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Adedokun SA, Pescatore AJ, Ford MJ, Ao T, Jacob JP. Investigating the effect of dietary calcium levels on ileal endogenous amino acid losses and standardized ileal amino acid digestibility in broilers and laying hens. Poult Sci 2018; 97:131-139. [PMID: 29077891 DOI: 10.3382/ps/pex271] [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: 04/28/2017] [Accepted: 08/30/2017] [Indexed: 11/20/2022] Open
Abstract
Two studies were conducted to evaluate the effect of dietary Ca levels (low, 1% and high, 3%) on ileal endogenous amino acid losses (IEAAL) and standardized ileal amino acid digestibility (SIAAD) in broilers (BR) and laying hens (LH) fed nitrogen-free diets (NFD) and distiller's dried grain with solubles (DDGS)-based diets. A total of 384 male Cobb 500 BR and 288 LH were used in a completely randomized design (CRD) with 16 (BR) or 12 (LH) replicate cages with 6 birds/replicate. IEAAL and apparent ileal digestibility (AID) of AA were analyzed using the GLM procedure of SAS appropriate for a CRD while SIAAD values were analyzed using the GLM procedure of SAS appropriate for a 2 × 2 factorial arrangement of treatments. For BR, IEAAL and N losses (mg/kg of dry matter intake, DMI) were higher (P < 0.05) when NFD with high Ca level was fed (total AA was 39%, N was 35% higher). For most of the AA, AID was higher (P < 0.05) in BR fed DDGS-based diet with high Ca level. High dietary Ca resulted in higher (P < 0.05) SIAAD for all the AA except for Arg, Lys, Met, Cys, and Tyr. For LH, AID of AA was higher (P < 0.05) for the DDGS diet with high Ca level in 13 of the 18 AA evaluated. There was interaction (P < 0.05) between diet Ca level and correction method on LH SIAAD values for Thr, Asp, Gly, and Ser. The SIAAD values for 8 AA were higher (P < 0.05) in birds on high Ca DDGS diet. Correction with low Ca NFD resulted in higher (P < 0.05) SIAAD values for all the AA. Result from this study showed that high Ca increased total IEAAL in BR by 39% but decreased same by 27% in LH. Finally, SIAAD values were increased in BR fed high Ca DDGS-based diet while SIAAD value in LH was lower when correction was done using values from high Ca-NFD fed birds.
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Affiliation(s)
- S A Adedokun
- Department of Animal and Food Sciences, University of Kentucky, Lexington KY, USA
| | - A J Pescatore
- Department of Animal and Food Sciences, University of Kentucky, Lexington KY, USA
| | - M J Ford
- Department of Animal and Food Sciences, University of Kentucky, Lexington KY, USA
| | - T Ao
- Alltech Inc., Catnip Pike, Nicholasville KY, USA
| | - J P Jacob
- Department of Animal and Food Sciences, University of Kentucky, Lexington KY, USA
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Olojede OC, Ford MJ, Jacob JP, Ao T, Pescatore AJ, Adedokun SA. The effect of drying method temperature, collection method, and marker type on apparent ileal amino acid digestibility in 21-day-old broilers fed corn-soybean meal-barley based diet. Poult Sci 2018; 97:2106-2112. [PMID: 29514296 DOI: 10.3382/ps/pey049] [Citation(s) in RCA: 4] [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] [Received: 04/25/2017] [Indexed: 12/17/2023] Open
Abstract
For accurate estimation of nutrient digestibility, an ideal drying and sampling method is required to preserve the quality of the digesta. A standard corn-soybean meal (corn-SBM) broiler starter diet was fed from d 0 to 10 before birds were placed on the experimental diets until d 21. One hundred and sixty-eight male Cobb 500 broiler chicks were used to evaluate the effect of two drying methods (freeze-dryer vs. forced air-oven) and two drying temperatures (40 vs. 55°C) (Exp 1), while ninety-six chicks were used to evaluate the effect of flushing and squeezing as well as marker types (titanium vs. chromium) on apparent ileal DM, N, Ca, P, and AA digestibility (Exp 2). There were seven (Exp 1) or eight (Exp 2) replicate cages per treatment with 6 birds/cage. Digesta from the distal two thirds of the ileum was obtained from birds following euthanasia on d 21 by squeezing (Exp 1) and squeezing or flushing (Exp 2). Samples collected were stored in the freezer at -20°C until they were either freeze-dried (FD) or oven-dried (OD) at 40 or 55°C. There were no interactions between the drying methods and drying temperatures (Exp 1) on apparent ileal DM, N, and AA digestibility. Met had the highest (92.3%) while Cys had the lowest (73.8%) digestibility value. In Exp 2, no interaction between sampling methods and marker types was observed. The effect of sampling methods was not significant except for Arg and Met where squeezing resulted in higher (P < 0.05) digestibility values. Furthermore, apparent ileal His, Ile, Cys, Ser, and Tyr digestibility tended to be higher (P < 0.1) in squeezed digesta compared to the flushed digesta. Results from these studies showed that OD ileal digesta at 40 or 55°C had no negative effect on apparent ileal AA digestibility. Likewise, marker type did not influence apparent ileal AA digestibility values.
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Affiliation(s)
- O C Olojede
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40546
| | - M J Ford
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40546
| | - J P Jacob
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40546
| | - T Ao
- Alltech Inc., Nicholasville KY, USA
| | - A J Pescatore
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40546
| | - S A Adedokun
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40546
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Adedokun SA, Pescatore AJ, Ford MJ, Jacob JP, Helmbrecht A. Examining the effect of dietary electrolyte balance, energy source, and length of feeding of nitrogen-free diets on ileal endogenous amino acid losses in broilers. Poult Sci 2018; 96:3351-3360. [PMID: 28854743 DOI: 10.3382/ps/pex159] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 01/24/2017] [Accepted: 05/12/2017] [Indexed: 11/20/2022] Open
Abstract
The effect of dietary electrolyte balance (DEB), energy source (ES), and length of feeding of nitrogen-free diet (NFD) on ileal endogenous amino acid (EAA) loss in mg/kg dry matter intake (DMI) was evaluated in broiler chickens. In Experiment 1, 720 chickens consisting of 15 replicate cages with 6 chickens/replicate were used. Treatments were arranged in a 2 × 2 × 2 factorial and consisted of 4 NFD with 2 levels (low or high) of DEB and 2 ES [corn starch (CS) or dextrose (DX)], and 2 sampling time-points (diets were fed for either 72 h (d 16 to 19) or 120 h (d 16 to 21). Experiment 2 used 360 chickens in a 2 × 2 factorial arrangement of treatments with 2 levels (low or high) of DEB and 2 ES (CS or DX). Diets were fed for 72 h (d 18 to 21). All birds had access to feed and water on an ad libitum basis. Data were analyzed using the GLM procedure of SAS appropriate for a completely randomized design for a factorial arrangement of treatments. For Experiment 1, there were interactions (P < 0.05) between the 3 main factors for nitrogen and all the AA except Trp. Broilers that were fed DX-based NFD with high DEB for 72 h had the highest (P < 0.05) EAA losses. In Experiment 2, there was no interaction between DEB and ES except for His and Lys. When ileal EAA losses from birds fed the low DEB, CS-based NFD were used to standardize apparent ileal digestibility values from a previous study, there was no effect of length of feeding on standardized ileal AA digestibility values. In conclusion, DX-based NFD with high DEB increased endogenous AA loses. Despite differences in ileal EAA losses from CS-based NFD, standardized ileal AA digestibility values were not influenced by the length of feeding of NFD. Based on the results from these studies, NFD could be fed for 72 h without influencing SIAAD values.
