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1.
Entropy (Basel) ; 26(3)2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38539746

RESUMEN

Studies of collective motion have heretofore been dominated by a thermodynamic perspective in which the emergent "flocked" phases are analyzed in terms of their time-averaged orientational and spatial properties. Studies that attempt to scrutinize the dynamical processes that spontaneously drive the formation of these flocks from initially random configurations are far more rare, perhaps owing to the fact that said processes occur far from the eventual long-time steady state of the system and thus lie outside the scope of traditional statistical mechanics. For systems whose dynamics are simulated numerically, the nonstationary distribution of system configurations can be sampled at different time points, and the time evolution of the average structural properties of the system can be quantified. In this paper, we employ this strategy to characterize the spatial dynamics of the standard Vicsek flocking model using two correlation functions common to condensed matter physics. We demonstrate, for modest system sizes with 800 to 2000 agents, that the self-assembly dynamics can be characterized by three distinct and disparate time scales that we associate with the corresponding physical processes of clustering (compaction), relaxing (expansion), and mixing (rearrangement). We further show that the behavior of these correlation functions can be used to reliably distinguish between phenomenologically similar models with different underlying interactions and, in some cases, even provide a direct measurement of key model parameters.

2.
Am J Physiol Lung Cell Mol Physiol ; 325(6): L788-L802, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37873566

RESUMEN

Ion channels play critical roles in the physiology and function of the nervous system and contractile tissue; however, their role in noncontractile tissue and embryonic development has yet to be understood. Tracheobronchomalacia (TBM) and complete tracheal rings (CTR) are disorders affecting the muscle and cartilage of the trachea and bronchi, whose etiology remains poorly understood. We demonstrated that trachealis muscle organization and polarity are disrupted after epithelial ablation of Wntless (Wls), a cargo receptor critical for the Wnt signaling pathway, in developing trachea. The phenotype resembles the anomalous trachealis muscle observed after deletion of ion channel encoding genes in developing mouse trachea. We sought to investigate whether and how the deletion of Wls affects ion channels during tracheal development. We hypothesize that Wnt signaling influences the expression of ion channels to promote trachealis muscle cell assembly and patterning. Deleting Wls in developing trachea causes differential regulation of genes mediating actin binding, cytoskeleton organization, and potassium ion channel activity. Wnt signaling regulates the expression of Kcnj13, Kcnd3, Kcnj8, and Abcc9 as demonstrated by in vitro studies and in vivo analysis in Wnt5a and ß-catenin-deficient tracheas. Pharmacological inhibition of potassium ion channels and Wnt signaling impaired contractility of developing trachealis smooth muscle and formation of cartilaginous mesenchymal condensation. Thus, in mice, epithelial-induced Wnt/ß-catenin signaling mediates trachealis muscle and cartilage development via modulation of ion channel expression, promoting trachealis muscle architecture, contractility, and cartilaginous extracellular matrix. In turn, ion channel activity may influence tracheal morphogenesis underlying TBM and CTR.NEW & NOTEWORTHY Ion channels play critical roles in the physiology and function of the nervous system and contractile tissue; however, their role in noncontractile tissue and embryonic development has yet to be understood. In this study, we focused on the role of ion channels in the differentiation and patterning of the large airways of the developing respiratory tract. We identify a mechanism by which Wnt-beta-catenin signaling controls levels of ion channel-encoding genes to promote tracheal differentiation.


