Th1 type lymphocyte reactivity to metals in patients with total hip arthroplasty

<p>Abstract</p> <p>Background</p> <p>All prostheses with metallic components release metal debris that can potentially activate the immune system. However, implant-related metal hyper-reactivity has not been well characterized. In this study, we hypothesized that adaptive immunity reaction(s), particularly T-helper type 1 (Th1) responses, will be dominant in any metal-reactivity responses of patients with total joint replacements (TJAs). We tested this hypothesis by evaluating lymphocyte reactivity to metal "ions" in subjects with and without total hip replacements, using proliferation assays and cytokine analysis.</p> <p>Methods</p> <p>Lymphocytes from young healthy individuals without an implant or a history of metal allergy (Group 1: n = 8) were used to assess lymphocyte responses to metal challenge agents. In addition, individuals (Group 2: n = 15) with well functioning total hip arthroplasties (average Harris Hip Score = 91, average time in-situ 158 months) were studied. Age matched controls with no implants were also used for comparison (Group 3, n = 8, 4 male, 4 female average age 70, range 49–80). Group 1 subjects' lymphocyte proliferation response to Aluminum⁺³, Cobalt⁺², Chromium⁺³, Copper⁺², Iron⁺³, Molybdenum⁺⁵, Manganeese⁺², Nickel⁺², Vanadium⁺³and Sodium⁺²chloride solutions at a variety of concentrations (0.0, 0.05, 0.1, 0.5, 1.0 and 10.0 mM) was studied to establish toxicity thresholds. Mononuclear cells from Group 2 and 3 subjects were challenged with 0.1 mM CrCl₃, 0.1 mM NiCl₂, 0.1 mM CoCl₂and approx. 0.001 mM titanium and the reactions measured with proliferation assays and cytokine analysis to determine T-cell subtype prominence.</p> <p>Results</p> <p>Primary lymphocytes from patients with well functioning total hip replacements demonstrated a higher incidence and greater magnitude of reactivity to chromium than young healthy controls (p < 0.03). Of the 15 metal ion-challenged subjects with well functioning total hip arthroplasties, 7 demonstrated a proliferative response to Chromium, Nickel, Cobalt and/or Titanium (as defined by a statistically significant >2 fold stimulation index response, p < 0.05) and were designated as metal-reactive. Metals such as Cobalt, Copper, Manganese, and Vanadium were toxic at concentrations as low as 0.5 mM while other metals, such as Aluminum, Chromium, Iron, Molybdenum, and Nickel, became toxic at much higher concentrations (>10 mM). The differential secretion of signature T-cell subsets' cytokines (Th1 and Th2 lymphocytes releasing IFN-gamma and IL-4, respectively) between those total hip arthroplasty subjects which demonstrated metal-reactivity and those that did not, indicated a Th1 type (IFN-gamma) pro-inflammatory response.</p> <p>Conclusion</p> <p>Elevated proliferation and production of IFN-gamma to metals in hip arthroplasty subjects' lymphocytes indicates that a Th1 (vs. Th2) type response is likely associated with any metal induced reactivity. The involvement of an elevated and specific lymphocyte response suggests an <it>adaptive </it>(macrophage recruiting) immunity response to metallic implant debris rather than an <it>innate </it>(nonspecific) immune response.</p

Diminishing benefits of urban living for children and adolescents’ growth and development

AbstractOptimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was &lt;1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.</jats:p

Fidedignidade entre peso e estatura reportados e medidos e a influência do histórico de atividade física em indivíduos que procuram a prática supervisionada de exercícios Fidedignidad entre el peso y la estatura reportados y medidos y la influencia de la historia de actividad física en indivíduos que procuran la prática supervisada de ejercícios Reliability between reported and measured weight and height, and influence of physical activity history on individuals who search for supervised practice of exercises

O objetivo deste estudo foi verificar a fidedignidade entre os valores auto-reportados e medidos de peso, estatura e índice de massa corporal, além da influência do histórico de atividade física em 328 indivíduos, sendo 200 mulheres (39 ± 11 anos) e 128 homens (35 ± 10 anos) que procuraram a prática supervisionada de exercícios. Todos os indivíduos passaram por uma avaliação funcional que registrou os valores medidos e auto-reportados de peso e estatura. Os indivíduos também foram classificados como ativos (exercitavam-se três vezes ou mais por semana), pouco ativos (exercitavam-se de uma a duas vezes por semana) e inativos (não se exercitavam), de acordo com o histórico de atividade física nos últimos três meses que precederam a avaliação. Os dados obtidos pelo cálculo do coeficiente de correlação intraclasse mostraram elevada fidedignidade entre as variáveis reportadas nos homens (CCIC > 0,94) e nas mulheres (CCIC > 0,96). A ANOVA de uma entrada não sugeriu qualquer associação, isolada ou combinada, entre o histórico de atividades físicas e a regularidade destas na magnitude do erro nos relatos de homens (p > 0,29) e mulheres (p > 0,07). De acordo com esses achados, os autores fomentam a utilização do relato do peso e estatura em estudos de grande número amostral, independentemente do nível de atividade física.<br>El objetivo de este estudio fue verificar al fidedignidad entre los valores auto-reportados y medidos del peso, la estatura y índice de masa corporal, además de la influencia de la historia de la actividad física en 328 individuos, siendo 200 mujeres (39 ± 11 años) y 128 hombres (35 ± 10 años) buscada con la práctica dirigida de ejercicios. Todos los individuos pasaron por una evaluación funcional que registró los valores moderados y auto-reportados de peso y estatura. Los individuos también fueron clasificados como activos (se entrenaron tres veces o más por semana), no muy activos (se entrenaron de una a dos veces por semana) y inactivos (no se entrenaban), de acuerdo con la historia de actividad física en los últimos tres meses que precedió la evaluación. Los datos obtenidos por el cálculo del coeficiente de intra-clase de la correlación mostraron fidedignidad alta entre los reportes inconstantes en los hombres (CCIC > 0.94) y en las mujeres (CCIC > 0.96). El uso de ANOVA de entrada no hizo pensar en ninguna asociación, aislada o combinada, entre la historia de actividades físicas y la regularidad de éstos en la magnitud del error en los informes de los hombres (p > 0,29) y mujeres (p > 0,07). De acuerdo con estos descubrimientos, nosotros fomentamos el uso del informe del peso y estatura en los estudios de gran número de muestra, independientemente del nivel de actividad física.<br>The objective of this study was to verify the reliability between self-reported and measured weight, height and body mass index values, as well as the influence of the physical activity history on 328 individuals, 200 women (39 ± 11 years) and 128 men (35 ± 10 years) who search for the supervised practice of exercises. All individuals underwent functional evaluation that recorded self-reported and measured weight and height values. The individuals were also classified as active (those who exercised three times a week or more), a low active (those who exercised from one to two times a week), and inactive (those who did not exercise), according to the physical activity history in the last three months previously to the evaluation. The data obtained through the calculation of the intraclass correlation coefficient showed high reliability between variables reported in men (ICC > 0.94) and women (ICC > 0.96). The one-way analysis of variance ANOVA did not suggest any association, either isolated or combined, between the physical activities review and regularity in the error magnitude in reports from men (p > 0.29) and women (p > 0.07). According to these findings, the authors encourage weight and height report use in studies with large sampling size, regardless the physical activity level