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1.
J Pediatr Psychol ; 49(3): 185-194, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38324735

RESUMEN

OBJECTIVE: Sensory elements are core features in chronic pain and autism, yet knowledge of the pain experience in autistic adolescents is limited. Little is known regarding how autistic adolescents experience chronic pain, manage their pain and perceive psychological treatment for their chronic pain. METHODS: Ten autistic adolescents (6 female, 3 male, and 1 self-identified as agender) with chronic pain and their mothers (n = 10) participated in semistructured interviews concerning their perceptions of living with chronic pain. Participants were recruited from U.K. pain management services. According to preference, interviews were conducted individually (n = 10) or dyadically (n = 10 participants across 5 dyads). Data were analyzed using inductive reflexive thematic analysis. RESULTS: Two themes were generated. Theme 1, "overstimulated and striving for control" described how adolescents' experience of heightened sensitivity enhanced adolescents' levels of anxiety and subsequent pain, illustrating a reciprocal relationship between anxiety, pain, and sensory elements. Theme 2, "not everyone fits the mold" captured how autistic adolescents positioned themselves as distinct from others due to the unique nature of being autistic and living with pain. This sense of difference negatively impacted adolescents' ability to engage with and benefit from the standard treatment for chronic pain. CONCLUSIONS: Findings suggest that autistic adolescents living with pain experience pain and face barriers to effective pain treatment. Our results identify the need for educational resources to facilitate clinicians to better understand the experience of autistic adolescents living with pain. In turn, such understanding may improve treatment and outcomes in this population.


Asunto(s)
Trastorno Autístico , Dolor Crónico , Humanos , Masculino , Adolescente , Femenino , Dolor Crónico/terapia , Trastorno Autístico/complicaciones , Trastorno Autístico/terapia , Ansiedad/psicología , Manejo del Dolor
2.
J Lipid Res ; 64(7): 100395, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37245563

RESUMEN

Type 2 diabetes mellitus (T2DM) increases the risk of cognitive decline and dementia. Disruptions in the cytochrome P450-soluble epoxide hydrolase (CYP450-sEH) pathway have been reported in T2DM, obesity and cognitive impairment. We examine linoleic acid (LA)-derived CYP450-sEH oxylipins and cognition in T2DM and explore potential differences between obese and nonobese individuals. The study included 51 obese and 57 nonobese participants (mean age 63.0 ± 9.9, 49% women) with T2DM. Executive function was assessed using the Stroop Color-Word Interference Test, FAS-Verbal Fluency Test, Digit Symbol Substitution Test, and Trails Making Test-Part B. Verbal memory was assessed using the California Verbal Learning Test, second Edition. Four LA-derived oxylipins were analyzed by ultra-high-pressure-LC/MS, and the 12,13-dihydroxyoctadecamonoenoic acid (12,13-DiHOME) considered the main species of interest. Models controlled for age, sex, BMI, glycosylated hemoglobin A1c, diabetes duration, depression, hypertension, and education. The sEH-derived 12,13-DiHOME was associated with poorer executive function scores (F1,98 = 7.513, P = 0.007). The CYP450-derived 12(13)-epoxyoctadecamonoenoic acid (12(13)-EpOME) was associated with poorer executive function and verbal memory scores (F1,98 = 7.222, P = 0.008 and F1,98 = 4.621, P = 0.034, respectively). There were interactions between obesity and the 12,13-DiHOME/12(13)-EpOME ratio (F1,97 = 5.498, P = 0.021) and between obesity and 9(10)-epoxyoctadecamonoenoic acid (9(10)-EpOME) concentrations (F1,97 = 4.126, P = 0.045), predicting executive function such that relationships were stronger in obese individuals. These findings suggest that the CYP450-sEH pathway as a potential therapeutic target for cognitive decline in T2DM. For some markers, relationships may be obesity dependent.