Asunto(s)
Tráquea , Vía de Señalización Wnt , Ratones , Animales , Vía de Señalización Wnt/genética , Tráquea/metabolismo , beta Catenina/genética , Músculo Liso/metabolismo , Canales de Potasio/metabolismo , Cartílago/metabolismo
3.
Clin Endocrinol (Oxf) ; 97(5): 622-633, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35150156

RESUMEN

OBJECTIVE: Roles for estradiol in modulating cognition in men remain uncertain. We assessed the isolated effects of estradiol on cognition in men in the absence of testosterone. DESIGN: Randomized trial of transdermal estradiol 0.9 mg daily, or matched placebo, for 6 months, hypothesizing that estradiol would improve verbal learning, verbal memory, and spatial problem solving over time. PATIENTS: Men receiving androgen deprivation therapy (ADT) for prostate cancer. MEASUREMENTS: Cognition was assessed by a tablet-based cognitive battery (Cogstate) at baseline, Month 1, Month 3, and Month 6. Anxiety and depression symptoms were assessed using the Hospital Anxiety and Depression Scale. RESULTS: Seventy-eight participants were randomized. Baseline mean scores were 21.0 (standard deviation [SD] 4.1) for the International Shopping List test (ISL), assessing verbal learning and memory (higher scores better), and 60.4 (SD 19.5) for the Groton Maze Learning test (GML), assessing spatial problem solving (lower scores better). There was no significant difference in performance over time for the estradiol group versus the placebo group for the ISL, mean adjusted difference (MAD) 0.7 (95% confidence interval [CI] -1.2 to 2.5), p = .36, or the GML, MAD -3.2 (95% CI -12.0 to 5.6), p = 0.53. There was no significant difference between groups over time in performance in any other cognitive domain, or on depression or anxiety scores. CONCLUSIONS: We found no major effects of estradiol on cognition in men with castrate testosterone concentrations. Although the cognitive effects of ADT are debated, this study suggests that any such effects are unlikely to be prevented by the administration of estradiol.


Asunto(s)
Estradiol , Neoplasias de la Próstata , Antagonistas de Andrógenos/uso terapéutico , Andrógenos/uso terapéutico , Cognición , Estradiol/uso terapéutico , Humanos , Masculino , Neoplasias de la Próstata/tratamiento farmacológico , Testosterona
4.
Anesth Prog ; 64(2): 88-96, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28604086

RESUMEN

Anesthetic management of elderly patients requires numerous physiological considerations. With aging, degenerative changes occur in the structure and functional capacity of tissues and organs. Typically, these patients experience clinical effects with lower doses of medication. Important considerations for the geriatric populations following anesthesia include increased time to recovery and avoidance of functional decline. A case is reported in which an 83-year-old Caucasian female with a complex medical history presented for routine dental treatment under intravenous sedation via dexmedetomidine infusion.


Asunto(s)
Agonistas de Receptores Adrenérgicos alfa 2/administración & dosificación , Anestesia Dental/métodos , Dexmedetomidina/administración & dosificación , Hipnóticos y Sedantes/administración & dosificación , Anciano de 80 o más Años , Sedación Consciente , Femenino , Humanos , Cuidados Preoperatorios
6.
Diabetologia ; 58(8): 1708-14, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25906755

RESUMEN

The advent of insulin treatment in 1923 meant fewer diabetes deaths from acute metabolic deterioration and sepsis and a progressive increase in the burden of disease caused by end-organ damage. These diabetic complications are the major cause of morbidity and premature mortality among diabetic subjects. Over the last 50 years it has become apparent that diabetic complications in disparate tissues may result from a combination of common pathological processes. Pathways activated by initial metabolic insults are promoted by co-factors such as renin-angiotensin-aldosterone system activation, hyperinsulinaemia, underlying genetic susceptibility, and traditional vascular risk factors, particularly hypertension and lipids. These common pathways include AGE formation, reactive oxygen species overproduction, protein kinase C activation, mitochondrial dysfunction and activation of proinflammatory and profibrotic signalling cascades. Once established, these interlinked pathways become self-perpetuating. Many drugs acting against individual downstream targets in these pathways have failed due to lack of efficacy or adverse effects. Gains in the future may be made by better control of existing risk factors, more sophisticated modulation of tissue glucose and insulin signalling, and interventions to improve mitochondrial function and reduce oxidative stress. Epigenetic and microRNA research may lead to methods to disrupt the mechanisms whereby pathological pathways are perpetuated. Expansion in capacity and expertise in biomarker measurement and analysis may allow better targeting of therapies to patients who are most likely to benefit. This is one of a series of commentaries under the banner '50 years forward', giving personal opinions on future perspectives in diabetes, to celebrate the 50th anniversary of Diabetologia (1965-2015).


