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Patterson M, Banks M, Laarman GJ. Definitive PCI for severe coronary disease masquerading as troponin-negative ACS. Neth Heart J 2006; 14:106-107. [PMID: 25696604 PMCID: PMC2557278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023] Open
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Druce MR, Wren AM, Park AJ, Milton JE, Patterson M, Frost G, Ghatei MA, Small C, Bloom SR. Ghrelin increases food intake in obese as well as lean subjects. Int J Obes (Lond) 2006; 29:1130-6. [PMID: 15917842 DOI: 10.1038/sj.ijo.0803001] [Citation(s) in RCA: 279] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To investigate whether effects on food intake are seen in obese subjects receiving exogenous administration of ghrelin. DESIGN Randomised, double-blind, placebo-controlled study of intravenous ghrelin at doses 1 pmol/kg/min and 5 pmol/kg/min. SUBJECTS In all, 12 healthy lean subjects (mean body mass index (BMI) 20.5+/-0.17 kg/m(2)) and 12 healthy overweight and obese subjects (mean BMI 31.9+/-1.02 kg/m(2)). MEASUREMENTS Food intake, appetite and palatability of food, ghrelin and other obesity-related hormones, growth hormone. RESULTS Low-dose infusion of ghrelin increased ad libitum energy intake at a buffet meal in the obese group only (mean increase 36.6+/-9.4%, P<0.01.) High-dose ghrelin infusion increased energy intake in both groups (mean increase 20.1+/-10.6% in the lean and 70.1+/-15.5% in the obese, P<0.01 in both cases.) Ghrelin infusion increased palatability of food in the obese group. CONCLUSION Ghrelin increases food intake in obese as well as lean subjects. Obese people are sensitive to the appetite-stimulating effects of ghrelin and inhibition of circulating ghrelin may be a useful therapeutic target in the treatment of obesity.
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le Roux CW, Batterham RL, Aylwin SJB, Patterson M, Borg CM, Wynne KJ, Kent A, Vincent RP, Gardiner J, Ghatei MA, Bloom SR. Attenuated peptide YY release in obese subjects is associated with reduced satiety. Endocrinology 2006; 147:3-8. [PMID: 16166213 DOI: 10.1210/en.2005-0972] [Citation(s) in RCA: 410] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The responses of the gut hormone peptide YY (PYY) to food were investigated in 20 normal-weight and 20 obese humans in response to six test meals of varying calorie content. Human volunteers had a graded rise in plasma PYY (R2 = 0.96; P < 0.001) during increasing calorific meals, but the obese subjects had a lower endogenous PYY response at each meal size (P < 0.05 at all levels). The ratio of plasma PYY(1-36) to PYY(3-36) was similar in normal-weight and obese subjects. The effect on food intake and satiety of graded doses of exogenous PYY(3-36) was also evaluated in 12 human volunteers. Stepwise increasing doses of exogenous PYY(3-36) in humans caused a graded reduction in food intake (R2 = 0.38; P < 0.001). In high-fat-fed (HF) mice that became obese and low-fat-fed mice that remained normal weight, we measured plasma PYY, tissue PYY, and PYY mRNA levels and assessed the effect of exogenous administered PYY(3-36) on food intake in HF mice. HF mice remained sensitive to the anorectic effects of exogenous ip PYY(3-36). Compared with low-fat-fed fed mice, the HF mice had lower endogenous plasma PYY and higher tissue PYY but similar PYY mRNA levels, suggesting a possible reduction of PYY release. Thus, fasting and postprandial endogenous plasma PYY levels were attenuated in obese humans and rodents. The PYY(3-36) infusion study showed that the degree of plasma PYY reduction in obese subjects were likely associated with decreased satiety and relatively increased food intake. We conclude that obese subjects have a PYY deficiency that would reduce satiety and could thus reinforce their obesity.