Asunto(s)
Diabetes Mellitus Tipo 2 , Ácido Linoleico , Humanos , Femenino , Persona de Mediana Edad , Anciano , Masculino , Ácido Linoleico/metabolismo , Diabetes Mellitus Tipo 2/complicaciones , Oxilipinas/metabolismo , Epóxido Hidrolasas/metabolismo , Cognición , Sistema Enzimático del Citocromo P-450 , Obesidad/complicaciones
3.
Int J Mol Sci ; 24(20)2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37894980

RESUMEN

The common bean (Phaseolus vulgaris L.) is a globally cultivated leguminous crop. Fusarium wilt (FW), caused by Fusarium oxysporum f. sp. phaseoli (Fop), is a significant disease leading to substantial yield loss in common beans. Disease-resistant cultivars are recommended to counteract this. The objective of this investigation was to identify single nucleotide polymorphism (SNP) markers associated with FW resistance and to pinpoint potential resistant common bean accessions within a core collection, utilizing a panel of 157 accessions through the Genome-wide association study (GWAS) approach with TASSEL 5 and GAPIT 3. Phenotypes for Fop race 1 and race 4 were matched with genotypic data from 4740 SNPs of BARCBean6K_3 Infinium Bea Chips. After ranking the 157-accession panel and revealing 21 Fusarium wilt-resistant accessions, the GWAS pinpointed 16 SNPs on chromosomes Pv04, Pv05, Pv07, Pv8, and Pv09 linked to Fop race 1 resistance, 23 SNPs on chromosomes Pv03, Pv04, Pv05, Pv07, Pv09, Pv10, and Pv11 associated with Fop race 4 resistance, and 7 SNPs on chromosomes Pv04 and Pv09 correlated with both Fop race 1 and race 4 resistances. Furthermore, within a 30 kb flanking region of these associated SNPs, a total of 17 candidate genes were identified. Some of these genes were annotated as classical disease resistance protein/enzymes, including NB-ARC domain proteins, Leucine-rich repeat protein kinase family proteins, zinc finger family proteins, P-loopcontaining nucleoside triphosphate hydrolase superfamily, etc. Genomic prediction (GP) accuracy for Fop race resistances ranged from 0.26 to 0.55. This study advanced common bean genetic enhancement through marker-assisted selection (MAS) and genomic selection (GS) strategies, paving the way for improved Fop resistance.


Asunto(s)
Fusarium , Phaseolus , Fusarium/genética , Estudio de Asociación del Genoma Completo , Phaseolus/genética , Genómica , Enfermedades de las Plantas/genética , Resistencia a la Enfermedad/genética
4.
Stroke ; 53(5): 1813-1822, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35259929

RESUMEN

People living with diabetes are at higher risk for stroke and have a poorer prognosis following a stroke event than those without diabetes. Data from cardiovascular outcome trials and meta-analyses indicate that GLP-1RAs (glucagon-like peptide 1 receptor agonists) reduce the risk of stroke in individuals with type 2 diabetes. Accordingly, many guidelines now recommend the addition of GLP-1RAs to ongoing antihyperglycemic regimens to lower the risk of stroke in type 2 diabetes. The current work summarizes evidence supporting the use of GLP-1RAs for stroke reduction in people with type 2 diabetes and offers 2 new resources for neurologists who are considering GLP-1RAs for their patients-a list of frequently asked questions with evidence-based answers on safely initiating and managing GLP-1RAs, and a practical decision-making algorithm to assist in using GLP-1RAs as part of a stroke reduction strategy.


Asunto(s)
Diabetes Mellitus Tipo 2 , Accidente Cerebrovascular , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Péptido 1 Similar al Glucagón , Receptor del Péptido 1 Similar al Glucagón/agonistas , Humanos , Neurólogos , Accidente Cerebrovascular/tratamiento farmacológico
5.
Curr Opin Cardiol ; 36(5): 661-671, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-33929367

RESUMEN

PURPOSE OF REVIEW: Elevated levels of triglycerides, independent of low-density lipoprotein cholesterol (LDL-C) levels and statin therapy, are associated with heightened cardiovascular risk. RECENT FINDINGS: Mixed omega-3 fatty acid formulations, which contain varying amounts of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), lower triglycerides levels but trial results with omega-3 fatty acids combinations have generally been neutral for cardiovascular outcomes. In contrast, the REDUCE-IT trial with icosapent ethyl (IPE), a highly purified ethyl ester of EPA, demonstrated reduced cardiovascular risk in individuals with established atherosclerotic cardiovascular disease or diabetes with at least one additional risk factor, despite having relatively well controlled LDL-C levels but triglycerides at least 135 mg/dl while on statin therapy. IPE offers an important new avenue for cardiovascular risk management in statin-treated individuals with elevated triglycerides. SUMMARY: This review summarizes the results from outcome trials conducted with omega-3 fatty acids, differentiating between those with combinations of EPA/DHA and those with pure EPA, as well as imaging and preclinical data that help explain the different cardiovascular efficacy observed. A list of frequently asked questions with evidence-based responses is provided to assist our colleagues and their patients in the shared-decision process when considering if IPE is appropriate for cardiovascular risk reduction.


