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Witt T, Robinson N, Palma AC, Cernusak LA, Pratt S, Redding M, Batstone DJ, Schmidt S, Laycock B. Evaluating novel biodegradable polymer matrix fertilizers for nitrogen-efficient agriculture. J Environ Qual 2024; 53:287-299. [PMID: 38453688 DOI: 10.1002/jeq2.20552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 01/24/2024] [Indexed: 03/09/2024]
Abstract
Enhanced efficiency fertilizers (EEFs) can reduce nitrogen (N) losses in temperate agriculture but are less effective in the tropics. We aimed to design a new EEF and evaluate their performance in simple-to-complex tests with tropical soils and crops. We melt-extruded urea at different loadings into biodegradable polymer matrix composites using biodegradable polyhydroxyalkanoate (PHA) or polybutylene adipate-co-terephthalate (PBAT) polymers with urea distributed throughout the pellet. These contrast with commercially coated EEF that have a polymer-coated urea core. We hypothesized that matrix fertilizers would have an intermediate N release rate compared to fast release from urea or slow release from coated EEF. Nitrogen release rates in water and sand-soil columns confirmed that the matrix fertilizer formulations had a more progressive N release than a coated EEF. A more complex picture emerged from testing sorghum [Sorghum bicolor (L.) Moench] grown to maturity in large soil pots, as the different formulations resulted in minor differences in plant N accumulation and grain production. This confirms the need to consider soil interactions, microbial processes, crop physiology, and phenology for evaluating fertilizer performance. Promisingly, crop δ15N signatures emerged as an integrated measure of efficacy, tracking likely N conversions and losses. The three complementary evaluations combine the advantages of standardized high-throughput screening and more resource-intensive and realistic testing in a plant-soil system. We conclude that melt-blended biodegradable polymer matrix fertilizers show promise as EEF because they can be designed toward more abiotically or more microbially driven N release by selecting biopolymer type and N loading rate.
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Affiliation(s)
- Torsten Witt
- School of Chemical Engineering, The University of Queensland, St Lucia, Queensland, Australia
| | - Nicole Robinson
- School of Agriculture and Food Sustainability, The University of Queensland, St Lucia, Queensland, Australia
| | - Ana C Palma
- College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
| | - Lucas A Cernusak
- College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
| | - Steven Pratt
- School of Chemical Engineering, The University of Queensland, St Lucia, Queensland, Australia
| | - Matthew Redding
- Department of Agriculture and Fisheries, Toowoomba, Queensland, Australia
| | - Damien J Batstone
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St Lucia, Queensland, Australia
| | - Susanne Schmidt
- School of Agriculture and Food Sustainability, The University of Queensland, St Lucia, Queensland, Australia
| | - Bronwyn Laycock
- School of Chemical Engineering, The University of Queensland, St Lucia, Queensland, Australia
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2
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Redding MR, Witt T, Lobsey CR, Mayer DG, Hunter B, Pratt S, Robinson N, Schmidt S, Laycock B, Phillips I. Screening two biodegradable polymers in enhanced efficiency fertiliser formulations reveals the need to prioritise performance goals. J Environ Manage 2022; 304:114264. [PMID: 34906809 DOI: 10.1016/j.jenvman.2021.114264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 12/01/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
Enhanced efficiency fertilisers (EEF) may reduce nitrogen (N) losses and improve uptake efficiency through synchronising N release with in-season plant requirements. We hypothesised that EEF formed via matrix encapsulation in biodegradable polymers will improve N use efficiency when compared to conventional urea fertiliser. This hypothesis was investigated for two biodegradable polymer matrices: polyhydroxyalkanoate (PHA), containing 11.6% urea (by mass), and polybutylene-adipate-co-terephthalate (PBAT), containing either 19.4 or 32.7% urea; and two contrasting soil types: sand and clay. Nitrogen availability and form was investigated under leaching conditions (water) with a growth accelerator pot experiment involving a horticultural crop and novel non-destructive three-dimensional scanning to measure in-season biomass development. The PBAT 32.7% formulation enabled greater above ground biomass production at both 50 and 100 kg N ha-1 equivalent application rates compared to conventional urea. For the sandy soil, plant scanning indicated that improved uptake performance with PBAT 32.7% was probably the result of greater N availability after 25 days than for conventional urea. Two of the encapsulated formulations (PHA and PBAT 19.4%) tended to decrease nitrogen leaching losses relative to urea (P < 0.05 for the red clay soil). However, decreased N leaching loss was accompanied by poorer N uptake performance, indicative of N being less available in these biopolymer formulations. A snapshot of nitrous oxide emissions collected during peak nitrate concentration (prior to planting and leaching) suggested that the biopolymers promoted N loss via gaseous emission relative to urea in the sandy soil (P < 0.05), and carbon dioxide emissions data suggested that biopolymer-carbon increased microbial activity (P < 0.1). Controlled testing of N release in water was a poor predictor of biomass production and leaching losses. The diverse behaviours of the tested formulations present the potential to optimise biopolymers and their N loadings by taking into account soil and environmental factors that influence the efficient delivery of N to target crops. The greater N uptake efficiency demonstrated for the PBAT 32.7% formulation confirms our hypothesis that matrix encapsulation can enable better synchronisation of N release with crop requirements and decrease leaching losses.