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Murray CDR, Martin NM, Patterson M, Taylor SA, Ghatei MA, Kamm MA, Johnston C, Bloom SR, Emmanuel AV. Ghrelin enhances gastric emptying in diabetic gastroparesis: a double blind, placebo controlled, crossover study. Gut 2005; 54:1693-8. [PMID: 16085693 PMCID: PMC1774813 DOI: 10.1136/gut.2005.069088] [Citation(s) in RCA: 259] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Diabetic gastroparesis is a disabling condition with no consistently effective treatment. In animals, ghrelin increases gastric emptying and reverses postoperative ileus. We present the results of a double blind, placebo controlled, crossover study of ghrelin in gastric emptying in patients with diabetic gastroparesis. METHODS Ten insulin requiring diabetic patients (five men, six type I) referred with symptoms indicative of gastroparesis received a two hour infusion of either ghrelin (5 pmol/kg/min) or saline on two occasions. Blood glucose was controlled by euglycaemic clamp. Gastric emptying rate (GER) was calculated by real time ultrasound following a test meal. Blood was sampled for ghrelin, growth hormone (GH), and pancreatic polypeptide (PP) levels. Cardiovagal neuropathy was assessed using the Mayo Clinic composite autonomic severity score (range 0 (normal)-3). RESULTS Baseline ghrelin levels were mean 445 (SEM 36) pmol/l. Ghrelin infusion achieved a peak plasma level of 2786 (188) pmol/l at 90 minutes, corresponding to a peak GH of 70.9 (19.8) pmol/l. Ghrelin increased gastric emptying in seven of 10 patients (30 (6)% to 43 (5)%; p = 0.04). Impaired cardiovagal tone correlated inversely with peak postprandial PP values (p < 0.05) but did not correlate with GER. CONCLUSIONS Ghrelin increases gastric emptying in patients with diabetic gastroparesis. This is independent of vagal tone. We propose that analogues of ghrelin may represent a new class of prokinetic agents.
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Hinton EC, Holland AJ, Gellatly MSN, Soni S, Patterson M, Ghatei MA, Owen AM. Neural representations of hunger and satiety in Prader–Willi syndrome. Int J Obes (Lond) 2005; 30:313-21. [PMID: 16276365 DOI: 10.1038/sj.ijo.0803128] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To investigate the neural basis of the abnormal eating behaviour in Prader-Willi syndrome (PWS), using brain imaging. We predicted that the satiety response in those with PWS would be delayed and insensitive to food intake. DESIGN AND PARTICIPANTS The design of this study was based on a previous investigation of the neural activation associated with conditions of fasting and food intake in a nonobese, non-PWS group. The findings were used to generate specific hypotheses regarding brain regions of interest for the current study, in which 13 adults with PWS took part (mean +/- s.d. age = 29 +/- 6; BMI = 31.5 +/- 5.1; IQ = 71 +/- 8, six were female). MEASUREMENTS Regional cerebral blood flow was measured using positron emission tomography in three sessions: one following an overnight fast and two following disguised energy controlled meals of similar volume and appearance--one of 1674 kJ (400 kcal) and another of 5021 kJ (1200 kcal). Subjective ratings of hunger, fullness and desire to eat, and blood plasma levels of glucose, insulin, leptin, ghrelin and PYY were measured before and after each imaging session. RESULTS The neural representation of hunger, after an overnight fast, was similar to that found in nonobese individuals in the control study. In contrast, after food intake, the patterns of neural activation previously associated with satiety were not found, even after the higher-energy load. Lateral and medial orbitofrontal cortical activation was associated with consumption of the 400- and 1200-kcal meals, respectively. The medial orbitofrontal activation, however, was only found in those who had shown a large percentage change in fullness ratings following the higher-energy meal. CONCLUSION We conclude that there is a dysfunction in the satiety system in those with PWS. These findings suggest that brain regions associated with satiety are insensitive even to high-energy food intake in those with the syndrome. This may be the neural basis of the hyperphagia seen in PWS.
