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1.
Curr Treat Options Oncol ; 22(3): 22, 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33560505

RESUMO

OPINION STATEMENT: The vast majority of patients newly diagnosed with melanoma present with clinically localized disease, and sentinel lymph node biopsy (SLNB) is a standard of care in the management of these patients, particularly in intermediate thickness cases, in order to provide important prognostic data. However, SLNB also has an important role in the management of patients with other subtypes of melanoma such as thick melanomas, certain thin melanomas, and specific histologic variants of melanoma such as desmoplastic melanoma. Furthermore, there have been technical advances in the SLNB technique, such as the development of newer radiotracers and use of SPECT/CT, and there is some data to suggest performing a SLNB may be therapeutic. Finally, the management of patients with a positive sentinel lymph node (SLN) has undergone dramatic changes over the past several years based on the results of recent important clinical trials. Treatment options for patients with SLN metastases now include surveillance, completion lymph node dissection, and adjuvant therapy with checkpoint inhibitors and targeted therapy. SLNB continues to play a crucial role in the management of patients with melanoma, allowing for risk stratification, potential regional disease control, and further treatment options for patients with a positive SLN.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33469993

RESUMO

The aim of this study was to assess the effects of feeding immunized egg proteins (IEP) on the health and performance of newborn dairy calves. Sixty-four Holstein calves, both male and female, were divided over two treatments. Calves either received IEP or a placebo (PCB) in their colostrum and calf milk replacer (CMR) for the first 14 days of their life. Until day 49, CMR was offered at 15% of birth weight (BW), at 10% on days 49-57 and at 5% on days 57-63. In addition, calves received starter concentrate, chopped straw and water from 3 days old until 70 days old at the end of study. Individual CMR and concentrate intake were measured daily whilst BW was recorded weekly. Visual faecal scoring and health observations were conducted daily. Faecal samples were collected weekly up to 4 weeks and during the first 4 days of scouring to screen for presence of Cryptosporidium parvum, rotavirus, coronavirus, E. coli and Salmonella. Results indicated that feeding IEP increased BW (p < .05) at 42 and 56 days old, and BW also tended (p = .06) to be higher after weaning at 63-70 days old compared to the PCB group. When analysed using a repeated measures model, compared to feeding PCB, feeding IEP increased total concentrate consumption (p = .001) by 3.6kg/calf. Over the entire study, daily water intake was higher (p = .002) for the IEP group when compared with the PCB group. In the IEP group, 12 calves were scored as scouring whereas there were 14 calves in the PCB group. There were no significant differences between treatments in faecal pathogen load of neither healthy nor scouring calves. In conclusion, supplementing IEP during the first 14 days of calf life improved the performance of newborn calves. Further work is warranted to understand the mode of action of IEP in calves.

3.
J Mot Behav ; : 1-9, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-32619148

RESUMO

Functional chewing patterns are achieved early in life prior to other motor skills like walking. Chewing seems to improve specific aspects of attention; however, there is limited research on chewing in dual motor tasks. This study examined relationships between chewing and secondary motor tasks in children. Sixteen typically developing children (13.1 ± 2.3 years) participated in finger tapping, simple reaction time, and walking while chewing at different speeds. The chewing rates varied when produced with a secondary motor task, especially for slow chewing and preferred chewing, and the secondary motor tasks were differentially influenced by the chewing. This relationship was not as strong as what has been reported in adults. It appears the neural oscillatory mechanisms involved in chewing and the secondary motor tasks may not be fully developed in children.