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Affiliation(s)
- S A Adedokun
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY.
| | - A J Pescatore
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY
| | - M J Ford
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY
| | - J P Jacob
- Department of Animal and Food Sciences, University of Kentucky, Lexington, KY
| | - A Helmbrecht
- Evonik Nutrition and Care GmbH, 10-B531, Rodenbacher Chaussee 4, 63457 Hanau-Wolfgang, Germany
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Ford MJ, Parsons KM, Ward EJ, Hempelmann JA, Emmons CK, Bradley Hanson M, Balcomb KC, Park LK. Inbreeding in an endangered killer whale population. Anim Conserv 2018. [DOI: 10.1111/acv.12413] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- M. J. Ford
- Conservation Biology Division; Northwest Fisheries Science Center; National Marine Fisheries Service; NOAA; Seattle WA USA
| | - K. M. Parsons
- North Gulf Oceanic Society, under contract to Marine Mammal Laboratory; Alaska Fisheries Science Center; National Marine Fisheries Service; NOAA; Seattle WA USA
| | - E. J. Ward
- Conservation Biology Division; Northwest Fisheries Science Center; National Marine Fisheries Service; NOAA; Seattle WA USA
| | - J. A. Hempelmann
- Conservation Biology Division; Northwest Fisheries Science Center; National Marine Fisheries Service; NOAA; Seattle WA USA
| | - C. K. Emmons
- Conservation Biology Division; Northwest Fisheries Science Center; National Marine Fisheries Service; NOAA; Seattle WA USA
| | - M. Bradley Hanson
- Conservation Biology Division; Northwest Fisheries Science Center; National Marine Fisheries Service; NOAA; Seattle WA USA
| | | | - L. K. Park
- Conservation Biology Division; Northwest Fisheries Science Center; National Marine Fisheries Service; NOAA; Seattle WA USA
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Abstract
The irritable bowel syndrome is a problem commonly found in the population as a whole, in general practice and in general hospital and specialist gastroenterological clinical practice. A population survey found that 14% of those interviewed exhibited symptoms of the irritable bowel syndrome but did not present to their general practitioner. In the gastroenterology clinic it is said to represent approximately one-third to one-half of referrals1.
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Abstract
We report density functional theory calculations for single layer MoS2 in its 2H, semiconducting and 1T metallic phases in order to understand the relative stability of these two phases and transition between them in the presence of adsorbed lithium atoms and under compressive strain. We have determined the diffusion barriers between the two phases and demonstrate how the presence of Li adatoms or strain can significantly reduce these barriers. We show that the 2H and 1T structures have the same energy under 15% biaxial, compressive strain. This is the same strain value posited by Lin et al (2014 Nat. Nanotechnology 9 391-396) for their intermediate α phase. Calculations of the 1T and 2H permittivity and electron energy loss spectrum are also performed and characterized.
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Affiliation(s)
- K M Fair
- School of Physics & Advanced Materials, University of Technology, Sydney, NSW 2007, Australia
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Fair KM, Arnold MD, Ford MJ. Determination of the elastic properties of graphene by indentation and the validity of classical models of indentation. J Phys Condens Matter 2014; 26:015307. [PMID: 24292235 DOI: 10.1088/0953-8984/26/1/015307] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Ab initio and empirical force field methods are used to simulate the loading of a large graphene membrane under an indenter analogous to an atomic force microscope tip. From these calculations we attempt to resolve ambiguities around determination of the elastic constants of graphene from such indentation experiments. We investigate the effect of the formation of wrinkles and more importantly the applicability of modelling the membrane as a continuous elastic sheet. By comparing empirical potential and large scale density functional theory calculations we have also assessed the performance of classical potentials in describing bending in this system. We find that the in-plane Young's modulus deduced from the indentation simulations using the classical expression for a clamped elastic membrane under a central point load is not consistent with that calculated directly from the in-plane stress-strain curve.
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Affiliation(s)
- K M Fair
- School of Physics and Advanced Materials, University of Technology, Sydney, NSW 2007, Australia
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Dobbin A, Dobbin J, Ross SC, Graham C, Ford MJ. Randomised controlled trial of brief intervention with biofeedback and hypnotherapy in patients with refractory irritable bowel syndrome. J R Coll Physicians Edinb 2013; 43:15-23. [PMID: 23516685 DOI: 10.4997/jrcpe.2013.104] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [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: 11/19/2022] Open
Abstract
Irritable bowel syndrome (IBS) is a common disorder associated with profoundly impaired quality of life and emotional distress. The management of refractory IBS symptoms remains challenging and non-pharmacological therapeutic approaches have been shown to be effective. We compared brief interventions with biofeedback and hypnotherapy in women referred by their GP with refractory IBS symptoms. Patients were randomised to one of two treatment groups, biofeedback or hypnotherapy, delivered as three one-hour sessions over 12 weeks. Symptom assessments were undertaken using validated, self-administered questionnaires. Two of the 128 consecutive IBS patients suitable for the study declined to consider nonpharmacological therapy and 29 patients did not attend beyond the first session. Of the 97 patients randomised into the study, 21 failed to attend the therapy session; 15 of 76 patients who attended for therapy dropped out before week 12 post-therapy. The mean (SD) change in IBS symptom severity score 12 weeks post-treatment in the biofeedback group was -116.8 (99.3) and in the hypnotherapy group -58.0 (101.1), a statistically significant difference between groups (difference=-58.8, 95% confidence interval [CI] for difference [-111.6, -6.1], p=0.029). In 61 patients with refractory IBS, biofeedback and hypnotherapy were equally effective at improving IBS symptom severity scores, total non-gastrointestinal symptom scores and anxiety and depression ratings during 24 weeks follow-up. Biofeedback may prove to be the more cost-effective option as it requires less expertise.
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Affiliation(s)
- A Dobbin
- School of Clinical Sciences and Community Health, University of Edinburgh, Edinburgh, UK.
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Ao T, Pierce JL, Pescatore AJ, Cantor AH, Dawson KA, Ford MJ, Paul M. Effects of feeding different concentration and forms of zinc on the performance and tissue mineral status of broiler chicks. Br Poult Sci 2012; 52:466-71. [PMID: 21919574 DOI: 10.1080/00071668.2011.588198] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
1. Two studies were conducted to investigate the effect of feeding different concentration and forms of zinc (Zn) on the performance and tibia Zn status of broiler chicks. 2. In Experiment 1, chicks fed on the control or the diet supplemented with 12?mg of Zn as sulphate had lower feed intake, weight gain and tibia Zn content than other treatment groups. Chicks given 12 and 24 mg of organic Zn in starter and grower phases, respectively, had the same performance and tibia Zn content as those fed 40 mg of Zn as sulphate and the same performance but higher tibia Zn content than those given 12 mg of Zn as organic over the 42 d. 3. In Experiment 2, chicks given 24 mg organic Zn had greater weight gain than chicks fed on the other treatment diets in the starter period. Chicks fed on the control diet had lower tibia Zn content than chicks fed other treatment diets. Chicks given 80 mg Zn as sulphate had higher tibia Zn content than chicks fed the other treatment diets except those given 40 mg of Zn as sulphate. 4. The results from these trials indicate that feeding lower concentration of Zn as organic form may better promote the growth performance of broiler chicks.
