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Reber D, Fritz M, Tossios P, Buchwald D, Lindstaedt M, Klak K, Marks P, Laczkovics A. Beating-Heart Coronary Artery Bypass Grafting Using a Miniaturized Extracorporeal Circulation System. Heart Surg Forum 2008; 11:E276-80. [DOI: 10.1532/hsf98.20081024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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77
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Reber D, Fritz M, Germing A, Marks P, Laczkovics A. Early outcome after off-pump coronary artery bypass grafting: effect on mortality and stroke. Braz J Cardiovasc Surg 2008; 23:23-8. [PMID: 18719824 DOI: 10.1590/s0102-76382008000100005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2007] [Accepted: 02/25/2008] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE One of the major and devastating complications of the coronary artery bypass grafting (CABG) is the stroke. Avoiding cardiopulmonary bypass (CPB) may reduce this neurological complication. In the past years there was an increased interest in the off-pump coronary artery grafting (OPCAB). The benefit of this method of revascularization in term of stroke and mortality is controversially discussed. METHODS A retrospective analysis of collected data from 252 patients were operated without cardiopulmonary bypass out of 1516 CABG procedures from January 2004 through May 2006. The mean age of the patient population was 70+/-11 years, within a range of 27-88 years. Forty-eight (19%) patients were older than 80 years and there were 172 (69%) males. Mean graft per patient was 1.78+/-0.79. The internal mammary artery (IMA) graft was used in 95% of the patients. For eight (3.17%) patients this was the second procedure. RESULTS Hospital mortality was 3.17%; Mean EuroSCORE in these patients was 10.36+/-6.67. No neurological complications occurred, six (2.38%) patients had temporary psycho syndrome. Postoperative myocardial infarction occurred in three (1.19%) patients. Two patients required rethoracotomy as a result of bleeding. Thirty-eight (15%) patients needed postoperative therapy for atrial fibrillation. CONCLUSION CABG with OPCAB technique has the benefit of low mortality and morbidity in terms of stroke. The advantages of this technique depends on the patient's general condition at the time of the operation, the sufficiency of pump function and coronary morphology, as well as on the surgeon's experience.
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Vichinsky E, Pakbaz Z, Onyekwere O, Porter J, Swerdlow P, Coates T, Lane P, Files B, Mueller BU, Coïc L, Forni GL, Fischer R, Marks P, Rofail D, Abetz L, Baladi JF. Patient-reported outcomes of deferasirox (Exjade, ICL670) versus deferoxamine in sickle cell disease patients with transfusional hemosiderosis. Substudy of a randomized open-label phase II trial. Acta Haematol 2008; 119:133-41. [PMID: 18408362 DOI: 10.1159/000125550] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 12/21/2007] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS There is increasing evidence demonstrating the value of transfusions in sickle cell disease (SCD). However, resultant iron overload can be life threatening if untreated. Chelation therapy with deferoxamine requires parenteral infusions that can negatively impact quality of life and adherence to treatment. METHODS As part of a phase II trial, SCD patient-reported outcomes were evaluated. One hundred and ninety-five patients were randomized (2:1) to receive oral deferasirox (5-30 mg/kg/day) or deferoxamine (20-50 mg/kg, 5 days per week); 121 had previously received deferoxamine. RESULTS At each time point, significantly more patients who had previously received deferoxamine were 'satisfied/very satisfied' with deferasirox, or found treatment to be 'convenient/very convenient' compared with deferoxamine (p < 0.001). In these patients, fewer hours were lost from daily activities with deferasirox than deferoxamine treatment. Most patients (77%) preferred deferasirox, and more were willing to continue taking deferasirox than deferoxamine at end-of-study (84 vs. 11%, respectively). CONCLUSIONS Patients with SCD are therefore more satisfied with deferasirox, which has a lower impact on daily activities than deferoxamine. Given the high levels of satisfaction, it is likely that quality of life will be improved. These results also suggest that treatment adherence with deferasirox may be better than with deferoxamine, which should lead to improved long-term outcomes.