4.
Surgery ; 168(3): 518-526, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32669204

RESUMO

BACKGROUND: It is unknown whether all thick melanomas share the same prognostic features. We present a large, multi-institutional study on thick melanoma, evaluating for factors prognostic of survival. METHODS: We queried the database of the Sentinel Lymph Node Working Group for patients with thick melanoma (>4 mm) who had a sentinel lymph node biopsy from 1993 to 2018. Clinicopathologic characteristics were correlated with overall survival. RESULTS: There were 1,235 patients with a median follow-up of 28 months. Median thickness was 5.9 mm, with 713, 356, and 166 cases having a thickness of >4 to 6, >6 to 10, and >10 mm, respectively. Ulceration was seen in 51.2% of cases, while sentinel lymph node metastases were seen in 439 of 1,235 (35.5%) cases. For melanomas >4 to 6 mm, age, thickness, ulceration, lymphovascular invasion, and sentinel lymph node metastasis were correlated with overall survival (all P < .05), but for melanomas >6 to 10 mm, only sex and sentinel lymph node metastasis were prognostic of overall survival (both P < .05). For melanomas >10 mm, only sentinel lymph node metastasis predicted overall survival on multivariable analyses (P < .05). CONCLUSION: Prognostic markers of overall survival for thick melanoma include thickness, ulceration, and sentinel lymph node metastasis, but also include other unique factors such as lymphovascular invasion. Moreover, certain prognostic markers for survival are associated with different subgroups of thick melanoma, which vary based on thickness group.


Assuntos
Procedimentos Cirúrgicos Dermatológicos , Melanoma/mortalidade , Recidiva Local de Neoplasia/epidemiologia , Neoplasias Cutâneas/mortalidade , Pele/patologia , Idoso , Vasos Sanguíneos/patologia , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Metástase Linfática/patologia , Vasos Linfáticos/patologia , Masculino , Melanoma/patologia , Melanoma/cirurgia , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Recidiva Local de Neoplasia/patologia , Prognóstico , Estudos Retrospectivos , Linfonodo Sentinela/patologia , Biópsia de Linfonodo Sentinela/estatística & dados numéricos , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/cirurgia , Carga Tumoral
5.
Paediatr Child Health ; 25(4): 228-234, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32549738

RESUMO

Background: Supracondylar humerus (SCH) fractures are the most common operatively treated paediatric fracture in Canada. Previous literature describing the low-energy (Gartland type II) subtype reports varying complication rates from a variety of practice settings. We sought to examine complications of type II SCH fractures treated at a Canadian specialized paediatric centre. Methods: We conducted a retrospective cohort study of patients aged 0 to 14 admitted to SickKids, Toronto, Ontario for surgical treatment of a type II SCH fracture from 2008 to 2015. The primary outcome of this study was relevant perioperative complications including: open fracture, compartment syndrome, pre- and postoperative vascular compromise, pre- and postoperative neurological compromise, failure to obtain a closed reduction (i.e., open reduction), postoperative infection, and reoperation within 3 months. Results: There were 370 patients included in the study with mean (standard deviation) age 5.14 years (±2.51). The overall rate of relevant complications in the study cohort was 3.6% (13/358, 12 missing), with 12 cases of nerve palsy (3.3%; 2 iatrogenic [0.6%]) that resolved by final follow-up and one case of preoperative nerve palsy (0.3%) that did not. Importantly, there were no cases of vascular compromise, open fracture, compartment syndrome, or infection. Discussion and conclusion: Complications associated with type II SCH fractures managed at a specialized paediatric centre that result in long-term morbidity are extremely rare (0.3%). Perioperative inpatient monitoring for patients with these fractures may not be justified based on these data. Prospective studies are required to confirm safety, evaluate patient perspectives, and demonstrate cost savings of outpatient surgical management.

