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1.
Orthopadie (Heidelb) ; 53(1): 1-10, 2024 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-37978051

RESUMEN

BACKGROUND: In this article, an overview and comparison of the most commonly used cemented hip stems, grouped into different stem types and cement mantle thickness, is given to see which combination performs well. METHODOLOGY: Revision rates of cemented stem types were categorized from the Endoprosthesis Register-Germany, and 3­ and 5­year revision rates were reported and analyzed. For the research, the focus was on the Exeter, C­Stem, MS-30, Excia, Bicontact, Charnley, Müller straight stem, Twinsys, Corail, Avenir, Quadra, and the Lubinus SP II stems. An important aspect was which stem is preferred to be implanted and which cementing technique is used with regard to the planned cement mantle thickness. In order to identify a trend in cemented hip arthroplasty, data from the Danish, Swedish, Norwegian, Swiss, New Zealand, English and Australian arthroplasty registers were also compared. RESULTS AND CONCLUSION: Most countries use cemented prostheses according to the taper slip principle (Exeter, MS30, C­Stem etc) or the composite beam (Charnley, Excia, Bicontact), which are implanted with a cement mantle thickness of 2-4 mm. However, a trend has emerged in Germany and Switzerland towards the line-to-line technique, with a planned cement mantle thickness of 1 mm (Twinsys, Corail, Avenir, Quadra), following the principle of the Müller straight stem prosthesis and the Kerboul-Charnley prosthesis, even though these are postulated to be "French paradoxes" in themselves. In the EPRD 5­year results, the newer line-to-line prostheses seem to perform slightly worse. The best results are achieved by the "MS 30" in Germany and the "Exeter" in England. These are polished straight stems with centralizer and subsidence space at the apex with a 2-4 mm cement mantle in good cementing technique.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Humanos , Artroplastia de Reemplazo de Cadera/métodos , Falla de Prótesis , Diseño de Prótesis , Australia , Cementos para Huesos/uso terapéutico
2.
Psychopharmacology (Berl) ; 240(9): 2005-2012, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37580441

RESUMEN

RATIONALE: Rodent vendors are often utilized interchangeably, assuming that the phenotype of a given strain remains standardized between colonies. Several studies, however, have found significant behavioral and physiological differences between Sprague Dawley (SD) rats from separate vendors. Prepulse inhibition of startle (PPI), a form of sensorimotor gating in which a low-intensity leading stimulus reduces the startle response to a subsequent stimulus, may also vary by vendor. Differences in PPI between rat strains are well known, but divergence between colonies within the SD strain lacks thorough examination. OBJECTIVES: We explored intrastrain variation in PPI by testing SD rats from two vendors: Envigo and Charles River (CR). METHODS: We selected drugs acting on four major neurotransmitter systems that have been repeatedly shown to modulate PPI: dopamine (apomorphine; 0.5, 1.5, 3.0 mg/kg), acetylcholine (scopolamine; 0.1, 0.5, 1.0 mg/kg), glutamate (dizocilpine; 0.5, 1.5, 2.5 mg/kg), and serotonin (2,5-Dimethoxy-4-iodoamphetamine, DOI; 0.25, 0.5, 1.0 mg/kg). We determined PPI and startle amplitude for each drug in male and female Envigo and CR SD rats. RESULTS: SD rats from Envigo showed dose-dependent decreases in PPI after apomorphine, scopolamine, or dizocilpine administration, without significant effects on startle amplitude. SD rats from CR were less sensitive to modulation of PPI and/or more sensitive to modulation of startle amplitude, across the three drugs. CONCLUSIONS: SD rats showed vendor differences in sensitivity to pharmacological modulation of PPI and startle. We encourage researchers to sample rats from separate vendors before experimentation to identify the most suited source of subjects for their specific endpoints.