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Thakor AS, Bloomfield MR, Patterson M, Giussani DA. Calcitonin gene-related peptide antagonism attenuates the haemodynamic and glycaemic responses to acute hypoxaemia in the late gestation sheep fetus. J Physiol 2005; 566:587-97. [PMID: 15860534 PMCID: PMC1464744 DOI: 10.1113/jphysiol.2005.085431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Accepted: 04/27/2005] [Indexed: 12/14/2022] Open
Abstract
The fetal defence to acute hypoxaemia involves cardiovascular and metabolic responses, which include peripheral vasoconstriction and hyperglycaemia. Both these responses are mediated via neuroendocrine mechanisms, which require the stimulation of the sympathetic nervous system. In the adult, accumulating evidence supports a role for calcitonin gene-related peptide (CGRP) in the activation of sympathetic outflow. However, the role of CGRP in stimulated cardiovascular and metabolic functions before birth is completely unknown. This study tested the hypothesis that CGRP plays a role in the fetal cardiovascular and metabolic defence responses to acute hypoxaemia by affecting sympathetic outflow. Under anaesthesia, five sheep fetuses at 0.8 of gestation were surgically instrumented with catheters and a femoral arterial Transonic flow-probe. Five days later, fetuses were subjected to 0.5 h hypoxaemia during either i.v. saline or a selective CGRP antagonist in randomised order. Treatment started 30 min before hypoxaemia and ran continuously until the end of the challenge. Arterial samples were taken for blood gases, metabolic status and hormone analyses. CGRP antagonism did not alter basal arterial blood gas, metabolic, cardiovascular or endocrine status. During hypoxaemia, similar falls in Pa,O2 occurred in all fetuses. During saline infusion, hypoxaemia induced hypertension, bradycardia, femoral vasoconstriction, hyperglycaemia and an increase in haemoglobin, catecholamines and neuropeptide Y (NPY). In contrast, CGRP antagonism markedly diminished the femoral vasoconstrictor and glycaemic responses to hypoxaemia, and attenuated the increases in haemoglobin, catecholamines and NPY. Combined, these results strongly support the hypothesis that CGRP plays a role in the fetal cardiovascular and metabolic defence to hypoxaemia by affecting sympathetic outflow.
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Diplock R, Brooksby B, Dehghani H, Davis S, Patterson M, Pogue B. Po-Poster - 33: A finite element model for bioluminescence imaging in small animals. Med Phys 2005. [DOI: 10.1118/1.2031012] [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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83
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Comsa D, Farrell T, Patterson M. Sci-PM Fri - 03: Potential use of diffusion theory for quantitative in vivo
fluorescence and bioluminescence imaging. Med Phys 2005. [DOI: 10.1118/1.2031035] [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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84
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Dysart J, Singh G, Patterson M. Sci-YIS Fri - 03: Calculation of singlet oxygen dose from photosensitizer photobleaching during mTHPC or Photofrin photodynamic therapy in vitro. Med Phys 2005. [DOI: 10.1118/1.2031025] [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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85
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Xu H, Patterson M, Farrell T. Sci-PM Fri - 02: Determination of optical properties of tissue in situ
using four different frequency domain models. Med Phys 2005. [DOI: 10.1118/1.2031034] [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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86
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le Roux CW, Patterson M, Vincent RP, Hunt C, Ghatei MA, Bloom SR. Postprandial plasma ghrelin is suppressed proportional to meal calorie content in normal-weight but not obese subjects. J Clin Endocrinol Metab 2005; 90:1068-71. [PMID: 15522935 DOI: 10.1210/jc.2004-1216] [Citation(s) in RCA: 188] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Circulating levels of the gastric hormone ghrelin rise before and decrease after a meal. In normal-weight subjects, postprandial suppression of ghrelin is proportional to calories consumed. Obese individuals have lower fasting ghrelin levels; however, it is unclear whether the obese show normal postprandial suppression. This study aimed to compare postprandial ghrelin responses in normal-weight and obese subjects, using mixed macronutrient meals with varied fat and calorie content. Postprandial ghrelin response was measured in normal-weight insulin-sensitive subjects and obese insulin-resistant subjects, after six test meals with different fat and calorie content (250-3000 kcal). Increasing the calorie content of meals in normal-weight subjects progressively lowered nadir levels of ghrelin. The obese had lower fasting ghrelin levels, and the reduction after the consumption of all test meals was less than the normal-weight subjects. The lowest postprandial levels in the obese were no different to the nadir in normal-weight volunteers after 1000-, 2000-, and 3000-kcal meals. Thus, circulating ghrelin levels decreased in normal-weight subjects after mixed meals. Obese subjects demonstrated a much reduced ghrelin postprandial suppression. This reduced suppression may influence satiety, thus reinforcing obesity.