Asunto(s)
Diabetes Mellitus Tipo 1/complicaciones , Hiperglucemia/complicaciones , Animales , Diabetes Mellitus Tipo 1/metabolismo , Humanos , Hiperglucemia/metabolismo , Mitocondrias/metabolismo , Estrés Oxidativo/fisiología , Especies Reactivas de Oxígeno/metabolismo
7.
Clin Endocrinol (Oxf) ; 83(1): 15-9, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25557216

RESUMEN

A 23-year-old woman with metastatic phaeochromocytoma was found to have a previously unclassified variant in the von Hippel Lindau disease gene (c.361G>C). We use this case to highlight the issue of unclassified single nucleotide variants and the approaches to help predict whether they are disease causing or neutral. With increasing use of genetic testing, and widespread clinical use of next-generation sequencing around the corner, this issue is likely to become more prominent.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Neoplasias Hepáticas/genética , Feocromocitoma/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Enfermedad de von Hippel-Lindau/genética , Neoplasias de las Glándulas Suprarrenales/patología , Simulación por Computador , Secuencia Conservada , Evolución Molecular , Femenino , Humanos , Neoplasias Hepáticas/secundario , Persona de Mediana Edad , Modelos Moleculares , Feocromocitoma/secundario , Polimorfismo de Nucleótido Simple , Adulto Joven
8.
Cell Tissue Bank ; 16(1): 109-21, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24737303

RESUMEN

Bone allografts are used to replace bone that has been removed or to augment bone tissue in a number of clinical scenarios. In order to minimize the risk of infection and immune response, the bone is delipidated and terminally sterilized prior to implantation. The optimal method for bone graft sterilization has been the topic of considerable research and debate. Recently, supercritical carbon dioxide (SCCO(2)) treatments have been shown to terminally sterilize bone against a range of bacteria and viruses. This study aimed to evaluate the effect of these SCCO(2) treatments on the anisotropic mechanical properties of cortical bone. Adult bovine cortical cubes were prepared and treated using SCCO(2) and a range of common processing additives (ethanol, peracetic acid and hydrogen peroxide). The bone was mechanically tested in uniaxial compression in the axial, radial and tangential orientations. Ultimate stress, strain, elastic modulus, energy and stiffness were evaluated. This study found that SCCO(2) treatment without additive did not alter the ultimate stress, stiffness or energy to failure depreciably in any orientation. The addition of sterilants peracetic acid and hydrogen peroxide also preserved mechanical function, with no deleterious effect on stress or stiffness. This study highlights the expediency of SCCO(2) treatment for bone allograft processing as terminal sterilization can be achieved while maintaining the intrinsic mechanical properties of the graft.


Asunto(s)
Huesos/microbiología , Huesos/virología , Dióxido de Carbono/administración & dosificación , Esterilización , Animales , Bovinos , Microscopía Electrónica de Rastreo
9.
Intern Med J ; 49(8): 1056, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31387145
10.
Eur J Orthop Surg Traumatol ; 24(1): 57-61, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23412267

RESUMEN

BACKGROUND: Ceramic-on-ceramic (CoC) total hip arthroplasty (THA) has been scrutinised for a high incidence of post-operative squeak. The psychological and social consequences, and subsequent request for revision surgery are not well documented. METHODS: Seventy consecutive primary CoC THA operated on by a single surgeon at a single institution were enroled and followed for an average 7.1 years. Information was obtained from routine post-operative review, medical records, mailed questionnaire and periodic phone interview. RESULTS: Of 70 THA, 69 were available for follow-up. Seventeen (24.6 %) reported at least one instance of squeak, occurring on average 34.2 months post-operatively. Five (7.5 %) recalled being warned preoperatively of squeak as a potential complication. Six reported infrequent squeak and 11 frequent squeak. Ten were concerned, reporting embarrassment, harassment and anxiety regarding the longevity of their THA. One patient was planning revision surgery. DISCUSSION: This study demonstrates the highest published prevalence of squeaking CoC THA and highlights the importance of warning patients of this potential complication.