Asunto(s)
Enfermedades Cardiovasculares , Ácido Eicosapentaenoico , Enfermedades Cardiovasculares/prevención & control , Ácido Eicosapentaenoico/análogos & derivados , Ácido Eicosapentaenoico/uso terapéutico , Factores de Riesgo de Enfermedad Cardiaca , Humanos , Factores de Riesgo , Triglicéridos
6.
Curr Opin Cardiol ; 35(2): 178-186, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31804229

RESUMEN

PURPOSE OF REVIEW: The aim of this article is to provide practical recommendations on safe initiation of sodium-glucose cotransporter 2 (SGLT2) inhibitors to in-patients as well as management of those who are already on SGLT2 inhibitors. RECENT FINDINGS: Robust data from stable outpatient cohorts indicate that the SGLT2 inhibitors are associated with clinically meaningful reductions in major adverse cardiovascular events, lower rates of hospitalization for heart failure, and a reduction in major kidney outcomes There is however a lack of information on how to initiate and manage SGLT2 inhibitors in an acute in-patient setting. SUMMARY: SGLT2 inhibitors may be cautiously appropriate for in-patients if all the criteria for safe use are met but good clinical judgment must prevail. Temporary withholding of SGLT2 inhibitors is appropriate in hospitalized patients during a period of stress and/or insulinopenia.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Cuidados Posteriores , Glucosa , Humanos , Hipoglucemiantes/uso terapéutico , Alta del Paciente , Sodio
7.
Diabetes Obes Metab ; 21(10): 2192-2202, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31183975

RESUMEN

Recent phase 3 clinical trials have evaluated the impact of adding sodium-glucose co-transporter (SGLT) inhibitors to the type 1 diabetes armamentarium. These trials studied SGLT2 inhibitors (dapagliflozin and empagliflozin) and a dual SGLT1 and SGLT2 inhibitor (sotagliflozin), and demonstrated that these oral non-insulin antihyperglycaemic medications are able not only to improve glycaemic control, but also to reduce body weight and extend time in range without increasing rates of hypoglycaemia in type 1 diabetes. Diabetic ketoacidosis (DKA) is a feature of type 1 diabetes and the risk is increased when SGLT inhibitors are used in type 1 diabetes. To minimize the risk of DKA and still gain the multiple benefits, we developed the "STOP DKA Protocol ", an easily accessible and practical tool, that provides a risk mitigation strategy for reducing DKA in patients with type 1 diabetes being treated with SGLT inhibitors.


Asunto(s)
Diabetes Mellitus Tipo 1/tratamiento farmacológico , Cetoacidosis Diabética , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Compuestos de Bencidrilo/uso terapéutico , Ensayos Clínicos Fase III como Asunto , Cetoacidosis Diabética/tratamiento farmacológico , Cetoacidosis Diabética/prevención & control , Glucósidos/uso terapéutico , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto
9.
J Pediatr Psychol ; 44(4): 453-462, 2019 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-30496433

RESUMEN

OBJECTIVE: Acceptance of pain is a predictor of pain-related disability and treatment outcome in adolescents with pain. This variable has been previously measured using the Chronic Pain Acceptance Questionnaire for Adolescents (CPAQ-A, McCracken, Gauntlett-Gilbert, & Eccleston, European Journal of Pain, 14, 316-320, 2010). We set out to create a short, eight-item, form of this instrument that retained its factor structure and clinical utility. METHODS: We used data collected from two independent samples of adolescents attending residential treatment for disabling chronic pain (N = 187 and N = 159). Both groups completed the 20-item CPAQ-A and indices of functioning and distress. We carried out item reduction and confirmatory factor analysis (CFA) on the first sample, repeating this on the second sample and examining the new scale's correlations with clinically relevant variables. RESULTS: An eight-item scale was created with four items assigned to each established factor (Pain Willingness and Activity Engagement). CFA confirmed this factor structure and it replicated in Sample 2. The new scale (the CPAQ-A8) was sensitive to treatment and correlated as well with clinically important variables as its full-length version. Some items in the new scale differed from the adult CPAQ-8. CONCLUSIONS: Measures of pain acceptance have been previously developed and validated in pediatric and adult samples. This study showed that pain acceptance can be indexed by a brief, yet factorially valid, short form of the CPAQ-A that uses fewer than 50% of the items of the full-length scale and has demonstrated acceptable validity and sensitivity-to-treatment.


