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Farquhar CM, van den Boogaard NM, Riddell C, MacDonald A, Chan E, Mol BW. Accessing fertility treatment in New Zealand: a comparison of the clinical priority access criteria with a prediction model for couples with unexplained subfertility. Hum Reprod 2011; 26:3037-44. [DOI: 10.1093/humrep/der279] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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77
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MacDonald A, Evans S, Cochrane B, Wildgoose J. Weaning infants with phenylketonuria: a review. J Hum Nutr Diet 2011; 25:103-10. [DOI: 10.1111/j.1365-277x.2011.01199.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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78
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Gokmen-Ozel H, Daly A, Davies P, MacDonald A. The development of nonweighed pilot methods for estimating phenylalanine exchanges in non-phenylketonuria volunteers. J Hum Nutr Diet 2011; 25:27-32. [DOI: 10.1111/j.1365-277x.2011.01191.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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79
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MacDonald A, Holmes S. Acquired progressive kinking of hair affecting the scalp and eyelashes in an adult woman. Clin Exp Dermatol 2011; 36:882-4. [PMID: 21623887 DOI: 10.1111/j.1365-2230.2011.04107.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acquired hair kinking of scalp hair in adults is an unusual, rarely reported phenomenon. There are several possible aetiologies, including drug-induced changes, diffuse partial woolly hair, and acquired progressive kinking of hair (APKH). We report a case of focal APKH occurring in an adult woman. This was associated with a previously unreported feature, that of eyelash involvement.
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MacDonald A, Scarrott C, Lee D, Darlow B, Reale M, Russell G. A flexible extreme value mixture model. Comput Stat Data Anal 2011. [DOI: 10.1016/j.csda.2011.01.005] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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81
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Tonkopi E, Ross A, MacDonald A. SU-E-I-156: CT Dose in Pediatric PET/CT Examinations. Med Phys 2011. [DOI: 10.1118/1.3611730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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82
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MacDonald A, Rocha JC, van Rijn M, Feillet F. Nutrition in phenylketonuria. Mol Genet Metab 2011; 104 Suppl:S10-8. [PMID: 21944460 DOI: 10.1016/j.ymgme.2011.08.023] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 08/24/2011] [Accepted: 08/24/2011] [Indexed: 12/31/2022]
Abstract
The same basic principles are used to deliver dietary treatment in PKU that was developed sixty years ago. Dietary treatment is undoubtedly very successful, but it has gradually evolved and been guided commonly by individual experience and expert opinion only. There is little international consensus about dietary practice with improvements in specialist dietary products concentrating on taste and presentation rather than nutritional composition. Many areas of dietary treatment have not been rigorously examined. In particular, the amino acid and micronutrient profile of Phenylalanine-free (phe-free) amino acids requires further study. In different formulations of phe-free amino acids, there are variations in the amino acid patterns as well the amount of essential and non essential amino acids per 100g/amino acids. The amount of added tyrosine and branch chain amino varies substantially, and in PKU specifically, there is little data about their relative absorption rates and bioavailability. In phe-free amino acids, there is evidence suggesting that some of the added micronutrients may be excessive and so the source and amount of each micronutrient should be scrutinized, with a need for the development of international nutritional composition standards exclusively for these products. There is a dearth of data about the life-long phenylalanine tolerance of patients or the nutritional state of adult patients treated with diet. There is a growing need to measure body composition routinely in children with PKU and with the rise in childhood obesity, it is important to measure body fatness and identify those who are at greatest risk of 'co-morbidities' of obesity. There is necessity for international collaboration to ensure robust data is collected on many basic aspects of nutritional care to guarantee that diet therapy is delivered to the highest standard.