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Martin NM, Small CJ, Sajedi A, Patterson M, Ghatei MA, Bloom SR. Pre-obese and obese agouti mice are sensitive to the anorectic effects of peptide YY(3-36) but resistant to ghrelin. Int J Obes (Lond) 2004; 28:886-93. [PMID: 15148507 DOI: 10.1038/sj.ijo.0802646] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The role of the melanocortin system in the feeding effects of peripheral peptide YY(3-36) (PYY(3-36)) and ghrelin was investigated using the agouti (A(y)/a) mouse as a model of abnormal melanocortin signalling. Furthermore, we examined whether the ectopic expression of agouti protein in A(y)/a mice results in complete MC4-R inhibition, by studying the effects of peripheral alpha-melanocyte-stimulating hormone (alpha-MSH) and leptin on food intake. DESIGN Adult A(y)/a mice were studied in the pre-obese state (7-8 weeks) and obese state (14-15 weeks). Animals received PYY(3-36) (0.02 micromol/kg), NDP-alpha-MSH (0.2 micromol/kg), leptin (2 micromol/kg) (all 24 h fasted state) and ghrelin (0.2 micromol/kg) (fed state) by intraperitoneal (i.p.) injection. Age-matched A(y)/a controls received i.p. saline. A separate cohort of wild-type (WT), age-matched controls received the same peptide dose or saline. Food intake was measured at 1, 2, 4, 8 and 24 h post-injection and compared in all four groups. Plasma leptin-, ghrelin- and PYY-like immunoreactivity (IR) were measured using radioimmunoassay (RIA). RESULTS At 2 h post-injection, PYY(3-36) reduced food intake in pre-obese and obese A(y)/a mice, whereas ghrelin had no effect. Plasma ghrelin levels were significantly reduced in pre-obese and obese A(y)/a mice compared to WT controls. Peripheral administration of NDP-alpha-MSH and leptin acutely suppressed feeding (0-2 h) in pre-obese and obese A(y)/a mice. CONCLUSIONS Responsiveness of pre-obese and obese A(y)/a mice to PYY(3-36) suggests that the melanocortin system may not be essential for the anorectic effects of this peptide. Melanocortinergic antagonism by agouti protein in A(y)/a mice may be sufficient to block the effects of endogenous, but not exogenous PYY(3-36), alpha-MSH and leptin. The mechanism underlying ghrelin resistance in A(y)/a mice may result from antagonism of hypothalamic melanocortin receptors-4 by agouti protein, supporting a role for the melanocortin system in mediating ghrelin's actions.