Asunto(s)
Adaptación Psicológica/fisiología , Dolor Crónico/psicología , Dimensión del Dolor , Adolescente , Niño , Femenino , Humanos , Masculino , Psicometría , Reproducibilidad de los Resultados , Encuestas y Cuestionarios
10.
J Arthroplasty ; 34(5): 991-1002, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30827717

RESUMEN

BACKGROUND: The short-term corrosion and micromechanical behavior of 32 unique head-neck taper design/material/assembly conditions was tested using an incremental cyclic fretting corrosion (ICFC) test method previously developed. METHODS: Seven materials, design, and simulated surgical parameters were evaluated, each being assigned 2 conditions for testing, using a 27-2 (7 factor, quarter factorial) design of experiments test matrix. The factors explored were (1) seating load, (2) head-neck offset, (3) material combination, (4) taper diameter, (5) taper roughness, (6) angular mismatch/engagement, and (7) taper length. Each sample underwent assembly, ICFC testing, pull off. RESULTS: Low seating load and high head offset correlated with increased fretting corrosion (P < .05). High head offset also contributed to a lower onset load for fretting current and higher micromotion (P < .05). Head subsidence measured over the ICFC test for samples seated at 100 N was significantly higher than samples seated at 4000 N. Micromotion for 12-mm head offsets was statistically higher than samples with a 1.5-mm head offset. A number of interactive effects were observed. For example, samples seated at 4000 N were less sensitive to head offset than samples seated at 100 N in terms of the resulting fretting current. CONCLUSION: Taper locking position, material combination, taper engagement length, taper roughness, and taper dimensions all had weak or no correlation with fretting current and taper micromotion. This test method and experimental design is a versatile means of assessing potential new taper designs in the future.


Asunto(s)
Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Cadera/instrumentación , Prótesis de Cadera/efectos adversos , Diseño de Prótesis , Falla de Prótesis , Corrosión , Técnicas In Vitro , Estrés Mecánico
11.
Diabetes Obes Metab ; 20(9): 2064-2074, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29707875

RESUMEN

Despite the availability of long-term data demonstrating the benefits of timely and aggressive intensification of antihyperglycaemic regimens among individuals with type 2 diabetes, intensification beyond basal insulin continues to be suboptimal and a global challenge. This review summarizes the evidence surrounding the various options of advancing glucose-lowering management beyond basal insulin and provides a practical algorithm to assist in optimizing patient care and enhancing glycaemic target achievements.


Asunto(s)
Algoritmos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/administración & dosificación , Insulina de Acción Prolongada/administración & dosificación , Glucemia/efectos de los fármacos , Diabetes Mellitus Tipo 2/sangre , Esquema de Medicación , Hemoglobina Glucada/efectos de los fármacos , Humanos
13.
J Pediatr Psychol ; 43(9): 1038-1046, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-29800347

RESUMEN

Objective: Dispositional mindfulness is the general tendency to pay attention to present-moment awareness without judgment. The main aim of this cross-sectional study was to determine (a) whether dispositional mindfulness is associated with psychological distress in adolescents with chronic pain and low-level pain, and (b) whether it accounts for unique variance in distress after controlling for key variables from the pain literature. A secondary aim was to explore the relationship between dispositional mindfulness and functioning. Method: 54 adolescents seeking help for chronic pain and 94 "healthy" adolescents with recent low-level pain from the general population completed the same battery of measures, including the Child and Adolescent Mindfulness Measure of dispositional mindfulness. Results: As predicted, dispositional mindfulness was associated with mood and anxiety in both groups and also accounted for unique variance in mood and anxiety in standard regression models after controlling for group, age, pain-intensity, pain-catastrophizing, and pain-acceptance. Dispositional mindfulness did not differ significantly across the two groups and did not predict physical functioning. However, it did account for unique variance in social functioning. Conclusions: Dispositional mindfulness may be an important construct to consider in the context of adolescents experiencing mood and anxiety problems in both low-level and chronic pain samples. Further research should aim to replicate these findings in larger clinical samples and explore the predictive power of dispositional mindfulness using longitudinal designs.