7.
Ann Surg Oncol ; 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32524460

RESUMO

BACKGROUND: Sentinel lymph node biopsy (SLNB) is recommended for intermediate thickness melanoma, but for thick melanoma, guidelines are less definitive about the use of SLNB in this population. We present a study on thick melanoma evaluating for prognostic factors. PATIENTS AND METHODS: The Sentinel Lymph Node Working Group database was queried for thick (> 4 mm) melanoma cases that had a SLNB from 1993 to 2018. Clinicopathologic characteristics were correlated with SLN status and melanoma-specific survival (MSS). RESULTS: There were 1235 patients. Median follow-up was 28 months. Median thickness was 5.9 mm, with 956, 175, and 104 cases presenting thickness > 4-8, > 8-12, and > 12 mm, respectively. SLN metastases were seen in 439 of 1235 (35.5%) cases and in 33.9%, 40.6%, and 42.3% of melanomas > 4-8, > 8-12, and > 12 mm, respectively. In each thickness group, MSS was significantly worse for SLN-positive compared with SLN-negative cases (all P < 0.005). Multivariable analysis showed that SLN metastasis, male gender, increasing thickness, lymphovascular invasion, and microsatellitosis significantly predicted worse MSS for melanomas > 4-8 mm, with SLN metastasis showing the greatest risk (HR 2.17, 95% CI 1.64-2.87, P < 0.0001). For melanomas > 8 mm, only SLN metastasis significantly predicted MSS (> 8-12 mm: HR 3.93, 95% CI 2.00-7.73, P < 0.0001; > 12 mm: HR 3.58, 95% CI 1.56-8.22, p < 0.0027). CONCLUSIONS: Thick melanoma patients with SLN metastasis have significantly worse MSS compared with SLN-negative patients, even in the thickest cases, and SLN status is the most powerful and/or only predictor of MSS. Given these results, SLNB shows important prognostic value in this population and is indicated for clinically localized thick melanoma.

8.
Scand J Med Sci Sports ; 30(8): 1518-1528, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32343021

RESUMO

INTRODUCTION: To determine whether individuals with a history of anterior cruciate ligament reconstruction (ACLR) exhibit altered neuromotor function compared to healthy controls. It was hypothesized that the ACLR group would have slower postural responses compared to healthy individuals of similar age. MATERIALS AND METHODS: Sixteen adults with a unilateral ACLR and 16 matched healthy controls participated. General assessments of neuromotor function were gathered and included measures of reaction time (both seated and postural conditions), walking ability, balance, ankle ROM, proprioception, knee joint laxity, patellar tendon reflex latency, and quadriceps strength. Data were analyzed using mixed generalized linear models with between-subject (ie, controls, ACLR) and within-subject factors (ie, affected, unaffected limb). RESULTS: Individuals with an ACLR exhibited a significant slowing of their postural reaction times compared to the control individuals. The ACLR group was slower under both the simple (ACLR: 484 ± 6.17 ms, control: 399 ± 1.95 ms) and choice reaction time conditions (ACLR: 550 ± 43 ms, control: 445 ± 43 ms). No other group differences were found in any of the other measures. CONCLUSION: Overall, ACLR individuals had a reduced ability to respond quickly under more challenging postural conditions (ie, stepping response). This finding would indicate that the impact of an ACLR is not purely mechanical and restricted to the joint. Rather, injury and reconstruction of the ACL impact neural mechanisms, altering individuals' ability to respond under challenging balance tasks.

9.
Vet Rec ; 187(10): 402, 2020 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-32253354

RESUMO

BACKGROUND: A number of European countries currently conduct mandatory farm-level benchmarking for antimicrobial usage (AMU). This review describes the systems used, with emphasis on metric type and practical implications. METHODS: This report describes examples of four types of metrics used to measure AMU: count-based, mass-based, daily dose-based and course-based, each with its own advantages and disadvantages. RESULTS: The Netherlands, Belgium, Denmark and Switzerland use daily dose-based metrics to benchmark AMU at farm-level, but each country diverges from the European Surveillance of Veterinary Antimicrobial Consumption methodology in its own way, including how the population 'at risk' is calculated. Germany operates a count-based system. Threshold AMU values have been specified at farm-level in the Netherlands, Belgium and Denmark, and action is required from producers to reduce AMU above these values. The Netherlands and Belgium also benchmark veterinarians. CONCLUSIONS: For mixed species farms common in the UK and Ireland, splitting AMU by species is recommended. It is also recommended that high priority critically important antimicrobials are benchmarked separately to other antimicrobials. No one metric is optimum; however, for ruminant livestock a daily dose-based metric allows for country-specific adaptations which may allow a higher degree of precision at farm-level benchmarking in the UK and Ireland.