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Troude P, Bailly E, Guibert J, Bouyer J, de La Rochebrochard E, Velez MP, Abad G, Robert JM, Bissonnette F, Kadoch IJ, Oudi M, Sazvar S, Alizadeh L, Ezabadi Z, Samani Omani R, Monnier P, Sheehy O, Fraser W, Bissonnette F, Tan SL, Trasler J, Chaabane S, Berard A, Nelson SM, Lawlor DA, Kasius JC, Eijkemans MJC, Mol BW, Fauser BC, Broekmans FJM, Farquhar C, Riddel C, MacDonald A, Raj N, Chan E, Mol BW, van den Boogaard N, Nikitin SV, Karpeev SA, Karpova SV. POSTER VIEWING SESSION - REPRODUCTIVE EPIDEMIOLOGY AND HEALTH ECONOMY. Hum Reprod 2011. [DOI: 10.1093/humrep/26.s1.91] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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84
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Ahring K, Bélanger-Quintana A, Dokoupil K, Gokmen-Ozel H, Lammardo AM, MacDonald A, Motzfeldt K, Nowacka M, Robert M, van Rijn M. Blood phenylalanine control in phenylketonuria: a survey of 10 European centres. Eur J Clin Nutr 2010; 65:275-8. [DOI: 10.1038/ejcn.2010.258] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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85
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Evans S, Preston F, Daly A, Neville C, MacDonald A. Accuracy of home enteral feed preparation for children with inherited metabolic disorders. J Hum Nutr Diet 2010; 24:68-73. [PMID: 21114554 DOI: 10.1111/j.1365-277x.2010.01132.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Many children with rare chronic disorders require home enteral tube feeds (HETF) consisting of multiple modular ingredients. Feeds are often complex and the risk of errors during their preparation is high. The consequences of over- or under-concentration can be critical. The aim of the present prospective observation study was to assess the accuracy, skills and technique of caregivers when preparing and administering HETF. METHODS Fifty-two HETF patients (median age 7.5 years, range 0.7-18.0 years) with inherited metabolic disorders (IMD) requiring special feeds were recruited. Using observation and a structured questionnaire, a practical assessment of feed preparation and storage by the main caregiver was undertaken by an independent dietitian and nurse in the child's home, including hygiene practices, accuracy of measuring recipe ingredients, and storage of both ingredients and prepared feeds. RESULTS The majority (85%; n = 44) of feeds were based on >1 ingredient (median 3; range 1-6). Almost half (48%; n = 25) of caregivers measured feed ingredients inaccurately. Of the 31% (n = 16) using scoops, 31% used incorrect measuring spoons and 25% did not level scoops appropriately. Some 45% (n = 20/44) of carers measured liquid ingredients inaccurately. Hygiene practices during feed preparation were poor, including a lack of hand washing (31%: n = 16) and incorrect storage procedures for unused feed ingredients (56%; n = 29). CONCLUSIONS Practices in the preparation of modular HETF for children with IMD were not ideal. A combination of inaccuracy, poor hygiene, inappropriate storage, and long feed hanging times increases both metabolic and microbial risk. Better education, regular monitoring and the development of ready-to-use or preweighed ingredients would be beneficial.
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86
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Kerr A, Rawluk N, MacDonald A, Marsh M, Schreiner J, Darko J. Cobalt-60 Source Based Image Guidance in Broad Beam Cobalt-60 IMRT. Int J Radiat Oncol Biol Phys 2010. [DOI: 10.1016/j.ijrobp.2010.07.1627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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87
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Gokmen-Ozel H, Daly A, Davies P, Chahal S, MacDonald A. Errors in emergency feeds in inherited metabolic disorders: a randomised controlled trial of three preparation methods. Arch Dis Child 2010; 95:776-80. [PMID: 20522472 DOI: 10.1136/adc.2010.161711] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE Glucose polymer-based emergency feeds (EF), used during illness to prevent metabolic decompensation and encephalopathy in inherited metabolic disorders, should be produced accurately and safely. DESIGN In a randomised, prospective, controlled study, the aim was to investigate if when preparing age-appropriate EF, a pre-measured sachet of glucose polymer, compared with scoops and weighing (using digital scales), decreased carer errors. SUBJECTS 47 carers (3 men, 44 women) of 52 inherited metabolic disorders patients were recruited. SETTING AND INTERVENTION The carers made EF using all three techniques (weighing, scoops and pre-measured sachets) under supervision in controlled and home conditions. A 100-ml aliquot of each EF was analysed for carbohydrate concentration. RESULTS Under controlled preparation conditions, with 1 litre EFs, the % median glucose polymer concentration closest to target amounts was (1) pre-measured sachets (105%), (2) weighing (107%) and (3) scoops (118%; p<0.001). Similarly, under home conditions, the closest method was (1) pre-measured sachets (111%), (2) weighing (112%) and (3) scoops (118%; p<0.05). Under home preparation conditions, with 200 ml EFs, the pre-measured sachets were more likely to be within 20% of target weight than weighing (p<0.05), but there was no difference with scoops. Common errors observed were inaccurate water measurements (40% controlled and home conditions), incorrect scoop measurements and difficulty using digital scales. CONCLUSIONS; Overall, using pre-measured sachets was more accurate in EF production. Pre-measured sachets are likely to decrease preparation error and, therefore, reduce the risk of feed intolerance, particularly osmotic diarrhoea and consequential metabolic decompensation and encephalopathy.
