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1.
Phys Rev Lett ; 130(24): 242501, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-37390416

RESUMO

Excited-state spectroscopy from the first experiment at the Facility for Rare Isotope Beams (FRIB) is reported. A 24(2)-µs isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV γ rays in coincidence with ^{32}Na nuclei. This is the only known microsecond isomer (1 µs≤T_{1/2}<1 ms) in the region. This nucleus is at the heart of the N=20 island of shape inversion and is at the crossroads of the spherical shell-model, deformed shell-model, and ab initio theories. It can be represented as the coupling of a proton hole and neutron particle to ^{32}Mg, ^{32}Mg+π^{-1}+ν^{+1}. This odd-odd coupling and isomer formation provides a sensitive measure of the underlying shape degrees of freedom of ^{32}Mg, where the onset of spherical-to-deformed shape inversion begins with a low-lying deformed 2^{+} state at 885 keV and a low-lying shape-coexisting 0_{2}^{+} state at 1058 keV. We suggest two possible explanations for the 625-keV isomer in ^{32}Na: a 6^{-} spherical shape isomer that decays by E2 or a 0^{+} deformed spin isomer that decays by M2. The present results and calculations are most consistent with the latter, indicating that the low-lying states are dominated by deformation.


Assuntos
Núcleo Celular , Coração , Isótopos , Nêutrons
2.
Phys Rev Lett ; 129(21): 212501, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36461950

RESUMO

New half-lives for exotic isotopes approaching the neutron drip-line in the vicinity of N∼28 for Z=12-15 were measured at the Facility for Rare Isotope Beams (FRIB) with the FRIB decay station initiator. The first experimental results are compared to the latest quasiparticle random phase approximation and shell-model calculations. Overall, the measured half-lives are consistent with the available theoretical descriptions and suggest a well-developed region of deformation below ^{48}Ca in the N=28 isotones. The erosion of the Z=14 subshell closure in Si is experimentally confirmed at N=28, and a reduction in the ^{38}Mg half-life is observed as compared with its isotopic neighbors, which does not seem to be predicted well based on the decay energy and deformation trends. This highlights the need for both additional data in this very exotic region, and for more advanced theoretical efforts.

3.
Dis Esophagus ; 34(6)2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-32960264

RESUMO

There are no internationally recognized criteria available to determine preparedness for hospital discharge after esophagectomy. This study aims to achieve international consensus using Delphi methodology. The expert panel consisted of 40 esophageal surgeons spanning 16 countries and 4 continents. During a 3-round, web-based Delphi process, experts voted for discharge criteria using 5-point Likert scales. Data were analyzed using descriptive statistics. Consensus was reached if agreement was ≥75% in round 3. Consensus was achieved for the following basic criteria: nutritional requirements are met by oral intake of at least liquids with optional supplementary nutrition via jejunal feeding tube. The patient should have passed flatus and does not require oxygen during mobilization or at rest. Central venous catheters should be removed. Adequate analgesia at rest and during mobilization is achieved using both oral opioid and non-opioid analgesics. All vital signs should be normal unless abnormal preoperatively. Inflammatory parameters should be trending down and close to normal (leucocyte count ≤12G/l and C-reactive protein ≤80 mg/dl). This multinational Delphi survey represents the first expert-led process for consensus criteria to determine 'fit-for-discharge' status after esophagectomy. Results of this Delphi survey may be applied to clinical outcomes research as an objective measure of short-term recovery. Furthermore, standardized endpoints identified through this process may be used in clinical practice to guide decisions regarding patient discharge and may help to reduce the risk of premature discharge or prolonged admission.


Assuntos
Esofagectomia , Alta do Paciente , Consenso , Técnica Delphi , Humanos , Inquéritos e Questionários
4.
Gait Posture ; 80: 391-396, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32650227

