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Murphy T, Mason JM, Leber B, Bray MR, Chan SM, Gupta V, Khalaf D, Maze D, McNamara CJ, Schimmer AD, Schuh AC, Sibai H, Trus M, Valiquette D, Martin K, Nguyen L, Li X, Mak TW, Minden MD, Yee KWL. Preclinical characterization and clinical trial of CFI-400945, a polo-like kinase 4 inhibitor, in patients with relapsed/refractory acute myeloid leukemia and higher-risk myelodysplastic neoplasms. Leukemia 2024; 38:502-512. [PMID: 38114624 DOI: 10.1038/s41375-023-02110-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 11/23/2023] [Accepted: 11/30/2023] [Indexed: 12/21/2023]
Abstract
CFI-400945 is a selective oral polo-like kinase 4 (PLK4) inhibitor that regulates centriole duplication. PLK4 is aberrantly expressed in patients with acute myeloid leukemia (AML). Preclinical studies indicate that CFI-400945 has potent in vivo efficacy in hematological malignancies and xenograft models, with activity in cells harboring TP53 mutations. In this phase 1 study in very high-risk patients with relapsed/refractory AML and myelodysplastic syndrome (MDS) (NCT03187288), 13 patients were treated with CFI-400945 continuously in dose escalation from 64 mg/day to 128 mg/day. Three of the 9 efficacy evaluable AML patients achieved complete remission (CR). Two of 4 AML patients (50%) with TP53 mutations and complex monosomal karyotype achieved a CR with 1 patient proceeding to allogenic stem cell transplant. A third patient with TP53 mutated AML had a significant reduction in marrow blasts by > 50% with an improvement in neutrophil and platelet counts. Responses were observed after 1 cycle of therapy. Dose-limiting toxicity was enteritis/colitis. A monotherapy and combination therapy study with a newer crystal form of CFI-400945 in patients with AML, MDS and chronic myelomonocytic leukemia (CMML) is ongoing (NCT04730258).
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Affiliation(s)
- Tracy Murphy
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Jacqueline M Mason
- Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
- Treadwell Therapeutics Canada Inc, Toronto, Canada
| | - Brian Leber
- Division of Hematology, Juravinski Cancer Centre, McMaster University, Hamilton, ON, Canada
| | - Mark R Bray
- Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
- Treadwell Therapeutics Canada Inc, Toronto, Canada
| | - Steven M Chan
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Vikas Gupta
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Dina Khalaf
- Division of Hematology, Juravinski Cancer Centre, McMaster University, Hamilton, ON, Canada
| | - Dawn Maze
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Caroline J McNamara
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Aaron D Schimmer
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Andre C Schuh
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Hassan Sibai
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Michael Trus
- Division of Hematology, Juravinski Cancer Centre, McMaster University, Hamilton, ON, Canada
| | - Debbie Valiquette
- Division of Hematology, Juravinski Cancer Centre, McMaster University, Hamilton, ON, Canada
| | - Kylie Martin
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Linh Nguyen
- Treadwell Therapeutics Inc., San Mateo, CA, USA
| | - Xuan Li
- Department of Biostatistics, University Health Network, Toronto, ON, Canada
| | - Tak W Mak
- Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
- Treadwell Therapeutics Canada Inc, Toronto, Canada
| | - Mark D Minden
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Karen W L Yee
- Leukemia Program, Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada.
