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BACKGROUND: The aims of this cross-sectional study were to (a) assess actigraphy-based sleep parameters (total sample and gender differences), (b) assess differences in morphological parameters and physical function between short- versus normal-sleepers and poor- versus good-sleepers, and (c) assess the possible correlations between sleep variables and morphological and physical function parameters in older subjects. METHODS: This study enrolled 42 healthy older participants (60-80 years). Participants completed the following clinical evaluations: (1) whole-body dual-energy X-ray absorptiometry to assess the appendicular skeletal muscle mass index; (2) magnetic resonance imaging acquisition to determine the cross-sectional muscle area of thigh muscles and intermuscular adipose tissue; (3) risk of fall assessment through the mini-Balance Evaluation Systems Test; (4) strength assessment: (a) chair stand test and (b) handgrip strength test; (5) sleep monitoring by actigraphy to assess total sleep time, sleep efficiency, wake after sleep onset, sleep latency, fragmentation index, mobile time, and subjective sleep quality. RESULTS: 31.0% of subjects were short-sleepers (total sleep time < 6 hr), 19.1% were poor-sleepers (sleep efficiency < 85%), and gender differences were detected in mobile time (males: 15.8 ± 6.0 and females: 13.4 ± 6.8; p < .001) and fragmentation index (males: 35.3 ± 14.3 and females: 29.6 ± 14.6; p < .001); no significant differences were observed between groups (short- vs. normal-sleepers and poor- vs. good-sleepers) in morphological and physical function variables; correlation analysis showed that sleep latency negatively correlated with Mini-Balance Evaluation Systems Test (r = -.352; p = .022) and a positive correlation was detected between cross-sectional muscle area and mobile time (r = .349, p = .023). CONCLUSION: No differences were observed in morphological and function parameters between good- versus poor-sleepers, those subjects with worse sleep onset latency (i.e., longer time to fall asleep) registered higher for risk of fall. The potential role of sleep in the physiological mechanisms of muscular aging must be explored through cross-sectional cohort studies with a larger population.
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OBJECTIVES: With the aim to better identify talented Track & Field performance development, this study estimated the relationships between chronological (decimal) age with 60-m sprint, high jump, triple jump, and pole vault performance. Then, to mitigate against expected Relative Age Effects (RAEs), Corrective Adjustment Procedures (CAPs) were applied to an independent sample. DESIGN: Mixed-longitudinal design examining public data between 2005 and 2019. METHODS: The performances of 5339 Italian sprinters and jumpers (53.1â¯%) spanning 11.01-17.99â¯years of age were examined, with trendlines between chronological age and performance established. Related to an independent sample (Nâ¯=â¯40,306; female 45.5â¯%), trendlines were then utilised to apply CAPs and adjust individual performance. Considering raw and adjusted performance data, RAE distributions were examined for the top 25â¯% and 10â¯% performers. RESULTS: For all male and female events, quadratic models best summarised the relationships between chronological age and performance (R2â¯=â¯0.74-0.89). When examining independent athletes in similar event, RAEs were more pronounced in males (Cramer's Vâ¯=â¯0.35-0.14) than females (Cramer's Vâ¯=â¯0.29-0.07). For both sexes, RAE magnitude decreased with age and increased according to performance level (i.e., Top25%-Top10%). However, following CAP applications, RAEs were reduced or removed within annual age groups and performance levels. CONCLUSIONS: With RAEs prevalent across Italian youth Track & Field events, findings validate CAPs as a strategy to account for the influence of relative age differences on athletic performance. CAPs help establish a more equitable strategy for performance evaluation and could help improve the efficacy of long-term athlete development programming.
