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Kurtz MA, Wessinger AC, Mace A, Moreno-Reyes A, Gilbert JL. Additively manufactured Ti-29Nb-21Zr shows improved oxide polarization resistance versus Ti-6Al-4V in inflammatory simulating solution. J Biomed Mater Res A 2023; 111:1538-1553. [PMID: 37129046 DOI: 10.1002/jbm.a.37552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/12/2023] [Accepted: 04/18/2023] [Indexed: 05/03/2023]
Abstract
Retrieval studies in the past two decades show severe corrosion of titanium and its alloys in orthopedic implants. This damage is promoted by mechanically assisted crevice corrosion (MACC), particularly within modular titanium-titanium junctions. During MACC, titanium interfaces may be subject to negative potentials and reactive oxygen species (ROS), generated from cathodic activation and/or inflammation. Additive manufacturing (AM) may be able to produce new, corrosion-resistant titanium alloys and admixtures that are less susceptible to these adverse electrochemical events. In this study, we characterize the impedance and corrosion properties of three new AM titanium materials, including Ti-6Al-4V with added 1% nano-yttria stabilized ZrO2 , admixed Ti-29Nb-21Zr, and pre-alloyed Ti-29Nb-21Zr. We aim to elucidate how these materials perform when subjected to high ROS solutions. We include conventionally and additively manufactured Ti-6Al-4V in our study as comparison groups. A 0.1 M H2 O2 phosphate-buffered saline (PBS) solution, simulating inflammatory conditions, significantly increased biomaterial OCP (-0.14 V vs. Ag/AgCl) compared to PBS only (-0.38 V, p = .000). During anodic polarization, Ti-6Al-4V passive current density more than doubled from 1.28 × 10-7 to 3.81 × 10-7 A/cm2 when exposed to 0.1 M H2 O2 . In contrast, Ti-29Nb-21Zr passive current density remained relatively unchanged, slightly increasing from 7.49 × 10-8 in PBS to 9.31 × 10-8 in 0.1 M H2 O2 . Ti-29Nb-21Zr oxide polarization resistance (Rp ) was not affected by 0.1 M H2 O2 , maintaining a high value (1.09 × 106 vs. 1.89 × 106 Ω cm2 ), while Ti-6Al-4V in 0.1 M H2 O2 solution had significantly diminished Rp (4.38 × 106 in PBS vs. 7.24 × 104 Ω cm2 in H2 O2 ). These results indicate that Ti-29Nb-21Zr has improved corrosion resistance in ROS containing solutions when compared with Ti-6Al-4V based biomaterials.
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Affiliation(s)
- Michael A Kurtz
- Department of Bioengineering, Clemson University, Clemson, South Carolina, USA
- The Clemson University-Medical University of South Carolina Bioengineering Program, Charleston, South Carolina, USA
| | - Audrey C Wessinger
- Department of Bioengineering, Clemson University, Clemson, South Carolina, USA
- The Clemson University-Medical University of South Carolina Bioengineering Program, Charleston, South Carolina, USA
| | - Annsley Mace
- Department of Bioengineering, Clemson University, Clemson, South Carolina, USA
- The Clemson University-Medical University of South Carolina Bioengineering Program, Charleston, South Carolina, USA
| | - Aldo Moreno-Reyes
- Department of Bioengineering, Clemson University, Clemson, South Carolina, USA
- The Clemson University-Medical University of South Carolina Bioengineering Program, Charleston, South Carolina, USA
| | - Jeremy L Gilbert
- Department of Bioengineering, Clemson University, Clemson, South Carolina, USA
- The Clemson University-Medical University of South Carolina Bioengineering Program, Charleston, South Carolina, USA
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Mace A, Gilbert JL. Low cycle fretting and fretting corrosion properties of low carbon CoCrMo and additively manufactured CoCrMoW alloys for dental and orthopedic applications. J Biomed Mater Res B Appl Biomater 2023. [PMID: 37081711 DOI: 10.1002/jbm.b.35258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 02/08/2023] [Accepted: 04/06/2023] [Indexed: 04/22/2023]
Abstract