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80
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Thompson SC, Nierman A, Schlehofer MM, Carter E, Bovin MJ, Wurzman L, Tauber P, Trifskin S, Marks P, Sumner J, Jackson A, Vonasch A. How Do We Judge Personal Control? Unconfounding Contingency and Reinforcement in Control Judgments. BASIC AND APPLIED SOCIAL PSYCHOLOGY 2007. [DOI: 10.1080/01973530701331189] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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82
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Krcmery V, Hricak V, Fischer V, Jurco R, Demitrovicova A, Mlkvy P, Karvaj M, Bauer F, Rudinsky B, Kovac M, Kalavsky E, Kisac P, Findova L, Marks P. Oral antibiotic use in misdiagnosed infective endocarditis-no impact on mortality. Int J Antimicrob Agents 2007; 30:564-5. [PMID: 17900871 DOI: 10.1016/j.ijantimicag.2007.07.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 07/30/2007] [Accepted: 07/31/2007] [Indexed: 11/20/2022]
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Abstract
Impairment is the result of unpredictable genetic variation, coexisting disease, or drug interaction, and is modified by hepatic metabolism. The introduction of alcohol tsars and alcohol health workers in trauma centres would capitalise on the 'teachable moment' (when the conceptual link between drinking and its consequences can be demonstrated at a time when the consequences are obvious) to prevent recurring injuries and to lower alcohol intake. Accident fatalities have reached a plateau and the only way of reducing them further is to lower the European legal limit of blood alcohol concentration to a harmonised 50 mg/100 ml.
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Hricak V, Liska B, Kovackova J, Mikusova J, Fischer V, Kovacik J, Karvaj M, Jurco R, Ondrusova A, Kalavsky E, Marks P, Beno P, Krcmery V. Trends in risk factors and etiology of 606 cases of infective endocarditis over 23 years (1984-2006) in slovakia. J Chemother 2007; 19:198-202. [PMID: 17434830 DOI: 10.1179/joc.2007.19.2.198] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The aim of this study was to assess trends in risk factors, etiology, outcome and treatment strategies for endocarditis over 23 years in Slovakia. A prospective survey of 606 cases of infective endocarditis (IE) was conducted from 1984-2006. Rheumatic fever as well as previous dental surgery showed decreasing trends within the last 23 years. Also embolic complications of IE declined along with increasing rates of surgically treated patients. No significant changes in etiology were detected apart from the fact that culture-negative endocarditis increased from 10.7% to 55.4% between 1998-2001. Surgically treated patients increased from 22.7% (1984-1990) to 50.1% (2002-2006) and mortality dramatically decreased from 26.7% (1984-1990) to 5.3% (2002-2006). Staphylococcus aureus and coagulase-negative staphylococci were the leading causes (22.4% - 48%) followed by viridans streptococci (12.2%-18.2%) were a relatively stable trend over 23 years of IE in Slovakia.
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Vichinsky E, Onyekwere O, Porter J, Swerdlow P, Eckman J, Lane P, Files B, Hassell K, Kelly P, Wilson F, Bernaudin F, Forni GL, Okpala I, Ressayre-Djaffer C, Alberti D, Holland J, Marks P, Fung E, Fischer R, Mueller BU, Coates T. A randomised comparison of deferasirox versus deferoxamine for the treatment of transfusional iron overload in sickle cell disease. Br J Haematol 2007; 136:501-8. [PMID: 17233848 PMCID: PMC1974786 DOI: 10.1111/j.1365-2141.2006.06455.x] [Citation(s) in RCA: 221] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Deferasirox is a once-daily, oral iron chelator developed for treating transfusional iron overload. Preclinical studies indicated that the kidney was a potential target organ of toxicity. As patients with sickle cell disease often have abnormal baseline renal function, the primary objective of this randomised, open-label, phase II trial was to evaluate the safety and tolerability of deferasirox in comparison with deferoxamine in this population. Assessment of efficacy, as measured by change in liver iron concentration (LIC) using biosusceptometry, was a secondary objective. A total of 195 adult and paediatric patients received deferasirox (n = 132) or deferoxamine (n = 63). Adverse events most commonly associated with deferasirox were mild, including transient nausea, vomiting, diarrhoea, abdominal pain and skin rash. Abnormal laboratory studies with deferasirox were occasionally associated with mild non-progressive increases in serum creatinine and reversible elevations in liver function tests. Discontinuation rates from deferasirox (11.4%) and deferoxamine (11.1%) were similar. Over 1 year, similar dose-dependent LIC reductions were observed with deferasirox and deferoxamine. Once-daily oral deferasirox has acceptable tolerability and appears to have similar efficacy to deferoxamine in reducing iron burden in transfused patients with sickle cell disease.
