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Xie C, Iroga P, Bound MJ, Grivell J, Huang W, Jones KL, Horowitz M, Rayner CK, Wu T. Impact of the timing of metformin administration on glycaemic and glucagon-like peptide-1 responses to intraduodenal glucose infusion in type 2 diabetes: a double-blind, randomised, placebo-controlled, crossover study. Diabetologia 2024:10.1007/s00125-024-06131-6. [PMID: 38561463 DOI: 10.1007/s00125-024-06131-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 02/14/2024] [Indexed: 04/04/2024]
Abstract
AIMS/HYPOTHESIS Metformin lowers postprandial glycaemic excursions in individuals with type 2 diabetes by modulating gastrointestinal function, including the stimulation of glucagon-like peptide-1 (GLP-1). The impact of varying the timing of metformin administration on postprandial glucose metabolism is poorly defined. We evaluated the effects of metformin, administered at different intervals before an intraduodenal glucose infusion, on the subsequent glycaemic, insulinaemic and GLP-1 responses in metformin-treated type 2 diabetes. METHODS Sixteen participants with type 2 diabetes that was relatively well-controlled by metformin monotherapy were studied on four separate days in a crossover design. On each day, participants were randomised to receive a bolus infusion of metformin (1000 mg in 50 ml 0.9% saline) via a nasoduodenal catheter at t = -60, -30 or 0 min (and saline at the other timepoints) or saline at all timepoints (control), followed by an intraduodenal glucose infusion of 12.56 kJ/min (3 kcal/min) at t = 0-60 min. The treatments were blinded to both participants and investigators involved in the study procedures. Plasma glucose, insulin and total GLP-1 levels were measured every 30 min between t = -60 min and t = 120 min. RESULTS There was a treatment-by-time interaction for metformin in reducing plasma glucose levels and increasing plasma GLP-1 and insulin levels (p<0.05 for each). The reduction in plasma glucose levels was greater when metformin was administered at t = -60 or -30 min vs t = 0 min (p<0.05 for each), and the increases in plasma GLP-1 levels were evident only when metformin was administered at t = -60 or -30 min (p<0.05 for each). Although metformin did not influence insulin sensitivity, it enhanced glucose-induced insulin secretion (p<0.05), and the increases in plasma insulin levels were comparable on the 3 days when metformin was given. CONCLUSIONS/INTERPRETATION In well-controlled metformin-treated type 2 diabetes, glucose-lowering by metformin is greater when it is given before, rather than with, enteral glucose, and this is associated with a greater GLP-1 response. These observations suggest that administration of metformin before meals may optimise its effect in improving postprandial glycaemic control. TRIAL REGISTRATION www.anzctr.org.au ACTRN12621000878875 FUNDING: The study was not funded by a specific research grant.
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Affiliation(s)
- Cong Xie
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
| | - Peter Iroga
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, Australia
| | - Michelle J Bound
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, Australia
| | - Jacqueline Grivell
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, Australia
| | - Weikun Huang
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, Australia
| | - Karen L Jones
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
| | - Michael Horowitz
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, Australia
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
| | - Christopher K Rayner
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, Australia
- Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, Australia
| | - Tongzhi Wu
- Adelaide Medical School and Centre of Research Excellence in Translating Nutritional Science to Good Health, The University of Adelaide, Adelaide, Australia.
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia.
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Li M, Bennett MK, Toubia J, Pope VS, Tea MN, Tamang S, Samuel MS, Anderson PH, Gliddon BL, Powell JA, Pitson SM. An orthotopic syngeneic mouse model of bortezomib-resistant multiple myeloma. Br J Haematol 2024; 204:566-570. [PMID: 38053270 DOI: 10.1111/bjh.19240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/11/2023] [Accepted: 11/21/2023] [Indexed: 12/07/2023]
Abstract
While bortezomib has significant benefits in multiple myeloma (MM) therapy, the disease remains incurable due to the invariable development of bortezomib resistance. This emphasises the need for advanced models for preclinical evaluation of new therapeutic approaches for bortezomib-resistant MM. Here, we describe the development of an orthotopic syngeneic bortezomib-resistant MM mouse model based on the most well-characterised syngeneic MM mouse model derived from spontaneous MM-forming C57BL/KaLwRij mice. Using bortezomib-resistant 5TGM1 cells, we report and characterise a robust syngeneic mouse model of bortezomib-resistant MM that is well suited to the evaluation of new therapeutic approaches for proteasome inhibitor-resistant MM.