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Desempenho Atlético , Atletismo , Humanos , Feminino , Masculino , Adolescente , Criança , Desempenho Atlético/fisiologia , Fatores Etários , Estudos Longitudinais , Itália , AptidãoRESUMO
Newly acquired motor skills can be critically driven by different rest periods during practice. Specifically, in the initial stages of motor skill acquisition, the interval between individual trials plays a pivotal role in facilitating effective motor performance, such as in the case of throwing. The objective of this research was to determine the optimal inter-trial rest period promoting efficient motor performance, focusing on two specific motor task actions. In a randomized counterbalanced cross-over research design 169 high-school students aged 14 were studied (M = 150; F = 19). In one block, participants performed 10 basketball free throws with a short rest interval (< 5 s) and 10 other throws with a long rest interval (â¼50-60 s). In a second block, they threw a regular size tennis ball into a 1-m diameter circle on the floor at 6.75 m, again throwing 10 times with a short inter-trial rest interval and 10 times with a long inter-trial rest interval. The order of the rest intervals within each block was randomized and counterbalanced. With a repeated measures two-way analysis of variance, greater accuracy seemed to be associated with short intra-set rest intervals as there were significant main effects of both conditions (F1,167 = 368.0, p < 0.001, η2p = 0.271) and resting time (F1,167 = 18.6, p < 0.001, η2p = 0.192) and no significant interaction "condition by time". Fast practice was efficient independently of the complexity of the throwing task, suggesting robust support for schema theory.
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Aprendizagem , Destreza Motora , Humanos , Adolescente , Projetos de PesquisaRESUMO
BACKGROUND: The aim of this study was to assess the effectiveness of a new Short Intermittent Taekwondo Test (SITT) in 17 black belt athletes. METHODS: Maximal oxygen uptake (VÌO
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Teste de Esforço , Consumo de Oxigênio , Humanos , Consumo de Oxigênio/fisiologia , Ácido Láctico , Frequência Cardíaca/fisiologia , Atletas , MetabolomaRESUMO
OBJECTIVE: The first COVID-19 lockdown was a very restrictive situation that may have impacted on the prevalence and patterns of cannabis use. The aim of this systematic review was to assess the evidence on cannabis use and reasons for use in different countries during first lockdown in young adults and general population. METHODS: This study followed PRISMA guidelines, and the review protocol was registered in PROSPERO (registration CRD42022303181). The search was carried out in PubMed, Scopus, Web of Science y Embase databases. Inclusion criteria were: cross-sectional or cohort studies; population ≥16 years; exploring cannabis use during lockdown; and English or Spanish language. RESULTS: Thirty studies, conducted in European countries (n=17), North America (n=12) and rest of the world (n=1), were analysed. The overall prevalence of cannabis use was found to be largely unchanged, but regular users tended to maintain (between 39.5% and 96.8% of the sample) or increase cannabis use (between 2.9% and 51.6%). The main decreases were among occasional users. Some reasons for the increase were boredom, loneliness, stress, coping and depressive symptoms. In addition, young people were the heaviest users, and being younger, live without family, financial problems and a low educational level were significantly (p-value<0.05) associated with increased use. CONCLUSIONS: Most regular users maintained or slightly increased their use, with young people being the main users. Concerning reasons for use like coping and depressive symptoms were found. Cannabis use needs to be addressed with strategies focused on the young population, considering occasional and regular use, as well as motivations.
OBJETIVO: El primer confinamiento por la COVID-19 fue una situación muy restrictiva que pudo haber impactado sobre la prevalencia y los patrones de consumo de cannabis. El objetivo de esta revisión sistemática fue evaluar la evidencia sobre el consumo y los motivos de consumo de cannabis en diferentes países durante el primer confinamiento en adultos jóvenes y población general. METODOS: Este estudio siguió las directrices PRISMA y el protocolo de revisión se registró en PROSPERO (registro CRD42022303181). Se realizó una búsqueda en las bases de datos PubMed, Scopus, Web of Science y Embase en julio de 2023. Los criterios de inclusión fueron: estudios transversales o de cohortes; población con edad igual o mayor de 16 años; explorar el consumo durante el confinamiento; e idioma inglés o español. RESULTADOS: Se analizaron treinta estudios, realizados en países europeos (n=17), norteamericanos (n=12) y resto del mundo (n=1). Se observó que la prevalencia global de consumo de cannabis no experimentó grandes cambios, pero los consumidores regulares tendieron a mantener (entre el 39,5% y el 96,8% de la muestra) o a incrementar el consumo (entre el 2,9% y el 51,6%). Las principales disminuciones se dieron en consumidores ocasionales. Algunos motivos para el aumento fueron aburrimiento, soledad, estrés, afrontamiento y síntomas depresivos. Además, los jóvenes fueron los mayores consumidores y ser más joven, vivir sin la familia, los problemas financieros y un bajo nivel de estudios se asociaron significativamente (p-valor menor de 0,05) con el aumento del consumo. CONCLUSIONES: La mayor parte de consumidores regulares mantuvieron o aumentaron ligeramente su consumo, siendo los jóvenes los principales consumidores. Se encontraron motivos de consumo alarmantes como el afrontamiento y los síntomas depresivos. Es necesario que el consumo de cannabis se aborde con estrategias enfocadas en la población joven, considerando el consumo ocasional y regular, así como las motivaciones.