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Gregg J, Marks P, Silberstein M, Schneider T, Kerr J. Histologic anatomy of the lesser metatarsophalangeal joint plantar plate. Surg Radiol Anat 2007; 29:141-7. [PMID: 17318282 DOI: 10.1007/s00276-007-0188-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Accepted: 07/06/2006] [Indexed: 10/23/2022]
Abstract
The plantar plate is the fibrocartilaginous structure that supports the ball of the foot, withstanding considerable compressive and tensile forces. This study describes the morphology of the plantar plate in order to understand its function and the pathologic disorders associated with it. Eight lesser metatarsophalangeal joint plantar plates from three soft-embalmed cadavers (74-92 years, two males, one female), and eight lesser metatarsophalangeal joint plantar plates from a fresh cadaver (19-year-old male) were obtained for histology assessment. Paraffin sections (10 microm) in the longitudinal and transverse planes were analyzed with bright-field and polarized light microscopy. The central plantar plate collagen bundles run in the longitudinal plane with varying degrees of undulation. The plantar plate borders run transversely and merge with collateral ligaments and the deep transverse intermetatarsal ligament. Bright-field microscopic evaluation shows the plantar aspect of the plantar plate becomes ligament-like the further distally it tapers, containing fewer chondrocytes, and a greater abundance of fibroblasts. The enthesis reveals longitudinal and interwoven collagen bundles entering the proximal phalanx with multiple interdigitations. Longer interdigitations centrally compared to the dorsal and plantar aspects suggest that the central fibers experience the greatest loads.
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Reber D, Fritz M, Bojara W, Marks P, Laczkovics A, Tossios P. Aortic valve replacement after previous coronary artery bypass grafting: experience with a simplified approach. THE JOURNAL OF CARDIOVASCULAR SURGERY 2007; 48:73-7. [PMID: 17308525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
AIM Aortic valve replacement (AVR) after previous coronary artery bypass grafting (CABG), particularly in a patent left internal thoracic artery (ITA), is a challenge. Avoidance of injuring the patent graft and ensuring myocardial protection are important issues in the management of these patients. The aim of this study was to evaluate a simplified surgical approach to these reoperations. METHODS Between January 2003 and June 2005, 19 of 287 AVRs performed at our institution were in a patient subset (mean age 70 years, range: 62-82) who received AVR after previous CABG surgery. The aortic valve gradients were between 50 and 107 mm Hg. Our operation strategy followed the KIS-principle (keep it simple): both femoral vessels were cannulated using the Seldinger technique. Only the area around the ascending aorta and the right atrium was dissected to permit x-clamping, aortotomy, and catheterization for retrograde cardioplegia and a left ventricular vent. The anterior aspect of the heart and the left side, where the ITA was embedded and patent, were left untouched and not clamped. RESULTS The mean interval between the first and second operation was 6.5 years. Fourteen patients received biological prostheses. Four patients received an additional surgery at the time of AVR. The mean operating time was 267 min; the mean AoX-clamp time was 63 min. One patient died because of severe heart failure. In all others the postoperative course was uneventful. CONCLUSIONS We believe that the indication for AVR in patients scheduled for CABG should be re-evaluated. In those in which Redo-surgery for new or increased valve stenosis is indicated, a simple and safe surgical option is presented.