RESUMO

BACKGROUND: Achondroplasia is characterised by a shorter appendicular limb to torso ratio, compared to age matched individuals of average stature (controls). Despite the well documented shorter leg length of individuals with compared to controls, there are few complete descriptions of gait kinematics reported for the population. AIM: The aim of this study was to report the spatio-temporal and kinematic characteristics of self-selected walking (SSW) in a group with Achondroplasia (N = 10) and age matched group without Achondroplasia (controls, N = 17). METHOD: Whole body 3D analysis of both groups was conducted using a 14 camera VICON system. Spatio-temporal and kinematic variables were determined through a Plug-in-Gait model. SSW was obtained from an average of three trials equating to a total of ∼120 m walking. RESULTS: The group with Achondroplasia were 23 % slower (P < 0.001), had a 29 % shorter stride length (P < 0.001) and a 13 % higher stride frequency (P < 0.001) compared to controls. There were no differences in time normalised temporal measures of left toe off (P = 0.365), right heel contact (P = 0.442) or the duration of double support (P = 0.588) between groups. A number of discrete joint kinematic differences existed between groups, resulting in the group with Achondroplasia having more 'flexed' lower limbs than controls throughout the gait cycle. CONCLUSION: Differences in absolute spatio-temporal variables between groups is likely due to the shorter leg length of the group with Achondroplasia, while their more flexed position of the lower limbs may facilitate toe-clearance during the swing phase.


Assuntos
Acondroplasia/fisiopatologia , Análise da Marcha , Caminhada , Adolescente , Adulto , Fenômenos Biomecânicos , Estudos de Casos e Controles , Feminino , Calcanhar , Humanos , Extremidade Inferior , Masculino , Amplitude de Movimento Articular , Análise Espaço-Temporal , Dedos do Pé , Adulto Jovem
5.
Phys Rev Lett ; 124(25): 252502, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32639781

RESUMO

In an experiment performed at Lawrence Berkeley National Laboratory's 88-inch cyclotron, the isotope ^{244}Md was produced in the ^{209}Bi(^{40}Ar,5n) reaction. Decay properties of ^{244}Md were measured at the focal plane of the Berkeley Gas-filled Separator, and the mass number assignment of A=244 was confirmed with the apparatus for the identification of nuclide A. The isotope ^{244}Md is reported to have one, possibly two, α-decaying states with α energies of 8.66(2) and 8.31(2) MeV and half-lives of 0.4_{-0.1}^{+0.4} and ∼6 s, respectively. Additionally, first evidence of the α decay of ^{236}Bk was observed and is reported.

7.
Nature ; 580(7801): 52-55, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32238942

RESUMO

Conservation laws are deeply related to any symmetry present in a physical system1,2. Analogously to electrons in atoms exhibiting spin symmetries3, it is possible to consider neutrons and protons in the atomic nucleus as projections of a single fermion with an isobaric spin (isospin) of t = 1/2 (ref. 4). Every nuclear state is thus characterized by a total isobaric spin T and a projection Tz-two quantities that are largely conserved in nuclear reactions and decays5,6. A mirror symmetry emerges from this isobaric-spin formalism: nuclei with exchanged numbers of neutrons and protons, known as mirror nuclei, should have an identical set of states7, including their ground state, labelled by their total angular momentum J and parity π. Here we report evidence of mirror-symmetry violation in bound nuclear ground states within the mirror partners strontium-73 and bromine-73. We find that a J π = 5/2- spin assignment is needed to explain the proton-emission pattern observed from the T = 3/2 isobaric-analogue state in rubidium-73, which is identical to the ground state of strontium-73. Therefore the ground state of strontium-73 must differ from its J π = 1/2- mirror bromine-73. This observation offers insights into charge-symmetry-breaking forces acting in atomic nuclei.

8.
Dis Esophagus ; 33(4)2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31608938

RESUMO

Delayed gastric conduit emptying (DGCE) after esophagectomy for cancer is associated with adverse outcomes and troubling symptoms. Widely accepted diagnostic criteria and a symptom grading tool for DGCE are missing. This hampers the interpretation and comparison of studies. A modified Delphi process, using repeated web-based questionnaires, combined with live interim group discussions was conducted by 33 experts within the field, from Europe, North America, and Asia. DGCE was divided into early DGCE if present within 14 days of surgery and late if present later than 14 days after surgery. The final criteria for early DGCE, accepted by 25 of 27 (93%) experts, were as follows: >500 mL diurnal nasogastric tube output measured on the morning of postoperative day 5 or later or >100% increased gastric tube width on frontal chest x-ray projection together with the presence of an air-fluid level. The final criteria for late DGCE accepted by 89% of the experts were as follows: the patient should have 'quite a bit' or 'very much' of at least two of the following symptoms; early satiety/fullness, vomiting, nausea, regurgitation or inability to meet caloric need by oral intake and delayed contrast passage on upper gastrointestinal water-soluble contrast radiogram or on timed barium swallow. A symptom grading tool for late DGCE was constructed grading each symptom as: 'not at all', 'a little', 'quite a bit', or 'very much', generating 0, 1, 2, or 3 points, respectively. For the five symptoms retained in the diagnostic criteria for late DGCE, the minimum score would be 0, and the maximum score would be 15. The final symptom grading tool for late DGCE was accepted by 27 of 31 (87%) experts. For the first time, diagnostic criteria for early and late DGCE and a symptom grading tool for late DGCE are available, based on an international expert consensus process.