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England JT, McNamara CJ, Kennedy JA, Capo-Chichi JM, Huang J, Arruda A, Nye T, Cheung V, Claudio JO, Maze D, Sibai H, Tierens A, Tsui H, Bankar A, Xu W, Stockley T, Gupta V. Clinical and molecular correlates of JAK-inhibitor therapy failure in myelofibrosis: long-term data from a molecularly annotated cohort. Leukemia 2022; 36:1689-1692. [PMID: 35347238 PMCID: PMC9162913 DOI: 10.1038/s41375-022-01544-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 03/01/2022] [Accepted: 03/09/2022] [Indexed: 11/09/2022]
Affiliation(s)
- James T. England
- grid.415224.40000 0001 2150 066XMedical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Caroline J. McNamara
- grid.415224.40000 0001 2150 066XMedical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - James A. Kennedy
- grid.413104.30000 0000 9743 1587Medical Oncology and Hematology, Sunnybrook Health Sciences Centre, Toronto, Ontario Canada
| | - Jose-Mario Capo-Chichi
- grid.231844.80000 0004 0474 0428Division of Clinical Laboratory Genetics, Laboratory Medicine Program, University Health Network, Toronto, Ontario Canada
| | - Jingyue Huang
- grid.415224.40000 0001 2150 066XBiostatistics, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Andrea Arruda
- grid.415224.40000 0001 2150 066XMedical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Taylor Nye
- grid.415224.40000 0001 2150 066XMedical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Verna Cheung
- grid.415224.40000 0001 2150 066XMedical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Jaime O. Claudio
- grid.415224.40000 0001 2150 066XMedical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Dawn Maze
- grid.415224.40000 0001 2150 066XMedical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Hassan Sibai
- grid.415224.40000 0001 2150 066XMedical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Anne Tierens
- grid.417184.f0000 0001 0661 1177Laboratory Hematology, Toronto General Hospital, Toronto, Ontario Canada
| | - Hubert Tsui
- grid.417184.f0000 0001 0661 1177Laboratory Hematology, Toronto General Hospital, Toronto, Ontario Canada
| | - Aniket Bankar
- grid.415224.40000 0001 2150 066XMedical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Wei Xu
- grid.415224.40000 0001 2150 066XBiostatistics, Princess Margaret Cancer Centre, Toronto, Ontario Canada
| | - Tracy Stockley
- grid.231844.80000 0004 0474 0428Division of Clinical Laboratory Genetics, Laboratory Medicine Program, University Health Network, Toronto, Ontario Canada ,grid.17063.330000 0001 2157 2938Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario Canada
| | - Vikas Gupta
- Medical Oncology and Hematology, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.
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Garcia-Horton A, Maze D, McNamara CJ, Sibai H, Gupta V, Murphy T. Azacitidine and venetoclax for the treatment of accelerated and blast phase myeloproliferative neoplasms and chronic myelomonocytic leukemia: a case series. Leuk Lymphoma 2021; 62:1525-1527. [PMID: 33448888 DOI: 10.1080/10428194.2020.1869961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Alejandro Garcia-Horton
- Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada
| | - Dawn Maze
- Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada
| | - Caroline J McNamara
- Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada
| | - Hassan Sibai
- Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada
| | - Vikas Gupta
- Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada
| | - Tracy Murphy
- Division of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada
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Chen R, Liu X, Law AD, Kanfar S, Maze D, Chan SM, Gupta V, Yee KW, Minden MD, Schimmer AD, Schuh AC, McNamara CJ, Murphy T, Xu A, Falcone U, Seki J, Sibai H. Risk of Thrombosis in Adult Philadelphia-Positive ALL Treated with an Asparaginase-Free ALL Regimen. Curr Oncol 2020; 28:128-137. [PMID: 33704181 PMCID: PMC7816186 DOI: 10.3390/curroncol28010016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND venous thromboembolism (VTE) is a well-known complication in adults with acute lymphoblastic leukemia (ALL), especially in patients treated with asparaginase (ASNase)-including regiments. However, VTE risk in adult Philadelphia-positive ALL (Ph+ve ALL) patients treated with non-hyperCVAD chemotherapy is unclear. In this study, we examined VTE incidence in adult Ph+ve ALL patients treated with imatinib plus a pediatric-inspired asparaginase (ASNase)-free regimen modified from the Dana Farber Cancer Institute (DFCI) ALL protocol. METHODS a single centre retrospective review of Ph+ve ALL patients treated at Princess Margaret Cancer Center (PMCC) from 2008-2019 with imatinib plus modified DFCI protocol was conducted. RESULTS of the 123 patients included, 30 (24.3%) had at least 1 radiology confirmed VTE event from diagnosis to the end of maintenance therapy. 86.7% (26/30) of the VTE events occurred during active treatment. Of all VTE events, the majority (53.3%) were DVT and/or PE while another significant portion were catheter-related (40.0%). Major bleeding was observed in 1 patient on VTE treatment with low molecular weight heparin (LMWH). CONCLUSION a high VTE incidence (24.3%) was observed in adults Ph+ve ALL patients treated with imatinib plus an ASNase-free modified DFCI pediatric ALL protocol, suggesting prophylactic anticoagulation should be considered for all adult Ph+ve ALL patients including those treated with ASNase-free regimens.
