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Barnes M, Sulé-Suso J, Millett J, Roach P. Fourier transform infrared spectroscopy as a non-destructive method for analysing herbarium specimens. Biol Lett 2023; 19:20220546. [PMID: 36946131 PMCID: PMC10031417 DOI: 10.1098/rsbl.2022.0546] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
Dried plant specimens stored in herbaria are an untapped treasure chest of information on environmental conditions, plant evolution and change over many hundreds of years. Owing to their delicate nature and irreplaceability, there is limited access for analysis to these sensitive samples, particularly where chemical data are obtained using destructive techniques. Fourier transform infrared (FTIR) spectroscopy is a chemical analysis technique which can be applied non-destructively to understand chemical bonding information and, therefore, functional groups within the sample. This provides the potential for understanding geographical, spatial and species-specific variation in plant biochemistry. Here, we demonstrate the use of mid-FTIR microspectroscopy for the chemical analysis of Drosera rotundifolia herbarium specimens, which were collected 100 years apart from different locations. Principal component and hierarchical clustering analysis enabled differentiation between three main regions on the plant (lamina, tentacle stalk and tentacle head), and between the different specimens. Lipids and protein spectral regions were particularly sensitive differentiators of plant tissues. Differences between the different sets of specimens were smaller. This study demonstrates that relevant information can be extracted from herbarium specimens using FTIR, with little impact on the specimens. FTIR, therefore, has the potential to be a powerful tool to unlock historic information within herbaria.
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Affiliation(s)
- M Barnes
- Department of Chemistry, Loughborough University, Loughborough, UK
| | - J Sulé-Suso
- School of Pharmacy and Bioengineering, Guy Hilton Research Centre, Keele University, Keele, UK
- Cancer Centre, University Hospitals of North Midlands, Stoke-on-Trent, UK
| | - J Millett
- Department of Geography and Environment, Loughborough University, Loughborough, UK
| | - P Roach
- Department of Chemistry, Loughborough University, Loughborough, UK
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2
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Younus ZM, Roach P, Forsyth NR. Acrylamide-based hydrogels with distinct osteogenic and chondrogenic differentiation potential. Prog Biomater 2022; 11:297-309. [PMID: 35840792 PMCID: PMC9374864 DOI: 10.1007/s40204-022-00196-5] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 06/28/2022] [Indexed: 12/02/2022] Open
Abstract
Regeneration solutions for the osteochondral interface depth are limited, where multi-material implants have the potential to delaminate affecting the regeneration process and impacting the final integrity of tissue interface. Here we explore regionally mixed hydrogel networks, presenting distinct chemical features to determine their compatibility in supporting osteogenic or chondrogenic cell behaviour and differentiation. Poly(N-isopropylacrylamide) (pNIPAM) and poly(N-tert-butylacrylamide) (pNTBAM) hydrogels were assessed in terms of their chemical differences, mechanical strength, internal architecture, porosity and capacity to support cell viability, migration, and differentiation. pNTBAM polymerized with a Young’s modulus of up to 371 ± 31 kPa compared to the more flexible pNIPAM, 16.5 ± 0.6 kPa. Viability testing revealed biocompatibility of both hydrogels with significantly increased cell numbers observed in pNTBAM (500 ± 95 viable cells/mm2) than in pNIPAM (60 ± 3 viable cells/mm2) (P ≤ 0.05). Mineralization determined through alkaline phosphatase (ALP) activity, calcium ion and annexin A2 markers of mineralization) and osteogenic behaviour (collagen I expression) were supported in both hydrogels, but to a greater extent in pNTBAM. pNTBAM supported significantly elevated levels of chondrogenic markers as evidenced by collagen II and glycosaminoglycan expression in comparison to little or no evidence in pNIPAM (P ≤ 0.05). In conclusion, structurally similar, chemically distinct, acrylamide hydrogels display variable capacities in supporting osteochondral cell behaviours. These systems demonstrate spatial control of cell interaction through simple changes in monomer chemistry. Fine control over chemical presentation during the fabrication of biomaterial implants could lead to greater efficacy and targeted regeneration of semi-complex tissues.
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Affiliation(s)
- Z. M. Younus
- School of Pharmacy and Bioengineering, Keele University, Keele, UK
- Department of Clinical Laboratory Sciences, College of Pharmacy, University of Mosul, Mosul, Iraq
| | - P. Roach
- Department of Chemistry, School of Science, Loughborough University, Leicestershire, UK
| | - N. R. Forsyth
- School of Pharmacy and Bioengineering, Keele University, Keele, UK
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3
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Merryweather D, Moxon SR, Capel AJ, Hooper NM, Lewis MP, Roach P. Impact of type-1 collagen hydrogel density on integrin-linked morphogenic response of SH-SY5Y neuronal cells. RSC Adv 2021; 11:33124-33135. [PMID: 35493559 PMCID: PMC9042137 DOI: 10.1039/d1ra05257h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/28/2021] [Indexed: 11/23/2022] Open
Abstract
Cellular metabolism and behaviour is closely linked to cytoskeletal tension and scaffold mechanics. In the developing nervous system functional connectivity is controlled by the interplay between chemical and mechanical cues that initiate programs of cell behaviour. Replication of functional connectivity in neuronal populations in vitro has proven a technical challenge due to the absence of many systems of biomechanical regulation that control directional outgrowth in vivo. Here, a 3D culture system is explored by dilution of a type I collagen hydrogel to produce variation in gel stiffness. Hydrogel scaffold remodelling was found to be linked to gel collagen concentration, with a greater degree of gel contraction occurring at lower concentrations. Gel mechanics were found to evolve over the culture period according to collagen concentration. Less concentrated gels reduced in stiffness, whilst a biphasic pattern of increasing and then decreasing stiffness was observed at higher concentrations. Analysis of these cultures by PCR revealed a program of shifting integrin expression and highly variable activity in key morphogenic signal pathways, such as mitogen-associated protein kinase, indicating genetic impact of biomaterial interactions via mechano-regulation. Gel contraction at lower concentrations was also found to be accompanied by an increase in average collagen fibre diameter. Minor changes in biomaterial mechanics result in significant changes in programmed cell behaviour, resulting in adoption of markedly different cell morphologies and ability to remodel the scaffold. Advanced understanding of cell-biomaterial interactions, over short and long-term culture, is of critical importance in the development of novel tissue engineering strategies for the fabrication of biomimetic 3D neuro-tissue constructs. Simple methods of tailoring the initial mechanical environment presented to SH-SY5Y populations in 3D can lead to significantly different programs of network development over time.
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Affiliation(s)
- D Merryweather
- Department of Chemistry, Loughborough University Leicestershire LE11 3TU UK
| | - S R Moxon
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre Manchester M13 9PL UK
| | - A J Capel
- National Centre for Sport and Exercise Medicine (NCSEM), School of Sport, Exercise and Health Sciences, Loughborough University Leicestershire LE11 3TU UK
| | - N M Hooper
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre Manchester M13 9PL UK
| | - M P Lewis
- National Centre for Sport and Exercise Medicine (NCSEM), School of Sport, Exercise and Health Sciences, Loughborough University Leicestershire LE11 3TU UK
| | - P Roach
- Department of Chemistry, Loughborough University Leicestershire LE11 3TU UK
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Harawaza K, Cousins B, Roach P, Fernandez A. Modification of the surface nanotopography of implant devices: A translational perspective. Mater Today Bio 2021; 12:100152. [PMID: 34746736 PMCID: PMC8554633 DOI: 10.1016/j.mtbio.2021.100152] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 10/16/2021] [Accepted: 10/19/2021] [Indexed: 01/24/2023] Open
Abstract
There is an increasing need for the development of superior, safe, and more sophisticated implants, especially as our society historically has been moving towards an increasingly aging population. Currently, most research is being focused on the next generation of advanced medical implants, that are not only biocompatible but have modified surfaces that direct specific immunomodulation at cellular level. While there is a plethora of information on cell-surface interaction and how surfaces can be nanofabricated at research level, less is known about how the academic knowledge has been translated into clinical trials and commercial technologies. In this review, we provide a clinical translational perspective on the use of controlled physical surface modification of medical implants, presenting an analysis of data acquired from clinical trials and commercial products. We also evaluate the state-of-the-art of nanofabrication techniques that are being applied for implant surface modification at a clinical level. Finally, we identify some current challenges in the field, including the need of more advanced nanopatterning techniques, the comparatively small number of clinical trials and comment on future avenues to be explored for a successful clinical translation.