Additive manufacturing (AM) of CoCrMo metallic implants is growing in the orthopedic and dental fields. This is due to the traditional alloy's excellent corrosion resistance and mechanical properties. AM processes like selective laser melting (SLM) require less time, materials, and waste than casting or subtractive manufacturing complex-geometry structures (bridges, partial dentures, etc.). The objective of this work was to investigate the low cycle tribological and tribocorrosion characteristics of AM CoCrMoW alloys compared to wrought LC CoCrMo (ASTM F-1537) to assess this AM alloy's performance. Fretting and tribocorrosion testing was performed in air (wear only), PBS (wear + corrosion), and PBS with 10 mM H2 O2 (wear + corrosion + inflammation) by a single diamond asperity. No variation between alloys in volume of material removed (p = .12), volume of plastic deformation (p = .13), and scratch depth (p = .84) showed that AM was substantially similar in wear resistance to LC in air and PBS. AM exhibited significantly higher fretting currents (p < .01) at loads up to 100 mN ( I AM PBS $$ {I}_{\mathrm{AM}}^{\mathrm{PBS}} $$ = 57 nA and I AM H 2 O 2 $$ {I}_{\mathrm{AM}}^{H_2{O}_2} $$ = 49 nA) than LC CoCrMo ( I LC PBS $$ {I}_{\mathrm{LC}}^{\mathrm{PBS}} $$ = 30 nA) and ( I LC H 2 O 2 $$ {I}_{\mathrm{LC}}^{H_2{O}_2} $$ = 29 nA). In PBS, wear track depth linearly correlates to fretting current, averaged over 100 cycles. Additionally, fretting currents of both alloys were significantly lower in simulated inflammatory conditions compared to PBS alone. AM alloy has generally similar wear and tribocorrosion resistance to wrought LC CoCrMo and would be ideal for patient specific dentistry or orthopedics where precise, complex geometries are required.
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Affiliation(s)
- Annsley Mace
- Department of Bioengineering, Clemson University - MUSC Bioengineering Program, Charleston, South Carolina, USA
| | - Jeremy L Gilbert
- Department of Bioengineering, Clemson University - MUSC Bioengineering Program, Charleston, South Carolina, USA
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Mace A, Goodwin CM, Gilbert JL. Fretting corrosion testing of acetabular modular tapers for total hip replacements: A comparison of two designs. J Orthop Res 2023. [PMID: 36606423 DOI: 10.1002/jor.25512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 12/01/2022] [Accepted: 01/04/2023] [Indexed: 01/07/2023]
Abstract
Acetabular components (DePuy Pinnacle (A) and Stryker Trident (B), Ti-6Al-4V shells and CoCrMo liners) with varying geometries were assembled under a 4 kN seating load. Liner-displacement was recorded. Cyclic compression to 4 kN, R = 0.01, 9 Hz was applied for three million cycles to evaluate fretting corrosion currents (n = 5). Fretting currents, load-displacement, ion dissolution, and disassembly loads were used to compare device performance. Data were analyzed using ANOVA with Tukey post hoc comparisons (p < 0.05). Liner seating displacements were not significantly different between groups. Fretting currents averaged over the initial 10 h and over three million cycles were 0.17 μA (A) and 0.55 μA (B) and 0.05 μA (A) and 0.17 μA (B), respectively (p = 0.19). No variation in ion averages between A and B (0.23 and 0.45 ppm for Ti [p = 0.21], 0.63 and 0.85 ppm for Co [p = 0.47]) existed. Average push-out forces, -2.41 (A) and -2.42 kN (B), were not significantly different (p = 0.97). SEM and EDS showed some titanium and metal oxide transfer from the shell to the liner in both designs. Overall, both implant designs exhibited very minor MACC in these experiments. This study demonstrates quantitative measures of in vitro fretting corrosion over the course of three million cycles and the minimal degree of acetabular taper damage. Clinical Significance: Retrieval studies show dual mobility acetabular shell-liner tapers with metal-on-metal contacts are susceptible to fretting corrosion in vivo.