Assuntos
Transtornos da Motilidade Esofágica/diagnóstico , Neoplasias Esofágicas/cirurgia , Esofagectomia/efeitos adversos , Complicações Pós-Operatórias/diagnóstico , Avaliação de Sintomas/normas , Adulto , Técnica Delphi , Transtornos da Motilidade Esofágica/etiologia , Feminino , Esvaziamento Gástrico , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento
9.
Gait Posture ; 68: 150-154, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30476692

RESUMO

BACKGROUND: Achondroplasia is characterised by a shorter appendicular limb-to-torso ratio, compared to age matched individuals of average stature (controls). Previous work shows gait kinematics of individuals with Achondroplasia differing to controls, but no global quantification of gait has been made in adults with Achondroplasia. AIM: The aim of this study was to quantify gait differences between a group of adult males with Achondroplasia and controls during self-selected walking (SSW) using the Gait Profile Score (GPS). DESIGN: Whole body motion analysis of 10 adults with Achondroplasia (22 ± 3 yrs) who had not undergone leg lengthening and 17 adult controls (22 ± 2 yrs) was undertaken using a 14 camera VICON system (100 Hz). For each group, fifteen root mean squared Gait Variable Scores (GVS, units °) were computed from lower limb kinematic data and then summed to calculate GPS (°). RESULTS: The group with Achondroplasia had higher GVSs than controls in 10 of the 15 measures (P < 0.05) with the largest differences found in ankle plantar/dorsiflexion (P < 0.001), knee flexion/extension (P < 0.001), and hip internal/external rotation (P < 0.001). The GPS value of the group with Achondroplasia was 64% higher than controls (11.4° (2.0) v 4.1° (1.8), P < 0.001). CONCLUSION: Gait is quantitatively different in adults with Achondroplasia compared to controls. The differences in GPS between groups are due to differences in joint kinematics, which are possibly manifested by maintaining toe-clearance during swing. Gait models derived from the anatomy of individuals with Achondroplasia may improve these data.


Assuntos
Acondroplasia/fisiopatologia , Marcha/fisiologia , Extremidade Inferior/fisiopatologia , Caminhada/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Tronco/fisiopatologia , Adulto Jovem
10.
Phys Rev Lett ; 121(22): 222501, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30547624

RESUMO

An experiment was performed at Lawrence Berkeley National Laboratory's 88-in. Cyclotron to determine the mass number of a superheavy element. The measurement resulted in the observation of two α-decay chains, produced via the ^{243}Am(^{48}Ca,xn)^{291-x}Mc reaction, that were separated by mass-to-charge ratio (A/q) and identified by the combined BGS+FIONA apparatus. One event occurred at A/q=284 and was assigned to ^{284}Nh (Z=113), the α-decay daughter of ^{288}Mc (Z=115), while the second occurred at A/q=288 and was assigned to ^{288}Mc. This experiment represents the first direct measurements of the mass numbers of superheavy elements, confirming previous (indirect) mass-number assignments.

11.
Forensic Sci Int Genet ; 37: 1-5, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30064044

RESUMO

Sexual assault cases where there is an allegation of digital or penile penetration but no semen is detected on the vaginal swabs have historically been difficult to investigate due to the high background levels of female DNA present. Previous studies have shown the value of Y-STR analysis in such cases. This study aims to provide: 17% of the cases in this study generated Y-STR profiles suitable for subjective or statistical evaluation following analysis with Yfiler® compared with 34% of the cases analysed with Powerplex® Y23, demonstrating the value of using more recently developed Y-STR multiplexes compared with older kits.