Asunto(s)
Dopamina , Inhibición Prepulso , Ratas , Masculino , Femenino , Animales , Dopamina/farmacología , Ratas Sprague-Dawley , Apomorfina/farmacología , Agonistas de Dopamina/farmacología , Acetilcolina , Preparaciones Farmacéuticas , Ácido Glutámico , Maleato de Dizocilpina/farmacología , Reflejo de Sobresalto , Estimulación Acústica , Derivados de Escopolamina/farmacología
3.
Clin Transl Radiat Oncol ; 28: 118-123, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33937532

RESUMEN

PURPOSE: Quality assessment of the treatment plans in the Danish Breast Cancer Group (DBCG) HYPO trial was carried out based on prospectively reported dosimetric parameters and evidence-based dose constraints for whole breast radiation therapy were derived. MATERIALS AND METHODS: From 2009 to 2014, 1882 patients (pts) were randomised between 50 Gy/25fractions (fr) versus 40 Gy/15fr. Doses to CTVp_breast (V95%, V107%-V110%, Dmax, and in addition for 40 Gy plans V105%-V107%), ipsilateral lung (V20Gy/V17Gy), heart (V20Gy/V17Gy, V40Gy/V35Gy), and left anterior descending coronary artery (LADCA) (Dmax) and use of respiratory gated technique were prospectively reported to the DBCG database. After end of accrual, these dosimetric parameters from all plans in the trial were compared to the pre-specified treatment constraints. RESULTS: In total, 1854 pts from eight radiation therapy (RT) centres in three countries were treated. No statistically significant differences were found between the results for 40 Gy and 50 Gy plans, except for CTVp_breast hot-spot volume (V107%-V110%). Of the 40 Gy pts, 90% with CTVp_breast > 600 mL and 95% with CTVp_breast ≤ 600 mL had a CTVp_breast hot-spot volume (V105%-V107%) <2%. In 95% of the 50 Gy plans, the CTVp_breast absolute hot-spot volume (V107%-V110%) was <0.5 mL and 1.7 mL for CTVp_breast ≤ 600 mL and > 600 mL, respectively. Compliance was >99% for both heart and lung constraints. Largest deviation from protocol constraints was found for the volume of CTVp_breast covered with 95% of the prescription dose or more (V95%). The CTV dose coverage (V95%) was >94.3% in 95% of the right-sided pts, whereas the figures for 95% of the left-sided pts treated with and without respiratory gating were 93.2% and 88.8%, respectively. CONCLUSION: A high degree of compliance with protocol dose constraints was found for treatment plans in the DBCG HYPO trial. New constraints for dose to organs at risk and high-dose volumes in the breast are suggested for breast-only RT planning.

4.
Pharmazie ; 74(10): 595-597, 2019 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-31685083

RESUMEN

Background: Adverse events case reports are important for signal generation in pharmacovigilance. They require a thorough collation of the facts, otherwise they may lead to erroneous conclusions which may conceal other treatment-related causes of the observation. Methods: We describe a case report from the literature that arrives at an erroneous conclusion merely from taking insufficient care when collating and interpreting the facts: The authors of the case report confused blackcurrant (Ribes nigrum) with St. John's wort preparation (Hypericum perforatum) and erroneously assumed that the intake of a herbal preparation was responsible for a drop in serum levels of everolimus. Results: The clinical observations in this case report may actually reflect a potentially lethal situation emerging from the prescribed medication everolimus. St. John's wort preparations rich in hyperforin do in fact reproducibly lead to the decrease of blood levels of medications metabolized through cytochrome P450 subtype 3A4. However, a case report requires more care than just ascribing the blame to something seemingly well-known. Conclusion: The readers of this report might have profited more from the description of the risks of treating graft-versus-host disease with everolimus, and the action to be taken in case of potentially severe adverse reactions to everolimus.