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Affiliation(s)
- T Ao
- Alltech-University of Kentucky Nutrition Research Alliance, Lexington, KY, USA.
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Denisyuk AI, Adamo G, MacDonald KF, Edgar J, Arnold MD, Myroshnychenko V, Ford MJ, García de Abajo FJ, Zheludev NI. Transmitting hertzian optical nanoantenna with free-electron feed. Nano Lett 2010; 10:3250-3252. [PMID: 20731411 DOI: 10.1021/nl1002813] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A pair of coupled gold nanorods excited by a beam of free electrons acts as a transmitting Hertzian antenna in the optical part of the spectrum. Significantly enhanced resonant emission is observed from the antenna when the electron beam is injected around the junction between the rods, where the local density of electromagnetic states is elevated.
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Affiliation(s)
- A I Denisyuk
- Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK
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Abstract
Alternative materials are required to enhance the efficacy of plasmonic devices. We discuss the optical properties of a number of alloys, doped metals, intermetallics, silicides, metallic glasses and high pressure materials. We conclude that due to the probability of low frequency interband transitions, materials with partially occupied d states perform poorly as plasmonic materials, ruling out many alloys, intermetallics and silicides as viable. The increased probability of electron-electron and electron-phonon scattering rules out many doped and glassy metals.
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Affiliation(s)
- M G Blaber
- Institute for Nanoscale Technology, Department of Physics and Advanced Materials, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia
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Hanson MB, Baird RW, Ford JKB, Hempelmann-Halos J, Van Doornik DM, Candy JR, Emmons CK, Schorr GS, Gisborne B, Ayres KL, Wasser SK, Balcomb KC, Balcomb-Bartok K, Sneva JG, Ford MJ. Species and stock identification of prey consumed by endangered southern resident killer whales in their summer range. ENDANGER SPECIES RES 2010. [DOI: 10.3354/esr00263] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Abstract
We use electronic structure calculations based upon density functional theory to search for ideal plasmonic materials among the alkali-noble intermetallics. Importantly, we use density functional perturbation theory to calculate the electron-phonon interaction and from there use a first order solution to the Boltzmann equation to estimate the phenomenological damping frequency in the Drude dielectric function. We discuss the necessary electronic features of a plasmonic material and investigate the optical properties of the alkali-noble intermetallics in terms of some generic plasmonic system quality factors. We conclude that at low negative permittivities, KAu, with a damping frequency of 0.0224 eV and a high optical gap to bare plasma frequency ratio, outperforms gold and to some extent silver as a plasmonic material. Unfortunately, a low plasma frequency (1.54 eV) reduces its utility in modern plasmonics applications. We also discuss, briefly, the effect of local fields on the optical properties of these materials.
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Affiliation(s)
- M G Blaber
- Institute for Nanoscale Technology, Department of Physics and Advanced Materials, University of Technology, Sydney, 15 Broadway, NSW 2007, Australia
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Blaber MG, Arnold MD, Ford MJ. Optical properties of intermetallic compounds from first principles calculations: a search for the ideal plasmonic material. J Phys Condens Matter 2009; 21:144211. [PMID: 21825328 DOI: 10.1088/0953-8984/21/14/144211] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
First principles calculations have been used to predict the optical properties for a range of intermetallic compounds for which little or no experimental optical data are currently available. Density functional theory combined with the random phase approximation is used to calculate the dielectric functions for these compounds. The aim of this work is to investigate how the band edge and plasma frequency vary with composition in order to identify materials with promising plasmonic properties. Towards this end the intermetallic compounds chosen are composed of elements which on their own have reasonable optical properties for plasmonic applications. The position of the band edge relative to the plasma frequency is most favourable in the simple binary compounds formed from the alkali plus noble metals NaAu, KAu and KAg. In particular, for KAu the band edge and plasma frequency occur at almost the same frequency, and hence the imaginary part of the dielectric function is practically zero for frequencies below the plasma frequency. In addition, the plasma frequency in this compound is at relatively low frequency, promising a material with strong plasmon response in the infrared.
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Affiliation(s)
- M G Blaber
- Institute for Nanoscale Technology, Physics and Advanced Materials, University of Technology Sydney, PO Box 123, Broadway 2007, NSW, Australia
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Ao T, Cantor AH, Pescatore AJ, Ford MJ, Pierce JL, Dawson KA. Effect of enzyme supplementation and acidification of diets on nutrient digestibility and growth performance of broiler chicks. Poult Sci 2009; 88:111-7. [PMID: 19096065 DOI: 10.3382/ps.2008-00191] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two experiments were conducted to examine the effects of alpha-galactosidase supplementation and acidification of diets on nutrient digestibility and growth performance of broiler chicks. In experiment 1, dietary treatments consisted of feeding a low-energy basal diet (2.74 Mcal of ME/kg) alone, the basal diet supplemented with 1,724 units of alpha-galactosidase per kg, the basal diet supplemented with 2% citric acid, or the basal diet supplemented with both. alpha-Galactosidase significantly increased feed intake, weight gain, AME(n) of the diets, and retention of CP and neutral detergent fiber (NDF) (P < 0.05). Citric acid significantly increased the retention of DM, CP, and NDF, but decreased feed intake and weight gain. The greatest values for DM and NDF retention and for AME(n) were obtained with the combination of alpha-galactosidase plus citric acid. In experiment 2, chicks were fed diets with 2 levels of energy (2.74 or 3.11 Mcal/kg), 2 levels of citric acid (0 or 1.5%), and 2 levels of alpha-galactosidase (0 or 1,724 units/kg) in a 2 x 2 x 2 factorial arrangement of treatments. alpha-Galactosidase significantly increased the reducing sugar concentration in the crop content, whereas citric acid decreased the pH and increased the reducing sugar concentration in the crop content. Citric acid decreased the gain to feed ratio in the absence but not in the presence of alpha-galactosidase. The data from these studies indicate that acidification of diet improves the efficacy of alpha-galactosidase.
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Affiliation(s)
- T Ao
- Department of Animal and Food Sciences, University of Kentucky, KY, USA
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Abstract
We perform density functional theory (DFT) calculations on molecular junctions consisting of a single molecule between two Au(111) electrodes. The molecules consist of an alkane or aryl bridge connecting acceptor, donor or thiol endgroups in various combinations. The molecular geometries are optimized and wavefunctions and eigenstates of the junction calculated using the DFT method, and then the electron transport properties for the junction are calculated within the non-equilibrium Green's function (NEGF) formalism. The current-voltage or i(V) characteristics for the various molecules are then compared. Rectification is observed for these molecules, particularly for the donor-bridge-acceptor case where the bridge is an alkane, with rectification being in the same direction as the original findings of Aviram and Ratner (1974 Chem. Phys. Lett. 29 277-83), at least for relatively large negative and positive applied bias. However, at smaller bias rectification is in the opposite direction and is attributed to the lowest unoccupied orbital associated with the acceptor group.
