151
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Kitrou P, Parthipun A, Diamantopoulos A, Padayachee S, Karunanithy N, Ahmed I, Zayed H, Katsanos K. Paclitaxel-coated balloons for failing peripheral bypass grafts: the BYPACS study. THE JOURNAL OF CARDIOVASCULAR SURGERY 2014; 55:217-224. [PMID: 24670829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
AIM Aim of the present study was to report the imaging and clinical outcomes of a prospective single-center study investigating paclitaxel-coated balloons (PCB) for the treatment of failing peripheral bypass grafts (BYPACS study). METHODS In total, 32 patients had their failing peripheral native or synthetic bypass graft treated with PCB angioplasty (Group PCB). Basic inclusion criteria were any significant proximal or distal anastomotic stenosis confirmed by Duplex ultrasound (DUS; PSVR>2.5) associated with significantly reduced in-graft velocities (<45 cm/s) putting the graft at risk of thrombosis. Results were compared with a similar historical control group of 24 patients who had their failing peripheral bypass treated with plain uncoated balloon angioplasty (Group PTA). Primary endpoint was binary lesion restenosis defined as >50% stenosis of the treated lesion on DUS. Secondary endpoints included freedom from target lesion revascularization (TLR) defined as a patent peripheral bypass graft regardless of restenosis but without any repeat intervention (driven by reduced in-graft velocities <45 cm/s), major amputations and graft thrombosis. Multivariable Cox proportional hazards regression analysis was applied to adjust for confounding factors of heterogeneity. Results are reported as Cox-adjusted hazard ratios (HR and 95% CI). RESULTS Baseline variables were equally distributed between the two groups. Median follow-up was 7 months in group PCB and 8 months in group PTA. Rates of binary restenosis were similar between the 2 groups (HR=1.08, 95% CI=0.49-2.40; P=0.84). Freedom from TLR was also similar (HR=0.97, 95% CI=0.36-2.66; P=0.88). One amputation occurred in the PCB group and 2 in the PTA (P=0.58). Four events of bypass thrombosis occurred in each group (P=0.71). CONCLUSION PCB does not significantly inhibit restenosis or improve freedom from repeat angioplasty after treatment of failing peripheral arterial vein or synthetic bypass grafts.
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MESH Headings
- Aged
- Aged, 80 and over
- Amputation, Surgical
- Angiography, Digital Subtraction
- Angioplasty, Balloon/adverse effects
- Angioplasty, Balloon/instrumentation
- Blood Flow Velocity
- Blood Vessel Prosthesis
- Blood Vessel Prosthesis Implantation/adverse effects
- Blood Vessel Prosthesis Implantation/instrumentation
- Cardiovascular Agents/administration & dosage
- Constriction, Pathologic
- Drug Carriers
- Equipment Design
- Female
- Graft Occlusion, Vascular/diagnosis
- Graft Occlusion, Vascular/etiology
- Graft Occlusion, Vascular/physiopathology
- Graft Occlusion, Vascular/therapy
- Humans
- Kaplan-Meier Estimate
- Limb Salvage
- London
- Male
- Middle Aged
- Multivariate Analysis
- Paclitaxel/administration & dosage
- Peripheral Arterial Disease/diagnosis
- Peripheral Arterial Disease/physiopathology
- Peripheral Arterial Disease/surgery
- Peripheral Arterial Disease/therapy
- Proportional Hazards Models
- Prospective Studies
- Prosthesis Failure
- Regional Blood Flow
- Reoperation
- Risk Factors
- Time Factors
- Treatment Failure
- Ultrasonography, Doppler, Duplex
- Vascular Access Devices
- Veins/physiopathology
- Veins/transplantation
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152
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Patel A, Gallacher D, Dourado R, Lyons O, Smith A, Zayed H, Waltham M, Sabharwal T, Bell R, Carrell T, Taylor P, Modarai B. Occupational Radiation Exposure During Endovascular Aortic Procedures. Eur J Vasc Endovasc Surg 2013; 46:424-30. [DOI: 10.1016/j.ejvs.2013.05.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 05/29/2013] [Indexed: 12/31/2022]
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153
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Feldstein J, Davis SN, Zayed H, Whitmore J. The new anti-interleukin-1beta monoclonal antibody, gevokizumab, reduces hs-crp in subjects with type 2 diabetes mellitus. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht310.p5511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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154
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Baranyi L, Doering CB, Denning G, Gautney RE, Harris KT, Spencer HT, Roy A, Zayed H, Dropulic B. Rapid Generation of Stable Cell Lines Expressing High Levels of Erythropoietin, Factor VIII, and an Antihuman CD20 Antibody Using Lentiviral Vectors. Hum Gene Ther Methods 2013; 24:214-27. [DOI: 10.1089/hgtb.2013.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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155