Asunto(s)
Artroplastia de Reemplazo de Cadera/métodos , Cerámica/efectos adversos , Articulación de la Cadera/cirugía , Prótesis de Cadera/efectos adversos , Ruido , Complicaciones Posoperatorias , Diseño de Prótesis/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Reoperación , Encuestas y Cuestionarios , Resultado del Tratamiento
11.
Endocr Connect ; 13(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38226639

RESUMEN

We investigated the effect of estradiol add-back therapy (EAT) on brain activation related to cognitive function and affect in addition to putative changes in gray and white matter volume in testosterone depleted participants with prostate cancer. We conducted a randomized controlled, double-blinded trial in which 40 patients received 0.9 mg of transdermal estradiol per day for 6 months or matched placebo. Anatomical MRI and three functional MRI (fMRI) scans were obtained for the emotion recognition task, verbal memory task, and visuospatial memory task. Activation in corresponding cognitive and affective brain networks was demonstrated for all tasks. Longitudinally, there was no difference in brain activation, reaction time, or accuracy in response to the fMRI tasks between the EAT group and placebo group at 6 months. In addition, there was no detectable change in whole-brain gray or white matter volume or in hippocampal volume between the two groups after 6 months. This study supports earlier findings that EAT does not improve verbal memory or affect and has no immediate effect on hippocampal volume in testosterone depleted patients with prostate cancer.

12.
Int J Public Health ; 69: 1607043, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38808213

RESUMEN

Objectives: Food insecurity (FI) remains a major public health problem globally. However, there is limited information about adolescents' experiences. The current study explored FI experiences of pregnant adolescents and adolescent mothers in Cape Coast, Ghana using a Photovoice method. Methods: This study recruited 34 pregnant adolescents and adolescent mothers from communities in Cape Coast, Ghana. Each participated in a training session then was provided prompts to take photos that portrayed food access barriers, facilitators and coping strategies. In a debrief session, each participant selected two pictures they took and explained the image, followed by a group discussion of the selected photos. Debrief sessions were audio recorded and transcribed verbatim to develop themes using a theory-driven approach. Results: Most participants reported several or many experiences with FI (64.7%) in the previous month. Participants discussed money, unwanted pregnancy, and unstable work as barriers to obtaining food and working, selling goods, and family support as facilitators to obtaining food. Coping strategies mentioned include providing services to others, borrowing food and goods, meal stretching, pawning personal items and trading. Conclusion: The FI experience of this population is complex; interventions, including trade training or school retention, should be multifaceted.


Asunto(s)
Inseguridad Alimentaria , Madres , Fotograbar , Embarazo en Adolescencia , Humanos , Femenino , Ghana , Adolescente , Embarazo , Madres/psicología , Embarazo en Adolescencia/psicología , Adaptación Psicológica , Adulto Joven , Abastecimiento de Alimentos
13.
Cell Tissue Bank ; 14(2): 231-42, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22644703

RESUMEN

Load bearing bone allografts are used to replace the mechanical function of bone that has been removed or to augment bone that has been damaged in trauma. In order to minimize the risk of infection and immune response, the bone is delipidated and terminally sterilized prior to implantation. The optimal method for bone graft sterilization has been the topic of considerable research. Recently, supercritical carbon dioxide (SCCO(2)) treatments have been shown to terminally sterilize bone against a range of bacteria and viruses. This study aimed to evaluate the effect of SCCO(2) treatment compared with two doses of gamma irradiation, on the mechanical properties of whole bone. Paired rabbit humeri were dissected and randomly assigned into either SCCO(2) control, SCCO(2) additive or gamma irradiation at 10 or 25 kGy treatment groups. The bones were mechanically tested in three-point and four-point bending and torsion, with the lefts acting as controls for the treated rights. Maximum load, energy to failure and stiffness were evaluated. This study found that SCCO(2) treatment with or without additive did not alter maximum load, energy to failure or stiffness significantly under any loading modality. Gamma irradiation had a deleterious dose dependant effect, with statistically significant decreases in all mechanical tests at 25 kGy; while at 10 kGy there were reductions in all loading profiles, though only reaching statistical significance in torsion. This study highlights the expediency of SCCO(2) treatment for bone allograft processing as terminal sterilization can be achieved while maintaining the intrinsic mechanical properties of the graft.