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Affiliation(s)
- M R Redding
- Department of Agriculture and Fisheries, PO Box 102, Toowoomba, Queensland, 4350, Australia.
| | - T Witt
- School of Chemical Engineering, University of Queensland, St Lucia, Queensland, Australia
| | - C R Lobsey
- School of Mechanical and Electrical Engineering, University of Southern Queensland, Toowoomba, Queensland, Australia
| | - D G Mayer
- Department of Agriculture and Fisheries, PO Box 102, Toowoomba, Queensland, 4350, Australia
| | - B Hunter
- Department of Agriculture and Fisheries, PO Box 102, Toowoomba, Queensland, 4350, Australia
| | - S Pratt
- School of Chemical Engineering, University of Queensland, St Lucia, Queensland, Australia
| | - N Robinson
- School of Agriculture and Food Science, University of Queensland, St Lucia, Queensland, Australia
| | - S Schmidt
- School of Agriculture and Food Science, University of Queensland, St Lucia, Queensland, Australia
| | - B Laycock
- School of Chemical Engineering, University of Queensland, St Lucia, Queensland, Australia
| | - I Phillips
- Department of Agriculture and Fisheries, PO Box 102, Toowoomba, Queensland, 4350, Australia
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Chapagai MK, Fletcher B, Witt T, Dhital S, Flanagan BM, Gidley MJ. Multiple length scale structure-property relationships of wheat starch oxidized by sodium hypochlorite or hydrogen peroxide. Carbohydrate Polymer Technologies and Applications 2021. [DOI: 10.1016/j.carpta.2021.100147] [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: 10/20/2022] Open
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Franchi F, Olthoff M, Krier J, Noble C, Al-Hijji M, Ramaswamy V, Witt T, Burke M, Benscoter M, Lerman A, Sandhu GS, Rodriguez-Porcel M. A Metabolic Intravascular Platform to Study FDG Uptake in Vascular Injury. Cardiovasc Eng Technol 2020; 11:328-336. [PMID: 32002814 DOI: 10.1007/s13239-020-00457-z] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 01/24/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE Metabolic alterations underlie many pathophysiological conditions, and their understanding is critical for the development of novel therapies. Although the assessment of metabolic changes in vivo has been historically challenging, recent developments in molecular imaging have allowed us to study novel metabolic research concepts directly in the living subject, bringing us closer to patients. However, in many instances, there is need for sensors that are in close proximity to the organ under investigation, for example to study vascular metabolism. METHODS In this study, we developed and validated a metabolic detection platform directly in the living subject under an inflammatory condition. The signal collected by a scintillating fiber is amplified using a photomultiplier tube and decodified by an in-house tunable analysis platform. For in vivo testing, we based our experiments on the metabolic characteristics of macrophages, cells closely linked to inflammation and avid for glucose and its analog 18F-fluorodeoxyglucose (18F-FDG). The sensor was validated in New Zealand rabbits, in which inflammation was induced by either a) high cholesterol (HC) diet for 16 weeks or b) vascular balloon endothelial denudation followed by HC diet. RESULTS There was no difference in weight, hemodynamics, blood pressure, or heart rate between the groups. Vascular inflammation was detected by the metabolic sensor (Inflammation: 0.60 ± 0.03 AU vs. control: 0.48 ± 0.03 AU, p = 0.01), even though no significant inflammation/atherosclerosis was detected by intravascular ultrasound, underscoring the high sensitivity of the system. These findings were confirmed by the presence of macrophages on ex vivo aortic tissue staining. CONCLUSION In this study, we validated a tunable very sensitive metabolic sensor platform that can be used for the detection of vascular metabolism, such as inflammation. This sensor can be used not only for the detection of macrophage activity but, with alternative probes, it could allow the detection of other pathophysiological processes.
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Affiliation(s)
- F Franchi
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA.
| | - M Olthoff
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - J Krier
- Department of Physiology and Biomedical Engineering, Mayo Clinic School of Medicine Rochester, Rochester, MN, 55902, USA
| | - C Noble
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - M Al-Hijji
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - V Ramaswamy
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - T Witt
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - M Burke
- Division of Engineering, Mayo Clinic School of Medicine Rochester, Rochester, MN, 55902, USA
| | - M Benscoter
- Division of Engineering, Mayo Clinic School of Medicine Rochester, Rochester, MN, 55902, USA
| | - A Lerman
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - G S Sandhu
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA
| | - M Rodriguez-Porcel
- Department of Cardiovascular Medicine, Mayo Clinic School of Medicine Rochester, Mayo Clinic, 200 First St SW, Rochester, MN, 55902, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic School of Medicine Rochester, Rochester, MN, 55902, USA
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Chakraborty P, Witt T, Harris D, Ashton J, Stokes JR, Smyth HE. Texture and mouthfeel perceptions of a model beverage system containing soluble and insoluble oat bran fibres. Food Res Int 2019; 120:62-72. [PMID: 31000279 DOI: 10.1016/j.foodres.2019.01.070] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 01/15/2019] [Accepted: 01/31/2019] [Indexed: 10/27/2022]
Abstract
Dietary fibre fortified products have increased in popularity as health-conscious consumers seek convenient ways to increase fibre intake. Fibres from wholegrains are particularly desirable inclusions in food products because of their proven physiological health-benefits. When fortifying beverages with fibre, however, the insoluble dietary fibre components present in wholegrains often contribute to unpleasant gritty sensations making the products unpalatable. Consequently, designing wholegrain-fortified beverages with sufficient fibre-content to make health related fibre claims is a major challenge in the food manufacturing industry. This work aims to take a systematic approach in identifying the texture/mouthfeel related sensory impact and interaction between two commercial oat fibre ingredients (Oatwell28XF® and Milled Oats) when added to a model beverage system. Eighteen samples were prepared containing either or both the ingredients, at varying levels, and were assessed by a trained panel using conventional sensory descriptive techniques. The results indicate that the two different oat bran fibres produced distinct mouthfeel perceptions which could be attributed to the varying soluble and insoluble fibre content of the samples. Insoluble dietary fibre concentrations above 2% (w/w) resulted in particle-related sensory properties chalkiness, dryness and particle perception, which dominated the overall mouthfeel and textural sensory perception of the samples. Samples with predominantly soluble β-glucan, resulted in perceptions of smoothness, sliminess and stickiness residue, while thickness, mouthcoating and cloying sensations were driven by total fibre concentration, irrespective of fibre solubility. This work provides a solid foundation for food manufacturers aiming to rationally design and develop nutritionally superior fibre-fortified beverages and is relevant to fibre content concentrations required for labelling/nutrition claims for consumer products in many developed nations.