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Ao T, Pierce JL, Pescatore AJ, Cantor AH, Dawson KA, Ford MJ, Shafer BL. Effects of organic zinc and phytase supplementation in a maize-soybean meal diet on the performance and tissue zinc content of broiler chicks. Br Poult Sci 2007; 48:690-5. [PMID: 18085451 DOI: 10.1080/00071660701694072] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [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: 10/22/2022]
Abstract
1. The purpose of this study was to investigate the effects of Bioplex Zn (a chelated zinc proteinate) and phytase supplementation in a maize-soybean meal diet on the performance and tissue zinc (Zn) content of broiler chicks. Treatment structure consisted of a 2 x 6 factorial arrangement with two inclusions of phytase (0 or 500 PU/kg) and 6 of Bioplex Zn providing 0, 2, 4, 8, 16 and 32 mg Zn/kg diet. A total of 864 chicks were randomly assigned to each of 12 dietary treatments with 6 replicate cages of 12 chicks. 2. Dietary inclusion of phytase increased feed intake, weight gain, plasma Zn content, tibia Zn content, tibia and ash weight. 3. Dietary supplementation of Bioplex Zn linearly increased feed intake, weight gain, gain to feed ratio, plasma Zn concentration, liver Zn concentration, tibia Zn content, tibia and ash weight. 4. An interactive effect of phytase and Bioplex Zn on feed intake, weight gain, tibia Zn concentration and tibia ash weight was found. 5. One slope, straight broken-line analysis of weight gain regressed on the supplemental Zn level provided as Bioplex Zn indicated that 12 mg/kg supplemental Zn without phytase and 7.4 mg/kg supplemental Zn with phytase were required for the optimal weight gain of chicks.
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Affiliation(s)
- T Ao
- Alltech-University of Kentucky Nutrition Research Alliance, Lexington, Kentucky 40356, USA.
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Krishnamurty S, Shafai GS, Kanhere DG, Soulé de Bas B, Ford MJ. Ab Initio Molecular Dynamical Investigation of the Finite Temperature Behavior of the Tetrahedral Au19and Au20Clusters. J Phys Chem A 2007; 111:10769-75. [PMID: 17914783 DOI: 10.1021/jp075896+] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Density functional molecular dynamics simulations have been carried out to understand the finite temperature behavior of Au19 and Au20 clusters. Au20 has been reported to be a unique molecule having tetrahedral geometry, a large HOMO-LUMO energy gap, and an atomic packing similar to that of the bulk gold (Li, J.; et al. Science 2003, 299, 864). Our results show that the geometry of Au19 is exactly identical with that of Au20 with one missing corner atom (called a vacancy). Surprisingly, our calculated heat capacities for this nearly identical pair of gold clusters exhibit dramatic differences. Au20 undergoes a clear and distinct solid-like to liquid-like transition with a sharp peak in the heat capacity curve around 770 K. On the other hand, Au19 has a broad and flat heat capacity curve with continuous melting transition. This continuous melting transition turns out to be a consequence of a process involving a series of atomic rearrangements along the surface to fill in the missing corner atom. This results in a restricted diffusive motion of atoms along the surface of Au19 between 650 to 900 K during which the shape of the ground state geometry is retained. In contrast, the tetrahedral structure of Au20 is destroyed around 800 K, and the cluster is clearly in a liquid-like state above 1000 K. Thus, this work clearly demonstrates that (i) the gold clusters exhibit size sensitive variations in the heat capacity curves and (ii) the broad and continuous melting transition in a cluster, a feature that has so far been attributed to the disorder or absence of symmetry in the system, can also be a consequence of a defect (absence of a cap atom) in the structure.
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Affiliation(s)
- Sailaja Krishnamurty
- Department of Physics and Centre for Modeling and Simulation, University of Pune, Ganeshkhind, Pune 411 007, India
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Hoft RC, Ford MJ, Cortie MB. The effect of reciprocal-space sampling and basis set quality on the calculated conductance of a molecular junction. Molecular Simulation 2007. [DOI: 10.1080/08927020701435811] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Ford MJ, Hoft RC, Gale JD. Adsorption and dimerisation of thiol molecules on Au(111) using aZ-matrix approach in density functional theory. Molecular Simulation 2006. [DOI: 10.1080/08927020601052872] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Nixon KL, Vos M, Bowles C, Ford MJ. Measuring the electronic structure of disordered overlayers by electron momentum spectroscopy: the Cu/Si interface. SURF INTERFACE ANAL 2006. [DOI: 10.1002/sia.2385] [Citation(s) in RCA: 3] [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: 11/11/2022]
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22
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Hoft RC, Gale JD, Ford MJ. Implementation of aZ-matrix approach within the SIESTA periodic boundary conditions code and its application to surface adsorption. Molecular Simulation 2006. [DOI: 10.1080/08927020600900337] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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23
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Cortie MB, Xu X, Ford MJ. Effect of composition and packing configuration on the dichroic optical properties of coinage metal nanorods. Phys Chem Chem Phys 2006; 8:3520-7. [PMID: 16871341 DOI: 10.1039/b604333j] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [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: 11/21/2022]
Abstract
When nanorods of Au, Ag and some other elements are aligned with a preferred orientation with respect to light, their optical extinction characteristics become dependent on the polarization and angle of incidence of the light. This effect is explored here and it is shown that it could potentially be exploited to produce a 'colour-change coating'. However, particle-particle interactions are also likely to occur in such coatings, with red shifting of extinction spectra occurring for end-on-end configurations of monodisperse rods, and blue shifting for side-by-side configurations. Surprisingly, the particle-particle interactions are attenuated if they are between rods of differing aspect ratios, and this offers a useful new means of control of the optical properties of coatings of nanorods.
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Affiliation(s)
- M B Cortie
- Institute for Nanoscale Technology, University of Technology Sydney, PO Box 123, Broadway NSW, 2007, Australia
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24
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Ford MJ, Hoft RC, McDonagh A. Theoretical Study of Ethynylbenzene Adsorption on Au(111) and Implications for a New Class of Self-Assembled Monolayer. J Phys Chem B 2005; 109:20387-92. [PMID: 16853638 DOI: 10.1021/jp053238o] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Density functional calculations of the adsorption of ethynylbenzene on the Au(111) surface show that, after cleavage of the C-H bond, the terminal carbon makes a strong covalent bond to the surface. The bond energy is shown to be about 70 kcal.mol(-1) with the fcc hollow site being most stable and the molecule oriented perpendicular to the surface. Adsorption without elimination of hydrogen is also possible via a hydrogen 1,2 shift to form a vinylidene surface-bound species, or opening of the C-C triple bond and adsorption through the two carbon atoms in a flat conformation. The reaction energy for formation of the surface-bound vinylidene is estimated to be 5 kcal.mol(-1) exothermic relative to the isolated ethynylbenzene and gold substrate.
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Affiliation(s)
- M J Ford
- Institute for Nanoscale Technology, University of Technology Sydney, P.O. Box 123, Broadway, NSW 2007, Australia.