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Affiliation(s)
- Annsley Mace
- Clemson University - MUSC Bioengineering Program, Charleston, South Carolina, USA
| | - Charley M Goodwin
- Clemson University - MUSC Bioengineering Program, Charleston, South Carolina, USA
| | - Jeremy L Gilbert
- Clemson University - MUSC Bioengineering Program, Charleston, South Carolina, USA
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Mace A, Gilbert JL. A mass balance analysis of the tribocorrosion process of titanium alloys using a single micro-asperity: Voltage and solution effects on plastic deformation, oxide repassivation, and ion dissolution. J Mech Behav Biomed Mater 2022; 136:105531. [PMID: 36308875 DOI: 10.1016/j.jmbbm.2022.105531] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 08/26/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022]
Abstract
Within modular taper junctions of total hip implants (THA), nominally "smooth" metallic surfaces contain multiple micro-asperities that slide, are plastically deformed, have their oxide film surfaces disrupted and corrode during the fretting corrosion processes. In this work, a mass/volume balance approach is developed and used to assess the contribution of individual components of wear and corrosion to the entirety of the single-asperity tribocorrosion process for the popular THA alloy, Ti-6Al-4V. This analysis measures the total volume change (trough) in the surface due to low cycle single asperity fretting corrosion and compares it to the measured pileup volume which is comprised of plastic deformation, metal particles and oxide particles, plus the fretting current and the concentration of solution-bound species. A simple 17 μm spherical geometry diamond asperity was used and the trough volume, pileup volume, fretting currents and ion concentrations were measured to assess their contribution to the fretting corrosion process. The effects fretting in or out of solution (phosphate buffered saline), and the role of electrode potential, e.g., freely corroding or forced potential (-1.0 V, 0 V, and +1.0 V vs Ag/AgCl) were investigated. Under constant 30 mN loading, 100 cycles duration, 3 Hz cyclic frequency and 80 μm sliding amplitude, the volume abraded, fretting currents, ion release, and pileup volume were all recorded. Damage was analyzed and quantified using digital optical microscopy (DOM), atomic force microscopy (AFM), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and inductive coupled plasma mass spectrometry (ICP-MS). The results were analyzed with ANOVA statistics (α = 0.05). The extent of wear damage (asperity trough volume) is as follows: air = Ecorr, air > -1.0 V = 0 V = +1.0 V. As the amount of pileup volume decreased between conditions, visible oxide generation increased, with V > 0 V having more oxide debris generation and air fretting resulting in the least oxide (and most plastic deformation). Ions in solution were not significant, accounting for less than 1% of the damage. Volume analysis showed trough volumes and pileup volumes were very close to one another and were dominated by plastic deformation. Synergy between wear and corrosion were not observed in this work.
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Affiliation(s)
- Annsley Mace
- Clemson University, MUSC Bioengineering Program, Charleston, SC, USA
| | - Jeremy L Gilbert
- Clemson University, MUSC Bioengineering Program, Charleston, SC, USA.