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Affiliation(s)
- Piyali Chakraborty
- School of Chemical Engineering, University of Queensland, Brisbane, Qld 4067, Australia
| | - Torsten Witt
- School of Agricultural and Food Sciences, The University of Queensland, Brisbane, Qld 4067, Australia
| | - David Harris
- Sanitarium Development and Innovation, Cooranbong, NSW 2265, Australia
| | - John Ashton
- Sanitarium Development and Innovation, Cooranbong, NSW 2265, Australia
| | - Jason R Stokes
- School of Chemical Engineering, University of Queensland, Brisbane, Qld 4067, Australia
| | - Heather E Smyth
- Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Coopers Plains, Qld 4108, Australia.
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Yu L, Witt T, Rincon Bonilla M, Turner M, Fitzgerald M, Stokes J. New insights into cooked rice quality by measuring modulus, adhesion and cohesion at the level of an individual rice grain. J FOOD ENG 2019. [DOI: 10.1016/j.jfoodeng.2018.07.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ai J, Witt T, Cowin G, Dhital S, Turner MS, Stokes JR, Gidley MJ. Anti-staling of high-moisture starchy food: Effect of hydrocolloids, emulsifiers and enzymes on mechanics of steamed-rice cakes. Food Hydrocoll 2018. [DOI: 10.1016/j.foodhyd.2018.05.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Ai J, Witt T, Gidley MJ, Turner MS, Stokes JR, Bonilla MR. Modelling of Thermal Sterilisation of High-Moisture Snack Foods: Feasibility Analysis and Optimization. FOOD BIOPROCESS TECH 2018. [DOI: 10.1007/s11947-018-2075-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Tran KN, Witt T, Gidley MJ, Fitzgerald M. Accounting for the effect of degree of milling on rice protein extraction in an industrial setting. Food Chem 2018; 253:221-226. [PMID: 29502825 DOI: 10.1016/j.foodchem.2018.01.147] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 11/02/2017] [Accepted: 01/23/2018] [Indexed: 11/27/2022]
Abstract
The by-products of rice milling (BRM), which are predominately rice bran, are a potential source of soluble protein that has been underexploited due to difficulties in extraction. Significant advances have been made understanding how protein content changes with degree of milling (DOM) at the laboratory scale. However, these results cannot be compared due to the lack of information on how DOM affects protein extractability in industrially produced BRM. The colorimetry or particle size analysis may estimate milling degree in industrial scale, and protein extractability changes due to a series of abrasive milling passes. Both colorimetry and particle size could differentiate the industrial abrasive passes and correlated with the amount of bran/protein present. Both the 1st and 2nd pass of milling were suitable sources for the extraction. While the relative amount of protein extracted in each fraction changed, the protein profile of the major fractions was conserved between mill passes.
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Affiliation(s)
- Khang N Tran
- School of Agriculture and Food Sciences, Faculty of Science, The University of Queensland, St Lucia, Brisbane, Australia
| | - Torsten Witt
- School of Agriculture and Food Sciences, Faculty of Science, The University of Queensland, St Lucia, Brisbane, Australia
| | - Michael J Gidley
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St Lucia, Brisbane, Australia
| | - Melissa Fitzgerald
- School of Agriculture and Food Sciences, Faculty of Science, The University of Queensland, St Lucia, Brisbane, Australia.
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Yu L, Turner M, Fitzgerald M, Stokes J, Witt T. Review of the effects of different processing technologies on cooked and convenience rice quality. Trends Food Sci Technol 2017. [DOI: 10.1016/j.tifs.2016.11.009] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [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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Myers D, Witt T, Cyriac A, Bown M, Mecking S, Williams CK. Ring opening polymerization of macrolactones: high conversions and activities using an yttrium catalyst. Polym Chem 2017. [DOI: 10.1039/c7py00985b] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The ring-opening polymerization of macrolactones (C15–C23) is reported using an yttrium catalyst which shows high rates and conversions in the production of long-chain aliphatic polyesters.
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Affiliation(s)
- D. Myers
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
| | - T. Witt
- Department of Chemistry
- University of Konstanz
- 78457 Konstanz
- Germany
| | - A. Cyriac
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
| | - M. Bown
- CSIRO Manufacturing
- Ian Wark Laboratory
- Clayton
- Australia
| | - S. Mecking
- Department of Chemistry
- University of Konstanz
- 78457 Konstanz
- Germany
| | - C. K. Williams
- Department of Chemistry
- Imperial College London
- London SW7 2AZ
- UK
- Department of Chemistry
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Göbel H, Heinze A, Niederberger U, Witt T, Zumbroich V. Efficacy of Phenazone in the Treatment of Acute Migraine Attacks: A Double-Blind, Placebo-Controlled, Randomized Study. Cephalalgia 2016; 24:888-93. [PMID: 15377321 DOI: 10.1111/j.1468-2982.2004.00764.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [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: 10/26/2022]
Abstract
In this study we compared the efficacy of 1000 mg phenazone with that of placebo in the treatment of acute migraine attacks in a randomized double-blind, placebo-controlled study of 208 patients. The main target criterion was the number of patients with a pain reduction from severe or moderate to slight or no pain 2 h after taking the pain medication. The percentage of patients satisfying the main target criterion was 48.6% for phenazone and 27.2% ( P < 0.05) for placebo. Freedom from pain after 2 h was reported by 27.6% with phenazone treatment and 13.6% ( P < 0.05) with placebo. Compared with placebo, the phenazone treatment also resulted in a significant improvement in the associated migraine symptoms of nausea, phonophobia and photophobia. Of patients treated with phenazone 11.4%, and 5.8% of those treated with placebo reported adverse events. There was no significant difference between the groups with regard to numbers of patients with adverse events. No serious adverse events occurred. The results show that phenazone at a dosage of 1000 mg is effective and well tolerated in the treatment of acute migraine attacks.