Asunto(s)
Afecto , Trastornos de Ansiedad/complicaciones , Trastornos de Ansiedad/psicología , Atención Plena/métodos , Dolor/complicaciones , Dolor/psicología , Adolescente , Dolor Crónico/complicaciones , Dolor Crónico/psicología , Estudios Transversales , Femenino , Humanos , Masculino , Índice de Severidad de la Enfermedad
14.
J Pediatr Psychol ; 43(9): 981-994, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-29788083

RESUMEN

Objective: Parental factors are central in the development and maintenance of chronic pain in youths. Only a handful of studies have investigated the impact of psychological treatments for pediatric chronic pain on parental factors, and the relationships between changes in parental and adolescent factors. In the current study, we evaluated the effects of an intensive interdisciplinary pain treatment (IIPT) program based on Acceptance and Commitment Therapy (ACT) for adolescents with chronic pain, on adolescent and parental variables, and the relationship between parental psychological flexibility and adolescent pain acceptance. Methods: Adolescents (N = 164) with chronic pain were included, with a mean age of 15.5 years, and completed the 3-week treatment with an accompanying parent (N = 164). Linear mixed-effects models were used to analyze change over time (from pretreatment to 3-month follow-up) on parent (depression, health-related quality of life and parent psychological flexibility) and adolescent (physical, social and emotional functioning, and adolescent pain acceptance) variables. Additionally, linear mixed-effects models were used to analyze the relationship between parent psychological flexibility and adolescent pain acceptance. Results: Results illustrated significant improvements over time in depressive symptoms and levels of psychological flexibility in parents. Excluding social development, adolescents improved significantly in all assessed aspects of functioning and pain acceptance. Additionally, changes in parent psychological flexibility were significantly associated with changes in adolescent pain acceptance. Conclusions: Results indicated that treatment had positive effects for parents and adolescents, and a significant positive relationship between changes in parent psychological flexibility and adolescent pain acceptance was found.


Asunto(s)
Terapia de Aceptación y Compromiso/métodos , Dolor Crónico/psicología , Dolor Crónico/terapia , Manejo del Dolor/métodos , Padres/psicología , Adolescente , Femenino , Humanos , Masculino , Resultado del Tratamiento
15.
J Arthroplasty ; 33(6): 1953-1961, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29486910

RESUMEN

BACKGROUND: Mechanically assisted crevice corrosion of modular tapers continues to be a concern in total joint arthroplasties. A surgical factor that may affect taper fretting corrosion during cyclic loading is seating load magnitude. In this study, modular head-neck taper junctions were seated, capturing load-displacement, over a range of axially oriented loads, and electrochemical and micromotion data were captured during short-term incremental cyclic fretting corrosion (ICFC) tests. The hypothesis is low seating loads result in greater motion and fretting corrosion in ICFC tests. The effect of assembly load on pull-off force post-ICFC testing was also evaluated. METHODS: The study employed custom-built test fixtures which measured head-neck micromotion and an electrochemical chamber to monitor electrochemical reactions. Head-neck motion measurements were captured using 2 noncontact differential variable reluctance transducers mounted to the head. Seating experiments ranged from 1000 to 8000 N. RESULTS: Significant differences due to seating loads were reported in seating displacement, ICFC subsidence, and fretting current at 4000 N cyclic load. Seating load decreased but did not eliminate currents. Fretting onset load remained fixed (approximately 1200 N) for tapers seated above 2000 N. Fretting subsidence was negligible for seating loads of 4000 N or higher, and increased subsidence was observed below 4000 N. CONCLUSION: This short-term test method evaluated the acute performance of modular implants which were assembled under various loads and demonstrated the link between seating loads, fretting motions, and electrochemical reactions. While increased seating loads reduced fretting corrosion and taper subsidence, it did not prevent fretting corrosion even at 8 kN seating.