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Thompson EL, Patterson M, Murphy KG, Smith KL, Dhillo WS, Todd JF, Ghatei MA, Bloom SR. Central and peripheral administration of kisspeptin-10 stimulates the hypothalamic-pituitary-gonadal axis. J Neuroendocrinol 2004; 16:850-8. [PMID: 15500545 DOI: 10.1111/j.1365-2826.2004.01240.x] [Citation(s) in RCA: 356] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Kisspeptin is the peptide product of the KiSS-1 gene and the endogenous agonist for the GPR54 receptor. Recent evidence suggests the kisspeptin/GPR54 system is a key regulator of the reproductive system. We examined the effect of intracerebroventricular (i.c.v.) and peripheral administration of the active kisspeptin fragment, kisspeptin-10, on circulating gonadotrophins and total testosterone levels in adult male rats. The effect of kisspeptin-10 in vitro on the release of hypothalamic peptides from hypothalamic explants and gonadotrophins from anterior pituitary fragments was also determined. The i.c.v. administration of kisspeptin-10 dose-dependently increased plasma luteinizing hormone (LH) and increased plasma follicle stimulating hormone (FSH) and total testosterone at 60 min postinjection. In a separate study investigating the time course of this response, i.c.v. administered kisspeptin-10 (3 nmol) significantly increased plasma LH at 10, 20 and 60 min, FSH at 60 min and total testosterone at 20 and 60 min postinjection. Kisspeptin-10 stimulated the release of luteinizing hormone-releasing hormone (LHRH) from in vitro hypothalamic explants. Peripheral administration of kisspeptin-10 increased plasma LH, FSH and total testosterone. However, doses of 100-1000 nM kisspeptin-10 did not influence LH or FSH release from pituitary fragments in vitro. Kisspeptin therefore potently stimulates the hypothalamic-pituitary-gonadal axis. These effects are likely to be mediated via the hypothalamic LHRH system.
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Batterham RL, Le Roux CW, Cohen MA, Park AJ, Ellis SM, Patterson M, Frost GS, Ghatei MA, Bloom SR. Pancreatic polypeptide reduces appetite and food intake in humans. J Clin Endocrinol Metab 2003; 88:3989-92. [PMID: 12915697 DOI: 10.1210/jc.2003-030630] [Citation(s) in RCA: 309] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pancreatic polypeptide (PP) is a gut hormone released from the pancreas in response to ingestion of food. Plasma PP has been shown to be reduced in conditions associated with increased food intake and elevated in anorexia nervosa. In addition peripheral administration of PP has been shown to decrease food intake in rodents. These findings suggest that PP may act as a circulating factor that regulates food intake. Therefore we investigated the effect of intravenous infusion of PP (10 pmol/kg/min) on appetite and food intake in a randomised double-blind placebo-controlled crossover study in ten healthy volunteers. Infusion of PP reduced appetite and decreased the energy intake at a buffet lunch two hours post-infusion by 21.8 +/- 5.7% (P < 0.01). More importantly the inhibition of food intake was sustained, such that energy intake, as assessed by food diaries, was significantly reduced both the evening of the study and the following morning. Overall PP infusion reduced cumulative 24-hour energy intake by 25.3 +/- 5.8%. In conclusion our data demonstrates that PP causes a sustained decrease in both appetite and food intake.
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90
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Pirko I, Kuntz NL, Patterson M, Keegan BM, Weinshenker BG, Rodriguez M. Contrasting effects of IFNbeta and IVIG in children with central and peripheral demyelination. Neurology 2003; 60:1697-9. [PMID: 12771272 DOI: 10.1212/01.wnl.0000064163.94122.eb] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Reported are three children with MS who responded dramatically to interferon-beta (IFNbeta) therapy. While on immunomodulatory therapy, they developed chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) that responded to IV immunoglobulin (IVIG) administration. These cases emphasize two interesting observations: 1) IFNbeta treatment did not prevent development of CIDP; 2) CIDP in the context of MS responded to IVIG, even though IVIG had no therapeutic effect on the central demyelinating disease.
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91
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Eng B, Patterson M, Walker L, Chui DH, Waye JS. Detection of severe nondeletional alpha-thalassemia mutations using a single-tube multiplex ARMS assay. GENETIC TESTING 2002; 5:327-9. [PMID: 11960579 DOI: 10.1089/109065701753617471] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Alpha-thalassemia is a common hereditary anemia due to decreased or absent synthesis of alpha-globin chains. The most common causes of alpha-thalassemia are deletions that remove one or both functional alpha-globin genes, with a small proportion of cases involving nondeletional mutations of the alpha2- or alpha1-globin genes. Herein, we describe a single-tube multiplex amplification refractory mutation system (ARMS) assay for rapid detection of six of the most common and severe nondeletional alpha-thalassemia mutations. These alleles are found predominantly among southeast Asian populations, and are associated with the most severe forms of hemoglobin (Hb) H disease or Hb H hydrops fetalis.