Asunto(s)
Interacciones Farmacológicas , Hypericum , Extractos Vegetales/efectos adversos , Ribes , Citocromo P-450 CYP3A , Humanos , Masculino , Odorantes
6.
Geophys Res Lett ; 46(1): 19-27, 2019 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-30828110

RESUMEN

We compare electron and UV observations mapping to the same location in Jupiter's northern polar region, poleward of the main aurora, during Juno perijove 5. Simultaneous peaks in UV brightness and electron energy flux are identified when observations map to the same location at the same time. The downward energy flux during these simultaneous observations was not sufficient to generate the observed UV brightness; the upward energy flux was. We propose that the primary acceleration region is below Juno's altitude, from which the more intense upward electrons originate. For the complete interval, the UV brightness peaked at ~240 kilorayleigh (kR); the downward and upward energy fluxes peaked at 60 and 700 mW/m2, respectively. Increased downward energy fluxes are associated with increased contributions from tens of keV electrons. These observations provide evidence that bidirectional electron beams with broad energy distributions can produce tens to hundreds of kilorayleigh polar UV emissions.

7.
Musculoskelet Sci Pract ; 41: 64-69, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30639245

RESUMEN

This study had the objective of measuring the validity of using a smartphone-based application to measure range of motion (ROM) and quality of movement (QOM) of neck motion by comparing it with 3D-motion capture analysis. METHODS: Thirty healthy volunteers participated in this cross-sectional study. A helmet fitted with markers for motion capture analysis and a smartphone were fastened to the head of the participants. The smartphone recorded data using a beta version of Balancy (MEDEI, Denmark). Assessments of full active movement in transverse and sagittal planes were performed. Recordings were made simultaneously with the camera system and the smartphone. ROM and jerkiness were compared with a repeated measures ANOVA and a Pearson product moment was calculated to compare the outcomes from the different applications. Bland-Altman plots were generated to determine the levels of agreement. RESULTS: No difference was found between modalities when comparing measurements of jerkiness or ROM. An excellent Pearson product moment was found for the outcomes of the two modalities for ROM (Pearson's r: 0.83 - 0.96) and jerkiness (Pearson's r: 0.86 - 0.95). The Bland-Altman plot revealed a systemic offset where the phone consistently measured higher values for ROM and lower values for jerkiness. CONCLUSIONS: This study demonstrated that a smartphone-based application can be used to accurately measure ROM and jerkiness during neck movements. These results indicate the utility of using a smartphone-based application to assess neck movement in humans. The findings have implications for assessment of neck movement in research and clinical practice.


Asunto(s)
Imagenología Tridimensional , Aplicaciones Móviles , Músculos del Cuello/fisiología , Rango del Movimiento Articular/fisiología , Teléfono Inteligente , Adulto , Estudios Transversales , Femenino , Voluntarios Sanos , Humanos , Masculino , Reproducibilidad de los Resultados , Adulto Joven
8.
Equine Vet J ; 51(2): 261-265, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30071153

RESUMEN

BACKGROUND: Studies have shown proximal diffusion of injected drugs in perineural blocks; such diffusion may affect specificity of the nerve block. OBJECTIVES: To investigate the effect of a compression bandage applied to the pastern region on proximal diffusion of contrast medium injected over the palmar digital nerves. STUDY DESIGN: Experimental study, randomised cross-over design. METHODS: Radiodense contrast medium was injected over the lateral and medial palmar digital nerves of the left front limb of nine mature horses. Each horse was injected on two separate occasions, once with a 5 cm wide compression bandage applied proximal to the injection site and once without. The order of the two treatments was randomised with a wash-out period between treatments of at least 7 days. Radiographs were obtained at 5, 10, 20 and 30 min and distribution of the contrast column assessed. RESULTS: Proximal distribution of the contrast medium was significantly reduced (P<0.01) with compression bandage. Furthermore, the compression bandage inhibited lymphatic drainage of the injected contrast medium. MAIN LIMITATIONS: Clinical effect of the differences in diffusion length was not assessed. CONCLUSIONS: The compression bandage reduced proximal diffusion and lymphatic drainage of contrast material causing it to stay localised around the injection site. Use of compression bandages could thus result in increased specificity of the nerve block and potentially prolong its effect.