Asunto(s)
Artroplastia de Reemplazo de Cadera/instrumentación , Corrosión , Prótesis de Cadera , Ensayo de Materiales , Aleaciones , Artroplastia de Reemplazo de Cadera/efectos adversos , Electroquímica , Humanos , Fenómenos Mecánicos , Movimiento , Diseño de Prótesis , Falla de Prótesis , Estrés Mecánico , Propiedades de Superficie
16.
BMC Health Serv Res ; 17(1): 166, 2017 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-28241758

RESUMEN

BACKGROUND: Developing new medicines relies on the successful conduct of clinical trials. As trial protocols become more arduous, it becomes harder to recruit and retain patient volunteers, although recent efforts such as OMERACT and I-SPY2 show that partnering with patients can be beneficial. We sought to describe drivers and barriers to trial participation, as well as condition-specific trial preferences. METHODS: An online survey was fielded via the patient-powered research network PatientsLikeMe to 1,621 members living with nine selected chronic health conditions. Questions included demographics, trial experience, reasons for non-participation, questions relating to aspects of trial design, and an adaptation of the Net Promoter Score (NPS) for trial satisfaction. RESULTS: Mean age of respondents was 55 years; most patients were white (93%), female (67%), and living in the United States (72%). Primary conditions were MS (21%), Parkinson's (20%), fibromyalgia (15%), ALS (10%), type 2 diabetes (10%), rheumatoid arthritis (RA, 8%), epilepsy (8%), major depressive disorder (MDD, 5%) and systemic lupus erythematosus (SLE, 3%). Most patients had not discussed a trial with their physician and only 21% had ever enrolled, with rates highest in ALS (36%), Parkinson's disease (36%) and MS (20%) and lowest among SLE (9%), MDD (11%) and Fibromyalgia (11%). Common reasons for non-participation were eligibility criteria, inconvenience of travel and concerns about side effects. NPS suggested that many patients were unsatisfied; patients with lupus, epilepsy, RA, and fibromyalgia reported negative scores, i.e. they would dissuade other patients like them from taking part in trials. The most important considerations in trial participation were the opportunity to improve one's own health and that of others, the reputation of the institution, and having medical bills covered in case of injury. Least important were remuneration and possibility of receiving a placebo. ALS patients were more willing to tolerate undesirable aspects of trials. CONCLUSIONS: Most patients are willing to enroll yet very few are invited. When they do, trial participation is often burdensome, but patients are willing to help improve their design. Researchers should let patients help design better trials to overcome recruitment and retention issues and hasten the development of new medicines.


Asunto(s)
Ensayos Clínicos como Asunto , Pacientes/psicología , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Persona de Mediana Edad , Selección de Paciente , Atención Dirigida al Paciente , Proyectos de Investigación , Encuestas y Cuestionarios , Estados Unidos
17.
J Arthroplasty ; 32(11): 3533-3538, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28712796

RESUMEN

BACKGROUND: Recent observations of specific metal damage patterns on retrieved total joint implants implied a cellular origin and was termed inflammatory cell-induced (ICI) corrosion. Although ICI corrosion continues to present a potential damage source for metallic biomaterials surfaces, an alternate source of some damage patterns may arise from electrosurgery instruments in total joint arthroplasty. METHODS: To characterize electrosurgically-induced damage patterns on metal implants, a model system of highly polished CoCrMo and Ti-6Al-4V disks and commercial electrosurgical generator was evaluated in various modes and power settings using monopolar and bipolar configurations. Surfaces were tested dry, wet with phosphate-buffered saline, or covered with known thicknesses of hydrated 5% agarose hydrogel. RESULTS: In all cases, surface damage was generated on both alloy surfaces, directly resulting from plasma discharge interacting with the metal. Direct surface contact caused pitting and oxide buildup at the contact area. Damage was produced through 3 mm thickness of hydrogel on the surface and across metal-metal junctions representing modular tapers. Damage patterns on wetted surfaces were highly consistent with damage patterns observed on retrieved total joint implants; circular, ruffled areas with centralized pits, occasionally presenting trail- and weld-like features. CONCLUSION: Surgeons using electrosurgical systems in proximity to metallic implants should exercise caution. Discharge of electrical energy through implants can induce localized surface damage and may result in other adverse outcomes. Although these results show some damage reported to be ICI corrosion is indeed the result of electrosurgery, there remains damage observed in retrievals not explained by this process.