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Affiliation(s)
- K. Harawaza
- Chemistry Department, School of Science, Loughborough University, Loughborough, LE11 3TU, UK
| | - B. Cousins
- Chemistry Department, School of Science, Loughborough University, Loughborough, LE11 3TU, UK
| | - P. Roach
- Chemistry Department, School of Science, Loughborough University, Loughborough, LE11 3TU, UK
| | - A. Fernandez
- Chemistry Department, School of Science, Loughborough University, Loughborough, LE11 3TU, UK
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Abstract
Developments in micro-manufacture as well as biofabrication technologies are driving our ability to create complex tissue models such as ‘organ-on-a-chip’ devices. The complexity of neural tissue, however, requires precisely specific cellular connectivity across many neuronal populations, and thus there have been limited reports of complex ‘brain-on-a-chip’ technologies modelling specific cellular circuit function. Here we describe the development of a model of in vitro brain circuitry designed to accurately reproduce part of the complex circuitry involved in neurodegenerative diseases; using segregated co-culture of specific basal ganglia (BG) neuronal subtypes to model central nervous system circuitry. Lithographic methods and chemical modification were used to form structured micro-channels, which were populated by specifically cultured neuronal sub-types to represent parts of the inter-communicating neural circuit. Cell morphological assessment and immunostaining showed connectivity, which was supported by electrophysiology measurements. Electrical activity of cells was measured using patch-clamp, showing voltage dependant Na+ and K+ currents, and blocking of Na+ current by TTX, and calcium imaging showing TTX-sensitive slow Ca2+ oscillations resulting from action potentials. Monitoring cells across connected ports post-TTX addition demonstrated both upstream and downstream changes in activity, indicating network connectivity. The model developed herein provides a platform technology that could be used to better understand neurological function and dysfunction, contributing to a growing urgency for better treatments of neurodegenerative disease. We anticipate the use of this advancing technology for the assessment of pharmaceutical and cellular therapies as a means of pre-clinical assessment, and further for the advancement of neural engineering approaches for tissue engineering.
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Chan B, Sim HW, Ravikumar A, Bailey D, Chan D, Lawrence B, McEwan A, Pavlakis N, Segelov E, Singh S, Roach P, Wyld D. 417P Availability and Utility of Functional Imaging (FI) and Peptide Receptor Radionuclide Therapy (PRRT) in the CommNETS Collaboration (Australia, Canada and New Zealand). Ann Oncol 2016. [DOI: 10.1016/s0923-7534(21)00575-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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7
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Everett J, Gunathilake D, Dufficy L, Roach P, Thomas J, Upton D, Naumovski N. Theanine consumption, stress and anxiety in human clinical trials: A systematic review. Journal of Nutrition & Intermediary Metabolism 2016. [DOI: 10.1016/j.jnim.2015.12.308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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8
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Whitby S, Christenson J, Dufficy L, Roach P, Thomas J, Naumovski N. The effects of resveratrol supplementation on obesity in humans: A systematic review. Journal of Nutrition & Intermediary Metabolism 2016. [DOI: 10.1016/j.jnim.2015.12.326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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9
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Walton J, Alexander MR, Fairley N, Roach P, Shard AG. Film thickness measurement and contamination layer correction for quantitative XPS. SURF INTERFACE ANAL 2016. [DOI: 10.1002/sia.5934] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- J. Walton
- TSTC Ltd; 5 Grosvenor Terrace Teignmouth TQ14 8NE UK
| | - M. R. Alexander
- School of Pharmacy; The University of Nottingham; Nottingham NG7 2RD UK
| | - N. Fairley
- Casa Software Ltd; 5 Grosvenor Terrace Teignmouth TQ14 8NE UK
| | - P. Roach
- Institute for Science and Technology in Medicine; Keele University; Keele ST5 5BG UK
| | - A. G. Shard
- National Physical Laboratory; Middlesex TW11 0LW UK
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10
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Alhumaid F, Almutairi S, Roach P, Fuller HR, Gates MA. Do neurons from the primary motor cortex grow in response to signals from the developing spinal cord in vitro? HAMDAN MEDICAL JOURNAL 2015. [DOI: 10.7707/hmj.537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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11
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Almaarik A, Dawary M, Moukannas A, Roach P. Microplasma pen designs for surface chemical pattern fabrication. HAMDAN MEDICAL JOURNAL 2015. [DOI: 10.7707/hmj.518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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12
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Almutairi S, Alhumaid F, Roach P, Gates MA, Fuller HR. What is the relationship between survival motor neuron expression and rat spinal cord development? HAMDAN MEDICAL JOURNAL 2015. [DOI: 10.7707/hmj.540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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13
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Roach P, Drummond N. 'It's nice to have something to do': early-onset dementia and maintaining purposeful activity. J Psychiatr Ment Health Nurs 2014; 21:889-95. [PMID: 24841949 DOI: 10.1111/jpm.12154] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/29/2014] [Indexed: 11/30/2022]
Abstract
As the global focus on dementia care increases due to the demand on health, social, legal and financial services, it is imperative to further understand the experience of those living with a diagnosis of dementia. There is a particular lack of research focused on younger people (under the age of 65 years) with dementia and virtually none focuses on the experience of the family unit. The literature suggests that periods of transition place significant stressors on families living with dementia. One such transition is the transition out of perceived purposeful activity, be this employment or voluntary work. This transition was explored during the course of a qualitative repeated interview study with younger people with dementia and their families. Nine families (20 participants) took part in semi-structured research interviews that were transcribed and analyzed using a Framework approach to qualitative analysis. Meaningful Activity emerged as a major theme through this analysis. Two subthemes also emerged: (1) the traumatic cessation of work; and (2) the need for purposeful activity. These themes have significant clinical implications as maintaining a purposeful role through high-quality, age-specific dementia services may decrease the direct and indirect costs of dementia to global economies.
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Affiliation(s)
- P Roach
- Family Medicine, University of Alberta, Edmonton, Alberta, Canada
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14
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Shon HI, Bernard E, Roach P, Delbridge L. The value of oblique pinhole images in pre-operative localisation with 99mTc-MIBI for primary hyperparathyroidism. ACTA ACUST UNITED AC 2014; 28:736-42. [DOI: 10.1007/s002590100523] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
Fouling of surfaces is often problematic in microfluidic devices, particularly when using protein or -enzymatic solutions. Various coating methods have been investigated to reduce the tendency for protein molecules to adsorb, mostly relying on hydrophobic surface chemistry or the antifouling ability of -polyethylene glycol. Here we present the potential use of superhydrophobic surfaces to not only reduce the amount of surface contamination but also to induce self-cleaning under flow conditions. The methodology is presented in order to prepare superhydrophobic surface coatings having micro- and nanoscale feature dimensions, as well as a step-by-step guide to quantify adsorbed protein down to nanogram levels. The fabrication of these surfaces as coatings via silica sol-gel and copper nano-hair growth is presented, which can be applied within microfluidic devices manufactured from various materials.