Assuntos
Muco do Colo Uterino/química , Cromossomos Humanos Y , Impressões Digitais de DNA , DNA/isolamento & purificação , Delitos Sexuais , Feminino , Dedos , Humanos , Masculino , Repetições de Microssatélites , Reação em Cadeia da Polimerase , Estupro , Manejo de Espécimes , Fatores de Tempo
12.
Scand J Med Sci Sports ; 28(2): 400-406, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28581678

RESUMO

Titin provides a molecular blueprint for muscle sarcomere assembly, and sarcomere length can vary according to titin isoform expression. If variations in sarcomere length influence muscle fascicle length, this may provide an advantage for running performance. Thus, the aim of this study was to investigate whether the titin (TTN) rs10497520 polymorphism was associated with muscle fascicle length in recreationally active men (RA; n=137) and marathon personal best time in male marathon runners (MR; n=141). Fascicle length of the vastus lateralis was assessed in vivo using B-mode ultrasonography at 50% of muscle length in RA. All participants provided either a whole blood, saliva or buccal cell sample, from which DNA was isolated and genotyped using real-time polymerase chain reaction. Vastus lateralis fascicle length was 10.4% longer in CC homozygotes, those carrying two copies of the C-allele, than CT heterozygotes (P=.003) in RA. In the absence of any TT homozygotes, reflective of the low T-allele frequency within Caucasian populations, it is unclear whether fascicle length for this group would have been smaller still. No differences in genotype frequency between the RA and MR groups were observed (P=.500), although within the MR group, the T-allele carriers demonstrated marathon personal best times 2 minutes 25 seconds faster than CC homozygotes (P=.020). These results suggest that the T-allele at rs10497520 in the TTN gene is associated with shorter skeletal muscle fascicle length and conveys an advantage for marathon running performance in habitually trained men.


Assuntos
Desempenho Atlético , Conectina/genética , Resistência Física/genética , Corrida/fisiologia , Frequência do Gene , Genótipo , Humanos , Masculino , Músculo Quadríceps/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Adulto Jovem
13.
Eur J Appl Physiol ; 117(7): 1393-1402, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28497386

RESUMO

PURPOSE: Firstly, to establish whether oral contraceptive pill (OCP) users are more susceptible to muscle damage compared to non-users, and secondly, to establish whether differences can be attributed to differences in patella tendon properties. METHODS: Nine female OCP users and 9 female non-users participated in the investigation. Combining dynamometry, electromyography and ultrasonography, patella tendon properties and vastus lateralis architectural properties were measured pre and during the first of 6 sets of 12 maximal voluntary eccentric knee extensions. Serum oestrogen levels were measured on the 7th day of the pill cycle and the 14th day of menstrual cycle in OCP users and non-users, respectively. Maximal voluntary isometric knee extension torque loss, creatine kinase and muscle soreness were measured 48 h pre-damage, post-damage, and 48, 96 and 168 h post-damage. RESULTS: Oestrogen levels were significantly lower in OCP users compared to non-users (209 ± 115 and 433 ± 147 pg/ml, respectively, p = 0.004). Proposed determinants of muscle damage, patella tendon stiffness and maximal eccentric torque did not differ between OCP users and non-users. The change in creatine kinase from pre to peak was significantly higher in OCP users compared to non-users (962 ± 968 and 386 ± 474 Ul, respectively, p = 0.016). There were no other differences in markers of muscle damage. CONCLUSION: Although our findings suggest that, when compared to non-users, the OCP may augment the creatine kinase response following eccentric exercise, it does not increase the susceptibility to any other markers of muscle damage.


Assuntos
Anticoncepcionais Orais/efeitos adversos , Exercício Físico , Contração Isométrica , Mialgia/etiologia , Adulto , Estudos de Casos e Controles , Creatina Quinase/sangue , Estrogênios/sangue , Feminino , Humanos , Músculo Esquelético/fisiologia , Ligamento Patelar/fisiologia , Torque
14.
Phys Rev Lett ; 118(17): 172501, 2017 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-28498679