Asunto(s)
Dióxido de Carbono/farmacología , Rayos gamma , Húmero/efectos de los fármacos , Húmero/efectos de la radiación , Esterilización/métodos , Torsión Mecánica , Animales , Fenómenos Biomecánicos , Trasplante Óseo/métodos , Relación Dosis-Respuesta a Droga , Relación Dosis-Respuesta en la Radiación , Húmero/microbiología , Técnicas In Vitro , Conejos , Soporte de Peso/fisiología
14.
Endocr Rev ; 44(5): 819-861, 2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-36974717

RESUMEN

Hyponatremia is the most common electrolyte disorder, affecting more than 15% of patients in the hospital. Syndrome of inappropriate antidiuresis (SIAD) is the most frequent cause of hypotonic hyponatremia, mediated by nonosmotic release of arginine vasopressin (AVP, previously known as antidiuretic hormone), which acts on the renal V2 receptors to promote water retention. There are a variety of underlying causes of SIAD, including malignancy, pulmonary pathology, and central nervous system pathology. In clinical practice, the etiology of hyponatremia is frequently multifactorial and the management approach may need to evolve during treatment of a single episode. It is therefore important to regularly reassess clinical status and biochemistry, while remaining alert to potential underlying etiological factors that may become more apparent during the course of treatment. In the absence of severe symptoms requiring urgent intervention, fluid restriction (FR) is widely endorsed as the first-line treatment for SIAD in current guidelines, but there is considerable controversy regarding second-line therapy in instances where FR is unsuccessful, which occurs in around half of cases. We review the epidemiology, pathophysiology, and differential diagnosis of SIAD, and summarize recent evidence for therapeutic options beyond FR, with a focus on tolvaptan, urea, and sodium-glucose cotransporter 2 inhibitors.


Asunto(s)
Hiponatremia , Síndrome de Secreción Inadecuada de ADH , Neoplasias , Humanos , Hiponatremia/diagnóstico , Hiponatremia/epidemiología , Hiponatremia/etiología , Síndrome de Secreción Inadecuada de ADH/diagnóstico , Síndrome de Secreción Inadecuada de ADH/terapia , Síndrome de Secreción Inadecuada de ADH/etiología , Equilibrio Hidroelectrolítico/fisiología
15.
Autism Res ; 16(12): 2350-2363, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37767546

RESUMEN

Scatter and heterogeneity in cognitive profiles is thought to be common in autism spectrum disorder (ASD), which may indicate differences in the construct of IQ. However, less research has investigated IQ scatter in attention-deficit/hyperactivity disorder (ADHD). Scatter is also thought to negatively impact the predictive validity of IQ summary scores, although there is research refuting this notion. Abbreviated IQ tests, such as the Stanford-Binet fifth edition (SB-5) abbreviated battery IQ (ABIQ), may be especially susceptible to the influence of scatter. We tested the measurement invariance of the SB-5 as well as the predictive validity of the ABIQ in predicting FSIQ in 1679 youth (21% female) ages 2-16 years with a clinical diagnosis of ASD or ADHD. Results indicated the SB-5 is measuring IQ the same way in ASD and ADHD. There were no differences between diagnostic groups in scatter between ABIQ (i.e., routing) subtests. Additionally, scatter was not related to dimensional autistic traits. Higher degree of scatter was associated with poorer predictive validity of the ABIQ and a higher likelihood of overestimating FSIQ, regardless of diagnosis. Overall, we found more similarities than differences between the ASD and ADHD groups. Our results show that the SB-5 ABIQ is generally a strong predictor of FSIQ in youth with neurodevelopmental disorders. However, the use of the SB-5 ABIQ in research and clinical applications, without consideration of scatter on routing subtests, is potentially problematic.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad , Trastorno del Espectro Autista , Trastorno Autístico , Adolescente , Humanos , Femenino , Masculino , Trastorno Autístico/complicaciones , Trastorno por Déficit de Atención con Hiperactividad/complicaciones , Trastorno del Espectro Autista/psicología , Inteligencia , Pruebas de Inteligencia
16.
bioRxiv ; 2023 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-36711918