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Baker DW, Gazmararian JA, Sudano J, Patterson M, Parker RM, Williams MV. Health literacy and performance on the Mini-Mental State Examination. Aging Ment Health 2002; 6:22-9. [PMID: 11827619 DOI: 10.1080/13607860120101121] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The objectives of the study were to determine the relationship between functional health literacy and performance on the Mini-Mental State Examination (MMSE). New Medicare managed-care enrollees aged 65 years and older, living independently in the community in four US cities (Cleveland, Houston, Tampa, and Fort Lauderdale/Miami), were eligible to participate. In-home interviews were conducted to determine demographics and health status, and interviewers then administered the Short Test of Functional Health Literacy in Adults (S-TOFHLA) and the MMSE. We then determined the relationship between functional health literacy and the MMSE, including total scores, subscale scores (orientation to time, orientation to place, registration, attention and calculation, recall, language, and visual construction), and individual items. Functional health literacy was linearly related to the total MMSE score across the entire range of S-TOFHLA scores (R(2) = 0.39, p < 0.001). This relationship between health literacy and MMSE was consistent across all MMSE subscales and individual items. Adjustment for chronic conditions and self-reported overall health did not change the relationship between health literacy and MMSE score. Health literacy was related to MMSE performance even for subscales of the MMSE that were not postulated to be directly dependent on reading ability or education (e.g. delayed recall). These results suggest that the lower MMSE scores for patients with low health literacy are only partly due to 'test bias' and also result from true differences in cognitive functioning. 'Adjusting' MMSE scores for an individual's functional health literacy may be inappropriate because it may mask true differences in cognitive functioning.
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Kalairajah Y, Molloy S, Patterson M. The effect of femoral stem size on failure rates in total hip replacement cemented with Boneloc. Acta Orthop Belg 2002; 68:33-6. [PMID: 11915456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
We report the clinical and radiological outcome of 111 primary Taperloc hip arthroplasties implanted with Boneloc bone cement and the effect of stem size on survival. The mean follow-up was 5.3 years (range 3.2-6.6 years). The average age of the patients at operation was 73.4 years. Twenty-seven were male and 84 female. We defined clinical failures as those who had revision for aseptic loosening, or those symptomatic with pain and subsequent confirmation of radiographic loosening. The overall failure rate noted for this type of stem was 20.7%. Failure occurred on average at 3.3 years (0.3-6.3 years). However, when the data is broken down to different sizes of stem, the patients who had smaller Taperloc stems (7.5 mm or 10 mm) had a 27% failure rate whereas stems equal to, or greater than, 12.5 mm had a 12% failure rate over the same period (p < 0.05). As compared to other types of femoral stems used with Boneloc cement, the Taperloc stems survive better. Furthermore, larger stems survive even better. We suggest that these larger stems behave more like uncemented femoral stems. The finish on the stem is not a major contributor as has been suggested in the past.
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Hinds PJ, Patterson M, Pfeffer J. Bothered by abstraction: the effect of expertise on knowledge transfer and subsequent novice performance. JOURNAL OF APPLIED PSYCHOLOGY 2001; 86:1232-43. [PMID: 11768064 DOI: 10.1037/0021-9010.86.6.1232] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Although experts should be well positioned to convey their superior knowledge and skill to novices, the organization of that knowledge, and particularly its level of abstraction, may make it difficult for them to do so. Using an electronic circuit-wiring task, the authors found that experts as compared with beginners used more abstract and advanced statements and fewer concrete statements when providing task instructions to novices. In a 2nd study, the authors found that beginner-instructed novices performed better than expert-instructed novices and reported fewer problems with the instructions when performing the same task. In Study 2, the authors found that although novices performed better on the target task when instructed by beginners, they did better on a different task within the same domain when instructed by experts. The evidence suggests that the abstract, advanced concepts conveyed by experts facilitated the transfer of learning between the different tasks.
