Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
1.
BMJ Case Rep ; 17(5)2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38697682

RESUMEN

Tumour-induced osteomalacia is caused by tumorous production of fibroblast growth factor 23 (FGF23) leading to urinary phosphate wasting, hypophosphataemia and decreased vitamin D activation. The resulting osteomalacia presents with muscle weakness and bone pain but progresses to multiple pathological fractures. Patients often remain undiagnosed for years with severe physical, psychological and economic ramifications. A young woman presented with multiple spontaneous fractures including bilateral femoral fractures. Laboratory tests revealed severe hypophosphataemia, elevated bone turnover markers and low to normal calcium and 25-hydroxy-vitamin D levels. Treatment with phosphate, alfalcalcidol, calcium and magnesium was initiated. 68Gallium-DOTATOC positron emission tomography imaging revealed a mass in the right foot and venous sampling of FGF23 from all extremities confirmed this tumour as the culprit. Biopsy and histology were consistent with a phosphaturic mesenchymal tumour, which was surgically resected. Phosphate levels quickly normalised postoperatively but a long convalescence with hungry bone syndrome, fracture healing and physical therapy followed.


Asunto(s)
Factor-23 de Crecimiento de Fibroblastos , Neoplasias de Tejido Conjuntivo , Osteomalacia , Humanos , Osteomalacia/etiología , Femenino , Neoplasias de Tejido Conjuntivo/diagnóstico , Neoplasias de Tejido Conjuntivo/cirugía , Adulto , Síndromes Paraneoplásicos/diagnóstico , Hipofosfatemia/etiología , Factores de Crecimiento de Fibroblastos/sangre , Fracturas del Fémur/cirugía , Fracturas del Fémur/diagnóstico por imagen , Fracturas Espontáneas/etiología , Fracturas Espontáneas/cirugía , Fracturas Espontáneas/diagnóstico por imagen , Fosfatos/sangre
2.
PLoS One ; 19(5): e0300776, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38809815

RESUMEN

PURPOSE: Studies indicate that the rated perceived exertion (RPE) during physical exercise can be lower in field environments than indoors. The environmental conditions of those studies are explored. Furthermore, we study if the same phenomenon is valid when cycling indoors versus in cycle commuting environments with high levels of stimuli from both traffic and suburban-urban elements. METHODS: Twenty commuter cyclists underwent measurements of heart rate (HR) and oxygen uptake ([Formula: see text]O2) and RPE assessments for breathing and legs, respectively, while cycling in both laboratory and field conditions. A validated mobile metabolic system was used in the field to measure [Formula: see text]O2. Three submaximal cycle ergometer workloads in the laboratory were used to establish linear regression equations between RPE and % of HR reserve (%HRR) and %[Formula: see text]O2max, separately. Based on these equations, RPE from the laboratory was predicted and compared with RPE levels at the participants' individual cycle commutes at equal intensities. The same approach was used to predict field intensities and for comparisons with corresponding measured intensities at equal RPE levels. RESULTS: The predicted RPE levels based on the laboratory cycling were significantly higher than the RPE levels in cycle commuting at equal intensities (67% of HRR; 65% of [Formula: see text]O2max). For breathing, the mean RPE levels were; 14.0-14.2 in the laboratory and 12.6 in the field. The corresponding levels for legs were; 14.0-14.2 and 11.5. The range of predicted field intensities in terms of %HRR and %[Formula: see text]O2max was 46-56%, which corresponded to median differences of 19-30% compared to the measured intensities in field at equal RPE. CONCLUSION: The cycle commuters perceived a lower exertion during their cycle commutes compared to ergometer cycling in a laboratory at equal exercise intensities. This may be due to a higher degree of external stimuli in field, although influences from other possible causes cannot be ruled out.