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O'Sullivan B, Griffin A, Saupe N, Catton C, Chung P, Ferguson P, Marks P, Kandel R, White L, Bell R, Wundere J. 250 Long term efficacy of radiotherapy for high risk pigmented villonodular synovitis. Radiother Oncol 2006. [DOI: 10.1016/s0167-8140(06)80991-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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89
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Baczkowski K, Marks P, Silberstein M, Schneider-Kolsky ME. A new look into kicking a football: An investigation of muscle activity using MRI. ACTA ACUST UNITED AC 2006; 50:324-9. [PMID: 16884417 DOI: 10.1111/j.1440-1673.2006.01591.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The kicking action predominantly used in Australian Rules football is considered to be responsible for many lower limb injuries. The aim of this study was to describe a non-invasive method of identifying the thigh muscles involved in kicking an Australian Rules football, using MRI. Both upper thighs of 10 recreational footballers were examined using a 1.5-T General Electric MRI scanner before and immediately after carrying out a set kicking exercise protocol. The signal intensity (SI) changes in 14 individual muscles were investigated using a standardized region of interest to determine the levels of muscle activity. Significant SI changes were observed in several muscles of the kicking and stance legs among all participants. In the kicking leg, the greatest SI changes were observed in the adductor longus and tensor fascia latae muscles (49.38% (+/-8.95) and 45.47% (+/-7.91), respectively; P < 0.05), whereas in the stance leg, the muscles displaying the highest changes were the semitendinosus and tensor fascia latae muscles (46.48% (+/-9.97) and 33.68% (+/-8.36), respectively; P < 0.05). This study has shown that MRI can be useful for observing the activity of individual muscles in the upper thigh during the kicking motion. This non-invasive approach provides a detailed analysis of anatomy and emphasizes the muscles at high risk of injury.
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90
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Mond JM, Marks P, Hay PJ, Rodgers B, Kelly C, Owen C, Paxton SJ. Mental Health Literacy and Eating-Disordered Behavior: Beliefs of Adolescent Girls Concerning the Treatment of and Treatment-Seeking for Bulimia Nervosa. J Youth Adolesc 2006. [DOI: 10.1007/s10964-006-9087-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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91
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Heng JB, Aksimentiev A, Ho C, Marks P, Grinkova YV, Sligar S, Schulten K, Timp G. The electromechanics of DNA in a synthetic nanopore. Biophys J 2006; 90:1098-106. [PMID: 16284270 PMCID: PMC1367096 DOI: 10.1529/biophysj.105.070672] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Accepted: 10/17/2005] [Indexed: 11/18/2022] Open
Abstract
We have explored the electromechanical properties of DNA on a nanometer-length scale using an electric field to force single molecules through synthetic nanopores in ultrathin silicon nitride membranes. At low electric fields, E < 200 mV/10 nm, we observed that single-stranded DNA can permeate pores with a diameter >/=1.0 nm, whereas double-stranded DNA only permeates pores with a diameter >/=3 nm. For pores <3.0 nm diameter, we find a threshold for permeation of double-stranded DNA that depends on the electric field and pH. For a 2 nm diameter pore, the electric field threshold is approximately 3.1 V/10 nm at pH = 8.5; the threshold decreases as pH becomes more acidic or the diameter increases. Molecular dynamics indicates that the field threshold originates from a stretching transition in DNA that occurs under the force gradient in a nanopore. Lowering pH destabilizes the double helix, facilitating DNA translocation at lower fields.