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Mace A, Khullar P, Bouknight C, Gilbert JL. Corrosion properties of low carbon CoCrMo and additively manufactured CoCr alloys for dental applications. Dent Mater 2022; 38:1184-1193. [PMID: 35710472 DOI: 10.1016/j.dental.2022.06.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/05/2022] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Additive manufacturing (AM) is being applied to metallic biomaterials and dental alloys, including CoCrMo. CoCrMo mechanical properties and corrosion resistance are vital to the structural integrity of implants and dental appliances. The goal of this work is to assess the resistivity of AM cobalt chromium alloys by comparing them with traditional CoCrMo, regarding electrochemical properties resulting from microstructural and oxide film differences. METHODS In this work, selective laser melting (SLM), was used to manufacture CoCrMoW. The corrosion characteristics of AM alloy were compared to that of wrought LC CoCrMo (ASTM F-1537) in both phosphate buffered saline (PBS) and PBS with 10 mM H2O2 to simulate increased inflammatory conditions. Anodic polarization and electrochemical impedance spectroscopy (EIS) were performed. RESULTS Both alloys were substantially similar in corrosion behavior in both solutions. They exhibited changes with the different solutions. Polarization resistances were statistically lower (RpAM = 1.4 MΩcm2 (PBS) vs. 0.72 MΩcm2 (H2O2), RpLC = 1.86 MΩcm2 (PBS) vs. 0.55 MΩcm2 (H2O2)), and open circuit potentials (OCP's) were statistically higher in 10 mM H2O2 for both alloys (0.20 V (in H2O2) vs. - 0.09 V in PBS). Chemistry variations were revealed by the corrosion tests indicating that wrought LC CoCrMo retained its casting-based chemical heterogeneity, while AM CoCrMoW had sub-cell structures within the solidified grains. SIGNIFICANCE As novel production methods like AM arise, it is necessary to understand any microstructural differences that may diminish the corrosion resistance properties. AM CoCrMoW alloys hold significant promise for use in dentistry where complex geometries are required.
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Affiliation(s)
- Annsley Mace
- Clemson University - MUSC Bioengineering Program, Charleston, SC, USA
| | - Piyush Khullar
- Clemson University - MUSC Bioengineering Program, Charleston, SC, USA
| | | | - Jeremy L Gilbert
- Clemson University - MUSC Bioengineering Program, Charleston, SC, USA.
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Ramos Ferrer P, Mace A, Thomas SN, Jeon JW. Nanostructured porous graphene and its composites for energy storage applications. Nano Converg 2017; 4:29. [PMID: 29152447 PMCID: PMC5661008 DOI: 10.1186/s40580-017-0123-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 10/14/2017] [Indexed: 05/10/2023]
Abstract
Graphene, 2D atomic-layer of sp2 carbon, has attracted a great deal of interest for use in solar cells, LEDs, electronic skin, touchscreens, energy storage devices, and microelectronics. This is due to excellent properties of graphene, such as a high theoretical surface area, electrical conductivity, and mechanical strength. The fundamental structure of graphene is also manipulatable, allowing for the formation of an even more extraordinary material, porous graphene. Porous graphene structures can be categorized as microporous, mesoporous, or macroporous depending on the pore size, all with their own unique advantages. These characteristics of graphene, which are further explained in this paper, may be the key to greatly improving a wide range of applications in energy storage systems.
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Affiliation(s)
- Pablo Ramos Ferrer
- Department of Chemical & Biological Engineering, University of Alabama, Tuscaloosa, AL 35487 USA
| | - Annsley Mace
- Department of Chemical & Biological Engineering, University of Alabama, Tuscaloosa, AL 35487 USA
| | - Samantha N. Thomas
- Department of Chemical & Biological Engineering, University of Alabama, Tuscaloosa, AL 35487 USA
| | - Ju-Won Jeon
- Department of Chemical & Biological Engineering, University of Alabama, Tuscaloosa, AL 35487 USA
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Nouraei S, Virk J, Middleton S, Aylin P, Mace A, Vaz F, Kaddour H, Darzi A, Tolley N. A national analysis of trends, outcomes and volume-outcome relationships in thyroid surgery. Clin Otolaryngol 2016; 42:354-365. [DOI: 10.1111/coa.12730] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2016] [Indexed: 01/08/2023]
Affiliation(s)
- S.A.R. Nouraei
- Department of ENT Surgery; Auckland City Hospital; Auckland New Zealand
- National Institute for Health and Care Excellence (2013) Scholar; London England
| | - J.S. Virk
- Department of ENT Surgery; Royal London Hospital; London England
| | | | - P. Aylin
- Dr Foster Unit at Imperial College; Department of Primary Care and Public Health; Imperial College London; London England
| | - A. Mace
- Department of ENT Surgery; Charing Cross Hospital; London England
| | - F. Vaz
- Department of ENT Surgery; University College Hospital; London England
| | - H. Kaddour
- Department of ENT Surgery; Barking Havering and Redbridge NHS Trust; Romford England
| | - A. Darzi
- Academic Surgical Unit; Department of Surgery and Cancer; Imperial College Healthcare Trust; St Mary's Hospital; London England
| | - N.S. Tolley
- Department of ENT Surgery; St Mary's Hospital; London England
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Lobo N, Hall A, McIntyre C, Meacher R, Mace A. Optimising surgical tracheostomy provision for the intensive care unit: a multicycle audit of 36 cases. Clin Otolaryngol 2016; 41:612-4. [PMID: 26400149 DOI: 10.1111/coa.12544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2015] [Indexed: 11/27/2022]
Affiliation(s)
- N Lobo
- Department of ENT, Charing Cross Hospital, Imperial College Hospital NHS Trust, London, UK.