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Affiliation(s)
- Manjun Li
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - Melissa K Bennett
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - John Toubia
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - Victoria S Pope
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - Melinda N Tea
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - Sarah Tamang
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - Michael S Samuel
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
- Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Paul H Anderson
- Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Briony L Gliddon
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
| | - Jason A Powell
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
- Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Stuart M Pitson
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, South Australia, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
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De Sousa SMC, Wu KHC, Colclough K, Rawlings L, Dubowsky A, Monnik M, Poplawski N, Scott HS, Horowitz M, Torpy DJ. Identification of monogenic diabetes in an Australian cohort using the Exeter maturity-onset diabetes of the young (MODY) probability calculator and next-generation sequencing gene panel testing. Acta Diabetol 2024; 61:181-188. [PMID: 37812285 PMCID: PMC10866744 DOI: 10.1007/s00592-023-02193-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 09/20/2023] [Indexed: 10/10/2023]
Abstract
AIMS This study aims to describe the prevalence of monogenic diabetes in an Australian referral cohort, in relation to Exeter maturity-onset diabetes of the young (MODY) probability calculator (EMPC) scores and next-generation sequencing with updated testing where relevant. METHODS State-wide 5-year retrospective cohort study of individuals referred for monogenic diabetes genetic testing. RESULTS After excluding individuals who had cascade testing for a familial variant (21) or declined research involvement (1), the final cohort comprised 40 probands. Incorporating updated testing, the final genetic result was positive (likely pathogenic/pathogenic variant) in 11/40 (27.5%), uncertain (variant of uncertain significance) in 8/40 (20%) and negative in 21/40 (52.5%) participants. Causative variants were found in GCK, HNF1A, MT-TL1 and HNF4A. Variants of uncertain significance included a novel multi-exonic GCK duplication. Amongst participants with EMPC scores ≥ 25%, a causative variant was identified in 37%. Cascade testing was positive in 9/10 tested relatives with diabetes and 0/6 tested relatives with no history of diabetes. CONCLUSIONS Contemporary genetic testing produces a high yield of positive results in individuals with clinically suspected monogenic diabetes and their relatives with diabetes, highlighting the value of genetic testing for this condition. An EMPC score cutoff of ≥ 25% correctly yielded a positive predictive value of ≥ 25% in this multiethnic demographic. This is the first Australian study to describe EMPC scores in the Australian clinic setting, albeit a biased referral cohort. Larger studies may help characterise EMPC performance between ethnic subsets, noting differences in the expected probability of monogenic diabetes relative to type 2 diabetes.
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Affiliation(s)
- Sunita M C De Sousa
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia.
- Adult Genetics Unit, Royal Adelaide Hospital, Adelaide, Australia.
- Adelaide Medical School, University of Adelaide, Adelaide, Australia.
| | - Kathy H C Wu
- Clinical Genomics, St Vincent's Hospital, Darlinghurst, NSW, Australia
- School of Medicine, University of New South Wales, Sydney, NSW, Australia
- Discipline of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- School of Medicine, University of Notre Dame, Sydney, NSW, Australia
| | - Kevin Colclough
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter, UK
| | - Lesley Rawlings
- Department of Genetics and Molecular Pathology, SA Pathology, Adelaide, Australia
| | - Andrew Dubowsky
- Department of Genetics and Molecular Pathology, SA Pathology, Adelaide, Australia
| | - Melissa Monnik
- Adult Genetics Unit, Royal Adelaide Hospital, Adelaide, Australia
| | - Nicola Poplawski
- Adult Genetics Unit, Royal Adelaide Hospital, Adelaide, Australia
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
| | - Hamish S Scott
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
- Department of Genetics and Molecular Pathology, SA Pathology, Adelaide, Australia
- Centre for Cancer Biology, an alliance between SA Pathology, The University of South Australia, Adelaide, Australia
| | - Michael Horowitz
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
| | - David J Torpy
- Endocrine and Metabolic Unit, Royal Adelaide Hospital, Adelaide, Australia
- Adelaide Medical School, University of Adelaide, Adelaide, Australia
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Duncanson E, Le Leu RK, Chur-Hansen A, Masotti T, Collins KL, Burke ALJ, Macauley LP, McDonald S, Jesudason S. Nephrology nurses' perspectives working with patients experiencing needle-related distress. J Ren Care 2023. [PMID: 37975628 DOI: 10.1111/jorc.12483] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 10/25/2023] [Accepted: 10/27/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND A key skill of nephrology nursing is cannulation of patients receiving haemodialysis. Traumatic and unsuccessful cannulation experiences, particularly in the initial weeks of haemodialysis, may contribute to the onset of needle distress for patients. OBJECTIVES To identify the key knowledge, skills and attitudes of nephrology nurses working with haemodialysis patients and the competencies relevant to nephrology nursing working with patients with needle-related distress. DESIGN A qualitative study involving semistructured interviews. Interviews were audio-recorded, transcribed and deductive, and inductive thematic analysis applied. PARTICIPANTS Nephrology nurses (n = 17) were interviewed from a tertiary kidney service in South Australia. Nurses had varying roles and years of experience (range 1-30 years) working with dialysis patients within the service. RESULTS Two overarching themes, (1) Flexibility in Practice and Care and (2) Responsibility of Nephrology Nursing, were identified as relevant across all knowledge, skills and attitudes of nephrology nurses working with patients with needle-related distress. Thirty-six knowledge, skills and attitudes were identified; 12 related to knowledge, 14 related to skills and 10 were identified as attitudes and were summarised under seven broad competencies. CONCLUSION This study identifies potential knowledge, skills and attitudes and competencies required for nephrology nurses working with patients with needle-related distress. It highlights strategies that may prevent the onset and worsening of needle-related distress, as well as reduce it. It also brings to light that nurses desire additional education regarding strategies to improve the patient experience of cannulation and nurse confidence and skill in this area.