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Affiliation(s)
- Ruiqi Chen
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Xing Liu
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada; (X.L.); (A.X.)
- Department of Pharmacy, Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada
| | - Arjun D. Law
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Solaf Kanfar
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Dawn Maze
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Steven M. Chan
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Vikas Gupta
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Karen W. Yee
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Mark D. Minden
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Aaron D. Schimmer
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Andre C. Schuh
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Caroline J. McNamara
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Tracy Murphy
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
| | - Anna Xu
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada; (X.L.); (A.X.)
| | - Umberto Falcone
- Department of Haematology, Istituto Nazionale Tumori IRCCS Fondazione Pascale, 80131 Naples, Italy;
| | - Jack Seki
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada; (X.L.); (A.X.)
- Department of Pharmacy, Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada
| | - Hassan Sibai
- Princess Margaret Cancer Centre, Department of Medical Oncology and Hematology, University Health Network, Toronto, ON M5G 2C1, Canada; (R.C.); (A.D.L.); (S.K.); (D.M.); (S.M.C.); (V.G.); (K.W.Y.); (M.D.M.); (A.D.S.); (A.C.S.); (C.J.M.); (T.M.); (J.S.)
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Lock AD, McNamara CJ, Rustin MHA. Sustained improvement in urticaria pigmentosa and pruritus in a case of indolent systemic mastocytosis treated with cladribine. Clin Exp Dermatol 2014; 40:142-5. [PMID: 25515765 DOI: 10.1111/ced.12488] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2014] [Indexed: 01/08/2023]
Abstract
Systemic mastocytosis (SM) is a myeloproliferative disorder, characterized by a clonal proliferation of abnormal mast cells accumulating in internal organs and sometimes in the skin, leading to cutaneous and systemic symptoms. Mutations within the gene KIT, which encodes the receptor tyrosine kinase (KIT) on mast cells, is found in most patients with SM. We report a case of a 62-year-old woman presenting with a pruritic rash on her limbs and trunk. Several years later she developed gastrointestinal symptoms, associated with raised serum tryptase. Skin and bone marrow biopsies confirmed a diagnosis of SM, initially presenting with urticaria pigmentosa. Responses to multiple therapies, including potent topical steroids, oral antihistamines, phototherapy and the tyrosine kinase inhibitor, nilotinib, were inadequate. Treatment with cladribine (2-chlorodeoxyadenosine) produced a marked and sustained reduction in her symptoms and serum tryptase level.
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Affiliation(s)
- A D Lock
- Department of Dermatology, Royal Free London NHS Foundation Trust, London, UK
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Smith TG, Brooks JT, Balanos GM, Lappin TR, Layton DM, Leedham DL, Liu C, Maxwell PH, McMullin MF, McNamara CJ, Percy MJ, Pugh CW, Ratcliffe PJ, Talbot NP, Treacy M, Robbins PA. Mutation of the von Hippel-Lindau gene alters human cardiopulmonary physiology. Adv Exp Med Biol 2008; 605:51-6. [PMID: 18085246 DOI: 10.1007/978-0-387-73693-8_9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Intracellular responses to hypoxia are coordinated by the von Hippel-Lindau--hypoxia-inducible factor (VHL-HIF) transcriptional system. This study investigated the potential role of the VHL-HIF pathway in human systems-level physiology. Patients diagnosed with Chuvash polycythaemia, a rare disorder in which VHL signalling is specifically impaired, were studied during acute hypoxia and hypercapnia. Subjects breathed through a mouthpiece and ventilation was measured while pulmonary vascular tone was assessed echocardiographically. The patients were found to have elevated basal ventilation and pulmonary vascular tone, and ventilatory, pulmonary vasoconstrictive and heart rate responses to acute hypoxia were greatly increased, as were heart rate responses to hypercapnia. The patients also had abnormal pulmonary function on spirometry. This study's findings demonstrate that the VHL-HIF signalling pathway, which is so central to intracellular oxygen sensing, also regulates the organ systems upon which cellular oxygen delivery ultimately depends.