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Li M, Witt T, Xie F, Warren FJ, Halley PJ, Gilbert RG. Biodegradation of starch films: the roles of molecular and crystalline structure. Carbohydr Polym 2015; 122:115-22. [PMID: 25817650 DOI: 10.1016/j.carbpol.2015.01.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 01/01/2015] [Accepted: 01/06/2015] [Indexed: 11/24/2022]
Abstract
The influences of molecular, crystalline and granular structures on the biodegradability of compression-molded starch films were investigated. Fungal α-amylase was used as model degradation agent. The substrates comprised varied starch structures obtained by different degrees of acid hydrolysis, different granular sizes using size fractionation, and different degrees of crystallinity by aging for different times (up to 14 days). Two stages are identified for unretrograded films by fitting degradation data using first-order kinetics. Starch films containing larger molecules were degraded faster, but the rate coefficient was independent of the granule size. Retrograded films were degraded much slower than unretrograded ones, with a similar rate coefficient to that in the second stage of unretrograded films. Although initially the smaller molecules or the easily accessible starch chains on the amorphous film surface were degraded faster, the more ordered structure (resistant starch) formed from retrogradation, either before or during enzymatic degradation, strongly inhibits film biodegradation.
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Affiliation(s)
- Ming Li
- School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane 4072, QLD, Australia
| | - Torsten Witt
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane 4072, QLD, Australia
| | - Fengwei Xie
- The University of Queensland, Australian Institute for Bioengineering and Nanotechnology, Brisbane 4072, QLD, Australia
| | - Frederick J Warren
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane 4072, QLD, Australia
| | - Peter J Halley
- The University of Queensland, Australian Institute for Bioengineering and Nanotechnology, Brisbane 4072, QLD, Australia; The University of Queensland, School of Chemical Engineering, Brisbane 4072, QLD, Australia
| | - Robert G Gilbert
- School of Pharmacy, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane 4072, QLD, Australia.
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Witt T, Gilbert RG. Causal Relations between Structural Features of Amylopectin, a Semicrystalline Hyperbranched Polymer. Biomacromolecules 2014; 15:2501-11. [DOI: 10.1021/bm500353e] [Citation(s) in RCA: 25] [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: 12/26/2022]
Affiliation(s)
- Torsten Witt
- Tongji
School of Pharmacy, Huazhong University of Science and Technology, Wuhan, China, 430030
- Centre
for Nutrition and Food Science, Queensland Alliance for Agriculture
and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Robert G. Gilbert
- Tongji
School of Pharmacy, Huazhong University of Science and Technology, Wuhan, China, 430030
- Centre
for Nutrition and Food Science, Queensland Alliance for Agriculture
and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
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16
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Sullivan MA, Powell PO, Witt T, Vilaplana F, Roura E, Gilbert RG. Improving size-exclusion chromatography separation for glycogen. J Chromatogr A 2014; 1332:21-9. [PMID: 24508396 DOI: 10.1016/j.chroma.2014.01.053] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 12/23/2013] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
Glycogen is a hyperbranched glucose polymer comprised of glycogen β particles, which can also form much larger composite α particles. The recent discovery using size-exclusion chromatography (SEC) that fewer, smaller, α particles are found in diabetic-mouse liver compared to healthy mice highlights the need to achieve greater accuracy in the size separation methods used to analyze α and β particles. While past studies have used dimethyl sulfoxide as the SEC eluent to analyze the molecular size and structure of native glycogen, an aqueous eluent has not been rigorously tested and compared with dimethyl sulfoxide. The conditions for SEC of pig-liver glycogen, phytoglycogen and oyster glycogen were optimized by comparing two different eluents, aqueous 50 mM NH₄NO₃/0.02% NaN₃ and dimethyl sulfoxide/0.5% LiBr, run through different column materials and pore sizes at various flow rates. The aqueous system gave distinct size separation of α- and β-particle peaks, allowing for a more detailed and quantitative analysis and comparison between liver glycogen samples. This greater resolution has also revealed key differences between the structure of liver glycogen and phytoglycogen.
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Affiliation(s)
- Mitchell A Sullivan
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia
| | - Prudence O Powell
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia
| | - Torsten Witt
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia
| | - Francisco Vilaplana
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia; Division of Glycoscience, School of Biotechnology and Wallenberg Wood Science Centre (WWSC), KTH Royal Institute of Technology, AlbaNova University Centre, SE-106 91 Stockholm, Sweden
| | - Eugeni Roura
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia
| | - Robert G Gilbert
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia.
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Witt T, Jürgens A, Gottsberger G. Nectar sugar composition of European Caryophylloideae (Caryophyllaceae) in relation to flower length, pollination biology and phylogeny. J Evol Biol 2013; 26:2244-59. [PMID: 24028472 DOI: 10.1111/jeb.12224] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 07/02/2013] [Indexed: 11/30/2022]
Abstract
Floral nectar composition has been explained as an adaptation to factors that are either directly or indirectly related to pollinator attraction. However, it is often unclear whether the sugar composition is a direct adaptation to pollinator preferences. Firstly, the lower osmolality of sucrose solutions means that they evaporate more rapidly than hexose solutions, which might be one reason why sucrose-rich nectar is typically found in flowers with long tubes (adapted to long-tongued pollinators), where it is better protected from evaporation than in open or short-tubed flowers. Secondly, it can be assumed that temperature-dependent evaporation is generally lower during the night than during the day so that selection pressure to secrete nectar with high osmolality (i.e. hexose-rich solutions) is relaxed for night-active flowers pollinated at night. Thirdly, the breeding system may affect selection pressure on nectar traits; that is, for pollinator-independent, self-pollinated plants, a lower selective pressure on nectar traits can be assumed, leading to a higher variability of nectar sugar composition independent of pollinator preferences, nectar accessibility and nectar protection. To analyse the relations between flower tube length, day vs. night pollination and self-pollination, the nectar sugar composition was investigated in 78 European Caryophylloideae (Caryophyllaceae) with different pollination modes (diurnal, nocturnal, self-pollination) using high-performance liquid chromatography (HPLC). All Caryophylleae species (Dianthus and relatives) were found to have nectar with more than 50% sucrose, whereas the sugar composition of Sileneae species (Silene and relatives) ranged from 0% to 98.2%. In the genus Silene, a clear dichotomous distribution of sucrose- and hexose-dominant nectars is evident. We found a positive correlation between the flower tube length and sucrose content in Caryophylloideae, particularly in day-flowering species, using both conventional analyses and phylogenetically independent contrasts.