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Evans S, Shelton F, Holden C, Daly A, Hopkins V, MacDonald A. Monitoring of home safety issues in children on enteral feeds with inherited metabolic disorders. Arch Dis Child 2010; 95:668-72. [PMID: 19395404 DOI: 10.1136/adc.2008.148338] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To assess the safety aspects of carers' enteral feeding technique when home enteral tube feeding children with inherited metabolic disorders (IMD). METHODS 40 patients (median age, 5.1 years; range, 0.3-13.6 years) with IMD requiring pump tube feeding were recruited. 12 patients had glycogen storage disease, 11 organic acidemias, 8 fatty acid oxidation disorders, 4 urea cycle disorders, and 5 had other conditions. 50% of the patients were fed by gastrostomy and 50% nasogastric tube. A questionnaire and practical assessment of feeding process was completed with carers by a dietician and nurse in the child's home. Areas investigated included carer hygiene, feed preparation, tube care, tube changing, use of feeding pumps and equipment, and storage of enteral feeding equipment. RESULTS The main issues identified were poor hygiene practices (78% unclean work surfaces; 25% no hand washing); inaccurate ingredient measuring (40%); irregular checking of tube position (40%); inadequate tube flushing (50%); poor knowledge of how to clear tube blockages (80%); incorrect priming of pump sets (50%); incorrect position of child for night feeding (63%); untrained secondary carers (43%); and poor knowledge of pump alarms, battery life, and charging time. Children commonly slept in parent's room as a safety precaution (58%). CONCLUSIONS Long term follow-up of children with IMD on home enteral tube feeding suggests that regular updates on knowledge and technique for carers may be necessary to reduce risk.
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Rawluk N, MacDonald A, Marsh M, Schreiner LJ, Darko J, Kerr A. Sci-Fri PM: Delivery - 10: Imaging Developments for Broad Beam Co-60 Radiation Therapy. Med Phys 2010. [DOI: 10.1118/1.3476198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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90
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Tonkopi E, Ross A, MacDonald A. WE-E-201C-08: CT Radiation Dose Optimization in Whole-Body PET/CT Examination. Med Phys 2010. [DOI: 10.1118/1.3469445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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91
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Qureshi M, MacDonald A, Wing L, Lim C, Ellis M, Franklin I, Davies A. Neither Ascending nor Descending Theory Can Fully Explain the Pattern of Venous Reflux in Patients with Primary Chronic Venous Disease. J Vasc Surg 2010. [DOI: 10.1016/j.jvs.2009.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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92
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McKenzie C, Alapati VR, MacDonald A, Shaw AM. Mechanisms involved in the regulation of bovine pulmonary vascular tone by the 5-HT1B receptor. Br J Pharmacol 2009; 159:188-200. [PMID: 19958363 DOI: 10.1111/j.1476-5381.2009.00519.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE 5-HT(1B) receptors may have a role in pulmonary hypertension. Their relationship with the activity of BK(Ca,) a T-type voltage-operated calcium channel (VOCC) and cyclic nucleotide-mediated relaxation was examined. EXPERIMENTAL APPROACH Ring segments of bovine pulmonary arteries were mounted in organ baths in modified Krebs-Henseleit buffer (37 degrees C) under a tension of 20 mN and gassed with 95% O(2)/5% CO(2). Isometric recordings were made using Chart 5 software. KEY RESULTS Contractile responses to 5-HT (10 nM-300 microM) were inhibited similarly by the 5-HT(1B) receptor antagonist SB216641 (100 nM) and the T-type VOCC blockers mibefradil (10 microM) and NNC550396 (10 microM) with no additive effect between SB216641 and mibefradil. Inhibition by SB216641 was prevented by the potassium channel blocker, charybdotoxin (100 nM). 5-HT(1B) receptor activation and charybdotoxin produced a mibefradil-sensitive potentiation of responses to U46619. Bradykinin (0.1 nM-30 microM), sodium nitroprusside (0.01 nM-3 microM), zaprinast (1 nM-3 microM), isoprenaline (0.1 nM-10 microM) and rolipram (1 nM-3 microM) produced 50% relaxation of arteries constricted with 5-HT (1-3 microM) or U46619 (30-50 nM) in the presence of 5-HT(1B) receptor activation, but full relaxation of arteries constricted with U46619, the 5-HT(2A) receptor agonist 2,5 dimethoxy-4 iodoamphetamine (1 microM) or 5-HT in the presence of 5-HT(1B) receptor antagonism. Enhanced relaxation of 5-HT-constricted arteries by cGMP-dependent pathways, seen in the presence of the 5-HT(1B) receptor antagonist, was reversed by charybdotoxin whereas cAMP-dependent relaxation was only partly reversed by charybdotoxin. CONCLUSIONS AND IMPLICATIONS 5-HT(1B) receptors couple to inhibition of BK(Ca), thus increasing tissue sensitivity to contractile agonists by activating a T-type VOCC and impairing cGMP-mediated relaxation. Impaired cAMP-mediated relaxation was only partly mediated by inhibition of BK(Ca).