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COVID-19 , Cannabis , Humanos , Adulto Jovem , Adolescente , COVID-19/epidemiologia , Estudos Transversais , Pandemias , Controle de Doenças Transmissíveis , EspanhaRESUMO
The phenomenon of doping is a public health issue that poses threats to sport and society. In recent decades, the emphasis on efforts to address the issue and reduce the incidence of doping by young people in sport has shifted from deterrence through testing and punishment to the promotion of clean sport behaviours through values-based education. The "I Run Clean project" sought to develop new and effective tools targeting grassroots athletes and those around them (coaches, medical support personnel, sport leaders, parents). These included sport-specific e-learning and in-person peer-to-peer workshops led by trained volunteer ambassadors. The aim of all "I Run Clean" measures is to go beyond the warnings and provision of factual information about early anti-doping campaigns to a more holistic educational approach that focuses participants on their personal and sport-related values in order to encourage good decision-making and resistance to doping-related behaviours. This study evaluates the efficacy of the peer-to-peer workshops and their impact on selected psycho-social variables. The collaboration of the volunteer ambassadors is shown to effectively transmit the desired reasoning, reduce doping risk factors and enhance protective factors.
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The purpose of this study was to investigate the effects of partial-body cryostimulation on middle-distance runners before two 3000-m tests at the speed of the first and second ventilatory threshold, and before a time to exhaustion test at 110% of the maximal aerobic speed. Twelve amateur runners (age: 46 ± 9 years; VO2max: 51.7 ± 4.9 ml·kg-1·min-1) completed six running testing sessions in a randomized counterbalanced cross-over fashion: three of them were preceded by a partial-body cryostimulation and the other three by a control condition. The testing sessions consisted of: 1) a 3000-m continuous running test at the speed of the first ventilatory threshold; 2) a 3000-m continuous running test at the speed of the second ventilatory threshold; 3) a time to exhaustion test at 110% of the maximal aerobic speed. Heart rate, ratings of perceived exertion and visual analogue scale relative to muscle pain were recorded throughout the tests. Total quality recovery was evaluated 24-48 h after the end of each test. Distance to exhaustion was higher after partial-body cryostimulation than control condition (p = 0.018; partial-body cryostimulation: 988 ± 332 m, control: 893 ± 311 m). There were differences in the ratings of perceived exertion during each split of the 3000-m continuous running test at the speed of the second ventilatory threshold (p = 0.001). Partial-body cryostimulation can be positively considered to enhance middle-distance running performance and reduce perception of effort in amateur runners.