Asunto(s)
Vendajes de Compresión/veterinaria , Medios de Contraste/farmacocinética , Caballos , Yopamidol/análogos & derivados , Bloqueo Nervioso/veterinaria , Animales , Estudios Cruzados , Femenino , Miembro Anterior/inervación , Inyecciones/veterinaria , Yopamidol/farmacocinética , Distribución Aleatoria
9.
Benef Microbes ; 9(6): 899-916, 2018 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-30232908

RESUMEN

Chemotherapy and radiotherapy treatment regimens for gastrointestinal, peritoneal and pelvic tumours can disrupt the intestinal microbiome and intestinal epithelia. Such disturbances can provoke symptoms such as diarrhoea, nausea and vomiting. Chemotherapy and radiotherapy induced gastrointestinal toxicity aggravating intestinal microbiome dysbiosis is postulated to adversely alter the intestinal microbiome, with a consequent induced pro-inflammatory effect that disrupts the intestinal microbiome-epithelia-mucosal immunity axis. Although not widely recognised, the intestinal mucosa is the largest and most densely and dynamically populated immune-environment. Cancer treatment adverse effects that affect intestinal and mucosal cells inadvertently target and disrupt resident intestinal macrophages, the cells that marshal immune activity in the intestinal mucosa by shaping pro-inflammatory and anti-inflammatory activities to control and eradicate infectious insults and maintain local homeostasis. Pathobionts (bacteria capable of pathogenic pro-inflammatory activity) and noxious environmental and bacterial antigens use the intestinal epithelia and gap junctions as a point of entry into the systemic circulation. This translocation movement promotes toxic sequelae that obstruct intestinal macrophage functions resulting in uncontrolled local and systemic pro-inflammatory activity, loss of phagocytic function and loss of expression of tight junction proteins. Probiotic bacteria as an adjunctive treatment shows efficacy in ameliorating enteropathies such as mucositis/diarrhoea resulting from chemotherapy or radiotherapy regimens. As such we posit that an important benefit that warrants a further focused research effort is the administration of adjuvant probiotics to help reduce the incidence of febrile neutropenia.


Asunto(s)
Antineoplásicos/efectos adversos , Traslocación Bacteriana , Disbiosis/prevención & control , Probióticos/administración & dosificación , Radioterapia/efectos adversos , Antineoplásicos/administración & dosificación , Disbiosis/complicaciones , Neoplasias Gastrointestinales/complicaciones , Neoplasias Gastrointestinales/tratamiento farmacológico , Neoplasias Gastrointestinales/radioterapia , Humanos , Incidencia , Neoplasias Pélvicas/complicaciones , Neoplasias Pélvicas/tratamiento farmacológico , Neoplasias Pélvicas/radioterapia , Neoplasias Peritoneales/complicaciones , Neoplasias Peritoneales/tratamiento farmacológico , Neoplasias Peritoneales/radioterapia , Resultado del Tratamiento
10.
BMC Clin Pathol ; 18: 7, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30158837

RESUMEN

BACKGROUND: The identification of implant wear particles and non-implant related particles and the characterization of the inflammatory responses in the periprosthetic neo-synovial membrane, bone, and the synovial-like interface membrane (SLIM) play an important role for the evaluation of clinical outcome, correlation with radiological and implant retrieval studies, and understanding of the biological pathways contributing to implant failures in joint arthroplasty. The purpose of this study is to present a comprehensive histological particle algorithm (HPA) as a practical guide to particle identification at routine light microscopy examination. METHODS: The cases used for particle analysis were selected retrospectively from the archives of two institutions and were representative of the implant wear and non-implant related particle spectrum. All particle categories were described according to their size, shape, colour and properties observed at light microscopy, under polarized light, and after histochemical stains when necessary. A unified range of particle size, defined as a measure of length only, is proposed for the wear particles with five classes for polyethylene (PE) particles and four classes for conventional and corrosion metallic particles and ceramic particles. RESULTS: All implant wear and non-implant related particles were described and illustrated in detail by category. A particle scoring system for the periprosthetic tissue/SLIM is proposed as follows: 1) Wear particle identification at light microscopy with a two-step analysis at low (× 25, × 40, and × 100) and high magnification (× 200 and × 400); 2) Identification of the predominant wear particle type with size determination; 3) The presence of non-implant related endogenous and/or foreign particles. A guide for a comprehensive pathology report is also provided with sections for macroscopic and microscopic description, and diagnosis. CONCLUSIONS: The HPA should be considered a standard for the histological analysis of periprosthetic neo-synovial membrane, bone, and SLIM. It provides a basic, standardized tool for the identification of implant wear and non-implant related particles at routine light microscopy examination and aims at reducing intra-observer and inter-observer variability to provide a common platform for multicentric implant retrieval/radiological/histological studies and valuable data for the risk assessment of implant performance for regional and national implant registries and government agencies.