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Affiliation(s)
- T Witt
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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Affiliation(s)
- Robert G. Gilbert
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia
- Corresponding author. Phone: +61 7 3365 4809. Fax: +61 7 3365 1188. E-mail:
| | - Torsten Witt
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia
| | - Jovin Hasjim
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia
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Abstract
Improving starch-containing materials, whether food, animal feed, high-tech biomaterials, or engineering plastics, is best done by understanding how biosynthetic processes and any subsequent processing control starch structure, and how this structure controls functional properties. Starch structural characterization is central to this. This review examines how information on the three basic levels of the complex multi-scale structure of starch – individual chains, the branching structure of isolated molecules, and the way these molecules form various crystalline and amorphous arrangements – can be obtained from experiment. The techniques include fluorophore-assisted carbohydrate electrophoresis, multiple-detector size-exclusion chromatography, and various scattering techniques (light, X-ray, and neutron). Some examples are also given to show how these data provide mechanistic insight into how biosynthetic processes control the structure and how the various structural levels control functional properties.
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Witt T, Doutch J, Gilbert EP, Gilbert RG. Relations between Molecular, Crystalline, and Lamellar Structures of Amylopectin. Biomacromolecules 2012; 13:4273-82. [DOI: 10.1021/bm301586x] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Torsten Witt
- Tongji School of
Pharmacy, Huazhong University of Science and Technology, Wuhan, China, 430030
- Centre for Nutrition
and Food Science, Queensland Alliance for Agriculture
and Food Innovation, The University of Queensland, Brisbane, Qld 4072, Australia
| | - James Doutch
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked
Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Elliot P. Gilbert
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked
Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Robert G. Gilbert
- Tongji School of
Pharmacy, Huazhong University of Science and Technology, Wuhan, China, 430030
- Centre for Nutrition
and Food Science, Queensland Alliance for Agriculture
and Food Innovation, The University of Queensland, Brisbane, Qld 4072, Australia
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Weiß C, Ganswindt U, Staebler A, Witt T. Späte Plexus-brachialis-Läsion bei radiogener Fibrose. KLIN NEUROPHYSIOL 2012. [DOI: 10.1055/s-0030-1248618] [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: 10/18/2022]
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Schwaab B, Karoff M, Völler H, Wirth A, Witt T. Herz-Kreislauf-Patienten mit Diabetes mellitus Typ 2. Dtsch Med Wochenschr 2011; 136:2152-7. [DOI: 10.1055/s-0031-1292027] [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: 10/17/2022]
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Witt T, Gidley MJ, Gilbert RG. Starch digestion mechanistic information from the time evolution of molecular size distributions. J Agric Food Chem 2010; 58:8444-8452. [PMID: 20572670 DOI: 10.1021/jf101063m] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Size-exclusion chromatography [SEC, also termed gel permeation chromatography (GPC)] is used to measure the time evolution of the distributions of molecular size and of branch length as starch is subjected to in vitro digestion, including studying the development of enzyme-resistant starch. The method is applied to maize starches with varying amylose contents; the starches were extruded so as to provide an analogue for processed food. The initial rates of digestion of amylose and amylopectin components were found to be the same for high-amylose starches. A small starch species, not present in the original starting material, was formed during the digestion process; this new species has a slower digestion rate and is probably formed by retrogradation of longer branches of amylose and amylopectin as they are partially or wholly liberated from their parent starch molecule during the digestion process. The data suggest that the well-known connection between high amylose content and resistant starch arises from the greater number of longer branches, which can form the small retrograded species. The method is useful for the purpose of comparisons between different starches undergoing the process of digestion, by observing the changes in their molecular structures, as an adjunct to detailed studies of the enzyme-resistant fraction.
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Affiliation(s)
- Torsten Witt
- Centre for Nutrition & Food Sciences, The University of Queensland, Brisbane, Qld 4072, Australia
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Dowlatshahi K, Alvarado R, Harrison M, Witt T, Gatta J, Bloom K. Five year follow-up of patients with operable breast cancer whose sentinel nodes were completely sectioned at 0.25mm. Cancer Res 2009. [DOI: 10.1158/0008-5472.sabcs-1017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Abstract #1017
Background: 20-30% of patients with operable breast cancer and negative axillary lymph nodes develop recurrence within 10 years. With the advent of sentinel lymph node biopsy (SLNB) as a substitute to axillary lymph node dissection for staging of these patients, detailed examination of sentinel nodes for metastases has become feasible. Our group has previously reported on detection of 25% occult metastases in 200 patients with T1-T2 invasive breast cancer whose sentinel nodes were initially sectioned at 2-3 mm intervals and stained with H&E. The blocks were then sectioned at 0.25 mm intervals in the entirety and stained with immuno-histochemical technique (IHC). Some patients were given conventional chemo-hormonal therapy based upon tumor prognostic factors. We now present the disease recurrence in these patients at median follow-up of five years.
 Methods: Prospectively registered records of 209 consecutive patients with T1-T2 invasive breast cancer treated with lumpectomy and sentinel node biopsy at Rush University Medical Center by three surgeons between December 1997 and May 2002 were reviewed. Of the remaining 175, the nodes were sectioned at 0.25 mm throughout and stained with IHC. The remaining 123 cases had no metastases. Adjuvant chemo-hormonal therapy was given to 38 patients with unfavorable prognostic factors and none to 85.
 Results: The mean age of the patients and their tumor size were 54.6 years and 1.44 cm respectively. The mean length of follow up was 5.8 years. 34 of 209 patients had metastases in their sentinel nodes based on 2-3 mm sectioning and H&E staining. They were offered adjuvant chemo-hormonal therapy. 27 accepted and7 did not. Of the 209 patients, 175 had negative SLNB by routine examination. Of these, 52 (29.7%) were found to have occult metastases (isolated cells: 31, colonies> 0.2 mm: 21) upon 0.25 mm sectioning and IHC staining. Details of the findings are summarized in the table. The incidence of disease recurrence was noted to be similar in the subsets of patients with and without occult metastases.