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Westphal V, Peterson S, Patterson M, Tournay A, Blumenthal A, Treacy EP, Freeze HH. Functional significance of PMM2 mutations in mildly affected patients with congenital disorders of glycosylation Ia. Genet Med 2001; 3:393-8. [PMID: 11715002 DOI: 10.1097/00125817-200111000-00003] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Congenital disorders of glycosylation (CDG) result from mutations in N-glycan biosynthesis. Mutations in phosphomannomutase (PMM2) cause CDG-Ia. Here, we report four clinically mild patients and their mutations in PMM2. METHODS Analysis of the PMM2 cDNA and gene revealed the mutations affecting the glycosylation efficiency. RESULTS The patients have 30% to 50% normal PMM activity in fibroblasts due to different mutations in PMM2, and we studied the effect of each mutation on the PMM activity in a Saccharomyces cerevisiae expression system. CONCLUSIONS Each patient carried a severe mutation that decreased the PMM activity to less than 10% as well as a relatively mild mutation. A new mutation, deletion of base 24, changed the reading frame. The C9Y, C241S, and L32R mutations showed 27% to 45% activity when expressed in the eukaryotic expression system, and the more severe D148N was shown to be thermolabile.
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Waye JS, Eng B, Patterson M, Carcao MD, Chang L, Olivieri NF, Chui DH. Identification of two new alpha-thalassemia mutations in exon 2 of the alpha1-globin gene. Hemoglobin 2001; 25:391-6. [PMID: 11791872 DOI: 10.1081/hem-100107876] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The most common causes of alpha-thalassemia are deletions that remove one or both of the functional alpha-globin genes. In addition, more than 30 different point mutations and small deletions/insertions have been reported for the alpha-globin genes. Here, we describe two new mutations occurring in exon 2 of the alpha1-globin gene. One mutation is an insertion of 21 bp that gives rise to a predicted alpha-globin chain containing a duplication of amino acid residues 93-99. The second mutation is a 33 bp deletion resulting in a predicted alpha-globin chain that is missing amino acid residues 64-74. Neither mutation results in a detectable hemoglobin variant, indicating that the variant alpha-globin chains are highly unstable. Carriers of these mutations have mild microcytosis and the phenotype of alpha+-thalassemia trait.
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Patterson M, Rintala TR, Lloyd TD, Abernethy L, Houghton TD, Williams J. Validation of electrode placement in neonatal electrogastrography. Dig Dis Sci 2001; 46:2245-9. [PMID: 11680604 DOI: 10.1023/a:1011931502985] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Electrogastrography (EGG) is the transcutaneous measurement of gastric electrical activity. The aims of this study were to validate the electrode placement position in neonatal electrogastrography using ultrasonography to localise the stomach, and to describe the observed EGG frequency characteristics. Fifteen neonates with no known abdominal disorder were studied. Two bipolar EGG recordings were obtained from each subject, the first from electrodes placed at sites localized by ultrasound and the second from electrodes placed at the currently recommended sites. Paired sample t tests were used to compare electrode positioning and electrogastrographic data. There were 15 subjects with a mean age of 36 days (range 1-95). While there was a significant difference in the position of electrodes at each site, the EGG recordings did not differ. The 3-cycle/minute (2.6-3.7cpm) activity ranged from 30% to 84% of recorded time (mean at sites localized with ultrasound was 53%, and at currently recommended sites it was 50%; difference not significant, P = 0.155). Bradygastria (<2.6 cpm) was observed in the range of 2-29% of recorded time (mean at sites localised with ultrasound was 12.9%, and at currently recommended sites it was 11.7%; difference not significant, P = 0.40). Tachygastria (3.2-10 cpm) was shown to be in the range of 10-58% of recorded time (mean at sites localized with ultrasound was 33.3%, and at currently recommended sites it was 38.7%; difference not significant; P = 0.044). In conclusion, there was no significant difference between EGG recordings taken from electrode sites localized by ultrasound and those recommended by manufacturers of the electrogastrogram, thus confirming the validity of the manufacturer's recommended electrode positioning. The pattern of electrical control activity in the normal neonatal stomach appears to be different from that demonstrated in adults. Bradygastria and tachygastria are seen more frequently, with fewer periods of 3 cpm activity.