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Affiliation(s)
- Emily Duncanson
- Central and Northern Adelaide Renal and Transplantation Service, Royal Adelaide Hospital, Adelaide, South Australia, Australia
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, South Australia, Australia
| | - Richard K Le Leu
- Central and Northern Adelaide Renal and Transplantation Service, Royal Adelaide Hospital, Adelaide, South Australia, Australia
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Anna Chur-Hansen
- School of Psychology, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Tahlia Masotti
- School of Psychology, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Kathryn L Collins
- School of Psychology, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
- Psychology Department, Central Adelaide Local Health Network, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Anne L J Burke
- School of Psychology, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
- Psychology Department, Central Adelaide Local Health Network, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Luke P Macauley
- School of Psychology, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Stephen McDonald
- Central and Northern Adelaide Renal and Transplantation Service, Royal Adelaide Hospital, Adelaide, South Australia, Australia
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
- Australia and New Zealand Dialysis and Transplant Registry, Adelaide, South Australia, Australia
| | - Shilpanjali Jesudason
- Central and Northern Adelaide Renal and Transplantation Service, Royal Adelaide Hospital, Adelaide, South Australia, Australia
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, South Australia, Australia
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Tran HB, Jersmann H, Truong TT, Hamon R, Roscioli E, Ween M, Pitman MR, Pitson SM, Hodge G, Reynolds PN, Hodge S. Disrupted epithelial/macrophage crosstalk via Spinster homologue 2-mediated S1P signaling may drive defective macrophage phagocytic function in COPD. PLoS One 2017; 12:e0179577. [PMID: 29112690 PMCID: PMC5675303 DOI: 10.1371/journal.pone.0179577] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 05/31/2017] [Indexed: 12/21/2022] Open
Abstract
Introduction We have previously established a link between impaired phagocytic capacity and deregulated S1P signaling in alveolar macrophages from COPD subjects. We hypothesize that this defect may include a disruption of epithelial-macrophage crosstalk via Spns2-mediated intercellular S1P signaling. Methods Primary alveolar macrophages and bronchial epithelial cells from COPD subjects and controls, cell lines, and a mouse model of chronic cigarette smoke exposure were studied. Cells were exposed to 10% cigarette smoke extract, or vehicle control. Spns2 expression and subcellular localization was studied by immunofluorescence, confocal microscopy and RT-PCR. Phagocytosis was assessed by flow-cytometry. Levels of intra- and extracellular S1P were measured by S1P [3H]-labeling. Results Spns2 expression was significantly increased (p<0.05) in alveolar macrophages from current-smokers/COPD patients (n = 5) compared to healthy nonsmokers (n = 8) and non-smoker lung transplant patients (n = 4). Consistent with this finding, cigarette smoke induced a significant increase in Spns2 expression in both human alveolar and THP-1 macrophages. In contrast, a remarkable Spns2 down-regulation was noted in response to cigarette smoke in 16HBE14o- cell line (p<0.001 in 3 experiments), primary nasal epithelial cells (p<0.01 in 2 experiments), and in smoke-exposed mice (p<0.001, n = 6 animals per group). Spns2 was localized to cilia in primary bronchial epithelial cells. In both macrophage and epithelial cell types, Spns2 was also found localized to cytoplasm and the nucleus, in line with a predicted bipartile Nuclear Localization Signal at the position aa282 of the human Spns2 sequence. In smoke-exposed mice, alveolar macrophage phagocytic function positively correlated with Spns2 protein expression in bronchial epithelial cells. Conclusion Our data suggest that the epithelium may be the major source for extracellular S1P in the airway and that there is a possible disruption of epithelial/macrophage cross talk via Spns2-mediated S1P signaling in COPD and in response to cigarette smoke exposure.
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Affiliation(s)
- Hai B. Tran
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, and Department of Medicine, University of Adelaide, Adelaide, Australia
- * E-mail:
| | - Hubertus Jersmann
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, and Department of Medicine, University of Adelaide, Adelaide, Australia
| | - Tung Thanh Truong
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, and Department of Medicine, University of Adelaide, Adelaide, Australia
- Department of TB & Lung Diseases, Hospital 175, Hochiminh City, Vietnam
| | - Rhys Hamon
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, and Department of Medicine, University of Adelaide, Adelaide, Australia
| | - Eugene Roscioli
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, and Department of Medicine, University of Adelaide, Adelaide, Australia
| | - Miranda Ween
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, and Department of Medicine, University of Adelaide, Adelaide, Australia
| | - Melissa R. Pitman
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
| | - Stuart M. Pitson
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
| | - Greg Hodge
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, and Department of Medicine, University of Adelaide, Adelaide, Australia
| | - Paul N. Reynolds
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, and Department of Medicine, University of Adelaide, Adelaide, Australia
| | - Sandra Hodge
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, and Department of Medicine, University of Adelaide, Adelaide, Australia
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