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Slim H, Tiwari A, Ahmed A, Ritter J, Zayed H, Rashid H. Distal versus Ultradistal Bypass Grafts: Amputation-free Survival and Patency Rates in Patients with Critical Leg Ischaemia. Eur J Vasc Endovasc Surg 2011; 42:83-8. [DOI: 10.1016/j.ejvs.2011.03.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 03/20/2011] [Indexed: 10/18/2022]
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156
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Ahmad A, Waltham M, Høyer-Hansen G, Sørensen T, Mattock K, Saha P, Modarai B, Zayed H, Smith A. Reduced Expression of Soluble Urokinase Receptor Fragment DII-III Predicts Venous Ulcers that Fail to Heal. J Vasc Surg 2011. [DOI: 10.1016/j.jvs.2010.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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157
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158
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Ali AM, Green D, Zayed H, Halawa M, El-sakka K, Rashid HI. Cerebral monitoring in patients undergoing carotid endarterectomy using a triple assessment technique. Interact Cardiovasc Thorac Surg 2010; 12:454-7. [DOI: 10.1510/icvts.2010.235598] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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159
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Zayed H, Chao R, Moshrefi A, Lopezjimenez N, Delaney A, Chen J, Shaw GM, Slavotinek AM. A maternally inherited chromosome 18q22.1 deletion in a male with late-presenting diaphragmatic hernia and microphthalmia-evaluation of DSEL as a candidate gene for the diaphragmatic defect. Am J Med Genet A 2010; 152A:916-23. [PMID: 20358601 DOI: 10.1002/ajmg.a.33341] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Using an Affymetrix GeneChip(R) Human Mapping 100K Set to study a patient with a late-presenting, right-sided diaphragmatic hernia and microphthalmia, we found a maternally inherited deletion that was 2.7 Mb in size at chromosome 18q22.1. Mapping of this deletion using fluorescence in situ hybridization revealed three deleted genes-CDH19, DSEL, and TXNDC10, and one gene that contained the deletion breakpoint, CCDC102B. We selected DSEL for further study in 125 patients with diaphragmatic hernias, as it is involved in the synthesis of decorin, a protein that is required for normal collagen formation and that is upregulated during myogenesis. We found p.Met14Ile in an unrelated patient with a late-presenting, anterior diaphragmatic hernia. In the murine diaphragm, Dsel was only weakly expressed at the time of diaphragm closure and its expression in C2C12 myoblast cells did not change significantly during myoblast differentiation, thus reducing the likelihood that the gene is involved in myogenesis of the diaphragm. Although it is possible that the 18q22.1 deletion and haploinsufficiency for DSEL contributed to the diaphragmatic defect in the patient, a definite role for DSEL and decorin in the formation of the collagen-containing, central tendon of the diaphragm has not yet been established.
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160
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Parisi MA, Zayed H, Slavotinek AM, Rutledge JC. Congenital diaphragmatic hernia and microtia in a newborn with mycophenolate mofetil (MMF) exposure: phenocopy for Fryns syndrome or broad spectrum of teratogenic effects? Am J Med Genet A 2009; 149A:1237-40. [PMID: 19449404 DOI: 10.1002/ajmg.a.32684] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A newborn female infant born to a woman on immunosuppressive medications including mycophenolate mofetil (MMF) for a renal graft secondary to lupus nephritis presented with congenital diaphragmatic hernia (CDH) and additional findings of microtia, esophageal atresia with tracheoesophageal fistula, cleft palate, congenital heart defect, digital anomalies, and dysmorphic facial features. Pulmonary hypoplasia resulted in death at day 2 of life. She was presumed to have Fryns syndrome based on diagnostic criteria established for this recessive disorder with prominent features including CDH, facial anomalies, and nail hypoplasia. In retrospect, this infant's findings are more likely the result of teratogenic exposure to MMF, as more recent data have emerged linking aural atresia, digital anomalies, and dysmorphic features to this drug. To date, this is the only human report of CDH in an infant with prenatal exposure to MMF, although the manufacturer's package insert alludes to animal studies with a broad spectrum of malformations, including CDH. Thus, a teratogenic exposure can mimic a known Mendelian genetic syndrome, and caution is urged in presuming a genetic etiology for infants with potential teratogenic exposure to relatively new drugs with limited published animal data.