 Conclusion
 Complete sectioning of the sentinel nodes in 209 patients with T1 and T2 breast cancer resulted in detection of occult metastases in 52 patients ranging in size from single cells to colonies of cells measuring up to 1500 microns. However, the incidence of disease recurrence at 5 year appears unaffected by these metastases.
 
 m*: Small metastases: isolated cells
 M*: Large metastases: colonies of cells.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1017.
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Affiliation(s)
- K Dowlatshahi
- 1 Department of Surgery, Rush University Medical Center, Chicago, IL
| | - R Alvarado
- 1 Department of Surgery, Rush University Medical Center, Chicago, IL
| | - M Harrison
- 1 Department of Surgery, Rush University Medical Center, Chicago, IL
| | - T Witt
- 1 Department of Surgery, Rush University Medical Center, Chicago, IL
| | - J Gatta
- 2 ECRA Group, Inc., Rosemont, IL
| | - K Bloom
- 3 Clarient, Inc., Aliso Viejo, CA
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Kiernan T, Yan B, Boilson B, Witt T, Simari R. Delivery of human CD34+ cells and human peripheral non-selected blood mononuclear cells decreases neointima formation greater than culture-modified mononuclear cells in an immunodeficient rat carotid balloon injury model. Cardiovascular Revascularization Medicine 2008. [DOI: 10.1016/j.carrev.2008.02.057] [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: 11/26/2022]
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Whetstine JR, Gifford AJ, Witt T, Liu XY, Flatley RM, Norris M, Haber M, Taub JW, Ravindranath Y, Matherly LH. Single nucleotide polymorphisms in the human reduced folate carrier: characterization of a high-frequency G/A variant at position 80 and transport properties of the His(27) and Arg(27) carriers. Clin Cancer Res 2001; 7:3416-22. [PMID: 11705857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
The presence of sequence variants in the human reduced folate carrier (hRFC) was assessed in leukemia blasts from children with acute lymphoblastic leukemia (ALL) and in normal peripheral blood specimens. A CATG frame shift insertion at position 191 was detected in 10-60% of hRFC transcripts from 10 of 16 ALL specimens, by RFLP analysis and direct sequencing of hRFC cDNAs. In genomic DNAs prepared from 105 leukemia (n = 54) and non-leukemia (n = 51) specimens, PCR amplifications and direct sequencing of exon 3 identified a high-frequency G to A single nucleotide polymorphism at position 80 that resulted in a change of arginine-27 to histidine-27. The allelic frequencies of G/A80 were nearly identical for the non-leukemia (42.2% CGC and 57.8% CAC) and leukemia (40.7% CGC and 59.3% CAC) genomic DNAs. In cDNAs prepared from 10 of these ALL patients, identical allelic frequencies (40 and 60%, respectively) were recorded. In up to 62 genomic DNAs, hRFC-coding exons 4-7 were PCR-amplified and sequenced. A high-abundance C/T696 polymorphism was detected with nearly identical frequencies for both alleles, and a heterozygous C/A1242 sequence variant was identified in two ALL specimens. Both C/T696 and C/A1242 were phenotypically silent. In transport assays with [(3)H]methotrexate and [(3)H]5-formyl tetrahydrofolate, nearly identical uptake rates were measured for the arginine-27- and histidine-27-hRFC proteins expressed in transport-impaired K562 cells. Although there were no significant differences between the kinetic parameters for methotrexate transport for the hRFC forms, minor (approximately 2-fold) differences were measured in the K(i)s for other substrates including Tomudex, 5,10-dideazatetrahydrofolate, GW1843U89, and 10-ethyl-10-deazaaminopterin and for 5-formyl tetrahydrofolate.
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Affiliation(s)
- J R Whetstine
- Department of Pharmacology, Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine, 110 East Warren Avenue, Detroit, MI 48201, USA
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Singh R, Pan S, Mueske CS, Witt T, Kleppe LS, Peterson TE, Slobodova A, Chang JY, Caplice NM, Simari RD. Role for tissue factor pathway in murine model of vascular remodeling. Circ Res 2001; 89:71-6. [PMID: 11440980 DOI: 10.1161/hh1301.092508] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tissue factor (TF) is a low-molecular-weight glycoprotein that initiates the extrinsic clotting cascade and is considered a major regulator of arterial thrombogenicity. TF pathway inhibitor (TFPI) is a major physiological inhibitor of TF-initiated coagulation. The aim of this study was to define the complex interplay between TF and TFPI and the regulation of vascular thrombogenicity in a model of vascular remodeling. To determine the levels and pattern of vascular expression of TF and TFPI associated with vascular remodeling, a murine model of flow cessation was studied. TF activity of the arteries increased after ligation (P<0.05). Quantitative analysis of homogenates of remodeled carotid arteries revealed increased TF expression but unchanged TFPI expression compared with normal carotid arteries, resulting in enhanced TF activity. To determine the potential therapeutic role of TFPI in this thrombogenic state, mice were treated with intravascular adenoviral delivery of either murine TFPI (Ad-mTFPImyc) or a control adenovirus (Ad-DeltaE1). Overexpression of TFPI decreased vascular TF activity compared with viral control (P<0.01). Overexpression of TFPI inhibited neointimal formation (P=0.038), resulting in enhanced luminal area (P=0.001) 4 weeks after flow cessation. In this murine model of vascular remodeling, an imbalance between TF and TFPI expression is generated, resulting in increased TF activity. Overexpression of TFPI in this model inhibits vascular TF activity and results in attenuation of vascular remodeling associated with flow interruption.