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Vacinas Anticâncer , Corrida , Adulto , Humanos , Pessoa de Meia-Idade , Atletas , Frequência Cardíaca/fisiologia , Consumo de Oxigênio/fisiologia , Corrida/fisiologia , Fatores de Tempo , Estudos Cross-OverRESUMO
PURPOSE: Few data are available on sleep characteristics of elite track-and-field athletes. Our study aimed to assess (1) differences in sleep between sexes and among different track-and-field disciplines, (2) the effect of individualized sleep-hygiene strategies on athletes' sleep parameters, and (3) daytime nap characteristics in track-and-field athletes. METHODS: Sleep characteristics of 16 elite Olympic-level track-and-field athletes (male: n = 8; female: n = 8) were assessed during the preseason period, at baseline (T0), and during the in-season period, after the adoption of individualized sleep-hygiene strategies (T1). Sleep parameters were objectively monitored by actigraphy for a minimum of 10 days, for each athlete, at both T0 and T1. A total of 702 nights were analyzed (T0 = 425; T1 = 277). RESULTS: Female athletes displayed better sleep efficiency (88.69 [87.69-89.68] vs 91.72 [90.99-92.45]; P = .003, effect size [ES]: 0.44), lower sleep latency (18.99 [15.97-22.00] vs 6.99 [5.65-8.32]; P < .001, ES: 0.65), higher total sleep time (07:03 [06:56-07:11] vs 07:18 [07:10-07:26]; P = .030, ES: 0.26), earlier bedtime (00:24 [00:16-00:32] vs 00:13 [00:04-00:22]; P = .027, ES: 0.18), and lower nap frequency (P < .001) than male athletes. Long-distance runners had earlier bedtime (00:10 [00:03-00:38] vs 00:36 [00:26-00:46]; P < .001, ES: 0.41) and wake-up time (07:41 [07:36-07:46] vs 08:18 [08:07-08:30]; P < .001, ES: 0.61), higher nap frequency, but lower sleep efficiency (88.79 [87.80-89.77] vs 91.67 [90.95-92.38]; P = .013, ES: 0.44), and longer sleep latency (18.89 [15.94-21.84] vs 6.69 [5.33-8.06]; P < .001, ES: 0.67) than athletes of short-term disciplines. Furthermore, sleep-hygiene strategies had a positive impact on athletes' total sleep time (429.2 [423.5-434.8] vs 451.4 [444.2-458.6]; P < .001, ES: 0.37) and sleep latency (14.33 [12.34-16.32] vs 10.67 [8.66-12.68]; P = .017, ES: 0.19). CONCLUSIONS: Sleep quality and quantity were suboptimal at baseline in Olympic-level track-and-field athletes. Large differences were observed in sleep characteristics between sexes and among different track-and-field disciplines. Given the positive effect of individualized sleep-hygiene strategies on athlete's sleep, coaches should implement sleep education sessions in the daily routine of top-level athletes.
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Distinções e Prêmios , Atletismo , Humanos , Masculino , Feminino , Tóquio , Sono , Atletas , HigieneRESUMO
BACKGROUND: Poor information is available regarding real field data on the different factors that could have an influence on curve sprint and its association with anthropometric and strength parameters. METHODS: We designed a crossover pilot-study that enrolled 14 track and field athletes of 200 and 400 m (8/14 men, age: 20.5±2.3 years, height: 1.73±0.06 m; body mass: 60.5±6.2 kg) that performed randomly in two different days assessment of anthropometric parameters, jump test by squat jump (SJ) and triple hop distance (THD), performance during a 20-m curve sprint (day 1), and assessment of 1RM for right and left limb on Bulgarian split squat (BSS) (day 2). The unpaired t test and Pearson's correlation were used for data analysis. RESULTS: No statistical differences for anthropometric and strength parametric parameters between right and left lower limbs were observed. Twenty-meter curve sprints were negatively associated with body mass (P=0.0059, R=-0.7) and Body Mass Index (BMI; P=0.032, R=0.6). Moreover, a negative association was observed with SJ height (P=0.0025, R=-0.7), speed (P=0.0028; R=-0.7), strength (P=0.009, R=-0.7) and power (P=0.009, R=-0.7). Finally, 20-m curve sprint negatively correlated with right (P=0.0021, R=-0.7) and left (P<0.0001, R=-0.9) THD and 1 RM right (P=0.025, R=-0.6;) and left (P=0.0049, R=-0.7) BSS, respectively. CONCLUSIONS: This pilot study demonstrated that 20-m curve sprint was negatively associated with body mass, BMI, vertical jump performance, THD and 1RM BSS. This information could be useful to coaches and sport scientists as a reference value to improve athlete performance for 200- and 400-m athletes.