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Affiliation(s)
- N J Shirtcliffe
- Biomimetic Materials, Hochschule Rhein-Waal, Rhine-Waal University of Applied Sciences, Kleve, Germany
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16
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Abstract
Microfluidic systems allow small volumes of liquids to be manipulated, either by being passed through channels or moved around as liquid droplets. Such systems have been developed to separate, purify, analyze, and deliver molecules to reaction zones. Although volumes are small, reaction rates, catalysis, mixing, and heat transfer can be high, enabling the accurate sensing of tiny quantities of agents and the synthesis of novel products. The incorporation of multiple components, such as pumps, valves, mixers, and heaters, onto a single microfluidic platform has brought about the field of lab-on-a-chip devices or micro total analysis systems (μTAS). Although used in the research laboratory for numerous years, few of these devices have made it into the commercial market, due to their complexity of fabrication and limited choice of material. As the dimensions of these systems become smaller, interfacial interactions begin to dominate in terms of device performance. Appropriate selection of bulk materials, or the application of surface coatings, can allow control over surface properties, such as the adsorption of (bio)molecules. Here we review current microfluidic technology in terms of biocompatibility issues, examining the use of modification strategies to improve device longevity and performance.
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Affiliation(s)
- N J Shirtcliffe
- Biomimetic Materials, Hochschule Rhein-Waal, Rhine-Waal University of Applied Sciences, Kleve, Germany
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Roach P, Keady J, Bee P. 'It's easier just to separate them': practice constructions in the mental health care and support of younger people with dementia and their families. J Psychiatr Ment Health Nurs 2012; 19:555-62. [PMID: 22070795 DOI: 10.1111/j.1365-2850.2011.01836.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
There is no standard model of specialist care for younger people with dementia (onset before the age of 65 years) and specialist service provision varies widely throughout the UK. In order to gain a clearer picture about ways in which clinical staff work with younger people with dementia, semi-structured interviews were conducted with dementia care staff working in the north-west of England. Interviews focused on exploring daily working practices and the meaning placed on clinical decision making when involving family/carers in routine practice. Content analysis generated three core themes: (1) Maintaining Separation: how clinical staff conceptualize the meaning of 'family' in the provision of dementia care services; (2) Providing Practical Help: the focus in care provision on assisting families with aspects of daily life such as finances, education and physical care; and (3) Acknowledging the Family Context: how staff understand and interact with family members in an attempt to initiate care, utilizing biographically informed practice. By understanding how staff view their role in providing younger people with dementia with effective, high-quality dementia care, it is anticipated that a more family-centred approach can be integrated into already established patterns of working that more holistically meet the needs of this group.
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Affiliation(s)
- P Roach
- Department of Clinical Neurosciences, University of Calgary, Foothills Medical Centre, 1403-29 Street N.W., Calgary, AB, Canada.
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Naumovski N, Veysey M, Ng X, Boyd L, Dufficy L, Blades B, Travers C, Lewis P, Sturm J, Townley-Jones M, Yates Z, Roach P, Lucock M. The folic acid endophenotype and depression in an elderly population. J Nutr Health Aging 2010; 14:829-33. [PMID: 21125200 DOI: 10.1007/s12603-010-0135-5] [Citation(s) in RCA: 8] [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] [Indexed: 10/19/2022]
Abstract
OBJECTIVES Folate status and/or genes have been linked to depression in a number of studies. This may be via a direct action (or actions) on neuronal membranes or indirect effects through the metabolism of methyl groups involved in neurotransmitter synthesis. This study examines folate and related thiol metabolism that might underpin either phenomenon. DESIGN Cohort study describing the relationship between several genetic and nutritional aspects of folic acid homeostasis and depression assessed by the HADS psychometric index in an elderly cohort. SETTING New South Wales (Australia) retirement village. PARTICIPANTS 118 elderly participants (age 65-90 years). RESULTS Stepwise multiple regression was used to determine the best statistical model to predict depression; C677T-MTHFR (p=0.0103) was found to be positively associated with depression, while the thiol dipeptide Cys-Gly was negatively associated (p=0.0403). The statistical models used accounted for the major folate related indices (genetic and biochemical) that are most often evaluated in the context of health and disease. When only genetic data were examined for interactions, C677T-MTHFR was found to be negatively associated with the HADS Depression Index Score (p=0.0191). CONCLUSION The potential influence of Cys-Gly on this phenotype is novel, and of considerable interest given that it has been linked to altered spontaneous activity and sedation in an animal model. Cys-Gly is a recognised ligand at the N-methyl-D-aspartatic acid (NMDA) subclass of glutamate receptor, a system associated with depression. In addition, the C677T-MTHFR association adds further support to existing findings underscoring the potential role of folate in depression.
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Affiliation(s)
- N Naumovski
- School of Environmental & Life Sciences, University of Newcastle, Ourimbah, NSW, Australia
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20
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Stern GA, Sanei H, Roach P, DeLaronde J, Outridge PM. Historical interrelated variations of mercury and aquatic organic matter in lake sediment cores from a subArctic lake in Yukon, Canada: further evidence toward the algal-mercury scavenging hypothesis. Environ Sci Technol 2009; 43:7684-7690. [PMID: 19921879 DOI: 10.1021/es902186s] [Citation(s) in RCA: 9] [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] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This study investigates the role of climate-driven aquatic productivity increases in conrolling the sedimentary accumulation of mercury (Hg) in Kusawa Lake, Yukon, Canada. Organic geochemistry data reveals a significant link between the increasing trends of Hg and of labile algal-derived organic matter (OM) over the centuries and in particular over recent decades. Sedimentary Hg accumulation rates continue to increase even though atmospheric concentrations of Hg have remained the same or even declined. Together, these findings indicate that the significant rise in Hg content recorded in the sediments since the early 1950s may not be representative of increasing atmospheric Hg levels but are strongly influenced by elevated concentrations of algal-derived OM in the water-column. These likely increase the scavenging rate of "available" Hg from the water column. Therefore, recent increases in algal productivity may result in overestimation of the historical rates of atmospheric Hg deposition recorded in the sediments. This study confirms earlier published findings from two High Arctic lakes, and shows that the Hg-OM scavenging hypothesis may also apply to sub-Arctic lakes.
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Affiliation(s)
- G A Stern
- Freshwater Institute, Department of Fisheries and Oceans, Winnipeg, MB, Canada.
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21
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Duxbury JA, Wright KM, Bradley DM, Roach P. A study of the views of patients and nurses about the administration of medication in the acute mental health setting. J Psychiatr Ment Health Nurs 2009; 16:672-7. [PMID: 19689562 DOI: 10.1111/j.1365-2850.2009.01423.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J A Duxbury
- Mental Health, University of Central Lancashire, Lancashire, UK
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Abstract
OBJECTIVES To evaluate the effects of gender, sex orientation, age, relationship status, age at first sex education, age at first sex, frequency of sex and number of sexual partners on the likelihood of unprotected sex in the United Kingdom (UK). METHODS A web-based survey was conducted in the UK in 2004 with 10,138 respondents. Eight variables were chosen as potential predictors of unprotected sex. Responses from sexually active participants were combined and crude/adjusted odds ratios (AORs) were calculated for binary/categorical variables. RESULTS No differences were found in AOR for gender, sex orientation, relationship status and frequency of sex. Differences were found in AOR for age, sex education, age at first sex and number of sexual partners, e.g. AOR 21-24 years of age versus under 16 (1.92, CI 1.38-2.68; p-value < 0.001); AOR sex education never received versus first sex education under 10 years of age (1.45, CI 1.12-1.87; p-value < 0.01); AOR first sex at 20 years versus at 14 years (0.56, CI 0.40-0.79; p-value < 0.01); and AOR 11-20 partners versus one partner (24.91, CI 20.02-30.98; p-value < 0.001). The association of sex orientation and relationship status with unprotected sex is confounded by the number of sexual partners. CONCLUSIONS UK health and education authorities should develop strategies to provide sex education starting in primary school and continuing throughout secondary school. Prevention programs and policies should focus on particular sexual behaviours. Furthermore, an understanding of sexual diversity and reducing stigmatisation of sexual orientation is necessary.
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Affiliation(s)
- M Fontes
- Bloomberg School of Public Health, Johns Hopkins University, Baltimore, USA.