10.
Exp Brain Res ; 238(3): 565-574, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31993683

RESUMO

Aging is associated with physiological changes which can manifest as age-related slowing of voluntary movements. Dual-task conditions can magnify this slowing process in older adults. The current study describes healthy adult chewing patterns and examined effects of concurrent chewing on performance of simple reaction time (RT), finger tapping, and gait. Chewing rates were measured from electromyographic (EMG) activity from the masseter muscle. Stepping rates were calculated using accelerometers mounted on the lower trunk and leg. Tapping rates were collected using accelerometers secured to a fixed surface. Simple RT was attained from a purposely designed switch. Results demonstrated that older adults walked slower, tapped slower, and had slower reaction times compared to young individuals, however chew rates were similar. This dichotomy became more pronounced when motor tasks were performed at faster speeds, with the exception being chewing. Additionally, chewing altered performance of secondary motor tasks for all individuals. Strong coupling emerged between cyclical actions (i.e., chewing-gait and chewing-tapping), reflecting entrainment between the respective neural oscillators driving the actions. In contrast, RT responses slowed appreciably when chewing was performed concurrently, indicating an interference effect. Taken together, these results illustrate the contrasting effects of chewing on a secondary motor task and highlights bidirectional effects of dual tasking on performance.


Assuntos
Envelhecimento/fisiologia , Marcha/fisiologia , Desempenho Psicomotor/fisiologia , Caminhada/fisiologia , Idoso , Cognição/fisiologia , Feminino , Humanos , Masculino , Músculo Masseter/fisiologia , Pessoa de Meia-Idade , Tempo de Reação , Adulto Jovem
11.
J Am Med Dir Assoc ; 21(9): 1267-1272.e2, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31859222

RESUMO

OBJECTIVES: To design a questionnaire to evaluate and distinguish between cognitive and physical aspects of fatigue in different age groups of "nondiseased" people and guide appropriate prevention and interventions for the impact of frailty occurring in normative aging. STUDY DESIGN AND PARTICIPANTS: The Norfolk QOL-Fatigue (QOL-F) with items of cognitive and physical fatigue, anxiety, and depression from validated questionnaires including items from the Patient-Reported Outcomes Measure Information System (PROMIS) databank was developed. The preliminary QOL-F was administered to 409 healthy multiethnic local participants (30-80 years old) in 5 age groups. METHODS: The authors distilled the item pool using exploratory (EFA) and confirmatory factor analysis (CFA). EFA identified 5 latent groups as possible factors related to problems due to fatigue, subjective fatigue, reduced activities, impaired activities of daily living (ADL), and depression. RESULTS: CFA demonstrated good overall fit [χ2(172) = 1094.23, P < .001; Tucker-Lewis index = 0.978; root mean square error of approximation = 0.049] with factor loadings >0.617 and strong interfactor correlations (0.69-0.83), suggesting that fatigue in each domain is closely related to other domains and to the overall scale except for ADL. The 5-factor solution displayed good internal consistency (Cronbach α = 0.78-0.94). Total and domain scores were fairly equivalent in all age groups except for the 40 to 49-year-old group with better overall scores. In addition, 70 to 79-year-olds had better ADL scores. In item response analysis, factor scores in different age groups were similar, so age may not be a significant driver of fatigue scores. Fatigue scores were significantly higher in females than in males (P < .05). CONCLUSIONS AND CLINICAL IMPLICATIONS: The developed Norfolk QOL-F tool demonstrated fatigue as a perceived cognitive phenomenon rather than an objective physical measure, suggesting mandatory inclusion of cognitive as well as physical measures in the evaluation of people as they age. QOL-F is able to distinguish QOL-F domain scores unique to different age groups, proposing clinical benefits from physical, balance, and cognitive interventions tailored to impact frailty occurring in normative aging.