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Desempenho Atlético , Corrida , Atletismo , Masculino , Humanos , Adolescente , Adulto Jovem , Adulto , Projetos Piloto , Força MuscularRESUMO
BACKGROUND: Although physical activity (PA) has been recognized as a favourable factor in the prevention of various diseases, including certain forms of cancer, the relationship between PA and gastric cancer (GC) is not yet fully understood. This study aims to provide data from a pooled analysis of case-control studies within the Stomach cancer Pooling (StoP) Project to estimate the association between leisure-time PA and the occurrence of GC. METHODS: Six case-control studies from StoP project collected data on leisure-time PA, for a total of 2,343 cases and 8,614 controls. Subjects were classified into three leisure-time PA categories, either none/low, intermediate or high, based on study-specific tertiles. We used a two-stage approach. Firstly, we applied multivariable logistic regression models to obtain study-specific odds ratios (ORs) and corresponding 95% confidence intervals (CIs) then, we used a random-effect models to obtain pooled effect estimates. We performed stratified analyses according to demographic, lifestyle and clinical covariates. RESULTS: The meta-analysis showed ORs of GC with no significant differences between intermediate vs low and high vs low PA level (OR 1.05 [95%CI 0.76-1.45]; OR 1.23 [95%CI 0.78-1.94], respectively). GC risk estimates did not strongly differ across strata of selected covariates except for age ≤ 55 years old (high vs low level: OR 0.72 [95%CI 0.55-0.94]) and for control population-based studies (high vs low level: OR 0.79 [95%CI 0.68-0.93]). CONCLUSIONS: No association was found between leisure time PA and GC, apart from a slight suggestion of decreased risk below age 55 and in control population-based studies. These results may reflect specific characteristics of GC at a younger age, or the presence of a cohort effect mediating and interacting with socioeconomic determinants of GC The different distribution of PA levels among hospitalized controls could have led to an underestimated effect of PA on GC risk.
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Neoplasias Gástricas , Humanos , Pessoa de Meia-Idade , Neoplasias Gástricas/epidemiologia , Atividade Motora , Exercício Físico , Atividades de LazerRESUMO
Partial Body Cryostimulation (PBC) involves a very cold air flow directed to the body of subjects with minimal clothing. PBC is performed in a rapid timeframe, inside an on-purposed designed cryo-cabin. Recently, cryo-cabins have been built with different energy systems, however a validation study on relative thermal responses is missing. This study was aimed at comparing thermal responses following a PBC in an electrically powered cryo-cabin based on forced convection or into a standard nitrogen-fueled cryo-cabin. In a randomized crossover fashion, thirty-six subjects (F=20; M=16) underwent both cryo-exposures lasting 150 s each. Thermal responses were assessed before and immediately after completing each PBC session. Mixed model analysis of variance revealed a significantly colder temperature after electric PBC in all the body regions (except for the thighs) with respect to a standard nitrogen based PBC (F: 16.4 ± 1.4 vs 18 ± 5.8 °C; M: 16.4 ± 1.7 vs 20.9 ± 4 °C). Moreover, a significant lower thermal discomfort was perceived at the end of electric PBC as compared to that one felt following standard PBC. For the first time, the safety and thermo-effectiveness of an electric cryo-cabin based on forced convection was ensured. This methodology can be viable for practitioners of PBC and clinicians.
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Temperatura Baixa , Convecção , HumanosRESUMO
The main purpose was to compare by each training the mental load and fatigue reported by semiprofessional soccer players comparing between regular season phase and the play-offs. Fifty-three players (Mage = 24.59 years) for two teams participated during the 2020/21 season. Mental load was measured with a Likert questionnaire. Mental fatigue was quantified with a Visual Analogue Scale. Four trainings were recorded each week (Monday = MD+1, Wednesday = MD-4, Thursday = MD-3 and Saturday = MD-1), with a competitive match on Sunday across 10 weeks (five dates of regular season - five dates of play-offs). A Linear Mixed Model was performed with R-studio, using the training days and the competitive phase as independent variables. The influence of time played as co-variable was also checked. Results showed MD+1 as the more mentally fatiguing day in both phases, although MD-4 were the training with higher mental load reported (p = 0.001). Comparing phases, mental fatigue was significantly higher during the play-offs (p = 0.037). With regard time played, players that did not usually play showed a decrease in mental load during the play-offs. Then, we recommend coaches to use recovery strategies for mental fatigue, avoid mentally fatiguing tasks close to competition and considerer the time played as a factor which may contribute to individual differences in player mental fatigue.