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161
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Zayed H, Halawa M, Maillardet L, Sidhu PS, Edmonds M, Rashid H. Improving limb salvage rate in diabetic patients with critical leg ischaemia using a multidisciplinary approach. Int J Clin Pract 2009; 63:855-8. [PMID: 18248395 DOI: 10.1111/j.1742-1241.2007.01608.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Diabetic patients are more likely to develop critical leg ischaemia (CLI) and subsequently major amputation than the general population. Major amputation rate in this group is reported to be high compared with non-diabetic patients with a devastating outcome. AIM The aim of this study was to assess the impact of a multidisciplinary approach on the major amputation rate in diabetic patients with CLI suitable for surgical or radiological revascularisation. METHODS A retrospective analysis of data of all diabetic patients with CLI presenting to a one-stop multidisciplinary clinic between December 2003 and May 2006 was performed. The multidisciplinary team included a vascular surgeon, diabetologist, podiatrist, tissue viability nurse, interventional radiologist and a radiology coordinator. Peripheral vascular disease was assessed by history taking, clinical examination, ankle brachial pressure index, Doppler arterial waveform analysis and transcutaneous oxygen tension. Duplex scan and magnetic resonance angiography were performed in selected patients. Based on the available information, suitable patients were offered percutaneous transluminal angioplasty (PTA), surgical arterial reconstruction (SAR) or both (hybrid arterial reconstruction). RESULTS Three hundred and twelve diabetic patients with CLI were suitable for revascularisation. Eighty-two per cent underwent PTA while 18% underwent SAR. Thirteen threatened grafts were detected during follow-up and early intervention was performed as required. Major amputation rate among the study group was 4.1%. CONCLUSION Multidisciplinary approach improves the care of diabetic patients with CLI. Close follow-up and early intervention in dedicated centres improve limb salvage rates in this group of high-risk patients.
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162
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Katsanos K, Black S, Ahmad F, Zayed H, Salter R, Sandhu C, Thomas S, Reidy J, Taylor P, Sabharwal T. Abstract No. 211: Featured Abstract. J Vasc Interv Radiol 2009. [DOI: 10.1016/j.jvir.2008.12.202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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163
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Katsanos K, Modarai B, Bell R, Zayed H, Salter R, Sandhu C, Thomas S, Reidy J, Taylor P, Sabharwal T. Abstract No. 149: Endovascular Repair of Abdominal Aortic Aneurysms with Large Proximal Necks: Does Size Matter? J Vasc Interv Radiol 2009. [DOI: 10.1016/j.jvir.2008.12.134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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164
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Clough RE, Black SA, Lyons OT, Bell RE, Zayed H, Carrell T, Waltham M, Sabharwal T, Reidy J, Taylor PR. Endovascular management of mycotic aortic aneurysms. Br J Surg 2009. [DOI: 10.1002/bjs.6510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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165
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Fassiadis N, Adams K, Zayed H, Goss D, Deane C, MacCarthy P, Rashid H. Occult carotid artery disease in patients who have undergone coronary angioplasty. Interact Cardiovasc Thorac Surg 2008; 7:855-7. [DOI: 10.1510/icvts.2008.179580] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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166
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Fassiadis N, Ananos D, Zayed H, Rashid H. Lymphoma masquerading as a recurrent brachial artery aneurysm. Surgeon 2008; 6:182-3. [PMID: 18581756 DOI: 10.1016/s1479-666x(08)80116-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Malignant lymphoma infiltrating the brachial artery in a renal transplant patient has not been documented previously. We report an angiodestructive B-cell lymphoma in a 64-year-old post-renal transplant recipient. Improved longevity post-transplantation has been associated with an increased incidence of cancer which means that we will be seeing such patients more frequently in the future.
