PMC1313229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Britain has developed a child protection system that relies on good interprofessional communication. However, some doctors are questioning the benefits to the child of triggering a child abuse referral. The system has become disproportionately skewed towards investigation and risk assessment, leaving few resources for meeting the needs of children, or helping parents provide better care. The Department of Health (DoH) is proposing a policy to redress the balance; creating a more cooperative and less adversarial relationship with parents, and paying more attention to assessing family needs and long-term family functioning. This paper examines the history of the current system and argues that, while the proposed changes are desirable, it needs to be acknowledged that they may reduce the accuracy of risk assessments. Professionals, therefore, need the backing of the general public to implement such a fundamental shift in emphasis.
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Munro E. Carotid surgery. Eur J Vasc Endovasc Surg 1998; 16:170-1. [PMID: 9728441 DOI: 10.1016/s1078-5884(98)80163-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Munro E. Summer school. Nurs Stand 1998; 12:20. [PMID: 9791460 DOI: 10.7748/ns.12.44.20.s40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Refson JS, Schachter M, Patel MK, Hughes AD, Munro E, Chan P, Wolfe JH, Sever PS. Vein graft stenosis and the heparin responsiveness of human vascular smooth muscle cells. Circulation 1998; 97:2506-10. [PMID: 9657470 DOI: 10.1161/01.cir.97.25.2506] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Vascular smooth muscle cell (VMSC) proliferation is an essential component of myointimal hyperplasia, which is implicated in the failure of 30% to 50% of vascular interventions, such as coronary angioplasty and peripheral vein grafting. We have shown that cells derived from stenotic lesions in infrainguinal vein grafts were significantly more resistant than controls to growth inhibition by heparin. METHODS AND RESULTS In a prospective study, we correlated antiproliferative responses to heparin in vitro with graft patency after 1 year. Sixty-two patients with infrainguinal vein grafts were entered into a graft surveillance program for > or = 1 year. At operation, saphenous vein segments were explanted for VSMC culture. Cell proliferation in response to fetal calf serum was later determined in the presence and absence of heparin. In 35 cell cultures, including 13 from the above-mentioned patients, [3H]heparin binding was also estimated. VSMCs from patients with patent grafts were significantly more sensitive to growth inhibition by heparin than cells from patients with stenoses (median, 54% versus 20.9%, P<0.001), and [3H]heparin binding was strongly correlated with inhibition of proliferation (r=0.81). CONCLUSIONS Responsiveness to heparin in cultured VSMCs is a strong predictor of outcome for infrainguinal vein grafts, and reduced sensitivity to heparin is correlated with decreased heparin binding. Relative resistance to the antiproliferative action of heparin may be a marker for aberrant regulation of VSMC growth.
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Munro E. Monday's child. Interview by Kate Williams. Nurs Stand 1996; 10:24-6. [PMID: 8695460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Munro E, Patel M, Chan P, Betteridge L, Clunn G, Gallagher K, Hughes A, Schachter M, Wolfe J, Sever P. Inhibition of human vascular smooth muscle cell proliferation by lovastatin: the role of isoprenoid intermediates of cholesterol synthesis. Eur J Clin Invest 1994; 24:766-72. [PMID: 7890015 DOI: 10.1111/j.1365-2362.1994.tb01074.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Restenosis remains the largest single obstacle to the long-term success of invasive vascular interventions. Lovastatin, an HMG-CoA reductase inhibitor, has been shown to reduce myointimal hyperplasia in animal models of restenosis and in one clinical coronary restenosis trial. We have assessed the effect of lovastatin on the growth of cultured human vascular smooth muscle cells derived from saphenous vein and vascular graft stenoses. Lovastatin (2 microM) inhibited proliferation over 14 days in saphenous vein (and graft stenoses) derived vascular smooth muscle cells by 42% and 32% respectively: this was not significantly different. Lovastatin (10 microM) reduced [methyl 3H]-thymidine uptake by 51% in saphenous vein-derived cells. These concentrations were significantly higher than those achieved in plasma during therapeutic dosage. Lovastatin-induced inhibition of vascular smooth muscle cell proliferation and [methyl 3H]-thymidine uptake was completely reversed by adding mevalonate (100 microM) but cholesterol (10-40 micrograms ml-1) had no effect. Isopentenyl adenine (25-50 microM) did not affect the inhibition of [methyl 3H]-thymidine uptake by lovastatin (10 microM), but farnesol (20 microM), another isoprenoid precursor of cholesterol synthesis, reversed the antiproliferative effect.