11.
Radiography (Lond) ; 24(2): e37-e43, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29605123

RESUMEN

INTRODUCTION: Producing x-ray images for radiostereometric analysis (RSA) is a demanding technique. Suboptimal examinations result in a high percentage of exposure repetition. The aim of this pilot study was to use an experiential training approach to sharpen the skills of radiographers in acquiring images of an optimal quality. METHODS: A controlled trial using action research strategy was used. The study entailed a two phased approach. Radiographers were purposefully recruited and trained to perform the required investigations. Each phase included 12 examinations of a total knee arthroplasty phantom followed by 10 patient examinations. The quality of all x-ray images performed during the two phases was characterized by measuring the number of visible beads, the center position of the prosthesis (CP) compared to the center of calibration field (CCF). The number of re-exposures used to obtain a usable image during patient examinations was also recorded. RESULTS: The radiographers undergoing the training resulted in a significant improvement in the quality of images produced and visualization of the beads. That is, the ability to move the CP on average 36.1 mm closer to the CCF (p < 0.001), the number of visible beads increased by 3.1 (p < 0.001) and radiographers needed 2.1-2.9 exposures less to obtain RSA images of sufficient qualities during patient examinations in phase 2 (p < 0.001). CONCLUSION: This study illustrates the value of experiential method of teaching and learning with minimal compromise on patient safety but a significant contribution in terms of establishing quality of RSA images.


Asunto(s)
Técnicos Medios en Salud/educación , Artroplastia de Reemplazo de Rodilla , Competencia Clínica , Análisis Radioestereométrico/normas , Tecnología Radiológica/educación , Calibración , Investigación sobre Servicios de Salud , Humanos , Fantasmas de Imagen , Proyectos Piloto , Dosis de Radiación
12.
Radiography (Lond) ; 24(2): e31-e36, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29605122

RESUMEN

INTRODUCTION: Increasing pressure in the clinic requires a more standardized approach to radiostereometric analysis (RSA) imaging. The aim of this study was to investigate whether implementation of personalized RSA patient protocols could increase image quality and decrease examination time and the number of exposure repetitions. METHODS: Forty patients undergoing primary total hip arthroplasty were equally randomized to either a case or a control group. Radiographers in the case group were assisted by personalized patient protocols containing information about each patient's post-operative RSA imaging. Radiographers in the control group used a standard RSA protocol. RESULTS: At three months, radiographers in the case group significantly reduced (p < 0.001) the number of exposures by 1.6, examination time with 19.2 min, and distance between centrum of prosthesis and centrum of calibration field with 34.1 mm when compared to post-operative (baseline) results. At twelve months, the case group significantly reduced (p < 0.001) number of exposures by two, examination time with 22.5 min, and centrum of prosthesis to centrum of calibration field distance with 43.1 mm when compared to baseline results. No significant improvements were found in the control group at any time point. CONCLUSION: There is strong evidence that personalized RSA patient protocols have a positive effect on image quality and radiation dose savings. Implementation of personal patient protocols as a RSA standard will contribute to the reduction of examination time, thus ensuring a cost benefit for department and patient safety.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Protocolos Clínicos , Análisis Radioestereométrico/normas , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación
13.
Equine Vet J ; 50(6): 818-824, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29658147