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25
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Abstract
The level of expression of normal cellular prion protein, PrP(c) (cellular prion protein), controls both the rate and the route of neuroinvasive infection, from peripheral entry portal to the CNS. Paradoxically, an overview of the distribution of PrP(c) within tissues outside the CNS is lacking. We have used novel antibodies that recognise cellular prion protein in glutaraldehyde-fixed tissue (in order to optimise immunohistochemical labelling of this conformationally labile protein), in combination with in situ hybridisation, to examine the expression of PrP(c) in peripheral tissues of the adult mouse. We found that although prion protein is expressed in many tissues, it is expressed at high levels only in discrete subpopulations of cells. Prominent amongst these are elements of the "hardwired neuroimmune network" that integrate the body's immune defence and neuroendocrine systems under CNS control. These prion protein-expressing elements include small diameter afferent nerves in the skin and the lamina propria of the aerodigestive tract, sympathetic ganglia and nerves, antigen presenting and processing cells (both follicular and non-follicular dendritic cells) and sub-populations of lymphocytes particularly in skin, gut- and bronchus-associated lymphoid tissues. Prion protein is also expressed in the parasympathetic and enteric nervous systems, in the dispersed neuroendocrine system, and in peripheral nervous system axons and their associated Schwann cells. This selective expression of cellular prion protein provides a variety of alternative routes for the propagation and transport of prion infection entering from peripheral sites, either naturally (via the aerodigestive tract or abraded skin) or experimentally (by intraperitoneal injection) to the brain. Key regulatory cells that express prion protein, and in particular enteroendocrine cells in the mucosal wall of the gut, and dendritic cells that convey pathogens from epithelial layers to secondary lymphoid organs, may be particularly important in the transmission of infection in the periphery.
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Affiliation(s)
- M J Ford
- MRC Centre for Developmental Neurobiology, Hodgkin Building, King's College London Guy's Campus, London Bridge, London SE1 1UL, UK
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26
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Paton ND, Cantor AH, Pescatore AJ, Ford MJ, Smith CA. The effect of dietary selenium source and level on the uptake of selenium by developing chick embryos. Poult Sci 2002; 81:1548-54. [PMID: 12412922 DOI: 10.1093/ps/81.10.1548] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [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: 11/14/2022] Open
Abstract
We studied the effect of dietary source (organic or inorganic) and level of Se on the Se uptake of chick embryos. After receiving a low-Se diet for 16 wk, 126 Leghorn laying hens were randomly assigned to one of seven dietary treatments. Treatments consisted of feeding a low-Se basal diet alone or with one of three levels of added Se (0.1,0.2, or 0.3 mg/kg Se) supplied by sodium selenite or Se-enriched yeast. Fertile eggs were collected after 33 d of feeding the experimental diets. Eggs were subjected to no incubation or incubation for 5, 10, 15, or 20 d. Non-incubated eggs were separated, and the yolk and albumen were assayed separately for Se. Incubated eggs were separated into the embryo and extra-embryonic portions, which were assayed separately for Se. Se concentrations of the yolk and albumen were significantly different among dietary treatments. Compared with eggs from hens fed sodium selenite, yolk and albumen Se concentrations were higher in eggs from hens fed Se yeast. Embryonic and extra-embryonic Se concentrations were higher in eggs from hens fed Se yeast than eggs from hens fed sodium selenite. The largest increase in embryonic Se concentration was observed during Days 10 to 15 of incubation. It was concluded that Se source and dietary inclusion level influenced the Se concentration of portions of developing embryonated eggs and that embryonic Se concentration changed during incubation.
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Affiliation(s)
- N D Paton
- Department of Animal Sciences, University of Kentucky, Lexington 40546-0215, USA
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27
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Ford MJ, Burton LJ, Li H, Graham CH, Frobert Y, Grassi J, Hall SM, Morris RJ. A marked disparity between the expression of prion protein and its message by neurones of the CNS. Neuroscience 2002; 111:533-51. [PMID: 12031342 DOI: 10.1016/s0306-4522(01)00603-0] [Citation(s) in RCA: 74] [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] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Expression of the normal cellular form of prion protein is both necessary and rate-limiting in the spread of prion disease, yet its cellular expression in vivo is poorly understood. To optimise immunohistochemical labelling of this protein in mouse brain, we have developed novel antibodies that recognise cellular prion protein in glutaraldehyde-fixed tissue. Expression was found to be predominantly neuronal, and to differ between different classes of neurone. Thus, neurones immunoreactive for GABA expressed very high levels of normal prion protein; most projection neurones expressed much lower levels, particularly on their axons in the major fibre tracts, and some neurones (e.g. those positive for dopamine) displayed no detectable prion protein. In marked contrast, all neurones, even those that were immunonegative, expressed high levels of message for prion protein, shown by non-radioactive in situ hybridisation. Glia expressed very low levels of message, and undetectable levels of prion protein. We conclude that the steady-state level of prion protein, which differs so markedly between different neuronal types, is primarily controlled post-transcriptionally, possibly by differences in protein trafficking or degradation. These marked differences in the way different neurones produce and/or degrade their normal cellular prion protein may influence the selective spread and neurotoxic targeting of prion diseases within the CNS.
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Affiliation(s)
- M J Ford
- MRC Centre for Developmental Neurobiology, KCL Guy's Campus, London, UK
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28
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Humphreys MJ, Ghaneh P, Greenhalf W, Campbell F, Clayton TM, Everett P, Huber BE, Richards CA, Ford MJ, Neoptolemos JP. Hepatic intra-arterial delivery of a retroviral vector expressing the cytosine deaminase gene, controlled by the CEA promoter and intraperitoneal treatment with 5-fluorocytosine suppresses growth of colorectal liver metastases. Gene Ther 2001; 8:1241-7. [PMID: 11509957 DOI: 10.1038/sj.gt.3301518] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2000] [Accepted: 05/11/2001] [Indexed: 01/02/2023]
Abstract
Targeting of colorectal liver metastases by regional gene therapy was tested in a clinically relevant syngeneic model. First, the CEA-CD-113 retroviral vector containing the cytosine deaminase gene controlled by the CEA specific tumour cell promoter, was shown in vitro to convert 5-fluorocytosine to 5-fluorouracil, resulting in cancer cell killing with a large bystander effect. Second, 10 days after the establishment of liver metastases, retroviral vectors were delivered to the liver by hepatic artery injection. After 5-fluorocytosine administration for 7 days, most surface metastases disappeared and tumour volumes were suppressed up to 8.2-fold. The results support the development of this approach for patient treatment.
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Affiliation(s)
- M J Humphreys
- Department of Surgery, University of Liverpool, Liverpool, UK
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29
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Abstract
Transferrins are iron-binding proteins that are involved in iron storage and resistance to bacterial disease. Previous work has shown that nonsynonymous-to-synonymous-site substitution ratios (d(n)/d(s) ratios) between transferrin genes from some salmonid species were significantly greater than 1.0, providing evidence for positive selection at the transferrin gene. The purpose of the current study was to put these earlier results in a broader evolutionary context by examining variation among 25 previously published transferrin sequences from fish, amphibians, and mammals. The results of the study show that evidence for positive selection at transferrin is limited to salmonids-d(n)/d(s) ratios estimated for nonsalmonid lineages were generally less than 1.0. Within the salmonids, approximately 13% of the transferrin codon sites are estimated to be subject to positive selection, with an estimated d(n)/d(s) ratio of approximately 7. The three- dimensional locations of some of the selected sites were inferred by comparing these sites to homologous sites in the bovine lactoferrin crystallographic structure. The selected sites generally fall on the outside of the molecule, within and near areas that are bound by transferrin-binding proteins from human pathogenic bacteria. The physical locations of sites estimated to be subject to positive selection support previous speculation that competition for iron from pathogenic bacteria could be the source of positive selection.