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23
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Naumovski N, Roach P. Abstract: 1488 EPIGALLOCATECHIN GALLATE LOWERS CHOLESTEROL IN THE CHOLESTEROL-FED RABBIT BY UPREGULATING THE LDL RECEPTOR AND INHIBITING CHOLESTEROL SYNTHESIS AT THE LEVEL OF SQUALENE EPOXIDASE. ATHEROSCLEROSIS SUPP 2009. [DOI: 10.1016/s1567-5688(09)70449-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Koc Y, de Mello AJ, McHale G, Newton MI, Roach P, Shirtcliffe NJ. Nano-scale superhydrophobicity: suppression of protein adsorption and promotion of flow-induced detachment. Lab Chip 2008; 8:582-586. [PMID: 18369513 DOI: 10.1039/b716509a] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Wall adsorption is a common problem in microfluidic devices, particularly when proteins are used. Here we show how superhydrophobic surfaces can be used to reduce protein adsorption and to promote desorption. Hydrophobic surfaces, both smooth and having high surface roughness of varying length scales (to generate superhydrophobicity), were incubated in protein solution. The samples were then exposed to flow shear in a device designed to simulate a microfluidic environment. Results show that a similar amount of protein adsorbed onto smooth and nanometer-scale rough surfaces, although a greater amount was found to adsorb onto superhydrophobic surfaces with micrometer scale roughness. Exposure to flow shear removed a considerably larger proportion of adsorbed protein from the superhydrophobic surfaces than from the smooth ones, with almost all of the protein being removed from some nanoscale surfaces. This type of surface may therefore be useful in environments, such as microfluidics, where protein sticking is a problem and fluid flow is present. Possible mechanisms that explain the behaviour are discussed, including decreased contact between protein and surface and greater shear stress due to interfacial slip between the superhydrophobic surface and the liquid.
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Affiliation(s)
- Y Koc
- Imperial College London, South Kensington, London, UKSW7 2AZ
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Fontes M, Roach P. T10-O-05 Age at first sex: when does it really happen? Sexologies 2008. [DOI: 10.1016/s1158-1360(08)72904-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Roach P, McHale G, Evans CR, Shirtcliffe NJ, Newton MI. Decoupling of the liquid response of a superhydrophobic quartz crystal microbalance. Langmuir 2007; 23:9823-30. [PMID: 17705513 DOI: 10.1021/la701089a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Recent reports using particle image velocimetry and cone-and-plate rheometers have suggested that a simple Newtonian liquid flowing across a superhydrophobic surface demonstrates a finite slip length. Slippage on a superhydrophobic surface indicates that the combination of topography and hydrophobicity may have consequences for the coupling at the solid--liquid interface observed using the high-frequency shear-mode oscillation of a quartz crystal microbalance (QCM). In this work, we report on the response of a 5 MHz QCM possessing a superhydrophobic surface to immersion in water--glycerol mixtures. QCM surfaces were prepared with a layer of SU-8 photoresist and lithographically patterned to produce square arrays of 5 mum diameter circular cross-section posts spaced 10 microm center-to-center and with heights of 5, 10, 15, and 18 microm. Non-patterned layers were also created for comparison, and both non-hydrophobized and chemically hydrophobized surfaces were investigated. Contact angle measurements confirmed that the hydrophobized post surfaces were superhydrophobic. QCM measurements in water before and after applying pressure to force a Cassie-Baxter (non-penetrating) to Wenzel (penetrating) conversion of state showed a larger frequency decrease and higher dissipation in the Wenzel state. QCM resonance spectra were fitted to a Butterworth-van Dyke model for the full range of water-glycerol mixtures from pure water to (nominally) pure glycerol, thus providing data on both energy storage and dissipation. The data obtained for the post surfaces show a variety of types of behavior, indicating the importance of the surface chemistry in determining the response of the quartz crystal resonance, particularly on topographically structured surfaces; data for hydrophobized post surfaces imply a decoupling of the surface oscillation from the mixtures. In the case of the 15 microm tall hydrophobized post surfaces, crystal resonance spectra become narrower as the viscosity-density product increases, which is contrary to the usual behavior. In the most extreme case of the 18 microm tall hydrophobized post surfaces, both the frequency decrease and bandwidth increase of the resonance spectra are significantly lower than that predicted by the Kanazawa and Gordon model, thus implying a decoupling of the oscillating surface from the liquid, which can be interpreted as interfacial slip.
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Affiliation(s)
- P Roach
- School of Biomedical and Natural Sciences, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, United Kingdom
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Abstract
AIM To compare insulin lispro mixture (25% insulin lispro and 75% NPL; Mix 25/75) twice-daily plus oral glucose-lowering medications (metformin and/or sulphonylurea) with once-daily insulin glargine plus oral agents with respect to postprandial glycaemic control and other glucose and lipid parameters in patients with Type 2 diabetes inadequately controlled with insulin and/or oral glucose-lowering agents. METHODS This was a randomized, open-label, crossover study. Prestudy oral agents were continued and patients not already on oral agents were treated with metformin. Mix 25/75 and insulin glargine were adjusted over 3 months to attain premeal plasma glucose (PG) < 6.0 mmol/l and were then given during a 24-h in-patient test meal period with frequent PG, serum triglyceride (TG) and free fatty acid (FFA) measurements. RESULTS Twenty patients (10 F/10 M; mean +/-sd age 54.0 +/- 10.7 years, body mass index 37.0 +/- 8.6 kg/m2, HbA1c 8.4 +/- 1.01%) participated. Mean doses were 23 U before the morning and 37 U before the evening meal for Mix 25/75 and 44 U for insulin glargine. The combined 2-h morning and evening meal postprandial plasma glucose (PPG) was not different between groups (9.2 +/- 2.04 vs. 9.9 +/- 1.66 mmol/l, P = 0.161). Mix 25/75 was associated with a lower mean 2-h PPG for all meals combined (9.0 +/- 1.88 vs. 9.9 +/- 1.80 mmol/l, P < 0.05) and lower mean 24-h PG (6.7 +/- 1.00 vs. 7.5 +/- 1.32 mmol/l, P < 0.01). Eight patients experienced mild hypoglycaemia (PG < 3.5 mmol/l) with Mix 25/75 and 3 with insulin glargine. The endpoint HbA1c was lower with Mix 25/75 (6.9 +/- 0.52% vs. 7.3 +/- 0.81%, P < 0.05). CONCLUSIONS In a 24-h test-meal setting in 20 patients, Mix 25/75 insulin plus oral glucose-lowering agents was associated with lower mean PPG and 24-h PG, more mild hypoglycaemia and similar TG, FFA and fasting PG concentrations. HbA1c was lower with Mix 75/25 plus oral agents, although it may not have reached steady state due to ongoing dose adjustment.
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Affiliation(s)
- P Roach
- Indiana University School of Medicine and Eli Lilly and Company, Indianapolis, IN 46202, USA.
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Ryan MJ, Stern GA, Diamond M, Croft MV, Roach P, Kidd K. Temporal trends of organochlorine contaminants in burbot and lake trout from three selected Yukon lakes. Sci Total Environ 2005; 351-352:501-22. [PMID: 16140362 DOI: 10.1016/j.scitotenv.2004.08.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2004] [Revised: 07/28/2004] [Accepted: 08/28/2004] [Indexed: 05/02/2023]
Abstract
Historical studies have demonstrated that organochlorine (OC) concentrations in top predators can vary considerably from lake to lake within a small geographic region but temporal trends of these contaminants have rarely been monitored in a sub-Arctic area for a long period of time. This study examined OC concentrations, including chlordane (CHL), DDT, hexachlorocyclohexane (HCH), toxaphene (CHB), PCB and chlorinated benzenes (CBz) in lake trout and burbot, from three Yukon lakes (Laberge, Kusawa, Quiet), over a span of 11 years (1992-2003). Temporal and spatial differences continue to exist in the OC concentrations of burbot and lake trout between these lakes. There is strong evidence that these contaminants are declining at various rates in lake trout (Salveninus namaycush) in Laberge, Kusawa and Quiet Lakes. For example, SigmaDDT concentrations have decreased 39%, 85% and 84% in Kusawa, Quiet and Laberge Lakes, respectively. Conversely, no consistent trends were observed in OC concentrations for burbot (Lota lota). For example, there is no evidence of a decline in toxaphene concentrations of Kusawa burbot yet a 58% decrease was observed in Laberge samples. Increases were also observed in the SigmaHCH levels of Kusawa Lake burbot, as well as increases in all OC groups (except SigmaHCH) for the Quiet Lake burbot samples. Decreases in burbot were evident in SigmaHCH and SigmaCHB for Lake Laberge fish and in SigmaCHL for Kusawa Lake samples. Spatial variations in OC levels are quite evident as Lake Laberge trout and burbot continued to maintain the highest levels over the eleven-year period from 1992 to 2003 followed by Kusawa Lake and then Quiet Lake. These differences were related to a variety of factors especially the species morphological characteristics such as log age, log weights and fish lipid content. A decreasing trend in Quiet and Laberge Lake trout lipid content, coupled with fluctuating condition factors and increases in body masses, suggest biotic changes may be occurring within the food webs due to fish population variations related to the cessation of commercial fishing or potentially an increase in lake plankton productivity related to annual climate variation. It is suspected that biotic factors rather than atmospheric inputs are the primary factors affecting the contaminant concentrations in lake trout and burbot in the study lakes.