Asunto(s)
Ciclismo , Frecuencia Cardíaca , Consumo de Oxígeno , Esfuerzo Físico , Humanos , Esfuerzo Físico/fisiología , Adulto , Masculino , Consumo de Oxígeno/fisiología , Frecuencia Cardíaca/fisiología , Ciclismo/fisiología , Percepción/fisiología , Ejercicio Físico/fisiología , Femenino , Prueba de Esfuerzo , Adulto Joven
3.
Artículo en Inglés | MEDLINE | ID: mdl-38170563

RESUMEN

AIMS: To compare patient-reported outcomes (PROs) in patients newly (< six months) diagnosed with atrial fibrillation (AF) with those who have had the diagnosis longer (≥ six months) and to investigate whether or not these outcomes change over a six month's period. METHODS AND RESULTS: In this longitudinal survey study, 129 patients with AF completed the Revised Illness Perception Questionnaire, the Arrhythmia-Specific questionnaire in Tachycardia and Arrhythmia, and the Hospital Anxiety and Depression Scale at baseline and after six months.At baseline, patients newly diagnosed with AF (n=53), compared to patients with a previous diagnosis (n=76), reported AF as more temporary (P = 0.003) and had higher belief in personal- and treatment control (P = 0.004, P = 0.041 respectively). At six months follow-up, patients newly diagnosed reported a lower symptom burden (P = 0.004), better health-related quality of life (HRQoL) (P = 0.015) and higher personal control (P < 0.001) than patients previously diagnosed. Over time, in patients newly diagnosed, symptom burden and anxiety symptom score decreased (P = 0.001, P = 0.014 respectively) and HRQoL improved (P = 0.002). CONCLUSIONS: Patients newly diagnosed with AF reported more positive PROs both at baseline and at six months follow-up than patients with a previous diagnosis of AF. Therefore, it is important to quickly capture patients newly diagnosed to support their belief in their own abilities. Such support may, alongside medical treatments, help the patients manage the disease, which may lead to reduced symptom burden and better HRQoL over time.

4.
Sci Total Environ ; 917: 170475, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38296092

RESUMEN

Under the increasing threat to native ecosystems posed by non-native species invasions, there is an urgent need for decision support tools that can more effectively identify non-native species likely to become invasive. As part of the screening (first step) component in non-native species risk analysis, decision support tools have been developed for aquatic and terrestrial organisms. Amongst these tools is the Weed Risk Assessment (WRA) for screening non-native plants. The WRA has provided the foundations for developing the first-generation WRA-type Invasiveness Screening Kit (ISK) tools applicable to a range of aquatic species, and more recently for the second-generation ISK tools applicable to all aquatic organisms (including plants) and terrestrial animals. Given the most extensive usage of the latter toolkits, this study describes the development and application of the Terrestrial Plant Species Invasiveness Screening Kit (TPS-ISK). As a second-generation ISK tool, the TPS-ISK is a multilingual turnkey application that provides several advantages relative to the WRA: (i) compliance with the minimum standards against which a protocol should be evaluated for invasion process and management approaches; (ii) enhanced questionnaire comprehensiveness including a climate change component; (iii) provision of a level of confidence; (iv) error-free computation of risk scores; (v) multilingual support; (vi) possibility for across-study comparisons of screening outcomes; (vii) a powerful graphical user interface; (viii) seamless software deployment and accessibility with improved data exchange. The TPS-ISK successfully risk-ranked five representative sample species for the main taxonomic groups supported by the tool and ten angiosperms previously screened with the WRA for Turkey. The almost 20-year continuous development and evolution of the ISK tools, as opposed to the WRA, closely meet the increasing demand by scientists and decision-makers for a reliable, comprehensive, updatable and easily deployable decision support tool. For terrestrial plant screening, these requirements are therefore met by the newly developed TPS-ISK.