RESUMEN

Ion channels play critical roles in the physiology and function of the nervous system and contractile tissue; however, their role in non-contractile tissue and embryonic development has yet to be understood. Tracheobronchomalacia (TBM) and complete tracheal rings (CTR) are disorders affecting the muscle and cartilage of the trachea and bronchi, whose etiology remains poorly understood. We demonstrated that trachealis muscle organization and polarity are disrupted after epithelial ablation of Wls, a cargo receptor critical for the Wnt signaling pathway, in developing trachea. The phenotype resembles the anomalous trachealis muscle observed after deletion of ion channel encoding genes in developing mouse trachea. We sought to investigate whether and how the deletion of Wls affects ion channels during tracheal development. We hypothesize that Wnt signaling influences the expression of ion channels to promote trachealis muscle cell assembly and patterning. Deleting Wls in developing trachea causes differential regulation of genes mediating actin binding, cytoskeleton organization, and potassium ion channel activity. Wnt signaling regulated expression of Kcnj13, Kcnd3, Kcnj8, and Abcc9 as demonstrated by in vitro studies and in vivo analysis in Wnt5a and ß-catenin deficient tracheas. Pharmacological inhibition of potassium ion channels and Wnt signaling impaired contractility of developing trachealis smooth muscle and formation of cartilaginous mesenchymal condensation. Thus, in mice, epithelial-induced Wnt/ß-catenin signaling mediates trachealis muscle and cartilage development via modulation of ion channel expression, promoting trachealis muscle architecture, contractility, and cartilaginous extracellular matrix. In turn, ion channel activity may influence tracheal morphogenesis underlying TBM and CTR.

17.
Front Psychol ; 14: 1217823, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37842710

RESUMEN

Postdoctoral researchers (postdocs) are an essential component of the scientific workforce in German universities and research institutions and play a vital role in advancing knowledge and innovation. However, the experiences of postdocs and other early career researchers (ECRs) indicate that working conditions pose a significant challenge to the pursuit of a long-term research career in Germany-particularly for international scientists and those from marginalized groups. We examine how unstable working conditions as well as insufficient structural support for equal opportunities and diversity are significant obstacles for the career development of ECRs in German academia. We discuss these issues with the aid of an extensive survey recently conducted and published by PostdocNet, a target-group network representing the interests of postdocs across Germany's Max Planck Society. The survey drew responses from 659 postdoctoral researchers working at the Max Planck Society and represents one of the few datasets of postdoctoral researchers' perspectives in Germany. Building on these findings, we suggest actions at governmental, institutional, and individual levels to improve the working conditions of postdoctoral researchers in Germany.