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Affiliation(s)
- T G Smith
- University of Oxford, Department of Physiology, Anatomy and Genetics
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McNamara CJ, Perry TD, Bearce K, Hernandez-Duque G, Mitchell R. Measurement of limestone biodeterioration using the Ca2+ binding fluorochrome Rhod-5N. J Microbiol Methods 2004; 61:245-50. [PMID: 15722151 DOI: 10.1016/j.mimet.2004.12.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Revised: 12/07/2004] [Accepted: 12/07/2004] [Indexed: 11/19/2022]
Abstract
Limestone and marble have been used extensively in the construction of modern and historic buildings. Microbial colonization and growth on these stone structures is common. Microbial deterioration of stone has been assessed by measuring Ca2+ released from the stone, using ion selective electrodes and titration with EDTA. In this study, the calcium binding fluorochrome Rhod-5N was used to measure Ca2+ released from limestone by endolithic bacteria as an indicator of biodeterioration. In a 17 d flask experiment, Ca2+ released by endolithic bacteria was twice that of uninoculated controls. Rhod-5N is a rapid and accurate method for measuring microbial biodeterioration of stone.
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Affiliation(s)
- C J McNamara
- Laboratory of Microbial Ecology, Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
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McNamara CJ, Leff LG. Response of biofilm bacteria to dissolved organic matter from decomposing maple leaves. Microb Ecol 2004; 48:324-330. [PMID: 15692852 DOI: 10.1007/s00248-003-1058-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2003] [Accepted: 11/03/2003] [Indexed: 05/24/2023]
Abstract
Stream bacteria play an important role in the utilization of dissolved organic matter (DOM) leached from leaves, and in transfer of this DOM to other trophic levels. Leaf leachate is a mixture of labile, recalcitrant, and inhibitory compounds, and bacterial communities vary in their ability to utilize leachate. The purpose of this study was to determine the effects of DOM from sugar maple leaves on bacterial populations in biofilms on decomposing leaf surfaces. Populations of Acinetobacter calcoaceticus, Burkholderia cepacia, and Pseudomonas putida were enumerated on decomposing maple leaves in a northeast Ohio stream using fluorescence in situ hybridization. Additionally, artificial substrata consisting of PVC-end caps filled with agar supplemented with leaf leachate and covered with cellulose filters were used to determine bacterial response to leachate from leaves at different stages of decomposition. Population sizes of bacterial species exhibited different responses. Leachate did not affect A. calcoaceticus. B. cepacia was tolerant of phenolic compounds released from leaves and the population size increased when DOM concentrations were greatest. In contrast, P. putida was inhibited by phenolic components of leachate when total DOM concentrations were greatest. Differences in response of the bacterial species to components of leaf leachate indicate the complexity of microbial population dynamics and interactions with DOM. Differences among species in response to DOM have the potential to influence transport and retention of organic matter in stream ecosystems.
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Affiliation(s)
- C J McNamara
- Department of Biological Sciences, Kent State University, Kent, OH, 44242, USA.
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McNamara CJ, Leff LG. In situ hybridization of Burkholderia cepacia cells. Methods Mol Biol 2002; 179:187-92. [PMID: 11692863 DOI: 10.1385/1-59259-238-4:187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Affiliation(s)
- C J McNamara
- Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
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