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167
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Zayed H, Xia L, Yerich A, Yant SR, Kay MA, Puttaraju M, McGarrity GJ, Wiest DL, McIvor RS, Tolar J, Blazar BR. Correction of DNA Protein Kinase Deficiency by Spliceosome-mediated RNA Trans-splicing and Sleeping Beauty Transposon Delivery. Mol Ther 2007; 15:1273-9. [PMID: 17457319 DOI: 10.1038/sj.mt.6300178] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Spliceosome-mediated RNA trans-splicing (SMaRT) is an emerging technology for the repair of defective pre-messenger RNA (pre-mRNA) molecules. It is especially useful in the treatment of genetic disorders involving large genes. Although viral vectors have been used for achieving long-lasting expression of trans-splicing molecules, the immunogenicity and suboptimal safety profiles associated with viral-based components could limit the widespread application of SMaRT in the repair of genetic defects. Here, we tested whether the non-viral Sleeping Beauty (SB) transposon system could mediate stable delivery of trans-splicing molecules designed to correct the genetic defect responsible for severe combined immune deficiency (SCID). This immunological disorder is caused by a point mutation within the 12.4 kilobase (kb) gene encoding the DNA protein kinase catalytic subunit (DNA-PKcs) and is associated with aberrant DNA repair, defective T- and B-cell production, and hypersensitivity to radiation-induced injury. Using a novel SB-based trans-splicing vector, we demonstrate stable mRNA correction, proper DNA-PKcs protein production, and conference of a radiation-resistant phenotype in a T-cell thymoma cell line and SCID multipotent adult progenitor cells (MAPCs). These results suggest that SB-based trans-splicing vectors should prove useful in facilitating the correction of endogenous mutated mRNA transcripts, including the DNA-PKcs defect present in SCID cells.
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168
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Zayed H, Wendler O, Fassiadis N, Maillardet L, Rajakaruna C, Rashid H. Value of carotid duplex scan prior to isolated heart valve surgery. Thorac Cardiovasc Surg 2007. [DOI: 10.1055/s-2007-967509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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169
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Fassiadis N, Zayed H, McDonnell N, Edmondson RE. Carotid Endarterectomy Under Local Anaesthetic Supplemented by an Inferior Alveolar Nerve Block. Ann R Coll Surg Engl 2007. [DOI: 10.1308/rcsann.2007.89.1.75a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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170
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Fassiadis N, Zayed H, Rashid H, Green DW. Invos Cerebral Oximeter compared with the transcranial Doppler for monitoring adequacy of cerebral perfusion in patients undergoing carotid endarterectomy. INT ANGIOL 2006; 25:401-6. [PMID: 17164748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
AIM The aim of this prospective study was to assess the correlation between signals obtained during carotid endarterectomy (CEA) under local (LA) or general anesthesia from the Somanetics Invos cerebral oximeter (CO) and transcranial Doppler (TCD). METHODS Forty patients were enrolled in the study. The percentages fall in TCD mean flow velocity (FVm) and CO regional oxygen saturation (rSO2) on the ipsilateral side following clamping were recorded and the correlation coefficient and Spearman's coefficient of rank correlation were calculated. RESULTS Fourteen patients were not included in the statistical analysis because either no TCD window or reliable TCD signal was obtained. The remaining 26 patients had a fall in either FVm, rSO2 or both during carotid clamping. There was a highly statistically significant correlation between the percentage fall in FVm and rSO2 with a correlation coefficient of 0.73, P<0.0001, with a 95% confidence interval (CI) for r=0.48 to 0.87; Spearman's coefficient of rank correlation (rho) =0.67, P=0.0008, with a 95% CI for rho=0.384 to 0.84. A significant decline in both TCD and rSO2 was noted in 3 patients under LA out of which 2 required shunts for alteration in conscious level. In 2 LA patients there was a significant decline in TCD but not in rSO2 and the endarterectomy was completed without a shunt. CONCLUSIONS Regional oxygen saturation correlates well with FVm during carotid clamping. However, the inability to obtain reliable TCD FVm readings in 35% of patients is a serious disadvantage for this monitor. It appears that CO is a satisfactory and possibly superior device for monitoring adequacy of cerebral perfusion and oxygenation during CEA in comparison with the TCD.