18.
Spine J ; 23(6): 912-920, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36736741

RESUMEN

BACKGROUND CONTEXT: Lateral mass screw fixation is the standard for posterior subaxial cervical fixation. Several freehand surgical techniques for placing lateral mass screws have been described which rely on anatomical landmarks and surgeon mastery of the technique to safely place screws. The accuracy of these freehand techniques is inherently variable and can be influenced by a surgeon's level of clinical experience. A novel technique was developed that utilizes the plane of the facet joint to create lateral mass screw pilot holes parallel with the joint line to improve the safety and accuracy of lateral mass screw placement regardless of experience. PURPOSE: To assess the safety and accuracy of lateral mass screw placement using a novel lateral mass drill guide instrument (LM Guide), compared to standard freehand technique. STUDY DESIGN: Randomized cadaveric study utilizing multiple surgeon evaluators to compare the safety and accuracy of guided cervical lateral mass placement compared to traditional freehand techniques. MATERIALS AND METHODS: Lateral mass screws were placed from C3 to C7 in 20 cadaver specimens by 8 spine surgeons of varying levels of clinical experience (4 attendings, 4 fellows). Screws were placed bilaterally using standard anatomic landmarks ("freehand") randomly allocated on one side and using the LM Guide on the other. Cadaveric specimens were imaged with high-resolution CT to assess screw placement. Zone grading for safety was conducted based on screw tip position and clinical severity of screw breach was based on proximity to surrounding neurovascular anatomy. Screws were graded as safe, at-risk, or critical, with at-risk and critical screws considered malpositioned. To assess the accuracy of screw trajectory placed using the LM Guide compared to freehand, sagittal screw angle was measured and compared to an "ideal" screw path parallel to the facet joint line. Freehand and LM Guide groups were compared using Pearson's chi-square correlation. RESULTS: Screw placement using the LM guide yielded a significantly lower rate of screw malpositioning, with 7 of 91 (7.7%) compared with 18 of 99 (18.2%) screws placed in the At-Risk or Critical Zones, p<.05. Of the 91 screws inserted using the LM Guide, 84 (92.3%) were in the Safe Zone, 7 (7.7%) were At-Risk, and 0 were in Critical zones. There was no incidence of neural or transverse foramen breaches with the LM Guide. In comparison, for the 99 screws inserted freehand, 81 (81.8%) were Safe, 14 (14.1%) were At-Risk, and 4 (4.1%) were in Critical zones. The 4 Critical zone freehand screw breaches included 1 neural foramen breach, 2 transverse foramen breaches, and 1 facet breach. The LM Guide also resulted in higher accuracy of screw trajectory, as indicated by a significant reduction in sagittal screw angle compared with freehand, p<.01. Notably, in the less-experienced surgeon cohort, the LM Guide significantly reduced the sagittal screw angle and resulted in no critical screw breaches compared to 3 critical breaches with freehand technique suggesting there might be a benefit in decreasing the learning curve associated with lateral mass screw placement. CONCLUSIONS: Lateral mass screw placement with a novel LM Guide that uses the facet joint to control screw trajectory improved the accuracy and reproducibility of screw placement with a significant reduction in screw breach rate and sagittal screw angle compared to freehand techniques regardless of surgeon experience level. CLINICAL SIGNIFICANCE: The inherent variability of freehand lateral mass screw placement can increase the risk of clinical complications associated with screw malpositioning. The technique presented in this cadaveric study may be a viable alternative to standard freehand technique that can improve the overall safety of lateral mass screw placement.


Asunto(s)
Tornillos Pediculares , Fusión Vertebral , Humanos , Tornillos Óseos , Cadáver , Vértebras Cervicales/cirugía , Reproducibilidad de los Resultados , Fusión Vertebral/métodos , Tomografía Computarizada por Rayos X/métodos
19.
J Cachexia Sarcopenia Muscle ; 14(1): 142-156, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36349684