Asunto(s)
Ecosistema , Especies Introducidas , Animales , Plantas , Medición de Riesgo , Factores de Riesgo
5.
Acta Derm Venereol ; 103: adv22336, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-38078690

RESUMEN

Fibromyalgia is a common chronic pain condition. Rates of contact allergy in individuals with fibromyalgia have not been widely studied. Systemic contact allergy can present with muscle and joint pain and general malaise. The aim of this study is to investigate contact allergy rates in individuals with fibromyalgia to the sensitizers in an extended dental series and compare with control groups. Contact allergy to gold was significantly more common in the fibromyalgia group than the dermatitis control group. When corrected for patch test system, contact allergy to gold was significantly more common in the fibromyalgia group than the dental control group. Contact allergy to hydroxyethyl methacrylate and grouped acrylates and methacrylates was significantly more common in the fibromyalgia group than the dental control group. In conclusion, individuals with fibromyalgia may have a propensity to sensitization to gold, either via an increased exposure or an alteration in the oral environment. Gold is also implicated in systemic contact dermatitis and may be a factor in elicitation of symptoms in individuals with fibromyalgia. Acrylate allergy is also common in the fibromyalgia population and may be a consequence of occupational exposure or dental treatment.


Asunto(s)
Dolor Crónico , Dermatitis Alérgica por Contacto , Dermatitis Profesional , Fibromialgia , Humanos , Dermatitis Profesional/diagnóstico , Dermatitis Profesional/epidemiología , Alérgenos , Pruebas del Parche , Oro/efectos adversos , Fibromialgia/diagnóstico , Fibromialgia/epidemiología , Dermatitis Alérgica por Contacto/diagnóstico , Dermatitis Alérgica por Contacto/epidemiología , Acrilatos/efectos adversos , Metacrilatos/efectos adversos
6.
Front Immunol ; 14: 1130930, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37138883

RESUMEN

The LIN28B RNA binding protein exhibits an ontogenically restricted expression pattern and is a key molecular regulator of fetal and neonatal B lymphopoiesis. It enhances the positive selection of CD5+ immature B cells early in life through amplifying the CD19/PI3K/c-MYC pathway and is sufficient to reinitiate self-reactive B-1a cell output when ectopically expressed in the adult. In this study, interactome analysis in primary B cell precursors showed direct binding by LIN28B to numerous ribosomal protein transcripts, consistent with a regulatory role in cellular protein synthesis. Induction of LIN28B expression in the adult setting is sufficient to promote enhanced protein synthesis during the small Pre-B and immature B cell stages, but not during the Pro-B cell stage. This stage dependent effect was dictated by IL-7 mediated signaling, which masked the impact of LIN28B through an overpowering stimulation on the c-MYC/protein synthesis axis in Pro-B cells. Importantly, elevated protein synthesis was a distinguishing feature between neonatal and adult B cell development that was critically supported by endogenous Lin28b expression early in life. Finally, we used a ribosomal hypomorphic mouse model to demonstrate that subdued protein synthesis is specifically detrimental for neonatal B lymphopoiesis and the output of B-1a cells, without affecting B cell development in the adult. Taken together, we identify elevated protein synthesis as a defining requirement for early-life B cell development that critically depends on Lin28b. Our findings offer new mechanistic insights into the layered formation of the complex adult B cell repertoire.


Asunto(s)
Linfocitos B , Células Precursoras de Linfocitos B , Ratones , Animales
7.
Artículo en Inglés | MEDLINE | ID: mdl-36834450

RESUMEN

It is important to examine how motorized traffic variables affect pedestrians along a gradient from rural to inner urban settings. Relations between pedestrians' perceptions of four traffic variables and appraisals of route environments as hindering-stimulating for walking as well as unsafe-safe for reasons of traffic, were therefore studied in the inner urban area of Stockholm, Sweden (n = 294). The pedestrians rated their perceptions and appraisals with the Active Commuting Route Environment Scale (ACRES). Correlation, multiple regression, and mediation analyses were used to study the relationships between the traffic variables and the outcome variables. Noise related negatively to both hindering-stimulating for walking, and to unsafety-safety for traffic reasons. Vehicle speed related negatively to unsafety-safety for traffic reasons. Furthermore, vehicle speed protruded as an important origin of the deterring effects of traffic among those who commute by foot. The study shows the value of both partial and simultaneous analyses of the effect of all four traffic variables in relation to outcome variables relevant for walking.