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Affiliation(s)
- M J Ford
- National Marine Fisheries Service, Northwest Fisheries Science Center, Conservation Biology Division, Seattle, Washington 98112, USA.
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30
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Abstract
A 17-week-old boy with a giant congenital melanocytic nevus (GCMN) of the left lower extremity was noted to have a reduction in circumference of the left lower extremity relative to the contralateral side. The skin overlying the GCMN was persistently warm when compared with the surrounding and contralateral skin. Comparative plain radiography, ultrasonography, and magnetic resonance imaging showed fat hypoplasia of the left lower extremity, with bone and muscle appearing unaffected. The possible role of cytokines produced by the nevus in fat hypoplasia in GCMN is discussed.
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Affiliation(s)
- S A Caradona
- Department of Dermatology, University of Florida College of Medicine, Gainesville, USA
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31
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Ford MJ. Effects of natural selection on patterns of DNA sequence variation at the transferrin, somatolactin, and p53 genes within and among chinook salmon (Oncorhynchus tshawytscha) populations. Mol Ecol 2000; 9:843-55. [PMID: 10886648 DOI: 10.1046/j.1365-294x.2000.00933.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [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
This paper describes DNA sequence variation within and among four populations of chinook salmon (Oncorhynchus tshawytscha) at the transferrin, somatolactin and p53 genes. Patterns of variation among salmon species at the transferrin gene have been hypothesized to be shaped by positive natural selection for new alleles because the rate of nonsynonymous substitution is significantly greater than the rate of synonymous substitution. The twin goals of this study were to determine if the history of selection among salmon species at the transferrin gene is also reflected in patterns of intraspecific variation in chinook salmon, and to look for evidence of local adaptation at the transferrin gene by comparing patterns of nonsynonymous and synonymous variation among chinook salmon populations. The analyses presented here show that unlike patterns of variation between species, there is no evidence of greater differentiation among chinook salmon populations at nonsynonymous compared to synonymous sites. There is also no evidence of a reduction of within-species variation due to the hitchhiking effect at the transferrin gene, although in some populations nonsynonymous and synonymous derived mutations are both at higher frequencies than expected under a simple neutral model. Population size weighted selection coefficients (4Ns) that are consistent with both the inter and intraspecific data range from approximately 10 to approximately 235, and imply that between 1 and 40% of new nonsynonymous mutations at the transferrin gene have been beneficial.
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Affiliation(s)
- M J Ford
- National Marine Fisheries Service, Northwest Fisheries Science Center, Conservation Biology Division, 2725 Montlake Blvd. E, Seattle, WA 98112, USA.
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32
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Quinn CM, Wiles AP, El-Shanawany T, Catchpole I, Alnadaf T, Ford MJ, Gordon S, Greaves DR. The human eukaryotic initiation factor 4AI gene (EIF4A1) contains multiple regulatory elements that direct high-level reporter gene expression in mammalian cell lines. Genomics 1999; 62:468-76. [PMID: 10644445 DOI: 10.1006/geno.1999.6031] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The gene encoding human eukaryotic initiation factor 4A (EIF4A1) is located on chromosome 17p13, 667 bp upstream from the gene encoding the macrophage endosomal protein CD68. The EIF4AI gene contains 10 intervening sequences with the 1397-bp first intron containing a CpG-rich methylation-free island. Sequences capable of enhancing gene expression reside between positions -69 and -371 and positions -504 and -1100 of the EIF4AI 5' flanking sequence and within introns 1, 2, 3, 7, and 9. In macrophage cell lines, EIF4A1 expression vectors give sustained high-level reporter gene expression to levels 10 times higher than that obtained using the human cytomegalovirus immediate-early gene promoter/enhancer. Sequences of the human EIF4AI gene may find application in the development of new vectors for gene therapy and genetic vaccination.
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Affiliation(s)
- C M Quinn
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, United Kingdom
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33
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Abstract
Juvenile dermatomyositis (JDM) is an uncommon disease that features muscle weakness, a characteristic rash, and vascular changes in skin, muscle, and other organs. We report a patient with JDM who developed multiple angiokeratomas, one of which was calcified. Electron microscopy of an angiokeratoma revealed altered connective tissue consistent with abnormal collagen. To our knowledge, angiokeratomas occurring in association with JDM have not been previously reported. Abnormal collagen distinguishes the angiokeratomas in our patient from those seen in other conditions. We propose that the angiokeratomas resulted from a progressive compensatory response to the obliterative angiopathy of JDM.
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Affiliation(s)
- P L Shannon
- University of Florida College of Medicine, Division of Dermatology and Cutaneous Surgery, Gainesville, Florida, USA
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34
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Affiliation(s)
- S W Spence
- University of Florida College of Medicine, Gainesville, USA
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35
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Spence SW, Cosgrove BF, Ford MJ. Malar rash in a child. Arch Dermatol 1999; 135:478037. [PMID: 24764031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
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36
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Affiliation(s)
- A C Jones
- Department of Pathology, The University of Texas Health Science Center at San Antonio, 78284-7750, USA.
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37
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Mead GE, Cunnington AL, Faulkner S, Russell KJ, Ford MJ. Can general practitioner referral letters for acute medical admissions be improved? Health Bull (Edinb) 1999; 57:257-61. [PMID: 12811886] [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: 03/03/2023]
Abstract
BACKGROUND General practitioner (GP) referral letters for emergency medical admissions should contain enough information to ensure that patients are managed safely and effectively. AIM Our aim was to assess the quality of referral letters for acute medical admissions. METHOD GP letters from 300 consecutive acute medical admissions were prospectively assessed by the admitting doctor and then independently assessed by a senior house officer (SHO), and a senior registrar. A random sample of 25 were assessed by a general practitioner. Content and legibility were evaluated for demographic details, current history, past history, social history, drugs and allergies, in order to grade the overall quality as "excellent", "good", "adequate" or "inadequate". RESULTS Two hundred and ninety one letters were received, of which 208 (71%) were from the patients' own GP practice and 83 (28%) from a co-operative or deputising service. The admitting doctor rated 38 (13%) as excellent, 108 (37%) as good, 96 (33%) as adequate and 49 (17%) as inadequate. Kappa values for overall quality between the admitting doctors and the other doctors (senior house officer, senior registrar and our general practitioner) were 0.32, 0.26 and 0.44 respectively, representing fair to moderate interobserver agreement. Co-operatives or deputising services used proformas more often than GP practices (65/83, 78% and 17/208, 8% respectively, p < 0.01). There was no significant difference in overall quality between GP practices and co-operatives or deputising services, or between letters received on headed note paper or proformas. CONCLUSION Most letters are satisfactory for the individual management of acutely ill patients, but collaborative work could usefully be undertaken to address the factors which result in the production of sub-optimal referral letters.
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Affiliation(s)
- G E Mead
- Western General Hospital, Edinburgh
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38
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Abstract
Transferrin is an iron-binding protein that plays an important role in iron metabolism and resistance to bacterial infection in a variety of organisms. A comparison of transferrin coding sequences from four salmonid species shows that the rate of evolution at nonsynonymous sites is significantly higher than the rate at synonymous sites, suggesting that positive natural selection for new alleles has played an important role in the evolution of transferrin in some salmon species. We hypothesize that the selective agent driving rapid divergence is interactions between host transferrin and the iron-scavenging proteins of pathogenic bacteria.