RESUMO

The (^{10}Be,^{10}B^{*}[1.74 MeV]) charge-exchange reaction at 100 AMeV is presented as a new probe for isolating the isovector (ΔT=1) nonspin-transfer (ΔS=0) response of nuclei, with ^{28}Si being the first nucleus studied. By using a secondary ^{10}Be beam produced by fast fragmentation of ^{18}O nuclei at the NSCL Coupled Cyclotron Facility, applying the dispersion-matching technique with the S800 magnetic spectrometer to determine the excitation energy in ^{28}Al, and performing high-resolution γ-ray tracking with the Gamma-Ray Energy Tracking In-beam Nuclear Array (GRETINA) to identify the 1022-keV γ ray associated with the decay from the 1.74-MeV T=1 isobaric analog state in ^{10}B, a ΔS=0 excitation-energy spectrum in ^{28}Al was extracted. Monopole and dipole contributions were determined through a multipole-decomposition analysis, and the isovector giant dipole resonance and isovector giant monopole resonance (IVGMR) were identified. The results show that this probe is a powerful tool for studying the elusive IVGMR, which is of interest for performing stringent tests of modern density functional theories at high excitation energies and for constraining the bulk properties of nuclei and nuclear matter. The extracted distributions were compared with theoretical calculations based on the normal-modes formalism and the proton-neutron relativistic time-blocking approximation. Calculated cross sections based on these strengths underestimate the data by about a factor of 2, which likely indicates deficiencies in the reaction calculations based on the distorted wave Born approximation.

15.
Eur J Appl Physiol ; 117(4): 713-720, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28251396

RESUMO

PURPOSE: The aim of the study was to investigate two single nucleotide polymorphisms (SNP) in PTK2 for associations with human muscle strength phenotypes in healthy men. METHODS: Measurement of maximal isometric voluntary knee extension (MVCKE) torque, net MVCKE torque and vastus lateralis (VL) specific force, using established techniques, was completed on 120 Caucasian men (age = 20.6 ± 2.3 year; height = 1.79 ± 0.06 m; mass = 75.0 ± 10.0 kg; mean ± SD). All participants provided either a blood (n = 96) or buccal cell sample, from which DNA was isolated and genotyped for the PTK2 rs7843014 A/C and rs7460 A/T SNPs using real-time polymerase chain reaction. RESULTS: Genotype frequencies for both SNPs were in Hardy-Weinberg equilibrium (X 2 ≤ 1.661, P ≥ 0.436). VL specific force was 8.3% higher in rs7843014 AA homozygotes than C-allele carriers (P = 0.017) and 5.4% higher in rs7460 AA homozygotes than T-allele carriers (P = 0.029). No associations between either SNP and net MVCKE torque (P ≥ 0.094) or peak MVCKE torque (P ≥ 0.107) were observed. CONCLUSIONS: These findings identify a genetic contribution to the inter-individual variability within muscle specific force and provides the first independent replication, in a larger Caucasian cohort, of an association between these PTK2 SNPs and muscle specific force, thus extending our understanding of the influence of genetic variation on the intrinsic strength of muscle.


Assuntos
Quinase 1 de Adesão Focal/genética , Força Muscular/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Frequência do Gene , Heterozigoto , Homozigoto , Humanos , Masculino , Músculo Esquelético/fisiologia , Fenótipo , Adulto Jovem
16.
Phys Rev Lett ; 118(5): 052501, 2017 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-28211717

RESUMO

Previous experiments observed a 4^{+} state in the N=28 nucleus ^{44}S and suggested that this state may exhibit a hindered E2-decay rate, inconsistent with being a member of the collective ground state band. We populate this state via two-proton knockout from a beam of exotic ^{46}Ar projectiles and measure its lifetime using the recoil distance method with the GRETINA γ-ray spectrometer. The result, 76(14)_{stat}(20)_{syst} ps, implies a hindered transition of B(E2;4^{+}→2_{1}^{+})=0.61(19) single-particle or Weisskopf units strength and supports the interpretation of the 4^{+} state as a K=4 isomer, the first example of a high-K isomer in a nucleus of such low mass.