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Affiliation(s)
- M J Ryan
- Department of Fisheries and Oceans, Winnipeg, MB and U. Manitoba, Winnipeg, MB 501 University Cresent, Canada, R3T 2N6.
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Lockhart WL, Stern GA, Low G, Hendzel M, Boila G, Roach P, Evans MS, Billeck BN, DeLaronde J, Friesen S, Kidd K, Atkins S, Muir DCG, Stoddart M, Stephens G, Stephenson S, Harbicht S, Snowshoe N, Grey B, Thompson S, DeGraff N. A history of total mercury in edible muscle of fish from lakes in northern Canada. Sci Total Environ 2005; 351-352:427-63. [PMID: 16169059 DOI: 10.1016/j.scitotenv.2004.11.027] [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] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Revised: 06/05/2004] [Accepted: 11/27/2004] [Indexed: 05/04/2023]
Abstract
Subsistence fishing has been an important source of food for Native People in northern Canada since prehistoric time. Measurements of the levels of mercury in edible muscle of northern fish have been undertaken for over three decades in efforts to evaluate the risks of consuming northern fish. This report summarizes the data obtained from 7974 fish of 25 species from sites distributed from the Yukon to Labrador. The most abundant species were lake trout, lake whitefish, arctic char, walleye, northern pike and burbot. The question being asked was essentially "Are the fish safe to eat?" The results were used to support decisions on fishing and consumption of fish. They were sorted in several ways, into concentration ranges corresponding to human consumption guidelines, into political jurisdictions and into types of bedrock geology. Overall walleye, northern pike and lake trout, usually exceeded the subsistence consumption guideline of 0.2 microg g-1 total mercury and often exceeded the higher guideline of 0.5 microg g-1 total mercury for commercial sales of fish. Mercury in burbot, another facultative predator, was often lower but several still exceeding a guideline. Arctic char collections were mostly from anadromous populations and these had very low levels of mercury, presumably reflecting marine food sources. Lake whitefish were among the cleanest fish examined with 69 of 81 collections falling in the lowest range. Most collections were from sites in sedimentary rock. However a few sites were in metamorphic, intrusive or volcanic rocks and these, taken together, tended to have a higher proportion of sites in the higher ranges of mercury. These results indicate a widespread problem with mercury in subsistence fisheries for predator species of fish with the problem being most problematic for Nunavut.
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Affiliation(s)
- W L Lockhart
- North-South Consultants Inc., 833 Harstone Road, Winnipeg, Manitoba, Canada R3R 1E1
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30
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Roach P, Woodworth J, Gudat U, Cerimele B, Diebler F, Pein M, Dreyer M. A 75% insulin lispro/25% NPL mixture provides a longer duration of insulin activity compared with insulin lispro alone in patients with Type 1 diabetes. Diabet Med 2003; 20:946-52. [PMID: 14632722 DOI: 10.1046/j.1464-5491.2003.01100.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To compare a new insulin formulation, high mix (HM) [75% lispro (LP) and 25% neutral protamine lispro (NPL)], to regular human insulin (HR) and LP with respect to glucose response and pharmacokinetics following a test meal in patients with Type 1 diabetes. METHODS After fasting overnight, patients received an intravenous insulin infusion to standardize blood glucose (BG) to 7.5 mmol/l (135 mg/dl). In a randomised, three-way crossover study, HR was injected 30 min before, and LP or HM was injected immediately before the test meal on three separate occasions. For each patient, LP and HR were administered at identical doses; the HM dose was one and one third times that of HR and LP to maintain the same dose of short or rapid-acting insulin. The insulin infusion was stopped 15 min after the insulin injection. Free insulin and BG concentrations were measured frequently for 7 h following the test meal. RESULTS HM and LP resulted in better glycaemic control than HR during the observation period. BG concentrations during the first 4-5 h did not differ between HM and LP. However, HM exhibited prolonged insulin activity relative to LP beyond 5 h, extending the duration of action by approximately 1 h, and resulting in lower overall BG concentrations when the 0-6- and 0-7-h intervals were considered. CONCLUSIONS Compared with LP, HM provided similar glycaemic control for up to 5 h and superior glycaemic control from 5 to 7 h following a standard test meal.
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Affiliation(s)
- P Roach
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Abstract
AIM To compare pre-meal injection of Humalog Mix50 (Mix50) and Humalog Mix25 (Humalog Mix75/25 in the US; Mix25) with respect to 2 h postprandial (2 h pp) blood glucose (BG) control after a carbohydrate-rich breakfast in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS One hundred and sixteen patients were enrolled in a 16-week crossover trial and received two treatment regimens in a randomized crossover fashion: (i) Mix50 before breakfast and Mix25 before the evening meal (Mix50/Mix25) and (ii) Mix25 before both breakfast and the evening meal (Mix25 twice daily). Insulin doses were adjusted according to stated glycaemic targets. After 6 and 8 weeks of treatment, the patient's usual morning insulin dose was administered, followed immediately by a test breakfast representative of the patient's usual breakfast meal. Fasting and 2 h pp BG concentrations were measured at the time of the test meal. Haemoglobin A1c (A1C) was measured, and information regarding hypoglycaemia (symptoms) was collected at the end of each treatment period. RESULTS Insulin doses were similar between treatments (morning = 31-33 U, evening = 26-28 U) at endpoint. Following the test breakfast, the 2 h pp BG was lower (10.9 +/- 0.3 mmol/l vs. 12.4 +/- 0.3 mmol/l, p = 0.0012) and the 2 h pp BG excursion was smaller (1.4 +/- 0.28 mmol/l vs. 3.5 +/- 0.28 mmol/l, p < 0.001) during treatment with Mix50/Mix25 than during treatment with Mix25 twice daily. There was no difference between the treatments with respect to fasting BG (Mix50/Mix25, 9.5 +/- 0.3 mmol/l vs. Mix25 twice daily, 8.9 +/- 0.3 mmol/l; p = NS), A1C (8.14% +/- 1.14% vs. 8.14% +/- 1.07%; p = NS) or the incidence of self-reported hypoglycaemia (34% vs. 23%; p = NS). CONCLUSIONS Compared with treatment with Mix25 twice daily, treatment with Mix50 before breakfast and Mix25 before the evening meal resulted in better pp glycaemic control following a carbohydrate-rich meal, and similar fasting BG, A1C and incidence of hypoglycaemia in patients with type 2 diabetes.