Asunto(s)
Peatones , Humanos , Transportes , Caminata , Suecia , Población Rural , Accidentes de Tránsito , Seguridad
8.
J Eur Acad Dermatol Venereol ; 37(1): 104-113, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36018078

RESUMEN

BACKGROUND: Contact allergy can manifest in a variety of ways clinically. Systemic contact allergy may occasionally present with pain in muscles and joints. Fibromyalgia is a chronic rheumatic disease characterized by pain and with virtually unknown aetiology. OBJECTIVES: The aim of this study was to investigate the contact allergy rates to the sensitizers in a baseline series and compare with corresponding rates in dermatitis patients and the general population. METHODS: Patch testing with the Swedish baseline series was performed in 120 individuals with fibromyalgia. Fisher's exact test was used for pair-wise comparisons of contact allergy rates between the fibromyalgia group and two control groups, dermatitis patients and individuals in the general population. RESULTS: Contact allergy was significantly more common in the fibromyalgia group compared to the general population concerning nickel and the fragrance markers Myroxolon pereirae and fragrance mix I. There were fewer allergic reactions to preservatives in the fibromyalgia group compared with the dermatitis group. CONCLUSIONS: Myroxolon pereirae and fragrance mix I represent besides fragrance allergy also allergy to flavouring substances which indicate that oral exposure to flavouring substances and hygiene products might be important for sensitization and possibly elicitation of systemic contact allergy symptoms in fibromyalgia individuals.


Asunto(s)
Dermatitis Alérgica por Contacto , Fibromialgia , Enfermedades del Sistema Inmune , Perfumes , Humanos , Pruebas del Parche/efectos adversos , Odorantes , Suecia/epidemiología , Fibromialgia/complicaciones , Fibromialgia/epidemiología , Perfumes/efectos adversos , Dermatitis Alérgica por Contacto/epidemiología , Dermatitis Alérgica por Contacto/etiología , Dermatitis Alérgica por Contacto/diagnóstico , Dolor , Alérgenos
9.
Nurs Open ; 10(3): 1821-1829, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36309946

RESUMEN

AIM: To explore the experiences of living with symptomatic atrial fibrillation. DESIGN: This study, with a descriptive qualitative design, was performed using semi-structured individual interviews. METHOD: Six women and nine men with symptomatic atrial fibrillation were included. The transcribed interviews were analysed using qualitative content analysis. The COREQ checklist was followed. RESULTS: The analysis resulted in a main theme, namely balancing life and included the themes striving for illness control, becoming a receiver or an active partner in care and dealing with changed self-image. The participants strived to understand their illness, prevent attacks and manage anxiety. Some of the participants were not involved in decision-making, were uninformed about self-care measures, reported a lack of continuity in care and felt that the doctors focused on information about the medical part of care.


Asunto(s)
Fibrilación Atrial , Médicos , Masculino , Humanos , Femenino , Fibrilación Atrial/terapia , Ansiedad , Trastornos de Ansiedad , Adaptación Psicológica
10.
Front Public Health ; 10: 911863, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36339183