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93
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Portnoi PA, MacDonald A. Determination of the lactose and galactose content of cheese for use in the galactosaemia diet. J Hum Nutr Diet 2009; 22:400-8. [PMID: 19486453 DOI: 10.1111/j.1365-277x.2009.00948.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Treatment of galactosaemia requires a low galactose diet. In the UK, traditionally, all cheeses have been excluded from the diet, although some types of mature hard cheese are likely to be low in lactose and galactose. The present study aimed to determine the lactose and galactose content of mature cheeses. METHODS Over 6 years, the UK Galactosaemia Support Group commissioned the analysis of 109 samples (by two laboratories) of 12 cheese types, in eight batches throughout the year. Cheeses, obtained from retail outlets, were homogenised, sugars were extracted using water or 40% alcohol for fatty samples, and samples were deproteinised. Enzymatic analysis using measuring light absorbance was conducted on filtered extracts. RESULTS Cheeses containing undetectable quantities of lactose (<2.8 mg 100 g(-1), Leatherhead Food International, Leatherhead, UK (LFI) analysis; <10 mg 100 g(-1), Laboratory of Government Chemist, Teddington, UK (LGC Limited) analysis) and galactose were: Gruyere (five samples); Emmental (block, sliced and grated) (16 samples); Jarlsberg (six samples); Parmigiano Reggiano and Grana Padano Italian Parmesan (block and grated) (16 samples); and mature Cheddar cheese from the UK West Country Farmhouse Cheese Makers Association (35 samples) only. Lactose containing cheeses included other mature Cheddar cheeses, Gouda and Edam. CONCLUSIONS Gruyere, Emmental, Jarlsberg, Italian Parmesan (Parmigiano Reggiano and Grana Padano), and mature Cheddar cheese produced in one area of England where the manufacturing process is standardised and guaranteed are now allowed in the UK galactosaemia diet.
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Rashid M, MacDonald A. Importance of duodenal bulb biopsies in children for diagnosis of celiac disease in clinical practice. BMC Gastroenterol 2009; 9:78. [PMID: 19835611 PMCID: PMC2771033 DOI: 10.1186/1471-230x-9-78] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 10/16/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The patchy nature of villous lesion in celiac disease is increasingly being recognized. Current guidelines recommend four endoscopic duodenal mucosal biopsies from the second or more distal part of the duodenum to confirm the diagnosis of celiac disease. The purpose of the study was to investigate the usefulness of duodenal bulb mucosal biopsies in confirming the diagnosis of celiac disease in everyday clinical practice. METHODS All patients with a positive tissue-transglutaminase antibody requiring biopsy-confirmation of celiac disease over a two-year period were studied. Two endoscopic biopsies were taken from the duodenal bulb and four biopsies from the second (or distal) part of the duodenum. RESULTS Thirty-five patients were included, mean age 8.1 (+/- 4.7) years. Thirty-one (88.6%) patients had abnormal distal duodenal biopsies, one had Marsh type 1, one had Marsh type 2 and twenty-nine had Marsh type 3 lesion. All but two patients with abnormal distal duodenal biopsies also had abnormal bulb biopsies. Four (11.4%) patients had normal distal duodenal biopsies but abnormal bulb biopsies. Of these, one patient had Marsh type 2 and three had Marsh type 3 lesion. The distal duodenum was also grossly normal in these four patients. The histological diagnosis of celiac disease would not have been possible in these four cases with distal duodenal biopsies only. CONCLUSION The lesion in celiac disease in children can be patchy with duodenal bulb mucosa being the only area showing histological changes. The recommendations regarding the site of biopsies should be revised to include biopsies not only from distal duodenum but also from bulb to improve the diagnostic yield.