12.
Animals (Basel) ; 9(11)2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31683846

RESUMO

The weaning of dairy calves is a significant stressor which can impact on calf performance and welfare. However, many traditional methods of assessing the effects of stressors can be invasive and impractical for farmers. This study aimed to use a combination of non-invasive monitoring technologies alongside traditional measures of calf performance to examine the impact of two contrasting weaning methods commonly used on dairy farms in the United Kingdom. Ninety group-housed Holstein Friesian calves were allocated to one of two weaning methods: (i) gradual weaning (GW) with volume of milk replacer (MR) stepping down from 36 days of age and complete withdrawal of MR at 57 days of age and (ii) abrupt weaning (AW) with consistent daily volume of milk replacer and complete withdrawal of MR at 50 days of age. Feeding regimes were such that calves from both treatments were offered the same total amount of milk powder. Gradually weaned calves displayed increased solid feed intake at an earlier age when compared with AW calves. Feed conversion efficiency (FCE) was reduced in gradually weaned calves between days 36 and 49. However, there was no difference in live weight (LWT) or average daily gain (ADG) throughout this period. Abrupt weaning at 50 days of age resulted in decreased ADG and FCE between days 50 and 56. However, there were no treatment differences in ADG between days 57 and 62. Live weight tended to be increased by 2.2 kg in GW calves when compared with AW calves at the end of experiment on day 63. Frequency of unrewarded visits to the milk feeder throughout the pre-wean period was consistently increased in GW calves. Daily lying time was reduced in AW compared with GW calves in the days following abrupt weaning (days 50-55). However, these differences did not persist between days 57 and 62. Heart rate variability (HRV) tended to be decreased in GW compared with AW calves in the period following complete withdrawal of milk replacer. Findings from the current study suggest that calves offered the same total amount of milk powder can be weaned either gradually from 36 days of age or abruptly at 50 days of age without significant impact to live weight at 63 days of age. However, both behavioural and physiological data collected using the methods described could suggest that gradual weaning of calves from 36 days of age results in an increase in underlying frustration. This study highlights the potential of using a combination of non-invasive monitoring technologies in assessing calf response to common management practices.

13.
Animals (Basel) ; 9(10)2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31581685

RESUMO

This study aimed to examine the use of non-invasive monitoring technologies as a means of capturing behavioural, physiological and health responses of calves allocated to different nutritional regimes. Seventy-four Holstein Friesian calves were individually penned and allocated to receive either high (HML) or conventional (CML) milk replacer (MR) levels between 5-70 days of age. Additionally calves were allocated to one of four forage treatments: (i) chopped straw offered between 14-70 days of age (CS14), (ii) chopped straw offered between 56-70 days of age (CS56), (iii) grass silage offered between 56-70 days of age (GS56), and (iv) no forage in the pre-wean period (NF). A representative sample of calves from each treatment were fitted with activity sensors and heart rate monitors throughout the experimental period to examine lying behaviour and heart rate variability, respectively. Thermal images of the eye and rectal area of each calf were taken 5 days/week between 5-77 days of age. Faecal and respiratory scoring of each individual calf was carried out on a daily basis throughout the experimental period. Milk replacer feeding level had limited effects on measures of calf health, although HML calves tended to have an increased likelihood for receiving treatment for scour than CML calves. Daily lying time (min/d) was lower in HML calves following reduction in MR feeding frequency at 43 days of age and weaning at 71 days of age when compared with CML calves. Additionally, HML calves displayed a lower heart rate variability following weaning, this suggestive of increased stress load. There were limited effects of forage treatment, however, CS14 calves displayed a greater daily lying time following MR step-down at 68 days of age, this potentially indicating increased rumination. Results of the present study highlight the benefits of using remote monitoring technologies as a means of detecting behavioural and physiological changes as a result of nutritional management strategy in individually housed dairy calves.