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Hellard M, Dore G, Haber P, Marks P, Matthews G, Yeung B, Nguyen O, Pan Y, Ffrench R, McCaughan G, Van Beek I, White P, Dolan K, Rawlinson W, Lloyd A, Kaldor J. P.250 Australian trial in acute hepatitis C: preliminary findings. J Clin Virol 2006. [DOI: 10.1016/s1386-6532(06)80430-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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93
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Hellard M, Haber P, Day C, Marks P, Matthew G, Yeung B, Nguyen O, Dolan K, Van Beek I, Kaldor J, Dore G. P.254 Australian trial in acute hepatitis C: baseline behavioural data. J Clin Virol 2006. [DOI: 10.1016/s1386-6532(06)80434-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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94
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Cappellini MD, Cohen A, Piga A, Bejaoui M, Perrotta S, Agaoglu L, Aydinok Y, Kattamis A, Kilinc Y, Porter J, Capra M, Galanello R, Fattoum S, Drelichman G, Magnano C, Verissimo M, Athanassiou-Metaxa M, Giardina P, Kourakli-Symeonidis A, Janka-Schaub G, Coates T, Vermylen C, Olivieri N, Thuret I, Opitz H, Ressayre-Djaffer C, Marks P, Alberti D. A phase 3 study of deferasirox (ICL670), a once-daily oral iron chelator, in patients with beta-thalassemia. Blood 2005; 107:3455-62. [PMID: 16352812 DOI: 10.1182/blood-2005-08-3430] [Citation(s) in RCA: 495] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Deferasirox (ICL670) is a once-daily oral iron chelator developed for the treatment of chronic iron overload from blood transfusions. A comparative phase 3 trial was conducted to demonstrate the efficacy of deferasirox in regularly transfused patients with beta-thalassemia aged 2 years or older. Patients were randomized and received treatment with deferasirox (n = 296) or deferoxamine (n = 290), with dosing of each according to baseline liver iron concentration (LIC). The primary endpoint was maintenance or reduction of LIC; secondary endpoints included safety and tolerability, change in serum ferritin level, and net body iron balance. In both arms, patients with LIC values of 7 mg Fe/g dry weight (dw) or higher had significant and similar dose-dependent reductions in LIC and serum ferritin, and effects on net body iron balance. However, the primary endpoint was not met in the overall population, possibly due to the fact that proportionally lower doses of deferasirox relative to deferoxamine were administered to patients with LIC values less than 7 mg Fe/g dw. The most common adverse events included rash, gastrointestinal disturbances, and mild nonprogressive increases in serum creatinine. No agranulocytosis, arthropathy, or growth failure was associated with deferasirox administration. Deferasirox is a promising once-daily oral therapy for the treatment of transfusional iron overload.
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Baczkowski K, Silberstein M, Marks P, Schneider-Kolsky M. 361 Assessing muscle activity of the upper thigh during kicking using magnetic resonance imaging (MRI). J Sci Med Sport 2005. [DOI: 10.1016/s1440-2440(17)30858-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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96
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O’Sullivan B, Griffin A, Wunder J, Marks P, Catton C, Ferguson P, Chung P, Kandel R, White L, Bell R. Sustained Remission Following Radiation Treatment for High-Risk Pigmented Villonodular Synovitis. Int J Radiat Oncol Biol Phys 2005. [DOI: 10.1016/j.ijrobp.2005.07.088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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97
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Hechler T, Beumont P, Marks P, Touyz S. How do clinical specialists understand the role of physical activity in eating disorders? EUROPEAN EATING DISORDERS REVIEW 2005. [DOI: 10.1002/erv.630] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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98
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Sheehan E, McKenna J, Mulhall KJ, Marks P, McCormack D. Adhesion of Staphylococcus to orthopaedic metals, an in vivo study. J Orthop Res 2004; 22:39-43. [PMID: 14656657 DOI: 10.1016/s0736-0266(03)00152-9] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This study describes a new model of biofilm study in rabbits. The primary focus of this study was to assess biofilm adhesion to orthopaedic metals in their first 48 h in a femoral intramedullary implantation model. Two previous inoculation methods i.e. that of pre- and direct inoculation were studied with two bacterial isolates namely Staphylococcus aureus and epidermidis, on titanium and stainless steel metallic implants. A method of sonication and log dilution/plating was used to assess biofilm bacteria adhering to implants. Silver coated metals were then compared with their respective control metals in the new model. The direct inoculation model gave larger and more reproducible biofilm adhesion to implanted metals. Staphylococcus epidermidis shows lower adhesion ability to metals, and biofilms adhere in greater numbers to stainless steel over titanium. Silver coated metals show no statistical difference over control metals when exposed to orthopaedic biofilms.