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Affiliation(s)
- P Roach
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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32
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Stone E, Roach P, Bernard E, Briggs G, Havryk A, Faulder K, Dennis C. Use of computed tomography pulmonary angiography in the diagnosis of pulmonary embolismin patients with an intermediate probability ventilation/perfusion scan. Intern Med J 2003; 33:74-8. [PMID: 12603578 DOI: 10.1046/j.1445-5994.2003.00345.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Computed tomography pulmonary -angiography (CTPA) plays an increasingly important role in the diagnosis of pulmonary embolism (PE). Although accurate in the detection of large PE, its accuracy in other patient groups is yet to be defined. AIM To compare CTPA with pulmonary angiography as a second-line investigation in patients with a ventilation/perfusion (VQ) scan indicating an intermediate probability of PE. METHODS We recruited 25 patients over a 17-month period. Subjects were eligible if they: (i). had clinically suspected PE, (ii). had a VQ scan indicating an intermediate probability of PE and (iii). were referred for pulmonary angiography. Subjects underwent CTPA within 36 h of the VQ scan. CTPA was interpreted without knowledge of the results of the pulmonary angiogram by two of the authors. RESULTS PE was prevalent (i.e. embolus detected at pulmonary angiography) in seven of 25 subjects (28%). The sensitivity of CTPA was 57% and the specificity was 94%. CONCLUSIONS In the setting of intermediate-probability VQ scanning, CTPA may be used to clarify the diagnosis of PE. However, a negative CTPA cannot -definitely exclude PE. Conventional pulmonary angiography may be necessary to determine the presence of PE if CTPA is negative.
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Affiliation(s)
- E Stone
- Department of Respiratory Medicine, Royal North Shore Hospital, University of Sydney, New South Wales, Australia.
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Blades B, Roach P, Lewis P. 3P-0832 The prevalence and treatment of hypercholesterolaemia in an Australian population sample. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)91050-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
PURPOSE The aim of this study was to assess the diagnostic value of RBC scintigraphy in the evaluation of possible splenic hemangioma. MATERIALS AND METHODS RBC scintigraphy was performed on a patient with an incidental finding of a splenic mass on computed tomographic scanning. Early and delayed planar and SPECT images were obtained. RESULTS Delayed images revealed blood pooling of the splenic mass. This finding is similar to the characteristics seen in RBC scintigraphy for hepatic hemangioma. CONCLUSION RBC scintigraphy may be useful in the evaluation of possible splenic hemangioma.
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Affiliation(s)
- J Wijaya
- Department of Nuclear Medicine, Royal North Shore Hospital, St. Leonards, New South Wales, Australia.
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35
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Hernández H, Hewitson KS, Roach P, Shaw NM, Baldwin JE, Robinson CV. Observation of the iron-sulfur cluster in Escherichia coli biotin synthase by nanoflow electrospray mass spectrometry. Anal Chem 2001; 73:4154-61. [PMID: 11569804 DOI: 10.1021/ac0102664] [Citation(s) in RCA: 17] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biotin synthase from Escherichia coli was analyzed by nanoflow electrospray ionization mass spectrometry. From solution conditions in which the protein is in its native state, a distribution of monomeric, dimeric, and tetrameric species was observed. The distribution of these species was sensitive to changes in ionic strength: in the positive ion spectrum, biotin synthase at low ionic strength (pH 7.0-8.5) yielded less than 10% dimer. The masses of the monomeric species were consistent with the presence of a [2Fe-2S] cluster with a mass difference of 175.3 Da from the apomonomer with one disulfide bond. Despite the molecular mass of the noncovalent dimer (77 kDa), it was possible to observe a dimeric species containing one iron-sulfur cluster in both positive and negative ion spectra. Additionally, observation of a series of charge states assigned to the apodimer indicated that binding of the iron-sulfur cluster was not required to maintain the dimer. Binding of Cu2+ to biotin synthase was also observed; in the presence of excess chelating agent, free metals were removed and the iron-sulfur cluster remained intact. Evidence for the coordination of the iron-sulfur cluster in biotin synthase was obtained in a tandem mass spectrometry experiment. A single charge state containing the cluster at m/z 2416.9 was isolated, and collision-induced dissociation resulted in sequential loss of sulfur and retention of Fe3+.
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Affiliation(s)
- H Hernández
- Oxford Centre for Molecular Sciences, Oxford University, New Chemistry Laboratory, UK
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36
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Affiliation(s)
- J Wijaya
- Department of Nuclear Medicine, Royal North Shore Hospital, St. Leonard's, New South Wales, Australia.
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37
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Roach P, Strack T, Arora V, Zhao Z. Improved glycaemic control with the use of self-prepared mixtures of insulin lispro and insulin lispro protamine suspension in patients with types 1 and 2 diabetes. Int J Clin Pract 2001; 55:177-82. [PMID: 11351771] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
Abstract
A total of 166 patients (102 type 1, 64 type 2) were randomised to insulin lispro (LP) combined with insulin lispro protamine suspension (NPL), an intermediate-acting formulation of LP, or to regular human insulin (HR) combined with human NPH insulin (NPH) in this open-label, parallel study. Insulin doses were similar at endpoint. Blood glucose (BG) measurements (before and two hours after meals, bedtime, 3 a.m.)(mmol/l) were lower with LP/NPL two hours after breakfast (8.84 +/- 0.32 vs 10.29 +/- 0.41, p < 0.001), before lunch (6.21 +/- 0.20 vs 7.10 +/- 0.31, p = 0.016), two hours after the evening meal (10.18 +/- 0.36 vs 7.86 +/- 0.28, p < 0.0.001), and at bedtime (7.85 +/- 0.28 vs 9.43 +/- 0.40, p = 001). HbA1c was lower for LP/NPL at endpoint (7.54 +/- 0.11% vs 7.92 +/- 0.10%, p = 0.019). There was no difference in hypoglycaemia or insulin antibody levels. LP/NPL resulted in better glycaemic control than HR/NPH without increasing the risk of hypoglycaemia.
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Affiliation(s)
- P Roach
- Lilly Research Laboratories, Eli Lilly and Company, DC2042, Indianapolis, IN 46285, USA
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Binasis A, Pratley S, Roach P, Bernard E, Aboud M, Tofler G. Increase in von willebrand factor with exercise: A potential mechanism of increased cardiovascular risk. Heart Lung Circ 2000. [DOI: 10.1046/j.1443-9506.2000.07352.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Gross G, Russell JD, Beumont PJ, Touyz SW, Roach P, Aslani A, Hansen RD, Allen BJ. Longitudinal study of patients with anorexia nervosa 6 to 10 years after treatment. Impact of adequate weight restoration on outcome. Ann N Y Acad Sci 2000; 904:614-6. [PMID: 10865814 DOI: 10.1111/j.1749-6632.2000.tb06525.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- G Gross
- Department of Psychology, University of Trier, Germany.
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Ollagnier-De Choudens S, Sanakis Y, Hewitson KS, Roach P, Baldwin JE, Münck E, Fontecave M. Iron-sulfur center of biotin synthase and lipoate synthase. Biochemistry 2000; 39:4165-73. [PMID: 10747808 DOI: 10.1021/bi992090u] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biotin synthase and lipoate synthase are homodimers that are required for the C-S bond formation at nonactivated carbon in the biosynthesis of biotin and lipoic acid, respectively. Aerobically isolated monomers were previously shown to contain a (2Fe-2S) cluster, however, after incubation with dithionite one (4Fe-4S) cluster per dimer was obtained, suggesting that two (2Fe-2S) clusters had combined at the interface of the subunits to form the (4Fe-4S) cluster. Here we report Mössbauer studies of (57)Fe-reconstituted biotin synthase showing that anaerobically prepared enzyme can accommodate two (4Fe-4S) clusters per dimer. The (4Fe-4S) cluster is quantitatively converted into a (2Fe-2S)(2+) cluster upon exposure to air. Reduction of the air-exposed enzyme with dithionite or photoreduced deazaflavin yields again (4Fe-4S) clusters. The (4Fe-4S) cluster is stable in both the 2+ and 1+ oxidation states. The Mössbauer and EPR parameters were DeltaE(q) = 1.13 mm/s and delta = 0.44 mm/s for the diamagnetic (4Fe-4S)(2+) and DeltaE(q) = 0.51 mm/s, delta = 0.85 mm/s, g(par) = 2.035, and g(perp) = 1.93 for the S = (1)/(2) state of (4Fe-4S)(1+). Considering that we find two (4Fe-4S) clusters per dimer, our studies argue against the early proposal that the enzyme contains one (4Fe-4S) cluster bridging the two subunits. Our study of lipoate synthase gave results similar to those obtained for BS: under strict anaerobiosis, lipoate synthase can accommodate a (4Fe-4S) cluster per subunit [DeltaE(q) = 1.20 mm/s and delta = 0.44 mm/s for the diamagnetic (4Fe-4S)(2+) and g(par) = 2.039 and g(perp) = 1.93 for the S = (1)/(2) state of (4Fe-4S)(1+)], which reacts with oxygen to generate a (2Fe-2S)(2+) center.