RESUMEN

Background: Quantification of movement intensity and energy utilization, together with frequency of trips, duration, distance, step counts and cadence, is essential for interpreting the character of habitual walking for transport, and its potential support of health. The purpose of the study is to illuminate this with valid methods and novel perspectives, and to thereby provide a new basis for characterizing and interpreting walking in relation to health outcomes. Methods: Habitual middle-aged commuting pedestrians (males = 10, females = 10) were investigated in the laboratory at rest and with maximal treadmill and cycle ergometer tests. Thereafter, levels of oxygen uptake, energy expenditure, ventilation, heart rate, blood lactate, rated perceived exertion, cadence, number of steps, duration, distance, and speed were recorded during the normal walking commute of each participant in Greater Stockholm, Sweden. The number of commutes per week over the year was self-reported. Results: Walking in the field demanded about 30% more energy per km compared to level treadmill walking. For both sexes, the walking intensity in field was about 46% of maximal oxygen uptake, and energy expenditure amounted to 0.96 kcal · kg- 1 · km- 1. The MET values (males: 6.2; females: 6.5) mirrored similar levels of walking speed (males: 5.7; females: 5.9 km · h- 1) and levels of oxygen uptake (males: 18.6; females: 19.5 mL · kg- 1 · min- 1). The average number of MET-hours per week in a typical month was 22 for males and 20 for females. This resulted in a total weekly energy expenditure of ~1,570 and 1,040 kcal for males and females, respectively. Over the year, the number of walking commutes and their accumulated distance was ~385 trips and 800 km for both sexes. Conclusion: Walking in naturalistic field settings demands its own studies. When males and females walk to work, their relative aerobic intensities and absolute energy demands for a given distance are similar. It is equivalent to the lower part of the moderate relative intensity domain. The combination of oxygen uptake, trip duration and frequency leads to high and sustained levels of MET-hours as well as energy expenditure per week over the year, with a clear health enhancing potential. Based on this study we recommend 6000 transport steps per day, or equivalent, during five weekdays, over the year, in order to reach optimal health gains.


Asunto(s)
Metabolismo Energético , Caminata , Persona de Mediana Edad , Masculino , Femenino , Humanos , Caminata/fisiología , Metabolismo Energético/fisiología , Frecuencia Cardíaca/fisiología , Oxígeno , Evaluación de Resultado en la Atención de Salud
11.
J Exp Biol ; 225(13)2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35647659

RESUMEN

Understanding how organismal traits determine performance and, ultimately, fitness is a fundamental goal of evolutionary eco-morphology. However, multiple traits can interact in non-linear and context-dependent ways to affect performance, hindering efforts to place natural populations with respect to performance peaks or valleys. Here, we used an established mechanistic model of suction-feeding performance (SIFF) derived from hydrodynamic principles to estimate a theoretical performance landscape for zooplankton prey capture. This performance space can be used to predict prey capture performance for any combination of six morphological and kinematic trait values. We then mapped in situ high-speed video observations of suction feeding in a natural population of a coral reef zooplanktivore, Chromis viridis, onto the performance space to estimate the population's location with respect to the topography of the performance landscape. Although the kinematics of the natural population closely matched regions of high performance in the landscape, the population was not located on a performance peak. Individuals were furthest from performance peaks on the peak gape, ram speed and mouth opening speed trait axes. Moreover, we found that the trait combinations in the observed population were associated with higher performance than expected by chance, suggesting that these combinations are under selection. Our results provide a framework for assessing whether natural populations occupy performance optima.


Asunto(s)
Perciformes , Conducta Predatoria , Animales , Fenómenos Biomecánicos , Conducta Alimentaria , Succión
12.
Mar Pollut Bull ; 181: 113763, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35752508

RESUMEN

In recent decades, gobies have dispersed or introduced from the Ponto-Caspian region of eastern Europe in a westerly direction to North American and western European waters. By contrast, the naked goby, Gobiosoma bosc, is the only known gobiid species to have been introduced in an easterly direction from North American to western Europe. The potential invasiveness of G. bosc was assessed using the Aquatic Species Invasiveness Screening Kit (AS-ISK) for rivers and transitional waters for the western and eastern sides of the North Sea. Using globally-derived thresholds, G. bosc was assessed as low-medium invasiveness risk for both sides of the North Sea under current climate conditions. Under future climate conditions, potential invasiveness will increase for both risk assessment areas. Environmental suitability assessment indicated an increase in environmental suitability for G. bosc on the eastern coastline of the North Sea under climate change scenarios and suitability remained unchanged on the western coastline, reflecting the authors' expectations of invasiveness risk.