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Evans S, Daly A, Davies P, MacDonald A. Fibre content of enteral feeds for the older child. J Hum Nutr Diet 2009; 22:414-21. [DOI: 10.1111/j.1365-277x.2009.00991.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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96
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Evans S, Daly A, Hopkins V, Davies P, MacDonald A. The impact of visual media to encourage low protein cooking in inherited metabolic disorders. J Hum Nutr Diet 2009; 22:409-13. [DOI: 10.1111/j.1365-277x.2009.00953.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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97
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Evans S, Daly A, Davies P, MacDonald A. The nutritional intake supplied by enteral formulae used in older children (aged 7-12 years) on home tube feeds. J Hum Nutr Diet 2009; 22:394-9. [DOI: 10.1111/j.1365-277x.2009.00993.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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98
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Gokmen-Ozel H, MacDonald A, Daly A, Hall K, Ryder L, Chakrapani A. Long-term efficacy of ‘ready-to-drink’ protein substitute in phenylketonuria. J Hum Nutr Diet 2009; 22:422-7. [DOI: 10.1111/j.1365-277x.2009.00998.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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99
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MacDonald A, Darko J, Schreiner LJ. Poster - Wed Eve-56: Megavoltage Digital Tomosynthesis Using a Radioactive Cobalt-60 Gamma Ray Source for Radiation Therapy Treatment Verification. Med Phys 2009. [DOI: 10.1118/1.3244160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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100
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McKenzie C, MacDonald A, Shaw AM. Mechanisms of U46619-induced contraction of rat pulmonary arteries in the presence and absence of the endothelium. Br J Pharmacol 2009; 157:581-96. [PMID: 19389160 DOI: 10.1111/j.1476-5381.2008.00084.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND AND PURPOSE Thromboxane A(2) and endothelial dysfunction are implicated in the development of pulmonary hypertension. The receptor-transduction pathway for U46619 (9,11-dideoxy-9 alpha, 11 alpha-methanoepoxy prostaglandin F(2 alpha))-induced contraction was examined in endothelium-intact (E+) and denuded (E-) rat pulmonary artery rings. EXPERIMENTAL APPROACH Artery rings were mounted on a wire myograph under a tension of 7-7.5 mN at 37 degrees C and gassed with 95% O(2)/5% CO(2). Isometric recording was made by using Powerlab data collection and Chart 5 software. KEY RESULTS Both E+ and E- contractile responses were sensitive to Rho-kinase inhibition and the chloride channel blocker NPPB [5-nitro-2-(3-phenylpropylamino)benzoic acid]. The E+ response was sensitive to the store-operated calcium channel blockers SKF-96365 {1-[B-[3-(4-methoxyphenyl)propoxy]-4-methoxy-phenethyl]-1H-imidazole hydrochloride} and 2-APB (2-amino ethoxy diphenylborate) (75-100 micromol x L(-1)). The E- response was sensitive to 2-APB (10-30 micromol x L(-1)), a putative IP(3) receptor antagonist, and the calcium and chloride channel blockers nifedipine, DIDS (4,4'-diisothiocyanostilbene-2,2'-disulphonic acid) and niflumic acid but was insensitive to SKF-96365. Inhibiting K(V) with 4-AP in E+ rings exposed a contraction sensitive to nifedipine, DIDS and niflumic acid, whereas inhibiting BK(Ca) exposed a contraction sensitive to mibefradil, DIDS and niflumic acid. This indicates that removal of the endothelium allows the TP receptor to inhibit K(V), which may involve coupling to phospholipase C, because inhibition of phospholipase C with U73122 (1-[6-[[(17beta)-3-methoxyestra-1,3,5(10)-trien-17-y]amino]hexyl]- 1H-pyrrole-2,5-dione) switched the E- pathway to the E+ pathway. CONCLUSIONS AND IMPLICATIONS The results from this study indicate that distinct transduction pathways can be employed by the TP receptor to produce contraction and that the endothelium is able to influence the coupling of the TP receptor.
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