RESUMEN

BACKGROUND: Sarcopenia is an age-associated skeletal muscle condition characterized by low muscle mass, strength, and physical performance. There is no international consensus on a sarcopenia definition and no contemporaneous clinical and research guidelines specific to Australia and New Zealand. The Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR) Sarcopenia Diagnosis and Management Task Force aimed to develop consensus guidelines for sarcopenia prevention, assessment, management and research, informed by evidence, consumer opinion, and expert consensus, for use by health professionals and researchers in Australia and New Zealand. METHODS: A four-phase modified Delphi process involving topic experts and informed by consumers, was undertaken between July 2020 and August 2021. Phase 1 involved a structured meeting of 29 Task Force members and a systematic literature search from which the Phase 2 online survey was developed (Qualtrics). Topic experts responded to 18 statements, using 11-point Likert scales with agreement threshold set a priori at >80%, and five multiple-choice questions. Statements with moderate agreement (70%-80%) were revised and re-introduced in Phase 3, and statements with low agreement (<70%) were rejected. In Phase 3, topic experts responded to six revised statements and three additional questions, incorporating results from a parallel Consumer Expert Delphi study. Phase 4 involved finalization of consensus statements. RESULTS: Topic experts from Australia (n = 62, 92.5%) and New Zealand (n = 5, 7.5%) with a mean ± SD age of 45.7 ± 11.8 years participated in Phase 2; 38 (56.7%) were women, 38 (56.7%) were health professionals and 27 (40.3%) were researchers/academics. In Phase 2, 15 of 18 (83.3%) statements on sarcopenia prevention, screening, assessment, management and future research were accepted with strong agreement. The strongest agreement related to encouraging a healthy lifestyle (100%) and offering tailored resistance training to people with sarcopenia (92.5%). Forty-seven experts participated in Phase 3; 5/6 (83.3%) revised statements on prevention, assessment and management were accepted with strong agreement. A majority of experts (87.9%) preferred the revised European Working Group for Sarcopenia in Older Persons (EWGSOP2) definition. Seventeen statements with strong agreement (>80%) were confirmed by the Task Force in Phase 4. CONCLUSIONS: The ANZSSFR Task Force present 17 sarcopenia management and research recommendations for use by health professionals and researchers which includes the recommendation to adopt the EWGSOP2 sarcopenia definition in Australia and New Zealand. This rigorous Delphi process that combined evidence, consumer expert opinion and topic expert consensus can inform similar initiatives in countries/regions lacking consensus on sarcopenia.


Asunto(s)
Entrenamiento de Fuerza , Sarcopenia , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Australia/epidemiología , Consenso , Nueva Zelanda/epidemiología , Sarcopenia/diagnóstico , Sarcopenia/prevención & control
20.
Australas J Ageing ; 42(1): 251-257, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36480154

RESUMEN

OBJECTIVES: To develop guidelines, informed by health-care consumer values and preferences, for sarcopenia prevention, assessment and management for use by clinicians and researchers in Australia and New Zealand. METHODS: A three-phase Consumer Expert Delphi process was undertaken between July 2020 and August 2021. Consumer experts included adults with lived experience of sarcopenia or health-care utilisation. Phase 1 involved a structured meeting of the Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR) Sarcopenia Diagnosis and Management Task Force and consumer representatives from which the Phase 2 survey was developed. In Phase 2, consumers from Australia and New Zealand were surveyed online with opinions sought on sarcopenia outcome priorities, consultation preferences and interventions. Findings were confirmed and disseminated in Phase 3. Descriptive statistical analyses were performed. RESULTS: Twenty-four consumers (mean ± standard deviation age 67.5 ± 12.8 years, 18 women) participated in Phase 2. Ten (42%) identified as being interested in sarcopenia, 7 (29%) were health-care consumers and 6 (25%) self-reported having/believing they have sarcopenia. Consumers identified physical performance, living circumstances, morale, quality of life and social connectedness as the most important outcomes related to sarcopenia. Consumers either had no preference (46%) or preferred their doctor (40%) to diagnose sarcopenia and preferred to undergo assessments at least yearly (54%). For prevention and treatment, 46% of consumers preferred resistance exercise, 2-3 times per week (54%). CONCLUSIONS: Consumer preferences reported in this study can inform the implementation of sarcopenia guidelines into clinical practice at local, state and national levels across Australia and New Zealand.


Asunto(s)
Fragilidad , Sarcopenia , Humanos , Femenino , Anciano , Anciano de 80 o más Años , Nueva Zelanda , Sarcopenia/diagnóstico , Sarcopenia/terapia , Calidad de Vida , Fragilidad/diagnóstico , Fragilidad/terapia , Australia
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