RESUMEN

BACKGROUND: The main criteria for lameness assessment in horses are head movement for forelimb lameness and pelvic movement for hindlimb lameness. However, compensatory head nod in horses with primary hindlimb lameness is a well-known phenomenon. This compensatory head nod movement can be easily misinterpreted as a sign of primary ipsilateral forelimb lameness. Therefore, discriminating compensatory asymmetries from primary directly pain-related movement asymmetries is a prerequisite for successful lameness assessment. OBJECTIVES: To investigate the association between head, withers and pelvis movement asymmetry in horses with induced forelimb and hindlimb lameness. STUDY DESIGN: Experimental study. METHODS: In 10 clinically sound Warmblood riding horses, forelimb and hindlimb lameness were induced using a sole pressure model. The horses were then trotted on a treadmill. Three-dimensional optical motion capture was used to collect kinematic data from reflective markers attached to the poll, withers and tubera sacrale. The magnitude and side (left or right) of the following symmetry parameters, vertical difference in minimum position, maximum position and range-up were calculated for head, withers, and pelvis. Mixed models were used to analyse data from induced forelimb and hindlimb lameness. RESULTS: For each mm increase in pelvic asymmetry in response to hindlimb lameness induction, withers movement asymmetry increased by 0.35-0.55 mm, but towards the contralateral side. In induced forelimb lameness, for each mm increase in head movement asymmetry, withers movement asymmetry increased by 0.05-0.10 mm, in agreement with the head movement asymmetry direction, both indicating lameness in the induced forelimb. MAIN LIMITATIONS: Results must be confirmed in clinically lame horses trotting overground. CONCLUSIONS: The vertical asymmetry pattern of the withers discriminated a head nod associated with true forelimb lameness from the compensatory head movement asymmetry caused by primary hindlimb lameness. Measuring movement symmetry of the withers may, thus, aid in determining primary lameness location.


Asunto(s)
Miembro Anterior/fisiopatología , Marcha/fisiología , Miembro Posterior/fisiopatología , Enfermedades de los Caballos/fisiopatología , Cojera Animal/fisiopatología , Animales , Fenómenos Biomecánicos , Cabeza/fisiopatología , Caballos , Masculino , Deportes
14.
Radiography (Lond) ; 23(4): e80-e86, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28965908

RESUMEN

INTRODUCTION: The purpose of this study was to design and evaluate a radiostereometric analysis (RSA) program aimed at radiographers in order to increase their cognitive and practical skills, thereby increasing image quality and minimizing exposure repetition. METHODS AND MATERIALS: Twenty radiographers were randomized into two identically sized study groups. Training consisted of a theoretical and practical workshop using a phantom. Tests were performed to compare the effect of training to nontraining, and the effect of time duration on the maintenance of RSA skills. The effect of training was measured by a written test and three defined parameters influencing image quality. RESULTS: Group A reduced significantly (p < 0.001) by 31.3 mm (21-31%) the distance between the centrum of the prosthesis (CP) and the centrum of the calibration field (CCF) and increased the number of beads (NB) visible by 3.6 (out of 18). A further significant reduction of 5.1 mm (p = 0.023), 1.0 bead more (p < 0.001) and a 2.1 (p = 0.022) point better rotation of the prosthesis (RP) was registered two months later. Group B was tested twice without training and no significant improvement was registered. One month after training group B had experienced overall significant improvement on a par with group A. CONCLUSION: It is realistic to implement an RSA X-ray training program where radiographers significantly improve their theoretical and practical skills in centering the CP closer to the CCF, NB and RP. A duration of up to two months after training does not influence the quality of participants' performance.