14.
Sports Med ; 49(8): 1199-1216, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31236903

RESUMO

BACKGROUND: The ageing process and several health conditions may increase tremor and reduce force steadiness and dexterity, which can severely impact on function and quality of life. Resistance training can evoke a range of neuromuscular adaptions that may significantly reduce tremor and/or increase force steadiness and/or dexterity in older adults, irrespective of their health condition. OBJECTIVES: The objective of this study was to systematically review the literature to determine if a minimum of 4 weeks' resistance training can reduce postural tremor and improve force steadiness and/or dexterity in older adults, defined as aged 65 years and over. METHODS: An electronic search using Ovid, CINAHL, SPORTDiscus and EMBASE was performed. Risk of bias was assessed using the Cochrane Risk of Bias Tool. RESULTS: Fourteen studies met the eligibility criteria, including six randomised controlled trials and two quasi-randomised controlled trials. All eight studies that recruited healthy older adults reported significant reductions in postural tremor and/or improvements in force steadiness and dexterity. Five out of seven studies that examined older adults with a particular health condition reported some improvements in force steadiness and/or dexterity. Specifically, significant benefits were observed for older adults with chronic obstructive pulmonary disease and essential tremor; however, small or no changes were observed for individuals with osteoarthritis or stroke. CONCLUSIONS: Resistance training is a non-pharmacological treatment that can reduce tremor and improve force steadiness and dexterity in a variety of older adult populations. Future research should employ randomised controlled trials with larger sample sizes, better describe training programme methods, and align exercise prescription to current recommendations for older adults.


Assuntos
Força Muscular , Treinamento de Resistência , Tremor/terapia , Extremidade Superior , Idoso , Humanos , Destreza Motora , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
CBE Life Sci Educ ; 18(2): ar19, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31074696

RESUMO

Next-generation sequencing (NGS)-based methods are revolutionizing biology. Their prevalence requires biologists to be increasingly knowledgeable about computational methods to manage the enormous scale of data. As such, early introduction to NGS analysis and conceptual connection to wet-lab experiments is crucial for training young scientists. However, significant challenges impede the introduction of these methods into the undergraduate classroom, including the need for specialized computer programs and knowledge of computer coding. Here, we describe a semester-long, course-based undergraduate research experience at a liberal arts college combining RNA-sequencing (RNA-seq) analysis with student-driven, wet-lab experiments to investigate plant responses to light. Students derived hypotheses based on analysis of RNA-seq data and designed follow-up studies of gene expression and plant growth. Our assessments indicate that students acquired knowledge of big data analysis and computer coding; however, earlier exposure to computational methods may be beneficial. Our course requires minimal prior knowledge of plant biology, is easy to replicate, and can be modified to a shorter, directed-inquiry module. This framework promotes exploration of the links between gene expression and phenotype using examples that are clear and tractable and improves computational skills and bioinformatics self-efficacy to prepare students for the "big data" era of modern biology.


Assuntos
Big Data , Perfilação da Expressão Gênica , Estudantes , Universidades , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Humanos , Aprendizagem , Fenótipo
16.
J Neurophysiol ; 122(2): 572-584, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31066616