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Condicionamento Físico Humano , Futebol , Humanos , Adulto Jovem , Adulto , Estações do Ano , Modelos Lineares , Inquéritos e QuestionáriosRESUMO
Background: A training program can stimulate physiological, anatomical, and performance adaptations, but these improvements can be partially or entirely reversed due to the cessation of habitual physical activity resulting from illness, injury, or other influencing factors. Purpose: To investigate the effects of detraining on cardiorespiratory, metabolic, hormonal, muscular adaptations, as well as short-term and long-term performance changes in endurance athletes. Methods: Eligible studies were sourced from databases and the library up until July 2023. Included studies considered endurance athletes as subjects and reported on detraining duration. Results: Total cessation of training leads to a decrease in VO2max due to reductions in both blood and plasma volume. Cardiac changes include decreases in left ventricular mass, size, and thickness, along with an increase in heart rate and blood pressure, ultimately resulting in reduced cardiac output and impaired performance. Metabolically, there are declines in lactate threshold and muscle glycogen, increased body weight, altered respiratory exchange ratio, and changes in power parameters. In the short term, there is a decrease in insulin sensitivity, while glucagon, growth hormone, and cortisol levels remain unchanged. Skeletal muscle experiences reductions in arterial-venous oxygen difference and glucose transporter-4. Implementing a partial reduction in training may help mitigate drastic losses in physiological and performance parameters, a consideration when transitioning between training seasons. Conclusion: There is a dearth of data investigating the detraining effects of training reduction/cessation among endurance athletes. Delving deeper into this topic may be useful for professionals and researchers to identify the optimal strategies to minimize these effects.
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The target of the rapamycin (TOR) signaling pathway plays a negative role in controlling virulence in phytopathogenic fungi. However, the actual targets involved in virulence are currently unknown. Using the corn smut fungus Ustilago maydis, we tried to address the effects of the ectopic activation of TOR on virulence. We obtained gain-of-function mutations in the Rheb GTPase, one of the conserved TOR kinase regulators. We have found that unscheduled activation of Rheb resulted in the alteration of the proper localization of the pheromone receptor, Pra1, and thereby pheromone insensitivity. Since pheromone signaling triggers virulence in Ustilaginales, we believe that the Rheb-induced pheromone blindness was responsible for the associated lack of virulence. Strikingly, although these effects required the concourse of the Rsp5 ubiquitin ligase and the Art3 α-arrestin, the TOR kinase was not involved. Several eukaryotic organisms have shown that Rheb transmits environmental information through TOR-dependent and -independent pathways. Therefore, our results expand the range of signaling manners at which environmental conditions could impinge on the virulence of phytopathogenic fungi.
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Ustilago , Ustilago/genética , Feromônios/metabolismo , Proteína Enriquecida em Homólogo de Ras do Encéfalo/genética , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Zea mays/metabolismo , Fungos/metabolismo , Cegueira , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismoRESUMO
Aldehyde dehydrogenase 1A1 (ALDH1A1) is a cancer stem cell (CSC) marker related to clinical outcomes in breast cancer (BC). The aim of this study was to analyze the relationship between ALDH1A1, programmed death ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) in triple negative (TN) and human epidermal growth factor receptor 2-positive (HER2+) BC tumors, and its association with clinicopathological characteristics and outcomes. A retrospective, historical cohort study of patients diagnosed with early or locally advanced BC treated with neoadjuvant chemotherapy was conducted. ALDH1A1, PD-L1 expression and TILs were assessed using immunohistochemistry. A total of 75 patients were analyzed (42.7% TN, 57.3% HER2+ tumors). ALDH1A1+ was related to HTILs (p = 0.005) and PD-L1+ tumors (p = 0.004). ALDH1A1+ tumors presented higher CD3+ (p = 0.008), CD4+ (p = 0.005), CD8+ (p = 0.003) and CD20+ (p = 0.006) TILs. ALDH1A1+ (p = 0.018), PD-L1+ (p = 0.004) and HTILs (p < 0.001) were related to smaller tumors. ALDH1A1+ was related to pathologic complete response (pCR) (p = 0.048). At the end of the follow-up (54.4 [38.3−87.6] months), 47 patients (62.7%) remained disease-free, and 20 (26.7%) had died. HTILs were related to improved disease-free survival (p = 0.027). ALDH1A1+ was related to PD-L1+ and HITLs, that might be related to higher pCR rates with neoadjuvant therapy.