Asunto(s)
Competencia Clínica , Radiología/educación , Análisis Radioestereométrico/normas , Curriculum , Evaluación Educacional , Humanos , Articulación de la Rodilla/diagnóstico por imagen , Prótesis de la Rodilla , Fantasmas de Imagen
16.
Unfallchirurg ; 120(2): 116-121, 2017 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-28108751

RESUMEN

Metal implants for osteosynthesis are nowadays standard in orthopedic and trauma surgery. Steel implants, especially cerclages, bands and wires, can show more corrosion due to friction and lead to encapsulation in connective tissue with fluid borders even without loosening. Corrosion and fluid borders are potentially more susceptible to incompatibility and infections. Titanium implants have the advantage of better allergic compatibility. Problems may occur in material removal, especially with titanium implants because material fractures occur more frequently. Particularly with fixed angle constructions, the blocking of titanium-titanium bonding and/or screws in bone can occur by adhesion and ingrowth. Apart from single case reports there is no evidence that modern steel implants cause more allergic reactions than titanium; therefore, in the treatment by osteosynthesis the stability, risk of loosening, manifestation of allergies and the possibility of material removal must always be considered.


Asunto(s)
Dermatitis por Contacto/epidemiología , Fijación Interna de Fracturas/instrumentación , Fijación Interna de Fracturas/estadística & datos numéricos , Fracturas Óseas/epidemiología , Fracturas Óseas/terapia , Acero , Titanio , Materiales Biocompatibles/química , Comorbilidad , Dermatitis por Contacto/prevención & control , Medicina Basada en la Evidencia , Humanos , Prevalencia , Diseño de Prótesis , Falla de Prótesis , Factores de Riesgo , Resultado del Tratamiento
17.
Acta Physiol (Oxf) ; 219(3): 660-668, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27459728

RESUMEN

AIM: In this study, we investigate the impact of altered action potential durations (APD) on ventricular repolarization time and proarrhythmia in mice with and without genetic deletion of the K+ -channel-interacting protein 2 (KChIP2-/- and WT respectively). Moreover, we examine the interrelationship between the dispersion of repolarization time and current pulse amplitude in provoking ventricular arrhythmia. METHODS: Intracardiac pacing in anesthetized mice determined refractory periods and proarrhythmia susceptibility. Regional activation time (AT), APD and repolarization time (=AT + APD) were measured in isolated hearts using floating microelectrodes. RESULTS: Proarrhythmia in WT and KChIP2-/- was not sensitive to changes in refractory periods. Action potentials were longer in KChIP2-/- hearts compared to WT hearts. Isolated WT hearts had large apico-basal dispersion of repolarization time, whereas hearts from KChIP2-/- mice had large left-to-right ventricular dispersion of repolarization time. Pacing from the right ventricle in KChIP2-/- mice in vivo revealed significant lower current pulse amplitudes needed to induce arrhythmias in these mice. CONCLUSION: Large heterogeneity of repolarization time is proarrhythmic when pacing is delivered from the location of earlier repolarization time. Ventricular repolarization time, location of the pacing stimulus and the amplitude of the stimulating current pulse are critical parameters underlying arrhythmia vulnerability.


Asunto(s)
Potenciales de Acción/fisiología , Arritmias Cardíacas/fisiopatología , Ventrículos Cardíacos/fisiopatología , Animales , Arritmias Cardíacas/metabolismo , Modelos Animales de Enfermedad , Electrofisiología , Proteínas de Interacción con los Canales Kv/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados
18.
J Geophys Res Space Phys ; 121(4): 2984-3005, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27867795

RESUMEN

Reconnection within planetary magnetotails is responsible for locally energizing particles and changing the magnetic topology. Its role in terms of global magnetospheric dynamics can involve changing the mass and flux content of the magnetosphere. We have identified reconnection related events in spacecraft magnetometer data recorded during Cassini's exploration of Saturn's magnetotail. The events are identified from deflections in the north-south component of the magnetic field, significant above a background level. Data were selected to provide full tail coverage, encompassing the dawn and dusk flanks as well as the deepest midnight orbits. Overall 2094 reconnection related events were identified, with an average rate of 5.0 events per day. The majority of events occur in clusters (within 3 h of other events). We examine changes in this rate in terms of local time and latitude coverage, taking seasonal effects into account. The observed reconnection rate peaks postmidnight with more infrequent but steady loss seen on the dusk flank. We estimate the mass loss from the event catalog and find it to be insufficient to balance the input from the moon Enceladus. Several reasons for this discrepancy are discussed. The reconnection X line location appears to be highly variable, though a statistical separation between events tailward and planetward of the X line is observed at a radial distance of between 20 and 30RS downtail. The small sample size at dawn prevents comprehensive statistical comparison with the dusk flank observations in terms of flux closure.