RESUMO

Many experiments have shown independence of the index finger dynamics under bilateral postural tremor protocols. Here we investigated in young adults the dynamics of bilateral multidirectional postural tremor and forearm muscle activity under the progressively fatiguing conditions supporting an external weight to the point of induced postural failure. When no loads were applied, tremor in the vertical (VT) and mediolateral (ML) directions was similar with prominent peaks within 2- to 4-Hz and 8- to 12-Hz bandwidths. Contrastingly tremor in the anterior-posterior (AP) direction was characterized by a single peak between 0 and 2 Hz. Although no tremor coupling occurred cross limbs, strong within-limb coupling was found between ML and VT directions when no loads were applied (coherence range: 0.77-0.85), implying that these oscillations are related and likely derived from mechanical sources. Applying an external load to the index finger(s) led to significant increases in the amplitude of VT tremor and EMG activity within that limb but also caused increases in tremor directions not aligned with the gravitational vector (AP and ML). Significant increases in VT and ML tremor and EMG activity in the contralateral (unloaded) limb were also found when a single index finger was loaded; however, this bilateral increase did not align with increases in interlimb coupling (coherence <0.21). The effects of fatigue caused by prolonged loading were widespread, affecting tremor and muscle activity in both limbs through a combination of neural and mechanical mechanisms. The single- and dual-limb loading to fatigue increased neural overflow but not tremor coupling between the index fingers.NEW & NOTEWORTHY This study investigated bilateral multidirectional tremor under unloaded and loaded conditions. We found that tremor in the mediolateral and vertical directions within a limb were strongly coupled, a result not reported previously. Furthermore, when holding a weight to failure, tremor in all directions increased. Tremor also increased in the contralateral (unloaded) limb despite no interlimb coupling. This contralateral increase in tremor following loading a limb until fatigue is hypothesized to stem from motor-overflow effects.


Assuntos
Fadiga/fisiopatologia , Músculo Esquelético/fisiologia , Postura/fisiologia , Tremor/fisiopatologia , Extremidade Superior/fisiologia , Adolescente , Adulto , Eletromiografia , Feminino , Dedos/fisiologia , Antebraço/fisiologia , Humanos , Masculino , Adulto Jovem
17.
Front Med (Lausanne) ; 6: 53, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31001532

RESUMO

Traumatic brain injuries (TBIs) are common and serious injuries to older adults. The majority of TBIs in older adults are sustained when the head impacts the ground or other surface during a fall. While several non-modifiable risk factors have been identified for fall-related TBIs in older adults, there still remains a dearth of knowledge surrounding modifiable risk factors. Thus, this significant knowledge gap warrants an investigation into research across disciplines. The sports medicine literature has examined several modifiable risk factors to prevent a mild form of TBI known as concussion. While this research has identified several risk factors, one particular risk factor may have potential implications to fall-related TBIs in older adults. The sports medicine literature has shown that decreased neck strength and slower neck muscle activation are significant predictors for sports-related concussion. Similarly, older adults experience age-related declines to neck muscle strength and muscle activation. Consequently, these age-related declines to the neck musculature may result in the inability of older adults to control their head during a fall, which results in greater impact forces being transmitted to the brain and increases the risk of TBI. This perspective article assesses the sports medicine literature related to the implications of neck strength and muscle activation in sports-related concussion, discusses age-related declines to neck strength and muscle activation, and highlights the potential impact of the neck musculature on fall-related TBIs in older adults.

18.
Gait Posture ; 70: 370-375, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30959428

RESUMO

BACKGROUND: Falls and injuries related to falls in older adults are a significant health care issue that affects the elderly population. Research suggests that exercise interventions can be effective in improving falls risk factors. RESEARCH QUESTION: Are there differences in falls risk reduction between two exercise interventions (The Lebed Method - TLM and Stay Active and Independent for Life - SAIL) for community-dwelling older adults? METHODS: A quasi-experimental pre- and post-test design was used for this study. One hundred and sixty-three older individuals aged between 60-79 years of age participated in the study. Assessments of falls risk (using the physiological profile assessment), simple reaction time, bilateral knee extension strength, proprioception, balance, visual acuity, and mobility (using timed-up-and-go, TUG) were performed. Analysis of covariance was conducted to compare the differences between the two interventions. Pre-intervention assessments were used as the covariate. RESULTS: SAIL participants' falls risk were reduced more than TLM. Reaction and TUG times were faster for SAIL participants. However, those individuals who participated in TLM had greater knee extension strength for both legs compared to SAIL participants. SIGNIFICANCE: Overall, both interventions were effective in reducing falls risk for older adults. The greater number of improved falls risk factors attained with the SAIL program suggests that multifactorial interventions may be more effective at reducing falls risk. However, since TLM also showed better improved strength, both dance-based and multifactorial interventions can be effective at reducing falls risk factors for older adults.