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Affiliation(s)
- R Singh
- Department of Internal Medicine and Cardiovascular Disease, Molecular Medicine Program, Mayo Clinic and Foundation, Rochester, MN 55905, USA
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Witt T, Hock FJ, Lehmann J. 7-Methyl-6,7,8,9,14,15-hexahydro-5H-benz[d]indolo[2,3-g]azecine: a new heterocyclic system and a new lead compound for dopamine receptor antagonists. J Med Chem 2000; 43:2079-81. [PMID: 10821720 DOI: 10.1021/jm9911478] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [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
Partially hydrogenated derivatives of the new heterocyclic ring systems benz[d]indolo[2,3-g]azecine and bisindolo[3,2-d][2, 3-g]azecine were synthesized starting from lactones and amines via the described synthetic methods. In binding assays with rat striatal receptors, 7-methyl-6,7,8,9,14,15-hexahydro-5H-benz[d]indolo[2, 3-g]azecine (LE 300) proved to be of high affinity for the D(1) binding site (K(i) = 0.08 nmol for displacement of [(3)H]SCH23390), being superior in this assay to standards such as butaclamol and SCH23390. This compound was characterized as a dopamine antagonist by conditioned avoidance response test with mice. Thus, LE 300 represents the lead of a new class of dopamine antagonists for future investigations.
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Affiliation(s)
- T Witt
- Institute of Pharmacy, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
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Meschia JF, Biller J, Witt T, Greist A, Rhinehart SN. Is hormone replacement a risk factor for ischemic stroke in women with factor V Leiden mutation? Arch Neurol 1998; 55:1137-9. [PMID: 9708966 DOI: 10.1001/archneur.55.8.1137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To describe a patient with multifocal cerebral ischemia whose only identified potential risk factors were use of postmenopausal hormone replacement and heterozygosity to factor V Leiden mutation. DESIGN A case report. SETTING A tertiary care center. PATIENT A 51-year-old woman taking hormone replacement (0.625 mg/d of estrogen alternating with 10 mg/d of medroxyprogesterone) presented with a generalized tonic-clonic seizure. She had persistent multifocal non-enhancing lesions on magnetic resonance imaging of the brain. A stereotactic biopsy of the brain performed to exclude gliomatosis cerebri was consistent with cerebral ischemia. An extensive evaluation to uncover the cause of stroke revealed only heterozygosity to factor V Leiden mutation. MAIN OUTCOME AND RESULTS Hormonal replacement was discontinued and the patient had no recurrent ischemic strokes. CONCLUSIONS Postmenopausal hormonal replacement may be a risk factor for ischemic stroke in women with the factor V Leiden mutation. Ongoing trials of hormonal replacement provide an opportunity to test this hypothesis.
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Affiliation(s)
- J F Meschia
- Department of Neurology, Mayo Clinic Jacksonville, Fla 32224, USA.
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31
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V Olshausen K, Witt T. [Holter monitoring during sudden arrhythmic death]. Herzschrittmacherther Elektrophysiol 1997; 8:235-237. [PMID: 19484325 DOI: 10.1007/bf03042613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/1997] [Accepted: 10/14/1997] [Indexed: 05/27/2023]
Abstract
Recordings of patients wearing a Holter monitor at the time of sudden cardiac death reveal that 16-20% of these patients die due to bradyarrhythmias. Tachyarrhythmic death is found in 80-84% of these patients. In about 40% lethal ventricular fibrillation is preceded by monomorphic ventricular tachyrcardias. in 20% by polymorphic ventricular tachycardias and torsades de pointes, respectively. Primary ventricular fibrillation is rare (3-5%). Typical "warning" arrhythmias, such as ventricular pairs or nonsustained ventricular tachycardias were found only inconsistently in the hours before death, as well as elevated heart rate. Thus it seems impossible at this time, to identify reliably those patients by telemetric ECG monitoring, who are at risk of imminent sudden arrhythmic death.
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Affiliation(s)
- K V Olshausen
- III. Medizinische Abteilung Schwerpunkt Kardiologie/Pneumologie, Allgemeines Krankenhaus Hamburg-Altona, Paul-Ehrlich-Strasse 1, 22763, Hamburg
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Glassman PA, Lopes JH, Witt T. Using proprietary methods to evaluate acute care admissions to a Veterans Affairs tertiary care center: are the appropriateness criteria appropriate? Am J Med Qual 1997; 12:165-8. [PMID: 9287456 DOI: 10.1177/106286069701200306] [Citation(s) in RCA: 6] [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: 02/05/2023]
Abstract
An important question for facilities monitoring acute care bed admissions with proprietary criteria is whether these methodologies remain valid after substantial changes to the criteria sets. This is especially true for publicly funded hospitals whose medical and social mission is often broader than that of private sector facilities for which insurance-based claim review is most relevant. To further address this issue, we used sequential sets (1994 and 1995) of InterQual Intensity, Severity, and Discharge criteria to assess a cohort of patients referred to our Veterans Affairs facility as acute care admissions between December 1, 1994, and February 28, 1995. We found that the appropriateness rate for the subset of medical admissions dropped from 88% when using the 1994 criteria set to 49% when using the more stringent 1995 criteria set (P < 0.001). We conclude that substantive changes to previously validated criteria sets require revalidation. Furthermore, consideration should be given to the role that insurance-based utilization review should play in publicly funded hospital systems.