19.
Sci Rep ; 6: 30698, 2016 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-27485575

RESUMEN

Human-secreted Ly-6/uPAR-related protein-2 (SLURP-2) regulates the growth and differentiation of epithelial cells. Previously, the auto/paracrine activity of SLURP-2 was considered to be mediated via its interaction with the α3ß2 subtype of the nicotinic acetylcholine receptors (nAChRs). Here, we describe the structure and pharmacology of a recombinant analogue of SLURP-2. Nuclear magnetic resonance spectroscopy revealed a 'three-finger' fold of SLURP-2 with a conserved ß-structural core and three protruding loops. Affinity purification using cortical extracts revealed that SLURP-2 could interact with the α3, α4, α5, α7, ß2, and ß4 nAChR subunits, revealing its broader pharmacological profile. SLURP-2 inhibits acetylcholine-evoked currents at α4ß2 and α3ß2-nAChRs (IC50 ~0.17 and >3 µM, respectively) expressed in Xenopus oocytes. In contrast, at α7-nAChRs, SLURP-2 significantly enhances acetylcholine-evoked currents at concentrations <1 µM but induces inhibition at higher concentrations. SLURP-2 allosterically interacts with human M1 and M3 muscarinic acetylcholine receptors (mAChRs) that are overexpressed in CHO cells. SLURP-2 was found to promote the proliferation of human oral keratinocytes via interactions with α3ß2-nAChRs, while it inhibited cell growth via α7-nAChRs. SLURP-2/mAChRs interactions are also probably involved in the control of keratinocyte growth. Computer modeling revealed possible SLURP-2 binding to the 'classical' orthosteric agonist/antagonist binding sites at α7 and α3ß2-nAChRs.


Asunto(s)
Potenciales Evocados/fisiología , Proteínas Ligadas a GPI/metabolismo , Queratinocitos/metabolismo , Receptores Muscarínicos/metabolismo , Receptores Nicotínicos/metabolismo , Receptor Nicotínico de Acetilcolina alfa 7/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Adulto , Animales , Sitios de Unión/fisiología , Células CHO , Línea Celular , Proliferación Celular/fisiología , Simulación por Computador , Cricetulus , Epilepsia del Lóbulo Temporal/patología , Femenino , Humanos , Persona de Mediana Edad , Resonancia Magnética Nuclear Biomolecular , Oocitos/metabolismo , Células PC12 , Unión Proteica/fisiología , Ratas , Xenopus
20.
Hautarzt ; 67(5): 347-51, 2016 May.
Artículo en Alemán | MEDLINE | ID: mdl-27116434

RESUMEN

Based on several clinical examples, the range of adverse or hypersensitive reactions to metal implants especially after total knee replacement are presented. In general, we found the patients to generally be women who present with pain, swelling, and local or generalized eczema. Some also present with early aseptic loosening mainly in the first 4 years after implantation. For these patients, a detailed allergy-specific history should be taken and a patch test should be performed; if necessary, blood ion levels should be evaluated to exclude cobaltism. Before revision surgery and exchange of the implant we always perform arthroscopic inspection to obtain biopsies for microbiology and histopathology. Using the Consensus Classification a good evaluation for planning revision with the different implant options is possible.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/efectos adversos , Hipersensibilidad/diagnóstico , Hipersensibilidad/etiología , Prótesis de la Rodilla/efectos adversos , Metales/efectos adversos , Pruebas del Parche/métodos , Artroplastia de Reemplazo de Rodilla/instrumentación , Medicina Basada en la Evidencia , Humanos , Hipersensibilidad/prevención & control , Reoperación
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