Asunto(s)
Perciformes , Animales , Europa (Continente) , Mar del Norte , Ríos , Agua de Mar
13.
BMC Med Res Methodol ; 22(1): 55, 2022 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-35220936

RESUMEN

BACKGROUND: The heart rate (HR) method enables estimating oxygen uptake (V̇O2) in physical activities. However, there is a paucity in knowledge about the interchangeability of this method when applied to cycling, walking and running. Furthermore, with the aim of optimization, there is a need to compare different models for establishing HR-V̇O2 relationships. METHODS: Twenty-four physically active individuals (12 males and 12 females) participated. For each participant, two models of HR-V̇O2 relationships were individually established in ergometer cycling, level treadmill walking and running. Model 1 consisted of five submaximal workloads, whereas model 2 included also a maximal workload. Linear regression equations were used to estimate V̇O2 at seven intensity levels ranging between 25 and 85% of heart rate reserve (HRR). The estimated V̇O2 levels were compared between the exercise modalities and models, as well as with data from a previous study. RESULTS: A high level of resemblance in estimated V̇O2 was noted between running and cycling as well as between running and walking, with both model 1 and model 2. When comparing walking and cycling, the V̇O2 levels for given intensities of %HRR were frequently slightly higher in walking with both models (range of significant differences: 5-12%). The variations of the estimated individual V̇O2 values were reduced when using model 2 compared to model 1, both between and within the exercise modalities. CONCLUSION: The HR method is optimized by more workloads and wider ranges. This leads to overall high levels of interchangeability when HR methods are applied in ergometer cycling, level treadmill walking and running.


Asunto(s)
Consumo de Oxígeno , Carrera , Prueba de Esfuerzo/métodos , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Oxígeno , Consumo de Oxígeno/fisiología , Carrera/fisiología , Caminata/fisiología
14.
Proc Biol Sci ; 289(1966): 20211968, 2022 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-35016537

RESUMEN

Suction-feeding in fishes is a ubiquitous form of prey capture whose outcome depends both on the movements of the predator and the prey, and on the dynamics of the surrounding fluid, which exerts forces on the two organisms. The inherent complexity of suction-feeding has challenged previous efforts to understand how the feeding strikes are modified when species evolve to feed on different prey types. Here, we use the concept of dynamic similarity, commonly applied to understanding the mechanisms of swimming, flying, walking and aquatic feeding. We characterize the hydrodynamic regimes pertaining to (i) the forward movement of the fish (ram), and (ii) the suction flows for feeding strikes of 71 species of acanthomorph fishes. A discriminant function analysis revealed that feeding strikes of zooplanktivores, generalists and piscivores could be distinguished based on their hydrodynamic regimes. Furthermore, a phylogenetic comparative analysis revealed that there are distinctive hydrodynamic adaptive peaks associated with zooplanktivores, generalists and piscivores. The scaling of dynamic similarity across species, body sizes and feeding guilds in fishes indicates that elementary hydrodynamic principles govern the trophic evolution of suction-feeding in fishes.


Asunto(s)
Hidrodinámica , Natación , Animales , Fenómenos Biomecánicos , Conducta Alimentaria , Peces , Masculino , Filogenia , Conducta Predatoria , Succión
15.
Nurs Open ; 9(6): 2657-2664, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-34132062

RESUMEN

AIM: The aim of this study was to explore patients' experiences of preventive anticoagulation therapy in atrial fibrillation. DESIGN: This was a descriptive qualitative study based on interviews. METHODS: Individual interviews with 15 patients, 6 women and 9 men, treated with preventive oral anticoagulant due to atrial fibrillation, were conducted. The interviews were analysed with qualitative content analysis. RESULTS: Based on the analysis, the theme Managing a necessary evil emerged. The theme comprised the three categories: Coping with anxiety and changes in daily life, Having confidence in care and Being a partner or only a receiver of treatment. Patients described it like being faced with a situation where a treatment perceived as vital was weighed against undesirable consequences and risks. Patients trusted caregivers and had confidence in care, but there was a risk of being a receiver of care instead of becoming a partner.