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Wu CJ, Hochberg EP, Rogers SA, Kutok JL, Biernacki M, Nascimento AF, Marks P, Bridges K, Ritz J. Molecular assessment of erythroid lineage chimerism following nonmyeloablative allogeneic stem cell transplantation. Exp Hematol 2003; 31:924-33. [PMID: 14550808 DOI: 10.1016/s0301-472x(03)00227-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Nonmyeloablative conditioning regimens for allogeneic stem cell transplantation are now commonly used in the treatment of patients with hematologic malignancies. Since this treatment often results in the establishment of mixed hematopoietic chimerism, this approach may also prove to be useful in the treatment of nonmalignant disorders, such as sickle cell disease and thalassemia major. To apply this approach to these diseases, it will be necessary to determine the levels of donor erythropoiesis required to correct hemolysis and ameliorate disease symptoms. Current methods for measuring hematopoietic chimerism are based on DNA polymorphisms that distinguish recipient from donor. These methods accurately measure donor leukocyte engraftment but do not quantify the relative contributions of recipient and donor erythropoiesis following transplant. METHODS To specifically measure erythroid-lineage chimerism, we used pyrosequencing of the sickle cell mutation to quantify the relative levels of normal and sickle beta-globin mRNA in patient samples. Results of beta-globin RNA chimerism were compared to assessment of beta-globin DNA chimerism as well as analysis of short tandem repeat (STR) polymorphisms, cytogenetics, and hemoglobin electrophoresis. RESULTS Donor engraftment was measured in two adult patients following nonmyeloablative stem cell transplant for sickle cell disease. In Patient 1, 25 to 30% of peripheral leukocytes were donor derived after day 41. In contrast, more than 55% of peripheral blood beta-globin mRNA was of donor origin, and these results correlated with posttransplant clinical improvement. Patient 2 achieved 40 to 50% donor leukocyte engraftment from day 33 onward. This was associated with 70 to 100% peripheral blood donor beta-globin mRNA. CONCLUSIONS These studies demonstrate that relatively low levels of donor leukocyte engraftment can be associated with higher levels of donor erythropoiesis and with significant clinical improvement. Pyrosequencing of lineage-specific mRNA directly measures functional reconstitution of donor cells and provides valuable information that can affect clinical decisions in patients with nonmalignant diseases following allogeneic transplant.
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Glogauer M, Marchal CC, Zhu F, Worku A, Clausen BE, Foerster I, Marks P, Downey GP, Dinauer M, Kwiatkowski DJ. Rac1 deletion in mouse neutrophils has selective effects on neutrophil functions. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:5652-7. [PMID: 12759446 DOI: 10.4049/jimmunol.170.11.5652] [Citation(s) in RCA: 250] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Defects in myeloid cell function in Rac2 knockout mice underline the importance of this isoform in activation of NADPH oxidase and cell motility. However, the specific role of Rac1 in neutrophil function has been difficult to assess since deletion of Rac1 results in embryonic lethality in mice. To elucidate the specific role of Rac1 in neutrophils, we generated mice with a conditional Rac1 deficiency restricted to cells of the granulocyte/monocyte lineage. As observed in Rac2-deficient neutrophils, Rac1-deficient neutrophils demonstrated profound defects in inflammatory recruitment in vivo, migration to chemotactic stimuli, and chemoattractant-mediated actin assembly. In contrast, superoxide production is normal in Rac1-deficient neutrophils but markedly diminished in Rac2 null cells. These data demonstrate that although Rac1 and Rac2 are both required for actin-mediated functions, Rac2 is specifically required for activation of the neutrophil NADPH oxidase.
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