17.
BMC Genet ; 18(1): 4, 2017 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-28103813

RESUMO

BACKGROUND: FTO gene variants have been associated with obesity phenotypes in sedentary and obese populations, but rarely with skeletal muscle and elite athlete phenotypes. METHODS: In 1089 participants, comprising 530 elite rugby athletes and 559 non-athletes, DNA was collected and genotyped for the FTO rs9939609 variant using real-time PCR. In a subgroup of non-resistance trained individuals (NT; n = 120), we also assessed structural and functional skeletal muscle phenotypes using dual energy x-ray absorptiometry, ultrasound and isokinetic dynamometry. In a subgroup of rugby athletes (n = 77), we assessed muscle power during a countermovement jump. RESULTS: In NT, TT genotype and T allele carriers had greater total body (4.8% and 4.1%) and total appendicular lean mass (LM; 3.0% and 2.1%) compared to AA genotype, with greater arm LM (0.8%) in T allele carriers and leg LM (2.1%) for TT, compared to AA genotype. Furthermore, the T allele was more common (94%) in selected elite rugby union athletes (back three and centre players) who are most reliant on LM rather than total body mass for success, compared to other rugby athletes (82%; P = 0.01, OR = 3.34) and controls (84%; P = 0.03, OR = 2.88). Accordingly, these athletes had greater peak power relative to body mass than other rugby athletes (14%; P = 2 x 10-6). CONCLUSION: Collectively, these results suggest that the T allele is associated with increased LM and elite athletic success. This has implications for athletic populations, as well as conditions characterised by low LM such as sarcopenia and cachexia.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Músculo Esquelético/metabolismo , Polimorfismo de Nucleotídeo Único , Treinamento Resistido , Adolescente , Adulto , Atletas , Futebol Americano , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Fenótipo , Adulto Jovem
18.
Int J Obes (Lond) ; 41(1): 102-111, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27569681

RESUMO

BACKGROUND/OBJECTIVES: The purpose of this study was to determine whether circulating pro-inflammatory cytokines, elevated with increased fat mass and ageing, were associated with muscle properties in young and older people with variable adiposity. SUBJECTS/METHODS: Seventy-five young (18-49 yrs) and 67 older (50-80 yrs) healthy, untrained men and women (BMI: 17-49 kg/m2) performed isometric and isokinetic plantar flexor maximum voluntary contractions (MVCs). Volume (Vm), fascicle pennation angle (FPA), and physiological cross-sectional area (PCSA) of the gastrocnemius medialis (GM) muscle were measured using ultrasonography. Voluntary muscle activation (VA) was assessed using electrical stimulation. GM specific force was calculated as GM fascicle force/PCSA. Percentage body fat (BF%), body fat mass (BFM), and lean mass (BLM) were assessed using dual-energy X-ray absorptiometry. Serum concentration of 12 cytokines was measured using multiplex luminometry. RESULTS: Despite greater Vm, FPA, and PCSA (P<0.05), young individuals with BF% ⩾40 exhibited 37% less GM specific force compared to young BF%<40 (P<0.05). Older adults with BF% ⩾40 showed greater isokinetic MVC compared to older BF%<40 (P=0.019) but this was reversed when normalised to body mass (P<0.001). IL-6 correlated inversely with VA in young (r=-0.376; P=0.022) but not older adults (p>0.05), while IL-8 correlated with VA in older but not young adults (r⩾0.378, P⩽0.027). TNF-alpha correlated with MVC, lean mass, GM FPA and maximum force in older adults (r⩾0.458; P⩽0.048). CONCLUSIONS: The age- and adiposity-dependent relationships found here provide evidence that circulating pro-inflammatory cytokines may play different roles in muscle remodelling according to the age and adiposity of the individual.


Assuntos
Adiposidade/fisiologia , Envelhecimento/fisiologia , Inflamação/fisiopatologia , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Obesidade/fisiopatologia , Absorciometria de Fóton , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/metabolismo , Fenômenos Biomecânicos , Citocinas/metabolismo , Feminino , Humanos , Inflamação/etiologia , Inflamação/metabolismo , Contração Isométrica , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Dinamômetro de Força Muscular , Obesidade/complicações , Obesidade/metabolismo , Reprodutibilidade dos Testes , Adulto Jovem
19.
J Nutr Health Aging ; 21(1): 51-58, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27999850