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Munro E, Chan P, Patel M, Betteridge L, Gallagher K, Schachter M, Sever P, Wolfe J. Consistent responses of the human vascular smooth muscle cell in culture: implications for restenosis. J Vasc Surg 1994; 20:482-7. [PMID: 8084043 DOI: 10.1016/0741-5214(94)90149-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE The mechanisms whereby restenoses occur at discrete sites within the vasculature remain uncertain. We have recently reported that vascular smooth muscle cells (VSMC) derived from patients with graft stenoses are resistant to growth inhibition by heparin. In this study, we have examined whether VSMC proliferation rates and responses to inhibition by heparin vary according to the individual or the anatomic site of origin. METHODS Long saphenous veins from seven patients were divided into proximal, middle, and distal portions, and VSMC were cultured separately from each. VSMC proliferation in response to 15% fetal calf serum +/- 100 micrograms/ml heparin was measured by counting triplicate samples at 0, 3, 7, 10, and 14 days. This experiment was repeated from the second to the sixth passage (n = 6) and for artery and vein pairs derived from four additional patients. RESULTS Differences between vein segment cultures of individual veins were found not to differ significantly from experimental error for either proliferation or heparin inhibition and were not altered by repeated passage (ANOVA). There were, however, significant differences in sensitivity to heparin inhibition between patients (p = 0.02) (ANOVA). There were no significant differences between paired samples of artery and vein for either proliferation or heparin inhibition (Mann-Whitney test). CONCLUSIONS VSMC growth characteristics reflect the individual patient and are maintained in cell culture.
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Munro E, Patel M, Chan P, Betteridge L, Gallagher K, Schachter M, Wolfe J, Sever P. Growth inhibition of human vascular smooth muscle cells by fenofibrate: a possible therapy for restenosis. Cardiovasc Res 1994; 28:615-20. [PMID: 8025905 DOI: 10.1093/cvr/28.5.615] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVE The aim was to assess the growth inhibitory effect of fibrates on human vascular smooth muscle cells. Restenosis is the most important factor limiting the long term success of invasive vascular interventions and there is as yet no effective preventive treatment. Platelet derived growth factor (PDGF) is considered to be an important growth promoting agent for vascular smooth muscle cells (VSMC) and fenofibric acid (a hypolipidaemic drug) has been reported to be a PDGF antagonist. METHODS The effect of the fibrate drugs fenofibrate, clofibrate, bezafibrate, and gemfibrozil were examined on the proliferation of cultured human vascular smooth muscle cells derived from saphenous vein (n = 20) and graft stenoses (n = 7). RESULTS Fenofibrate (100 microM) produced potent inhibition (48%) of VSMC proliferation at a concentration equivalent to that of its circulating metabolite fenofibric acid, but none of the other drugs produced any significant effect on growth. VSMC derived from graft stenoses were equally sensitive to inhibition as saphenous vein derived controls, in contrast to our previous work which reported that graft stenosis derived VSMC were resistant to growth inhibition by the physiological inhibitor heparin. The antiproliferative effect of fenofibrate was independent of inhibition of cellular cholesterol synthesis or toxicity. Fenofibrate inhibited VSMC growth induced by 15% fetal calf serum, PDGF, and basic fibroblast growth factor to a similar degree, indicating that it is not a specific PDGF antagonist. CONCLUSIONS Fenofibrate is not a specific PDGF antagonist. Fenofibric acid, one of the principal metabolites of fenofibrate, did not produce any inhibition of growth, suggesting that oral administration of fenofibrate would not be efficacious. Fenofibrate is the first potent inhibitor to be described for VSMC derived from human myo-intimal hyperplastic lesions.
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Munro E, Patel M, Chan P, Betteridge L, Gallagher K, Schachter M, Wolfe J, Sever P. Effect of calcium channel blockers on the growth of human vascular smooth muscle cells derived from saphenous vein and vascular graft stenoses. J Cardiovasc Pharmacol 1994; 23:779-84. [PMID: 7521461 DOI: 10.1097/00005344-199405000-00013] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Vascular restenosis after invasive interventions is an important clinical problem for which no preventive pharmacologic therapy exists. Calcium channel blockers have been shown to inhibit myointimal hyperplasia in animal models of restenosis and in some small and flawed clinical coronary restenosis trials. We examined the inhibitory effect of amlodipine, verapamil, and diltiazem on the growth of cultured human vascular smooth muscle cells (VSMC) derived from saphenous vein (n = 20) and graft stenoses (n = 7), in 14-day proliferation assays and [methyl 3H]thymidine uptake studies. Amlodipine and verapamil produced significant inhibition (30%) of VSMC proliferation and DNA synthesis at 10 microM but not at 500 nM-1 microM. To our knowledge, this is the first study to examine the antiproliferative effect of calcium channel blockers in VSMC derived from human graft stenoses. Growth inhibition of VSMC from graft stenoses was not significantly different from that of control saphenous vein-derived cells. We conclude, therefore, that calcium channel blockers inhibit human VSMC proliferation in vitro, regardless of whether the cells were grown from graft stenoses or saphenous vein. However, the concentrations at which these calcium channel blockers elicit antiproliferative effects may not be attainable during therapeutic dosing in humans.
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Munro E. Beating the narcos. Interview by Michael Gillard. Nurs Stand 1993; 7:18-9. [PMID: 8518145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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