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Lorey F, Charoenkwan P, Witkowska HE, Lafferty J, Patterson M, Eng B, Waye JS, Finklestein JZ, Chui DH. Hb H hydrops foetalis syndrome: a case report and review of literature. Br J Haematol 2001; 115:72-8. [PMID: 11722414 DOI: 10.1046/j.1365-2141.2001.03080.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Haemoglobin H (Hb H) disease is caused by deletion or inactivation of three alpha-globin genes, leaving only one intact and active alpha-globin gene. People with Hb H disease usually have moderate anaemia, but are generally thought to be asymptomatic. Some Hb H disease patients require transfusions, and there are reports of fetuses with Hb H disease who have severe anaemia in utero resulting in fatal hydrops foetalis syndrome. We now report a case of Hb H hydrops foetalis syndrome, caused by the inheritance of a hitherto novel alpha-globin gene point mutation (codon 35 TCC-->CCC or Serine-->Proline) and an alpha-thalassaemia deletion of the Filipino type removing all zeta-alpha-globin genes on the other chromosome 16. The infant was delivered prematurely because of pericardial effusion and fetal distress, and was found to have severe anaemia and congenital anomalies. A review of the relevant literature on this syndrome is presented, and serves to underscore the phenotypic variations of Hb H disease and the need for surveillance for this condition among newborns and genetic counselling in communities with a high proportion of at-risk populations.
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99
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Waye JS, Eng B, Patterson M, Walker L, Carcao MD, Olivieri NF, Chui DH. Hemoglobin H (Hb H) disease in Canada: molecular diagnosis and review of 116 cases. Am J Hematol 2001; 68:11-5. [PMID: 11559931 DOI: 10.1002/ajh.1142] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Over the past decade, we have characterized at the DNA level a total of 116 hemoglobin H (Hb H) disease patients living in Canada. The majority of patients were of southeast Asian descent (Chinese, Filipino, Laotian, Vietnamese), with a small number being of Mediterranean, Middle Eastern or East Indian background. A total of 15 distinct genotypes were detected, all but one being compound heterozygotes for a two-gene cis deletion and a single-gene deletion (-alpha/-) or a non-deletion mutation of the alpha2-globin gene (alpha(T) alpha/-). Seven different two-gene cis deletions were encountered, along with nine single-gene deletions and point mutations. The wide range of mutations associated with Hb H disease in Canada is a reflection of the population heterogeneity. The diagnosis of Hb H disease at the molecular level is important with respect to genetic counseling and the identification of families at risk for having pregnancies affected with Hb Bart's hydrops fetalis syndrome and/or Hb H disease. Six of the Hb H disease patients in our cohort had spouses who carried single-gene deletions, making these couples at risk for having children with Hb H disease. More important, seven patients had partners who carried two-gene cis deletions. These couples are at reproductive risk for both Hb Bart's hydrops fetalis syndrome and Hb H disease.
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Gibbons CE, Solan MC, Ricketts DM, Patterson M. Cryotherapy compared with Robert Jones bandage after total knee replacement: a prospective randomized trial. INTERNATIONAL ORTHOPAEDICS 2001; 25:250-2. [PMID: 11561502 PMCID: PMC3620829 DOI: 10.1007/s002640100227] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Sixty patients undergoing total knee replacement were randomized to receive either a cold compression dressing (Cryo/Cuff, Aircast, UK) or a modified Robert Jones bandage immediately after surgery. The cold compression dressing was used for a minimum of 6 h per day throughout the hospital stay, and the modified Robert Jones bandage remained in place for 48 h from the time of operation. The 2 groups of patients were compared during their hospital stay for blood loss, range of movement, pain scores and need for analgesia. No difference was found between the 2 groups except for less blood loss in the surgical drains in the cold compression group (P < 0.05). Postoperative complications were seen in both groups, but no complication was associated with either the cold compression dressing or the modified Robert Jones bandage.
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