| | - A Hall
- Department of ENT, Charing Cross Hospital, Imperial College Hospital NHS Trust, London, UK
| | - C McIntyre
- Department of ENT, Charing Cross Hospital, Imperial College Hospital NHS Trust, London, UK
| | - R Meacher
- Department of Critical Care Medicine, Charing Cross Hospital, Imperial College Hospital NHS Trust, London, UK
| | - A Mace
- Department of ENT, Charing Cross Hospital, Imperial College Hospital NHS Trust, London, UK
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Nouraei S, Middleton S, Hudovsky A, Branford O, Lau C, Clarke P, Wood S, Aylin P, Mace A, Jallali N, Darzi A. Role of reconstructive surgery in the management of head and neck cancer: A national outcomes analysis of 11,841 reconstructions. J Plast Reconstr Aesthet Surg 2015; 68:469-78. [DOI: 10.1016/j.bjps.2014.11.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/02/2014] [Accepted: 11/11/2014] [Indexed: 10/24/2022]
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Smith FM, Wiland H, Mace A, Pai RK, Kalady MF. Assessment of a novel, full-thickness incisional biopsy model to restage rectal tumours after neoadjuvant chemoradiotherapy: results of an ex vivo pilot study. Tech Coloproctol 2015; 19:159-64. [PMID: 25687376 DOI: 10.1007/s10151-015-1272-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 01/15/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND There is currently no reliable means to restage rectal cancers after neoadjuvant chemoradiation. Recent histological evidence shows that the epicentre for residual cancer cells is focussed directly underneath any residual mucosal abnormality (RMA). This proof-of-concept study aimed to determine the utility of a novel, minimally invasive method of incisional biopsy as a restaging tool. A secondary aim was to compare its performance to clinical response assessment. METHODS After surgical resection, 0.5 × 0.5 cm, full-thickness incisional biopsy was performed in 15 rectal cancers. Of these, 13 had RMA and 2 had mucosal cCR but a palpable intramural abnormality. In all patients, a full-thickness incisional biopsy was taken through the centre of these areas. The ypT stage of the incisional biopsy and the final total specimen were compared. Complete mucosal clinical response was deemed to have occurred when either no residual tumour or only a flat mucosal scar remained. RESULTS Incisional biopsy correctly identified all patients that had been downstaged to ypT0; however, it also falsely identified 5 of 10 patients (50%) with yp residual disease as ypT0. Overall performance of incisional biopsy to detect residual cancer was 50% sensitivity, 100 % specificity, 100% PPV, and 50% NPV with an accuracy of 66%. A complete mucosal clinical response occurred in only one of five patients downstaged to ypT0 (20% sensitive). It also occurred in one patient, which was ultimately staged as ypT3. CONCLUSION This prospective data demonstrates that incisional biopsy is not suitable as a stand-alone method to restage rectal cancer after CRT. Alternate or complementary means of restaging are needed.