Asunto(s)
Electrocirugia/efectos adversos , Prótesis Articulares , Aleaciones , Artroplastia , Materiales Biocompatibles , Corrosión , Humanos , Ensayo de Materiales , Ortopedia , Propiedades de Superficie , Titanio , Vitalio
19.
Clin Orthop Relat Res ; 474(11): 2414-2427, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27146655

RESUMEN

BACKGROUND: Fretting corrosion in medical alloys is a persistent problem, and the need for biomaterials that can effectively suppress mechanically assisted crevice corrosion in modular taper junctions or otherwise insulate metal-on-metal interfaces in mechanically demanding environments is as yet unmet. QUESTIONS/PURPOSES: The purpose of this study is to characterize a novel material, self-reinforced composite polyetheretherketone (SRC-PEEK) and to evaluate its ability to inhibit fretting corrosion in a pin-on-disk metal-on-metal interface test. METHODS: SRC-PEEK was fabricated by hot compaction of in-house-made PEEK fibers by compacting uniaxial layups at 344°C under a load of 18,000 N for 10 minutes. SRC-PEEK, bulk isotropic PEEK, and the in-house-made PEEK fibers were analyzed for thermal transitions (Tg, Tm) through differential scanning calorimetry, crystallinity, crystal size, crystalline orientation (Hermanns orientation parameter) through wide-angle x-ray scattering, and modulus, tensile strength, yield stress, and strain to failure through monotonic tensile testing. SRC-insulated pin-on-disk samples were compared with metal-on-metal control samples in pin-on-disk fretting corrosion experiments using fretting current and fretting mechanics measurements. Fifty-micron cyclic motion at 2.5 Hz was applied to the interface, first over a range of loads (0.5-35 N) while held at -0.05 V versus Ag/AgCl and then over a range of voltages (-0.5 to 0.5 V) at a constant contact stress of 73 ± 19 MPa for SRC-PEEK and 209 ± 41 MPa for metal-on-metal, which were different for each group as a result of changes in true contact area due to variations in modulus between sample groups. Pins, disks, and SRC samples were imaged for damage (on alloy and SRC surfaces) and evidence of corrosion (on alloy pin and disk surfaces). SRC specimens were analyzed for traces of alloy transferred to the surface using energy dispersive spectroscopy after pin-on-disk testing. RESULTS: SRC-PEEK showed improved mechanical properties to bulk PEEK (modulus = 5.0 ± 0.3 GPa, 2.8 ± 0.1 GPa, respectively, p < 0.001) and higher crystallinity to bulk PEEK (44.2% ± 3%, 39.5% ± 0.5%, respectively, p = 0.039), but had comparable crystalline orientation as compared with the initial PEEK fibers. SRC-PEEK reduced fretting currents compared with metal-on-metal controls by two to three orders of magnitude in both variable load (4.0E-5 ± 3.8E-5 µA versus 2.9E-3 ± 7.1E-4 µA, respectively, p = 0.018) and variable potential (7.5E-6 ± 4.7E-6 µA versus 5.3E-3 ± 1.4E-3 µA, respectively, p = 0.022) fretting corrosion testing. Minimal damage was observed on surfaces insulated with SRC-PEEK, whereas control surfaces showed considerable fretting corrosion damage and metal transfer. CONCLUSIONS: The SRC-PEEK gaskets in this study demonstrated higher crystallinity and crystalline orientation and improved monotonic tensile properties compared with bulk PEEK with the ability to effectively insulate Ti6Al4V and CoCrMo alloy surfaces and prevent the initiation of fretting corrosion under high contact-stress conditions. CLINICAL RELEVANCE: This novel SRC-PEEK material may offer potential as a thin film gasket material for modular tapers. Pending further in vitro and in vivo analyses, this approach may be able to preserve the advantages of modular junctions for surgeons while potentially limiting the downside risks associated with mechanically assisted crevice corrosion.