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171
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Khalil H, Elaffandi A, Alsayed Y, Zayed H, Sallam K. 193 POSTER Technical details of intraoperative lymphatic mapping for sentinel lymph node biopsy for NO stage lip cancer. Eur J Surg Oncol 2006. [DOI: 10.1016/s0748-7983(06)70628-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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172
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El Sakka K, Fassiadis N, Gambhir RPS, Halawa M, Zayed H, Doxford M, Greensitt C, Edmonds M, Rashid H. An integrated care pathway to save the critically ischaemic diabetic foot. Int J Clin Pract 2006; 60:667-9. [PMID: 16805750 DOI: 10.1111/j.1368-5031.2006.00953.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
This prospective study describes and evaluates the efficacy of an integrated care pathway for the management of the critically ischaemic diabetic foot patients by a multidisciplinary team. A weekly joint diabetes/vascular/podiatry ward round and outpatient clinic was established where patients were assessed within 7 days of referral by clinical examination, ankle-brachial-index-pressures, duplex angiogram and transcutaneous oxygen pressures. An angiogram +/- angioplasty or alternatively a magnetic resonance angiography prior to surgical revascularisation was performed in patients deemed not suitable for angioplasty based on the above vascular assessment. Between January 2002 and June 2003(18 months), 128 diabetic patients with lower limb ischaemia were seen. Thirty-four (26.6%) patients received medical treatment alone, and 18 (14.1%) were deemed 'palliative' due to their significant co-morbidities. The remaining 76 (59.4%) patients underwent either angioplasty (n = 56), surgical reconstruction (n = 18), primary major amputation (n = 2) or secondary amputation after surgical revascularisation (n = 1). Minor toe amputations were required in 35 patients. The mortality in the intervention group was 14% (11/76). This integrated multidisciplinary approach offers a consistent and equitable service to diabetic patients with critically ischaemic feet and appears to have a beneficial major/minor amputation ratio.
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173
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Zayed H, McIvor RS, Wiest DL, Blazar BR. In vitro functional correction of the mutation responsible for murine severe combined immune deficiency by small fragment homologous replacement. Hum Gene Ther 2006; 17:158-66. [PMID: 16454649 DOI: 10.1089/hum.2006.17.158] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A homologous recombination (HR) approach for site-specific correction of mutations would be highly desirable for the treatment of genetic disorders if recombination efficiencies were sufficiently high as to permit a biological effect. Using a T cell thymoma line derived from severe combined immunodeficient (SCID) mice with a point mutation in the gene encoding the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), we have shown that short DNA fragments (SDFs; 621 bases) can provide genotypic and functional correction of these cells. Double-stranded SDFs (dsSDFs) or single-stranded SDFs (ssSDFs) were designed to span the wild-type sequence of exon 85 in the DNA-PKcs gene and part of the 3' and 5' flanking intron regions. SCID cells were nucleofected with both single- and double-stranded wild-type SDF sequences. Corrected cells were selected on the basis of protection from radiation hypersensitivity that occurs as a consequence of the SCID mutation. Correction was mediated by both SDF forms (double and single stranded). These results indicate that SDFs can correct point mutations by HR with the possibility of harnessing ionizing radiation (IR) as a selection method to eliminate noncorrected cells and enrich for corrected SCID radioresistant cells.
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174
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Zayed H, McIvor RS, Wiest DL, Blazar BR. In Vitro Functional Correction of the Mutation Responsible for Murine Severe Combined Immune Deficiency by Small Fragment Homologous Replacement. Hum Gene Ther 2005. [DOI: 10.1089/hum.2005.17.ft-166] [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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175
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Zayed H, Izsvák Z, Walisko O, Ivics Z. Development of hyperactive sleeping beauty transposon vectors by mutational analysis. Mol Ther 2004; 9:292-304. [PMID: 14759813 DOI: 10.1016/j.ymthe.2003.11.024] [Citation(s) in RCA: 173] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2003] [Accepted: 11/29/2003] [Indexed: 01/27/2023] Open
Abstract
The Sleeping Beauty (SB) transposable element is a promising vector for transgenesis in vertebrates and is being developed as a novel, nonviral system for gene therapeutic purposes. A mutagenesis approach was undertaken to improve various aspects of the transposon, including safety and overall efficiency of gene transfer in human cells. Deletional analysis of transposon sequences within first-generation SB vectors showed that the inverted repeats of the element are necessary and sufficient to mediate high-efficiency transposition. We constructed a "sandwich" transposon, in which the DNA to be mobilized is flanked by two complete SB elements arranged in an inverted orientation. The sandwich element has superior ability to transpose >10-kb transgenes, thereby extending the cloning capacity of SB-based vectors. We derived hyperactive versions of the SB transposase by single-amino-acid substitutions. These mutations act synergistically and result in an almost fourfold enhancement of activity compared to the wild-type transposase. When combined with hyperactive transposons and transiently overexpressed HMGB1, a cellular cofactor of SB transposition, hyperactive transposases elevate transposition by almost an order of magnitude compared to the first-generation transposon system. The improved vector system should prove useful for efficient gene transfer in vertebrates.
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