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Affiliation(s)
- F M Smith
- Department of Colorectal Surgery, Digestive Disease Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA,
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Smith FM, Wiland H, Mace A, Pai RK, Kalady MF. Depth and lateral spread of microscopic residual rectal cancer after neoadjuvant chemoradiation: implications for treatment decisions. Colorectal Dis 2014; 16:610-5. [PMID: 24593015 DOI: 10.1111/codi.12608] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Accepted: 11/27/2013] [Indexed: 02/08/2023]
Abstract
AIM The aim of this study was to determine the distribution of residual tumour within the bowel wall in relation to residual mucosal abnormalities (RMAs) and surrounding normal mucosa in patients with rectal cancer who underwent neoadjuvant chemoradiation followed by curative surgery. METHOD Archived pathological slides from a cohort of 60 patients with residual tumour were retrieved. The incidence, distance and depth of tumour spread (ypT) under RMAs and adjacent normal mucosa were reviewed and recorded. RESULTS Histological sections containing both RMA and adjacent normal mucosa were available for 45 of 60 patients with ypT1 (n = 6), ypT2 (n = 18) and ypT3 (n = 21) disease. The maximal depth of invasion, as measured by ypT stage, was found underneath the RMA in 44 of 45 (98%) patients. Microscopic tumour spread lateral to the RMA and under adjacent normal mucosa was found in 32 of 45 (71%) patients. The median and maximum distances of lateral spread for ypT1 tumours were 0 and 4 mm; for ypT2 were 2.5 and 9 mm; and for ypT3 were 4 and 9 mm respectively. CONCLUSION Lateral tumour spread under normal mucosa adjacent to RMAs is a common finding and extended up to 9 mm in this study. The epicentre for maximum depth of invasion was directly underneath the RMAs in nearly all cases. These data have clinical and technical implications if local excision is to be considered.
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Affiliation(s)
- F M Smith
- Department of Colorectal Surgery, Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA
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Vasani S, Smith R, Mace A. How to avoid the pitfalls of prescribing to athletes in this Olympic Year. Clin Otolaryngol 2012; 37:251-2. [DOI: 10.1111/j.1749-4486.2012.02480.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Bernicot I, Dechanet C, Mace A, Hedon B, Hamamah S, Pellestor F, Anahory T. Predictive value of sperm-FISH analysis on the outcome of preimplantation genetic diagnosis (PGD) for a pericentric inversion inv5(p15.3q11.2) carrier. Hum Reprod 2010; 25:1818-23. [PMID: 20406738 DOI: 10.1093/humrep/deq101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Pericentric inversions (PIs) are structural chromosomal abnormalities, potentially associated with infertility or multiple miscarriages. More rarely, at meiosis, odd numbers of genetic recombinations within the inversion loop produce recombinant gametes which may lead to aneusomy of recombination in the offspring. METHODS We report a FISH segregation analysis of an inv5(p15.3q11.2) carrier, both in sperm and blastomeres. In sperm, we directly evaluated the proportion of recombinant gametes and compared the results with chromosomal abnormalities found in blastomeres collected from embryos obtained following a preimplantation genetic diagnosis (PGD) procedure. RESULTS A total of 7006 sperm nuclei were analyzed. The size of the inverted segment represented 27% of the total length of chromosome 5. The frequencies of balanced chromosomes (normal or inverted), recombinant chromosomes and unbalanced combinations were 97.1, 0.17 and 2.73%, respectively. Of six embryos, PGD FISH analysis revealed that one was a balanced embryo, whereas five were unbalanced and there were no recombinants. CONCLUSIONS This study demonstrated the value of sperm-FISH analysis in providing reproductive genetic counseling for PI carriers. Our study also highlights the clinical relevance of performing PGD instead of prenatal diagnosis.