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BACKGROUND: Toenails are commonly used as biomarkers of exposure to zinc (Zn), but there is scarce information about their relationship with sources of exposure to Zn. OBJECTIVES: To investigate the main determinants of toenail Zn, including selected sources of environmental exposure to Zn and individual genetic variability in Zn metabolism. METHODS: We determined toenail Zn by inductively coupled plasma mass spectrometry in 3,448 general population controls from the MultiCase-Control study MCC-Spain. We assessed dietary and supplement Zn intake using food frequency questionnaires, residential proximity to Zn-emitting industries and residential topsoil Zn levels through interpolation methods. We constructed a polygenic score of genetic variability based on 81 single nucleotide polymorphisms in genes involved in Zn metabolism. Geometric mean ratios of toenail Zn across categories of each determinant were estimated from multivariate linear regression models on log-transformed toenail Zn. RESULTS: Geometric mean toenail Zn was 104.1 µg/g in men and 100.3 µg/g in women. Geometric mean toenail Zn levels were 7 % lower (95 % confidence interval 1-13 %) in men older than 69 years and those in the upper tertile of fibre intake, and 9 % higher (3-16 %) in smoking men. Women residing within 3 km from Zn-emitting industries had 4 % higher geometric mean toenail Zn levels (0-9 %). Dietary Zn intake and polygenic score were unrelated to toenail Zn. Overall, the available determinants only explained 9.3 % of toenail Zn variability in men and 4.8 % in women. DISCUSSION: Sociodemographic factors, lifestyle, diet, and environmental exposure explained little of the individual variability of toenail Zn in the study population. The available genetic variants related to Zn metabolism were not associated with toenail Zn.
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Unhas , Zinco , Biomarcadores/análise , Exposição Ambiental/análise , Feminino , Humanos , Masculino , Unhas/química , Compostos Orgânicos/análise , Solo , Espanha , Zinco/análiseRESUMO
The aim of this cross-sectional study was to investigate the association between lower limb strength, muscle mass and composition, and balance ability in elders. Thirthy-four older participants (Age: 65.6 ± 4.73 years; male = 10 and female = 24) were assessed for muscle strength (maximal isometric strength of knee extensors and one repetition maximum by leg press, the one repetition maximum [1RM]), balance and gait capacity (Mini-BESTest), body composition by whole-body dual energy x-ray absorptiometry (obtaining Appendicular Skeletal Muscle Mass Index, ASMMI), and magnetic resonance imaging of thigh to evaluate Intermuscular Adipose Tissue (IMAT) and muscle Cross Sectional Area (CSA). Positive correlations between 1RM and ASMMI (rs = 0.64, P < .0001) and thigh CSA (rs = 0.52, P = .0017), but not with thigh IMAT, were found. In addition, significant correlations between knee extensors strength and ASMMI (rs = 0.48, P = .004) and thigh CSA (rs = 0.49, P = .0033) and IMAT (rs = -0.35, P = .043) were observed, whereas no significant correlations between the Mini-BESTest with ASMMI, thigh CSA, and IMAT were observed. Lower limb strength positively correlated with appendicular muscle mass. Further, the maximal isometric strength of knee extensors negatively correlated with thigh IMAT in elderly patients, whereas the dynamic balance ability did not correlate with any of the morphological variables of the muscle (i.e., ASMMI, CSA, and IMAT). A reduced muscle size and strength could affect movement and reduce physical function in older patients. Improving the composition and size of muscle in elder subjects could reduce frailty and risk of falls.