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Affiliation(s)
- S Ollagnier-De Choudens
- Laboratoire de Chimie et Biochimie des Centres Rédox Biologiques, DBMS-CB, CEA/CNRS/Université Joseph Fourier, 17 Avenue des Martyrs, 38054 Grenoble Cedex 09, France
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Matlow AG, Harrison A, Monteath A, Roach P, Balfe JW. Nosocomial transmission of tuberculosis (TB) associated with care of an infant with peritoneal TB. Infect Control Hosp Epidemiol 2000; 21:222-3. [PMID: 10738995 DOI: 10.1086/501749] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Nosocomial transmission of tuberculosis (TB) after exposure to infected peritoneal fluid has not been described. We report the exposure of 111 healthcare workers to infected dialysate from an infant with TB peritonitis. Two (5%) of 39 primary-care nurses, but no doctors or environmental service workers, had apparent tuberculin skin test conversions, raising the concern that patients with peritoneal TB may be a source for nosocomial transmission of TB.
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Affiliation(s)
- A G Matlow
- Department of Pediatrics, Hospital for Sick Children, University of Toronto, Ontario, Canada
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Abbey M, Owen A, Suzakawa M, Roach P, Nestel PJ. Effects of menopause and hormone replacement therapy on plasma lipids, lipoproteins and LDL-receptor activity. Maturitas 1999; 33:259-69. [PMID: 10656504 DOI: 10.1016/s0378-5122(99)00054-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A cross-sectional study of ninety six women was conducted to examine the effect of menopause and hormone replacement therapy (HRT) on plasma lipids, lipoproteins and oxidation of low density lipoproteins. The sample consisted of 26 premenopausal women, 26 postmenopausal women taking no replacement hormones and 43 postmenopausal women on hormone replacement therapy. Postmenopausal women not taking replacement hormones had significantly higher plasma cholesterol, low density lipoprotein (LDL) cholesterol and lipoprotein[a] (Lp[a]) levels compared to premenopausal women or postmenopausal women on HRT [6.00 +/- 0.15, 5.36 +/- 0.17 (P < 0.01), 5.63 +/- 0.13 (P < 0.05) mmol/l, respectively for total cholesterol; 4.13 +/- 0.15, 3.64 +/- 0.15 (P < 0.05), 3.82 +/- 0.12 (P < 0.05) mmol/l, respectively for LDL-cholesterol; 48.19 +/- 9.90, 26.59 +/- 5.53 (P < 0.03), 25.12 +/- 4.62 (P < 0.03) mg/dl, respectively for Lp[a]]. The differences in LDL cholesterol concentrations were inversely related to changes in LDL receptor activity (r = -0.27, P < 0.01). HRT use was found to be associated with a significantly smaller LDL particle size. Plasma triglyceride was significantly higher in women on HRT (1.16 +/- 0.07 mmol/l) than in the premenopausal group (0.96 +/- 0.07) or postmenopausal group not using HRT (0.87 +/- 0.06). There were no differences in LDL oxidation between the groups when LDL was oxidised in the presence of copper. Nor was there any difference in the uptake of copper-oxidised or macrophage-modified LDL into J774 macrophages. These results confirm the effect of menopause and exogenous hormones on plasma lipids and lipoproteins, and suggest that HRT modifies the activity of the LDL receptor. Hormone replacement did not appear to protect LDL from oxidation.
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Affiliation(s)
- M Abbey
- Commonwealth Scientific and Industrial Research Organisation, Human Nutrition, Adelaide BC, SA, Australia.
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Roach P, Yue L, Arora V. Improved postprandial glycemic control during treatment with Humalog Mix25, a novel protamine-based insulin lispro formulation. Humalog Mix25 Study Group. Diabetes Care 1999; 22:1258-61. [PMID: 10480767 DOI: 10.2337/diacare.22.8.1258] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Humalog Mix25 is a manufactured premixed insulin formulation containing insulin lispro and a novel insulin lispro-protamine formulation (NPL) in a ratio of 25:75%. The objective of this study was to compare Humalog Mix25 to human insulin 30/70 (30% regular insulin/70% NPH) with respect to glycemic control. RESEARCH DESIGN AND METHODS Humalog Mix25 was compared with human insulin 30/70 in 89 individuals with type 2 diabetes during a 6-month randomized open-label two-period crossover study. Each insulin was administered twice daily, before the morning and evening meals. Information regarding self-monitored blood glucose (BG), hypoglycemic episodes (hypoglycemic signs or symptoms or BG < or = 3.0 mmol/l), insulin dose, and HbA1c was collected. RESULTS Treatment with Humalog Mix25 resulted in better postprandial glycemic control after the morning and evening meals compared with treatment with human insulin 30/70. Overall glycemic control and the incidence of hypoglycemia were comparable between the treatments. CONCLUSIONS In comparison to treatment with human insulin 30/70, twice daily administration of Humalog Mix25 resulted in improved postprandial glycemic control, similar overall glycemic control, and the convenience of dosing immediately before meals.
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Affiliation(s)
- P Roach
- Lilly Research Laboratories, Eli Lilly, Indianapolis, Indiana 46285, USA.
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Affiliation(s)
- P Davies
- Department of Nuclear Medicine, Royal North Shore Hospital, St. Leonards, Sydney, Australia
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Roach P, Trautmann M, Arora V, Sun B, Anderson JH. Improved postprandial blood glucose control and reduced nocturnal hypoglycemia during treatment with two novel insulin lispro-protamine formulations, insulin lispro mix25 and insulin lispro mix50. Mix50 Study Group. Clin Ther 1999; 21:523-34. [PMID: 10321421 DOI: 10.1016/s0149-2918(00)88307-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The objective of this 6-month, open-label, randomized, two-period crossover study was to compare glycemic control when patients were treated with (1) 2 manufactured premixed insulin formulations containing insulin lispro and a novel insulin lispro-protamine formulation, neutral protamine lispro (NPL), and (2) 2 manufactured premixed human insulin formulations, human insulin 50/50 and human insulin 30/70. One hundred individuals, 37 with type 1 diabetes mellitus (12 females, 25 males; mean age, 39.4 years; mean body mass index [BMI], 24.8; mean duration of diabetes, 12.9 years) and 63 with type 2 diabetes mellitus (33 females, 30 males; mean age, 59.0 years; mean BMI, 28.4; mean duration of diabetes, 12.6 years), were treated with insulin lispro mixtures. Insulin lispro Mix50 (50% insulin lispro/50% NPL) and human insulin 50/50 (50% regular insulin/50% neutral protamine Hagedorn [NPH] insulin) were administered before breakfast; insulin lispro Mix25 (25% insulin lispro/75% NPL) and human insulin 30/70 (30% regular insulin/70% NPH) were administered before dinner. Blood glucose (BG), hypoglycemic episodes (hypoglycemic signs or symptoms or BG <3.0 mmol/L), insulin dose and timing of dose before meals, and hemoglobin A1c were measured. Mean doses of insulin lispro and human insulin mixtures were similar overall and for both diabetes subgroups. However, compared with human insulin mixtures, twice-daily administration of insulin lispro mixtures resulted in improved postprandial glycemic control, similar overall glycemic control, and less nocturnal hypoglycemia, as well as offering the convenience of dosing closer to meals.