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Affiliation(s)
- M J Ford
- National Marine Fisheries Service, Northwest Fisheries Science Center, Seattle, WA 98112, USA.
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39
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Searle PF, Weedon SJ, McNeish IA, Gilligan MG, Ford MJ, Friedlos F, Springer CJ, Young LS, Kerr DJ. Sensitisation of human ovarian cancer cells to killing by the prodrug CB1954 following retroviral or adenoviral transfer of the E. coli nitroreductase gene. Adv Exp Med Biol 1999; 451:107-13. [PMID: 10026858 DOI: 10.1007/978-1-4615-5357-1_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Affiliation(s)
- P F Searle
- University of Birmingham, CRC Institute for Cancer Studies, Birmingham, United Kingdom.
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40
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Chung JY, Ramos-Caro FA, Beers B, Ford MJ, Flowers FP. Hypersensitivity reactions to parenteral vitamin K. Cutis 1999; 63:33-4. [PMID: 9951592] [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] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Cutaneous hypersensitivity reactions to vitamin K are rare. They occur almost exclusively with fat-soluble vitamin K (K1). The lesion is most commonly a pruritic, indurated plaque at the site where the vitamin was injected. Most plaques resolve within 4 to 8 week without sequelae, but some progress to produce scar-like changes that may last for years.
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Affiliation(s)
- J Y Chung
- Department of Medicine, University of Florida College of Medicine, Gainesville, USA
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41
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Jones E, Quinn CM, See CG, Montgomery DS, Ford MJ, Kölble K, Gordon S, Greaves DR. The linked human elongation initiation factor 4A1 (EIF4A1) and CD68 genes map to chromosome 17p13. Genomics 1998; 53:248-50. [PMID: 9790779 DOI: 10.1006/geno.1998.5515] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- E Jones
- Sir William Dunn School of Pathology, South Parks Road, Oxford, OX1 3RE, United Kingdom
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42
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Ferguson NS, Gates RS, Taraba JL, Cantor AH, Pescatore AJ, Ford MJ, Burnham DJ. The effect of dietary crude protein on growth, ammonia concentration, and litter composition in broilers. Poult Sci 1998; 77:1481-7. [PMID: 9776054 DOI: 10.1093/ps/77.10.1481] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.5] [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: 11/14/2022] Open
Abstract
An experiment was conducted to determine the effect of diets with reduced CP and supplemental amino acids on broiler performance, N excretion, litter characteristics, and equilibrium NH3 gas concentration. Results suggest that reducing CP (and lysine) below 241 g/kg (13.7 g/kg lysine) in the diets fed during the first 3 wk may slightly increase feed:gain and therefore may not be advisable. During the period 22 to 43 d of age there were no significant differences in weight gain and BW at 6 wk of age when reducing CP from 215 g/kg (11.5 g/kg lysine) to 196 g/kg (11.3 g/kg lysine), but feed intake and feed:gain ratio increased. However, reducing CP did cause equilibrium NH3 gas concentration and litter N to decline by 31 and 16.5%, respectively. Both of these advantages will improve air quality within the housing facility and possibly reduce heating costs during winter associated with higher ventilation rates required to reduce elevated NH3 gas concentrations.
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Affiliation(s)
- N S Ferguson
- Animal Science and Poultry Science Department, University of Natal, Scottsville, South Africa
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43
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McNeish IA, Green NK, Gilligan MG, Ford MJ, Mautner V, Young LS, Kerr DJ, Searle PF. Virus directed enzyme prodrug therapy for ovarian and pancreatic cancer using retrovirally delivered E. coli nitroreductase and CB1954. Gene Ther 1998; 5:1061-9. [PMID: 10326029 DOI: 10.1038/sj.gt.3300744] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.9] [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: 12/24/2022]
Abstract
Expression of the E. coli enzyme nitroreductase (NTR) in tumour cells enables them to activate the prodrug CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide), leading to interstrand DNA crosslinking and cell death. Using transfected or retrovirally transduced SKOV3 ovarian carcinoma cell clones, we show a strong correlation between sensitivity to CB1954 and level of NTR enzyme activity. Importantly for clinical application in ovarian cancer, a cisplatin-resistant ovarian tumour cell line remains as susceptible to the NTR-dependent cytotoxicity of CB1954 as parental cells. In mixed populations of NTR-expressing and non-expressing cells, we observe a marked 'bystander killing' effect with this system. The use of NTR-encoding retroviruses from clonal producer cell lines at titres of 5 x 10(5) c.f.u./ml to transduce either established or low passage primary ovarian carcinoma lines only achieves an average 10-fold sensitisation of the cultures at gene transfer efficiencies of 15-25%. Concentration of the retrovirus to 3 x 10(7) c.f.u./ml elevates gene transfer to 80-90% in a single exposure to target cells, resulting in up to 500-fold sensitisation of the entire, unselected SKOV3 population to CB1954. In an initial investigation of NTR/CB1954 for the treatment of tumours in vivo, we observe regression of tumours expressing NTR following administration of CB1954, resulting in significantly increased median survival.
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Affiliation(s)
- I A McNeish
- CRC Institute for Cancer Studies, University of Birmingham, UK
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44
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Ferguson NS, Gates RS, Taraba JL, Cantor AH, Pescatore AJ, Straw ML, Ford MJ, Burnham DJ. The effect of dietary protein and phosphorus on ammonia concentration and litter composition in broilers. Poult Sci 1998; 77:1085-93. [PMID: 9706071 DOI: 10.1093/ps/77.8.1085] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [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: 11/13/2022] Open
Abstract
An experiment was conducted to determine whether broiler litter concentration of N and P and equilibrium NH3 gas concentration can be reduced by reducing dietary CP and P levels and supplementing with amino acids and phytase, respectively, without adversely affecting bird performance. Equilibrium NH3 gas concentration above the litter was measured. The experiment was divided into a starter period (1 to 21 d) and grower period (22 to 42 d), each having two different CP and P levels in a 2 x 2 factorial arrangement. The CP treatments consisted of a control with a mean CP of 204 and 202 g/kg for starter and grower periods, respectively, and a low CP diet with means of 188 and 183 g/kg, respectively, but with similar amino acid levels as the control. The P treatments comprised starter and grower control diets containing means of 6.7 and 6.3 g/kg P, respectively, and low P treatment means of 5.8 and 5.4 g/kg P supplemented with 1.0 g/kg phytase. Reducing starter diet CP by 16 g/kg reduced weight gain by 3.5% and, hence, body weight at 21 d of age, but did not affect feed intake or feed efficiency. Reducing P did not affect feed intake and weight gain, but improved feed efficiency by 2.0%. Responses in feed intake and efficiency to CP depended on the level of dietary P. For the grower period there were no significant differences in feed intake, weight gain, and feed efficiency, nor in body weight at 42 d of age, after correcting for 21-d body weight, between CP and P treatments. There were significant (P < 0.001) reductions in litter N and P concentrations, but not equilibrium NH3 gas concentration, moisture content, or pH, for low CP and P diets. Mean equilibrium NH3 gas concentration was 63 ppm. Litter N concentration was reduced 16.3% with the low CP diets, and litter P by 23.2% in low P treatments. The results suggest that dietary manipulation shows merit for reducing litter N and P concentrations while maintaining acceptable production performance from broilers.