RESUMO

OBJECTIVES: Muscle size decreases in response to short-term limb immobilisation. This study set out to determine whether two potential protein-sparing modulators (eicosapentaenoic acid and vitamin D) would attenuate immobilisation-induced changes in muscle characteristics. DESIGN: The study used a randomised, double-blind, placebo-controlled design. SETTING: The study took part in a laboratory setting. PARTICIPANTS: Twenty-four male and female healthy participants, aged 23.0±5.8 years. INTERVENTION: The non-dominant arm was immobilised in a sling for a period of nine waking hours a day over two continuous weeks. Participants were randomly assigned to one of three groups: placebo (n=8, Lecithin, 2400 mg daily), omega-3 (ω-3) fatty acids (n=8, eicosapentaenoic acid (EPA); 1770 mg, and docosahexaenoic acid (DHA); 390 mg, daily) or vitamin D (n=8, 1,000 IU daily). MEASUREMENTS: Muscle and sub-cutaneous adipose thickness (B-mode ultrasonography), body composition (DXA) and arm girth (anthropometry) were measured before immobilisation, immediately on removal of the sling and two weeks after re-mobilisation. RESULTS: Muscle thickness (-5.4±4.3%), upper and lower arm girth (-1.3±0.4 and -0.8±0.8%, respectively), lean mass (-3.6±3.7%) and bone mineral content (BMC) (-2.3±1.5%) decreased significantly with limb immobilisation in the placebo group (P<0.05). Despite no significant effect of group, ω-3 and vitamin D supplementation showed trends (p>0.05) towards attenuating the decreases in muscle thickness, upper/lower arm girths and BMC observed in the placebo group. The ω-3 supplementation group demonstrated a non-significant attenuation of the decrease in DXA quantified lean mass observed in the placebo group. Sub-cutaneous adipose thickness increased in the placebo group (P<0.05). ω-3 and vitamin D both blunted this response, with ω-3 having a greater effect (P<0.05). All parameters had returned to baseline values at the re-mobilisation phase of the study. CONCLUSION: Overall, at the current doses, ω-3 and vitamin D supplementation only attenuated one of the changes associated with non-injurious limb immobilisation. These findings would necessitate further research into either a) supplementation linked to injury-induced immobilisation, or b) larger doses of these supplements to confirm/refute the physiological reserve potential of the two supplements.


Assuntos
Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/administração & dosagem , Imobilização , Vitamina D/administração & dosagem , Adiposidade/efeitos dos fármacos , Adolescente , Adulto , Composição Corporal , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Humanos , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Adulto Jovem
20.
J Nutr Health Aging ; 21(1): 59-66, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27999851

RESUMO

OBJECTIVES: This study set out to determine whether two potential protein-sparing modulators (eicosapentaenoic acid and vitamin D) would modulate the anticipated muscle functional and related blood vessels function deleterious effects of immobilisation. DESIGN: The study used a randomised, double-blind, placebo-controlled design. SETTING: The study took part in a laboratory setting. PARTICIPANTS: Twenty-four male and female healthy participants, aged 23.0±5.8 years. INTERVENTION: The non-dominant arm was immobilised in a sling for a period of nine waking hours a day over two continuous weeks. Participants were randomly assigned to one of three groups: placebo (n=8, Lecithin, 2400 mg daily), omega-3 (ω-3) fatty acids (n=8, eicosapentaenoic acid (EPA); 1770 mg, and docosahexaenoic acid (DHA); 390 mg, daily) or vitamin D (n=8, 1,000 IU daily). MEASUREMENTS: Isometric and isokinetic torque, antagonist muscle co-contraction (activation profile), muscle fatigability indices, and arterial resting blood flow were measured before, at the end of the immobilisation period, and two weeks after re-mobilisation. RESULTS: Muscle elbow flexion and extension isometric and isokinetic torque decreased significantly with limb immobilisation in the placebo group (P<0.05). Despite no significant effect of supplementation, ω-3 and vitamin D supplementation showed trends (P>0.05) towards attenuating the decreases observed in the placebo group. There was no significant change in muscle fatigue parameters or co-contraction values with immobilisation and no effect of supplementation group (P>0.05). Similarly, this immobilisation model had no impact on the assessed blood flow characteristics. All parameters had returned to baseline values at the re-mobilisation phase of the study. CONCLUSION: Overall, at the current doses, neither ω-3 nor vitamin D supplementation significantly attenuated declines in torque associated with immobilisation. It would appear that muscle function (described here in Part B) might not be as useful a marker of the effectiveness of a supplement against the impact of immobilisation compared to tissue composition changes (described in Part A).


Assuntos
Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/sangue , Ácido Eicosapentaenoico/sangue , Imobilização , Vitamina D/sangue , Adolescente , Adulto , Biomarcadores/sangue , Ácidos Docosa-Hexaenoicos/administração & dosagem , Método Duplo-Cego , Ácido Eicosapentaenoico/administração & dosagem , Feminino , Humanos , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Vitamina D/administração & dosagem , Adulto Jovem
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