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Affiliation(s)
- P A Glassman
- West Los Angeles Veterans Affairs Medical Center, CA 90073, USA
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Witt T. Admission standard contributes to long-term operating success. Provider 1993; 19:63. [PMID: 10125715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- T Witt
- WittCare Senior Living Investments, Alexandria, VA
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Morgan J, Wartsell W, Julien M, Recine D, Murthy A, Witt T, Straus A, Staren E, Griem K. The results of re-excisional biopsy for women undergoing breast conservation therapy for early stage invasive carcinoma of the breast. Int J Radiat Oncol Biol Phys 1993. [DOI: 10.1016/0360-3016(93)90862-p] [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: 10/20/2022]
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Abstract
The Holter tapes of 61 patients (46 men, mean age +/- standard deviation 65 +/- 11 years) with sudden cardiac death while being monitored were analyzed. Thirty-eight patients were known to have coronary artery disease, 5 had cardiomyopathy, and 7 had aortic valve disease. Etiology remained unknown in 11 patients. Mean New York Heart Association functional class was 2.5 +/- 0.7. Thirty patients had received antiarrhythmic drugs and 32 had received digitalis. Sudden death occurred at rest in 73%. In the hours before death, repetitive ventricular arrhythmias were found in 50 patients (82%), with atrial fibrillation in 34%. Patients with bradyarrhythmic death (18%) had less complex ventricular activity compared to patients with tachyarrhythmic death (p less than 0.01). Lethal arrhythmias--monomorphic ventricular tachycardia, polymorphic ventricular tachycardia, torsades de pointes, primary ventricular fibrillation, and 1:1 conducting atrial tachycardia--were found in 26 (43%), 15 (25%), 5 (8%), 3 (5%), and 1 patient, respectively. The coupling interval of the final ventricular tachycardia correlated inversely with the initial frequency of ventricular tachycardia (p less than 0.05). For patients with tachyarrhythmic death, an increase of heart rate within the last 3 hours was noted (83 vs 89 beats/min, p less than 0.05). Ventricular premature complexes and the proportion of patients with greater than 2 couplets and greater than 2 triplets increased significantly only within the last hour before death.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K V Olshausen
- Medizinische und Poliklinik, Universität Mainz, Federal Republic of Germany
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Goetz CG, Tanner CM, Penn RD, Stebbins GT, Gilley DW, Shannon KM, Klawans HL, Comella CL, Wilson RS, Witt T. Adrenal medullary transplant to the striatum of patients with advanced Parkinson's disease: 1-year motor and psychomotor data. Neurology 1990; 40:273-6. [PMID: 2300248 DOI: 10.1212/wnl.40.2.273] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.9] [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: 12/31/2022] Open
Abstract
We studied motor and psychomotor changes over 1 year after surgery in 7 patients with severe idiopathic Parkinson's disease (PD) who underwent intrastriatal autologous adrenal medulla transplant. Significant clinical improvements were present 1 year after surgery and primarily involved increased quantity of "on" time and increased quality of "off" time: "on" time increased from a mean 60.7% of the waking day to 82.7%, and "off" function improved. In contrast, although "on" function also improved, statistically significant improvement occurred in only 1 measure, the Unified Parkinson's Disease Rating Scale activities of daily living subscale. Medications did not change, and motor fluctuations persisted. Improvement began several weeks after surgery, was maximal at 4 to 6 months, and was sustained thereafter. There was significant group improvement in quality of life measures of sleep and rest, social isolation, and ambulation. One patient had severe, recurrent depression postoperatively. The efficacy of adrenal transplant surgery is not transient, and specific functional improvements can be prolonged.
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Affiliation(s)
- C G Goetz
- Department of Neurological Sciences, Rush-Presbyterian St. Luke's Medical Center, Chicago, IL 60612
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Nägele M, Lienemann A, Hahn D, Witt T. [Intraneuronal ganglia: value of diagnostic radiologic possibilities]. Digitale Bilddiagn 1988; 8:14-7. [PMID: 2838215] [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] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This report describes two cases of intraneuronal ganglia cysts with degeneration of the peroneal and suprascapular nerve. In addition to standard radiographs other diagnostic studies such as CT and MRI may be required to ascertain the extent of the lesion. Histopathologic information is derived from biopsy.
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Affiliation(s)
- M Nägele
- Radiologische Klinik, Univ. München, Klinikum Grosshadern
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Abstract
Melanoma is characterized by a tendency to metastasize widely throughout the body and its relative affinity for gallium-67. Because of the ability of this nuclide to image tumor sites in numerous organ systems, it has been used to detect metastases in patients with malignant melanoma. The effectiveness of this technique, however, has been controversial. This article documents the retrospective analysis of results from 296 gallium-67 scintiscans from 222 patients with melanoma. Patients were placed in two groups. The low suspicion group (148 patients undergoing 191 scans) consisted of patients with no evidence of disease; the gallium scans were performed solely for screening purposes. There were 175 true-negative scans, nine true-positive scans (eight of the nine were positive only at the untreated primary site), three false-negative scans, and four false-positive scans. Therefore, in only one patient (0.5%) did a "screening" gallium scan reveal disease that was not expected. The high suspicion group (85 patients undergoing 105 scans) consisted of patients with established evidence of metastatic disease; the gallium scan was performed to confirm those findings and to search for involvement of other organ systems. Of these scans, ten were true-negative, 73 true-positive, 21 false-negative, and one false-positive. In this group the 20% false-negative results indicate that gallium scanning is considerably less sensitive than the combination of clinical and standard radiographic assessment. It was concluded that gallium-67 scintiscanning of patients with melanoma, whether for screening or evaluation of patients with known metastases, provides little information that affects clinical staging or therapeutic design. Therefore, the technique is of limited value for routinely investigating the extent of disease.
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Affiliation(s)
- R Kagan
- Department of General Surgery, Rush University, Presbyterian-St. Luke's Hospital, Chicago, Illinois 60612
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Albrecht J, Witt T, König G. [Diminished efficiency and narcoleptic attacks with loud snoring in severe obesity]. Internist (Berl) 1983; 24:298-301. [PMID: 6347954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Abstract
The anterior tarsal tunnel syndrome, first described in 1968 by Marinacci, is characterized by a compression of the deep peroneal nerve under the inferior extensor retinaculum. The patients complaint of pains on the dorsum of the foot, especially at night. Clinically result sensory deficits in the involved area between the first and second toes as well as paresis and atrophy of the extensor digitorum brevis. The distal latency of the deep peroneal nerve is increased, the EMG shows active and chronic denervation of the extensor digitorum brevis. In cases with partial anterior tarsal tunnel syndrome only the motoric branch to the extensor digitorum brevis or only the sensory branch of the deep peroneal nerve after the division under the inferior extensor retinaculum is compressed. Two cases with complete and one with partial anterior tarsal tunnel syndrome are presented, etiology, symptomatology, differential diagnosis and therapeutic possibilities are discussed.
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