Asunto(s)
Artroplastia de Reemplazo/instrumentación , Prótesis Articulares , Cetonas/química , Polietilenglicoles/química , Artroplastia de Reemplazo/efectos adversos , Benzofenonas , Rastreo Diferencial de Calorimetría , Corrosión , Cristalización , Cristalografía , Módulo de Elasticidad , Análisis de Falla de Equipo , Calor , Luz , Ensayo de Materiales , Prótesis Articulares de Metal sobre Metal , Polímeros , Diseño de Prótesis , Dispersión de Radiación , Espectrometría por Rayos X , Estrés Mecánico , Propiedades de Superficie , Resistencia a la Tracción
20.
Clin Orthop Relat Res ; 474(4): 985-94, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26847452

RESUMEN

BACKGROUND: Metal release resulting from taper fretting and corrosion is a clinical concern, because wear and corrosion products may stimulate adverse local tissue reactions. Unimodular hip arthroplasties have a conical taper between the femoral head (head bore taper) and the femoral stem (stem cone taper). The use of ceramic heads has been suggested as a way of reducing the generation of wear and corrosion products from the head bore/stem cone taper junction. A previous semiquantitative study found that ceramic heads had less visual evidence of fretting-corrosion damage compared with CoCr heads; but, to our knowledge, no studies have quantified the volumetric material loss from the head bore and stem cone tapers of a matched cohort of ceramic and metal heads. QUESTIONS/PURPOSES: We asked: (1) Do ceramic heads result in less volume of material loss at the head-stem junction compared with CoCr heads; (2) do stem cone tapers have less volumetric material loss compared with CoCr head bore tapers; (3) do visual fretting-corrosion scores correlate with volumetric material loss; and (4) are device, patient, or intraoperative factors associated with volumetric material loss? METHODS: A quantitative method was developed to estimate volumetric material loss from the head and stem taper in previously matched cohorts of 50 ceramic and 50 CoCr head-stem pairs retrieved during revision surgery for causes not related to adverse reactions to metal particles. The cohorts were matched according to (1) implantation time, (2) stem flexural rigidity, and (3) lateral offset. Fretting corrosion was assessed visually using a previously published four-point, semiquantitative scoring system. The volumetric loss was measured using a precision roundness machine. Using 24 equally spaced axial traces, the volumetric loss was estimated using a linear least squares fit to interpolate the as-manufactured surfaces. The results of this analysis were considered in the context of device (taper angle clearance, head size, head offset, lateral offset, stem material, and stem surface finish) and patient factors that were obtained from the patients' operative records (implantation time, age at insertion, activity level, and BMI). RESULTS: The cumulative volumetric material losses estimated for the ceramic cohort had a median of 0.0 mm(3) per year (range, 0.0-0.4 mm(3)). The cumulative volumetric material losses estimated for the CoCr cohort had a median of 0.1 mm(3) per year (range, 0.0-8.8 mm(3)). An order of magnitude reduction in volumetric material loss was found when a ceramic head was used instead of a CoCr head (p < 0.0001). In the CoCr cohort, the femoral head bore tapers had a median material loss of 0.02 mm(3) (range, 0.0-8.7 mm(3)) and the stem cone tapers had a median material loss of 0.0 mm(3) (range, 0.0-0.32 mm(3)/year). There was greater material loss from femoral head bore tapers compared with stem cone tapers in the CoCr cohort (p < 0.001). There was a positive correlation between visual scoring and volumetric material loss (Spearman's ρ = 0.67, p < 0.01). Although visual scoring was effective for preliminary screening to separate tapers with no or mild damage from tapers with moderate to severe damage, it was not capable of discriminating in the large range of material loss observed at the taper surfaces with moderate to severe fretting-corrosion damage, indicated with a score of 3 or 4. We observed no correlations between volumetric material loss and device and patient factors. CONCLUSIONS: The majority of estimated material loss from the head bore-stem cone junctions resulting from taper fretting and corrosion was from the CoCr head bore tapers as opposed to the stem cone tapers. Additionally, the total material loss from the ceramic cohort showed a reduction in the amount of metal released by an order of magnitude compared with the CoCr cohort. CLINICAL RELEVANCE: We found that ceramic femoral heads may be an effective means by which to reduce metal release caused by taper fretting and corrosion at the head bore-stem cone modular interface in THAs.


Asunto(s)
Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Cadera/instrumentación , Cerámica , Aleaciones de Cromo , Cabeza Femoral/cirugía , Articulación de la Cadera/cirugía , Prótesis de Cadera , Adulto , Anciano , Corrosión , Femenino , Humanos , Análisis de los Mínimos Cuadrados , Modelos Lineales , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Factores de Riesgo , Estrés Mecánico , Propiedades de Superficie , Factores de Tiempo , Resultado del Tratamiento
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