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Affiliation(s)
- I Bernicot
- CHU Montpellier, Unité de Cytogénétique DPI, Hôpital Arnaud de Villeneuve, 34295 Montpellier, France
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Bernicot I, Mace A, Hedon B, Pellestor F, Hamamah S, Anahory T. Predictive value of sperm fish analysis on the outcome of preimplantation genetic diagnosis (PGD) for a pericentric inversion (PI) INV 5(p15.3q11.2) carrier. Fertil Steril 2009. [DOI: 10.1016/j.fertnstert.2009.07.1437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
Sialorrhoea can be a significant problem in both adults and children and can cause both physical and psychosocial problems. Botulinum toxin has enjoyed an emergence in the treatment of sialorrhoea, a systematic review of the evidence for botulinum toxin reveals two randomised controlled trials (RCTs) and four other trials that fulfilled our inclusion criteria. Both RCTs demonstrate the effectiveness of botulinum toxin in the management of sialorrhoea. There was no clear evidence for one antigenic type of botulinum toxin over another and minimal evidence for the optimal dose of botulinum toxin for each antigenic type. No advantage is conferred in using ultrasound guidance in injecting the glands. None of the RCTs or other studies directly compared submandibular versus parotid injection or directly compared botulinum toxin against surgery. Minor side effects were reported in one of the RCTs but overall botulinum toxin is a safe, minimally invasive and effective means in the treatment of sialorrhoea with the potential to become the treatment of choice. Our review demonstrates that further randomised controlled trials are required to more fully evaluate this new modality of treatment.
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Affiliation(s)
- M Lim
- Department of Otolaryngology and Head and Neck Surgery, Royal Free Hospital, London, UK.
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Smith R, Barnsley L, Kannangara S, Mace A. Rheumatological prescribing in athletes: a review of the new World Anti-Doping Agency guidelines. Rheumatology (Oxford) 2004; 43:1473-5. [PMID: 15292526 DOI: 10.1093/rheumatology/keh338] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Rheumatologists, with their musculoskeletal background, often care for athletes. The effect of a positive anti-doping test, whether through illegitimate use or accidental prescribing of banned drugs, is devastating to an athlete's career. It is therefore incumbent upon rheumatologists to be aware of issues relating to drugs in sport. This involves both therapeutic drugs and doping. It is vital to ensure that any substance prescribed should be approved for use and should not adversely affect (or benefit) the athlete's performance. In March 2004, 5 months prior to the 2004 Olympic Games in Athens, the joint World Anti-Doping Agency/International Olympic Committee published the revised list of banned substances in athletes. This article aims to provide an overview of the current status of medications commonly prescribed in rheumatological practice.
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Affiliation(s)
- R Smith
- New South Wales Institute of Sports Medicine and Department of Rheumatology, Concord Hospital, NSW 2139, Australia
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Stelmachowicz PG, Kopun J, Mace A, Lewis DE, Nittrouer S. The perception of amplified speech by listeners with hearing loss: acoustic correlates. J Acoust Soc Am 1995; 98:1388-1399. [PMID: 7560508 DOI: 10.1121/1.413474] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Audibility-based approaches to hearing-aid selection generally have focused on the long-term average speech spectrum (LTASS). Advances in amplification technology (e.g., multiband signal processing, level-dependent frequency shaping, full dynamic range compression, adaptive compression) make it difficult to predict the audibility of short-term components of speech from the amplified LTASS. This study was designed to quantify the audibility of a specific phonemes as processed by two different hearing-aid circuits (linear and full dynamic range compression), and to investigate the relation between audibility and performance on a nonsense syllable recognition task. Data were obtained from three subjects with moderate sensorineural hearing loss. Nine unvoiced consonants were presented in two vowel contexts (/i/ and /a/) in both the pre- and post-vocalic position at three intensities. While the performance on selected conditions appeared to vary by hearing-aid type, only one subject showed a statistically significant difference between the two hearing-aid systems. Acoustic analyses revealed a variety of spectral and temporal changes to the speech signal following processing. Estimates of audibility were based upon each subject's thresholds and an acoustic analysis of the amplified signal that varied across phonemes and consonant position. A signal detection approach was used to predict performance from a simple measure of audibility.
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Elyaderani MK, Mace A. Percutaneous thin needle cholangiography. W V Med J 1985; 81:92-5. [PMID: 3859101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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