Asunto(s)
Fibrilación Atrial , Humanos , Masculino , Femenino , Fibrilación Atrial/complicaciones , Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/inducido químicamente , Anticoagulantes/uso terapéutico , Anticoagulantes/efectos adversos , Coagulación Sanguínea , Investigación Cualitativa , Administración Oral
16.
Front Physiol ; 12: 687566, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34295264

RESUMEN

PURPOSE: Quantifying intensities of physical activities through measuring oxygen uptake (V̇O2) is of importance for understanding the relation between human movement, health and performance. This can in principle be estimated by the heart rate (HR) method, based on the linear relationship between HR and V̇O2 established in the laboratory. It needs, however, to be explored whether HR methods, based on HR-V̇O2 relationships determined in the laboratory, are valid for estimating spectrums of V̇O2 in field exercise. We hereby initiate such studies, and use cycle commuting as the form of exercise. METHODS: Ten male and ten female commuter cyclists underwent measurements of HR and V̇O2 while performing ergometer cycling in a laboratory and a normal cycle commute in the metropolitan area of Stockholm County, Sweden. Two models of individual HR-V̇O2 relationships were established in the laboratory through linear regression equations. Model 1 included three submaximal work rates, whereas model 2 also involved a maximal work rate. The HR-V̇O2 regression equations of the two models were then used to estimate V̇O2 at six positions of field HR: five means of quintiles and the mean of the whole commute. The estimations obtained were for both models compared with the measured V̇O2. RESULTS: The measured quintile range during commuting cycling was about 45-80% of V̇O2max. Overall, there was a high resemblance between the estimated and measured V̇O2, without any significant absolute differences in either males or females (range of all differences: -0.03-0.20 L⋅min-1). Simultaneously, rather large individual differences were noted. CONCLUSION: The present HR methods are valid at group level for estimating V̇O2 of cycle commuting characterized by relatively wide spectrums of exercise intensities. To further the understanding of the external validity of the HR method, there is a need for studying other forms of field exercises.

17.
Br J Haematol ; 193(5): 915-921, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33782950

RESUMEN

Clinical trials show that tyrosine kinase inhibitor (TKI) treatment can be discontinued in selected patients with chronic myeloid leukaemia (CML). Although updated CML guidelines support such procedure in clinical routine, data on TKI stopping outside clinical trials are limited. In this retrospective study utilising the Swedish CML registry, we examined TKI discontinuation in a population-based setting. Out of 584 patients diagnosed with chronic-phase CML (CML-CP) in 2007-2012, 548 had evaluable information on TKI discontinuation. With a median follow-up of nine years from diagnosis, 128 (23%) discontinued TKI therapy (≥1 month) due to achieving a DMR (deep molecular response) and 107 (20%) due to other causes (adverse events, allogeneic stem cell transplant, pregnancy, etc). Among those stopping in DMR, 49% re-initiated TKI treatment (median time to restart 4·8 months). In all, 38 patients stopped TKI within a clinical study and 90 outside a study. After 24 months 41·1% of patients discontinuing outside a study had re-initiated TKI treatment. TKI treatment duration pre-stop was longer and proportion treated with second-generation TKI slightly higher outside studies, conceivably affecting the clinical outcome. In summary we show that TKI discontinuation in CML in clinical practice is common and feasible and may be just as successful as when performed within a clinical trial.


Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/administración & dosificación , Sistema de Registros , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/diagnóstico , Leucemia Mielógena Crónica BCR-ABL Positiva/mortalidad , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Suecia/epidemiología
19.
PLoS One ; 15(8): e0237388, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32760167

RESUMEN

INTRODUCTION: The heart rate (HR) method is a promising approach for evaluating oxygen uptake ([Formula: see text]), energy demands and exercise intensities in different forms of physical activities. It would be valuable if the HR method, established on ergometer cycling, is interchangeable with other regular activities, such as level walking. This study therefore aimed to examine the interchangeability of the HR method when estimating [Formula: see text] for ergometer cycling and level treadmill walking in submaximal conditions. METHODS: Two models of [Formula: see text] regression equations for cycle ergometer exercise (CEE) and treadmill exercise (TE) were established with 34 active commuters. Model 1 consisted of three submaximal intensities of ergometer cycling or level walking, model 2 included also one additional workload of maximal ergometer cycling or running. The regression equations were used for estimating [Formula: see text] with seven individual HR values based on 25-85% of HR reserve (HRR). The [Formula: see text] estimations were compared between CEE and TE, within and between each model. RESULTS: Only minor, and in most cases non-significant, average differences were observed when comparing the estimated [Formula: see text] levels between CEE and TE. Model 1 ranged from -0.4 to 4.8% (n.s.) between 25-85%HRR. In model 2, the differences between 25-65%HRR ranged from 1.3 to -2.7% (n.s.). At the two highest intensities, 75 and 85%HRR, [Formula: see text] was slightly lower (3.7%, 4.4%; P < 0.05), for CEE than TE. The inclusion of maximal exercise in the [Formula: see text] relationships reduced the individual [Formula: see text] variations between the two exercise modalities. CONCLUSION: The HR methods, based on submaximal ergometer cycling and level walking, are interchangeable for estimating mean [Formula: see text] levels between 25-85% of HRR. Essentially, the same applies when adding maximal exercise in the [Formula: see text] relationships. The inter-individual [Formula: see text] variation between ergometer cycling and treadmill exercise is reduced when using the HR method based on both submaximal and maximal workloads.


Asunto(s)
Ergometría/instrumentación , Prueba de Esfuerzo/instrumentación , Frecuencia Cardíaca , Caminata/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oxígeno/metabolismo
20.
Integr Comp Biol ; 60(5): 1251-1267, 2020 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-32333778

RESUMEN

The complex interplay between form and function forms the basis for generating and maintaining organismal diversity. Fishes that rely on suction-feeding for prey capture exhibit remarkable phenotypic and trophic diversity. Yet the relationships between fish phenotypes and feeding performance on different prey types are unclear, partly because the morphological, biomechanical, and hydrodynamic mechanisms that underlie suction-feeding are complex. Here we demonstrate a general framework to investigate the mapping of multiple phenotypic traits to performance by mapping kinematic variables to suction-feeding capacity. Using a mechanistic model of suction-feeding that is based on core physical principles, we predict prey capture performance across a broad range of phenotypic trait values, for three general prey types: mollusk-like prey, copepod-like prey, and fish-like prey. Mollusk-like prey attach to surfaces, copepod-like prey attempt to escape upon detecting the hydrodynamic disturbance produced by the predator, and fish-like prey attempt to escape when the predator comes within a threshold distance. This approach allowed us to evaluate suction-feeding performance for any combination of six key kinematic traits, irrespective of whether these trait combinations were observed in an extant species, and to generate a multivariate mapping of phenotype to performance. We used gradient ascent methods to explore the complex topography of the performance landscape for each prey type, and found evidence for multiple peaks. Characterization of phenotypes associated with performance peaks indicates that the optimal kinematic parameter range for suction-feeding on different prey types are narrow and distinct from each other, suggesting different functional constraints for the three prey types. These performance landscapes can be used to generate hypotheses regarding the distribution of extant species in trait space and their evolutionary trajectories toward adaptive peaks on macroevolutionary fitness landscapes.


Asunto(s)
Conducta Alimentaria , Peces , Hidrodinámica , Modelos Biológicos , Animales , Fenómenos Biomecánicos , Conducta Predatoria , Succión
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...