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Affiliation(s)
- N S Ferguson
- Animal Science and Poultry Science Department, University of Natal, Scottsville, South Africa
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Affiliation(s)
- L S Machado
- Department of Medicine, University of Florida College of Medicine, Gainesville 32610-0277, USA
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46
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Abstract
The ATP requirement of influenza A virus RNA-dependent RNA polymerase was studied during in vitro transcription reactions. In complete transcription reactions, the Km for ATP was 10-fold higher than the Km values for the other NTPs. However, during transcription elongation the Km for ATP was as low as the Km values for the other NTPs, suggesting a special requirement for ATP during transcription initiation. Gel analysis of RNA products of transcription initiation reactions showed that the incorporation of AMP into nascent RNA was more efficient at positions 4, 6 and 7 relative to the template RNA than at position 5. The polymerase produced short, abortive transcripts with lengths corresponding to positions 3 and 4 relative to the template but never to position 5 or longer. These results suggest that incorporation of AMP at position 5 induces the influenza A virus polymerase to go through a transition from a transcription initiation to an elongation complex. This functional change of the polymerase complex rather than a requirement for ATP beta-gamma bond hydrolysis is the most likely reason for the particularly high Km for ATP during the early phase of transcription. This conclusion is supported by the fact that the ATP analogue ATPgammaS [adenosine 5'-O-(3-thiotriphosphate)] can efficiently replace ATP in in vitro transcription reactions and shows a comparable drop of Km between transcription initiation and elongation.
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Affiliation(s)
- K Klumpp
- EMBL Grenoble Outstation, France.
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Abstract
AIM To review the physiology of colonic motility and sensation in healthy humans and the pathophysiological changes associated with constipation and diarrhoea. SOURCE Medline Search from 1965 using the index terms: human, colonic motility, sensation, pharmacology, neurohormonal control, gastrointestinal transit, constipation, diarrhoea and combinations of these. RESULTS In health, the ascending and transverse regions of colon function as reservoirs to accommodate ileal chyme and the descending colon acts as a conduit; the neuromuscular functions and transmitters control colonic motility and sensation and play pivotal roles in disorders associated with constipation and/or diarrhoea. Disorders of proximal colonic transit contribute to symptoms in idiopathic constipation, diarrhoea-predominant irritable bowel syndrome and carcinoid diarrhoea. Colonic function in patients presenting with constipation is best assessed clinically by colonic transit time using radiopaque markers ingested orally. Measurements of colonic contractility are less useful clinically but they can help identify motor abnormalities including colonic inertia; in some patients with irritable bowel syndrome, abdominal pain, urgency and diarrhoea are temporally associated with high amplitude contractions, which originate in the proximal colon and traverse the distal conduit at very high propagation velocities. Visceral hypersensitivity contributes to the urgency and tenesmus in irritable bowel syndrome and inflammatory bowel disease. Colonic motility and sensation can be reduced by anticholinergic agents, somatostatin analogues and 5HT3 antagonists. CONCLUSION Physiological and pharmacological studies of the human colon have provided new insights into the pathophysiology of colonic disorders, and offer possibilities of novel therapeutic approaches for constipation or diarrhoea associated with colonic motor or sensory dysfunction.
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Affiliation(s)
- M Camilleri
- Mayo Medical School, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA
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Craig JE, Ford MJ, Blaydon DC, Sonenshein AL. A null mutation in the Bacillus subtilis aconitase gene causes a block in Spo0A-phosphate-dependent gene expression. J Bacteriol 1997; 179:7351-9. [PMID: 9393699 PMCID: PMC179685 DOI: 10.1128/jb.179.23.7351-7359.1997] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The citB gene of Bacillus subtilis encodes aconitase, the enzyme of the Krebs citric acid cycle, which is responsible for the interconversion of citrate and isocitrate. A B. subtilis strain with an insertion mutation in the citB gene was devoid of aconitase activity and aconitase protein, required glutamate for growth in minimal medium, and was unable to sporulate efficiently in nutrient broth sporulation medium. Mutant cells failed to form the asymmetric septum characteristic of sporulating cells and were defective in transcription of the earliest-expressed spo genes, that is, the genes dependent on the Spo0A phosphorelay. However, this early block in sporulation was partially overcome when cells of the citB mutant were induced to sporulate by resuspension in a poor medium. Accumulation of citrate in the mutant cells or in their culture fluid may be responsible for the early block, possibly because citrate can chelate divalent cations needed for the activity of the phosphorelay.
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Affiliation(s)
- J E Craig
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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Willett CS, Ford MJ, Harrison RG. Inferences about the origin of a field cricket hybrid zone from a mitochondrial DNA phylogeny. Heredity (Edinb) 1997; 79 ( Pt 5):484-94. [PMID: 9369011 DOI: 10.1038/hdy.1997.188] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [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] Open
Abstract
Two closely related eastern North American field crickets, Gryllus firmus and G. pennsylvanicus, hybridize along a zone that extends from Connecticut and the Hudson River Valley, south along the eastern front of the Appalachian Mountains to at least Virginia. Here we use mitochondrial DNA (mtDNA) sequences to construct a population phylogeny for this pair of hybridizing cricket species. Using a phylogenetic approach, we attempt to discriminate between alternative population histories (secondary contact vs. primary intergradation) leading to formation of the hybrid zone. A strict consensus tree, based on > 1600 bp of the COI-COII region of the mtDNA genome, reveals four exclusive groups, which correspond to regional grouping of conspecific crickets. Surprisingly, the mtDNA sequence data do not reveal any synapomorphies for either G. pennsylvanicus or G. firmus. However, the mtDNA data do reveal a clear north-south split within each of the cricket species, a pattern not seen for morphological or other molecular characters. The biogeographical history of the north-south divergence events remains a puzzle. Observed gene genealogies support a model of secondary contact for the southern part of the hybrid zone. Sequence divergence data argue that lineages currently found in New York and New England were already distinct when this region became habitable following the most recent glaciation.
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Affiliation(s)
- C S Willett
- Section of Ecology and Systematics, Cornell University, Ithaca, NY 14853, USA
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Cosgrove BF, Reeves K, Mullins D, Ford MJ, Ramos-Caro FA. Congenital cutaneous candidiasis associated with respiratory distress and elevation of liver function tests: a case report and review of the literature. J Am Acad Dermatol 1997; 37:817-23. [PMID: 9366843 DOI: 10.1016/s0190-9622(97)80002-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [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: 02/05/2023]
Abstract
We describe congenital cutaneous candidiasis (CCC) in a term newborn. The mother had candidal vaginitis 1 week before delivery. At birth, the infant had a generalized, intensely erythematous, papulovesicular eruption, respiratory distress and elevation of liver function tests. The child responded well to intravenous amphotericin B plus topical and oral nystatin. There have been 13 previously reported cases of CCC in infants weighing more than 1500 gm who had evidence of systemic infection. Two deaths were attributed to candidal pneumonia and sepsis. The majority of infants with CCC have infection localized to the skin, but if there is any evidence of respiratory distress or signs of sepsis the possibility of systemic candidiasis and the need for parenteral antifungal therapy must be considered.
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Affiliation(s)
- B F Cosgrove
- Division of Dermatology and Cutaneous Surgery, University of Florida College of Medicine, Gainesville, USA
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