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Affiliation(s)
- P Roach
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, USA
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Yue LQ, Roach P. A note on the sample size determination in two-period repeated measurements crossover design with application to clinical trials. J Biopharm Stat 1998; 8:577-84. [PMID: 9855035 DOI: 10.1080/10543409808835261] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The two-period repeated measurements crossover design is often used in clinical trials. In this article we give a formula for sample size determination for testing treatment effect in two-period repeated measurements crossover design by taking an analysis of variance approach to the repeated measurements analysis. A balanced situation is considered: two treatment sequences that have the same number of patients, and the time points of measurements on each subject within each treatment period equal in number. The formula reveals the relationship between the required number of patients for each treatment sequence, the number of repeated measurements within each treatment period, the detectable treatment difference with respect to a primary response variable, and the power for testing the treatment difference. A clinical trial example is given to illustrate the use of the formula.
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Affiliation(s)
- L Q Yue
- Lilly Research Laboratories, Eli Lilly Company, Indianapolis, Indiana 46285, USA
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Avila NA, Shawker TH, Roach P, Bradford MH, Skarulis MC, Eastman R. Sonography of gallbladder abnormalities in acromegaly patients following octreotide and ursodiol therapy: incidence and time course. J Clin Ultrasound 1998; 26:289-294. [PMID: 9641388 DOI: 10.1002/(sici)1097-0096(199807/08)26:6<289::aid-jcu2>3.0.co;2-e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
PURPOSE We studied the effects of octreotide and ursodiol on the gallbladders of patients with acromegaly. METHODS We performed gallbladder sonography in patients with acromegaly at various intervals during treatment. Group I (18 patients) was treated with subcutaneous injections of the somatostatin analogue octreotide. Group II (10 patients) was treated with ursodiol while receiving octreotide therapy. RESULTS Seventy-eight percent of patients receiving octreotide developed gallbladder abnormalities: sludge in 72% (13/18) and calculi in 39% (7/18). Ursodiol reversed the gallbladder abnormalities in 7 of 10 patients. CONCLUSIONS A majority of patients receiving octreotide develop gallbladder abnormalities. Ursodiol appears to reverse the abnormalities in most cases.
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Affiliation(s)
- N A Avila
- Diagnostic Radiology Department, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892-1182, USA
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Heise T, Weyer C, Serwas A, Heinrichs S, Osinga J, Roach P, Woodworth J, Gudat U, Heinemann L. Time-action profiles of novel premixed preparations of insulin lispro and NPL insulin. Diabetes Care 1998; 21:800-3. [PMID: 9589244 DOI: 10.2337/diacare.21.5.800] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To study the pharmacodynamic properties of three premixed formulations of the rapid-acting insulin analog insulin lispro and its protamine-retarded preparation, neutral protamine lispro (NPL) insulin. RESEARCH DESIGN AND METHODS In this open, single-center, euglycemic glucose clamp study, 30 healthy volunteers (12 women, 18 men) aged 27 +/- 2 years (mean +/- SD), whose BMI was 23.0 +/- 2.3 kg/m2, received subcutaneous injections of 0.3 U/kg body wt of insulin mixture (high-mixture 75/25, mid-mixture 50/50, or low-mixture 25/75 insulin lispro/NPL insulin), insulin lispro, or NPL insulin on one of the five study days in randomized order. Glucose infusion rates were determined over a period of 24 h after administration. RESULTS Maximal metabolic activity decreased after subcutaneous injection of the mixtures with lower insulin lispro content; however, the time point of maximal and of early half-maximal metabolic activity was comparable among the three mixtures. Higher proportions of insulin lispro resulted in higher values for area under the curve within the first 360 min after injection and a more rapid decline to late half-maximal activity. Serum insulin concentrations showed a similar pattern. CONCLUSIONS This study shows that the pharmacodynamic and pharmacokinetic properties of insulin lispro are preserved in stable mixtures with NPL insulin.
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Affiliation(s)
- T Heise
- Department of Metabolic Diseases and Nutrition, World Health Organization Collaborating Center for Diabetes, Heinrich-Heine-University of Düsseldorf, Germany
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Radziuk J, Pye S, Bradley B, Braaten J, Vignati L, Roach P, Bowsher R, DiMarchi R, Chance R. Basal activity profiles of NPH and [Nepsilon-palmitoyl Lys (B29)] human insulins in subjects with IDDM. Diabetologia 1998; 41:116-20. [PMID: 9498640 DOI: 10.1007/s001250050876] [Citation(s) in RCA: 18] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
[Nepsilon-palmitoyl Lys (B29)] human insulin is a fatty acid-acylated derivative of insulin with extended action compared to unmodified insulin when infused intravenously (i.v.) secondary to its binding to circulating albumin. The duration and activity profile of the acylated (A) and NPH (B) insulins were assessed following subcutaneous (s.c.) doses of (A) 6 nmol/kg and (B) 1.2 nmol/kg (equivalent to 0.2 U/kg) in 9 subjects with IDDM. After overnight i.v. infusion of regular human insulin, morning glucose was (A) 6.9 +/- 0.1 and (B) 6.8 +/- 0.1 mmol/l. After the s.c. injection, i.v. human insulin or glucose was infused to maintain near-basal glycaemia and tracer glucose to assess hepatic glucose production (HGP). An activity profile was deduced for each study by expressing the glucose infusion rate at each time point, as a fraction (%) of the basal (measured) HGP, and the i.v. insulin infusion rate as a fraction (%) of the basal requirement. The two fractions are combined by adding the fractional glucose infusion rate and subtracting the fractional insulin infusion rate. Infusion rates of i.v. insulin in the morning were (A) 0.96 +/- 0.096 and (B) 1.22 +/- 0.09 pmol x kg(-1) x min(-1). After insulin injection, i.v. insulin requirements decreased and were below 10% of basal between 100 and 150 min. A constant activity profile of 0% represents a perfect substitution of the basal i.v. insulin infusion by the s.c. dose. The actual profile is defined by deviations from this (above) and was -17 +/- 11, 7 +/- 10, -9 +/- 6 and -18 +/- 18% for [Nepsilon-palmitoyl Lys (B29)] human insulin and 17 +/- 12, 5 +/- 6, -9 +/- 15, 22 +/- 18% for NPH insulin at 3, 6, 9 and 12 h after s.c. injection. HGP was similar for the two insulins, demonstrating similar metabolic actions and profiles both peripherally and at the liver.
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Affiliation(s)
- J Radziuk
- Diabetes and Metabolism Research Unit, Ottawa Civic Hospital, ON, Canada
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Janssen MM, Casteleijn S, Devillé W, Popp-Snijders C, Roach P, Heine RJ. Nighttime insulin kinetics and glycemic control in type 1 diabetes patients following administration of an intermediate-acting lispro preparation. Diabetes Care 1997; 20:1870-3. [PMID: 9405909 DOI: 10.2337/diacare.20.12.1870] [Citation(s) in RCA: 19] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To determine insulin kinetics and overnight glycemic control after bedtime administration of a new intermediate-acting insulin preparation called neutral protamine lispro (NPL). RESEARCH DESIGN AND METHODS We studied 12 patients with well-controlled type 1 diabetes. The study had a double-blind, randomized, crossover design. After a lead-in period of 10-14 days two experiments were carried out with an interval of 2-7 days. During these experiments overnight insulin kinetics and fasting blood glucose levels were studied after evening administration of NPH insulin and NPL. Blood glucose levels < 3.8 mmol/l were treated by means of a variable infusion of a 20% glucose solution. RESULTS A trend toward a shorter time to peak insulin concentration was observed after administration of NPL (P = 0.07). No differences between NPH and NPL were detected in the total area under the curve (AUC) for insulin, in insulin levels before breakfast, or in glucose levels before breakfast (P = 0.5, 0.6, and 0.4, respectively). CONCLUSIONS We detected no major differences between NPH and NPL in the total AUC for insulin, prebreakfast glucose levels, or prebreakfast insulin levels. Therefore, we conclude that NPH and NPL are equally effective in controlling overnight glycemia.
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Affiliation(s)
- M M Janssen
- Research Institute for Endocrinology, Reproduction, and Metabolism, Faculty of Medicine, Vrije Universiteit, Amsterdam, The Netherlands
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