Assuntos
Acidentes por Quedas/prevenção & controle , Dança/fisiologia , Equilíbrio Postural/fisiologia , Idoso , Feminino , Serviços de Saúde para Idosos , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , Modalidades de Fisioterapia , Fatores de Risco , Resultado do Tratamento
19.
Neurosci Lett ; 698: 90-96, 2019 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-30634010

RESUMO

Chewing and walking are two oscillatory behaviors performed on an everyday basis. The current study examined the impact chewing at different speeds (i.e. fast, slow, preferred) had on walking performance for fifteen young healthy adults (23.2 + 4.2 years) and fifteen healthy older participants (66.5 + 3.2 years). Chewing rates were attained from surface EMG activity recorded from the masseter muscle. For gait, accelerometers mounted on the lower trunk and lower leg were used to determine the timing of individual steps. In addition, a pressure sensitive walkway was also used to collect gait metrics (i.e., gait velocity, step length, step time). Our results demonstrated a strong link between chewing and walking for all participants, with increases or decreases in a person's chewing rate leading to similar changes in their stepping rate (and hence walking speed). One explanation for this coupling is that the neural drive related to chewing entrains the muscles involved in the basic gait action of stepping. The coupling of stepping with chewing rates for all individuals was observed despite the older adults tending to walk slower overall. However, there were no age-related differences in chewing rates, suggesting that despite the general slowing of motor function seen with increasing age, mastication itself does not appear to be similarly affected.


Assuntos
Marcha/fisiologia , Músculo Masseter/fisiologia , Mastigação/fisiologia , Caminhada/fisiologia , Adulto , Idoso , Fenômenos Biomecânicos/fisiologia , Eletromiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Rotação , Adulto Jovem
20.
Transl Anim Sci ; 3(1): 564-576, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32704827

RESUMO

Three experiments were undertaken to 1) quantify the repeatability and reproducibility of thermal imaging across day and operator experience and 2) assess the correlation between descriptive infrared (IR) temperature parameters from different anatomical areas and core body temperature in dairy calves under 12 wk of age. In experiment 1, a single operator captured 30 replicate images of both the left and right eyes (defined as the whole eye + 1 cm margin) and the rectal area (defined as the anus +1.5 cm margin) from each of 16 calves. In experiment 2, three operators of varying experience captured images from both the left and right eyes and the rectal area of each of 12 calves. In experiment 3, a single operator captured images of the right eye and rectal area for a period of 5 consecutive days for each of 205 calves. All images were captured between 0900 and 1300 h. Core body temperature, obtained via rectal thermometer, was recorded every day for each of the 205 calves following completion of IR image capture. Ambient temperature and relative humidity were adjusted for each thermal image prior to manual extraction of maximum, minimum, and average temperature parameters. In experiment 1, lowest error variance was found within the maximum temperature parameter and the right eye was determined as the most repeatable anatomical area, with 80.48% of the total proportion of variance attributed to the calf. Results indicated that capturing at least three replicate images would provide the precision required to identify ill-health in calves. In experiment 2, operator variance was low across anatomical areas, with values of ≤0.01°C2 for the right and left eyes and ≤0.04°C2 for the rectal area. In experiment 3, day to day variation of thermal image measurements and core body temperature were minimal across anatomical areas with values of ≤0.008°C2. Correlations ranging from 0.16 to 0.32, and from 0.31 to 0.47 were found between maximum eye and core body temperature and maximum rectal area and core body temperature, respectively. Results of the present study indicate a low level of variability and high level of repeatability within IR temperature measurements in calves under 12 wk of age, particularly within maximum temperature parameters. Providing operators of varying abilities with a basic standardized protocol is sufficient to limit between-operator variation. Further research is required to investigate whether correlation between IR and core body temperature can be improved.

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