Effect of photobiomodulation therapy on performance and running economy in runners: A randomized double-blinded placebo-controlled trial.

The objective of this study was to evaluate effects of photobiomodulation therapy (PBMT) on the 3000 m running performance (primary outcome), running economy (RE), metabolic cost and ratings of perceived exertion during running (secondary outcomes). Twenty male endurance athletes performed 4-min treadmill rectangular test at 12 km.h-1 monitored by a gas analyser. After that, PBMT or placebo in each lower limb was applied, followed performed a maximum test of 3000 m. Immediately after 3000 m test, the athletes repeated the treadmill test. Another application of PBMT/placebo was done after the treadmill test, and athletes went back to the laboratory 24 h later to repeat the treadmill test. After a 72 h interval, athletes repeated all procedures with another treatment intervention (PBMT/placebo). Athletes performed the 3000 m running test ~7s faster when treated with PBMT with similar effort score compared placebo condition. The RE remains unchanged immediately post 3000 m running test, nonetheless RE measured post-24 h improved by 5% with PBMT application without changes in metabolic cost. The PBMT pre- and post-conditioning enhanced the 3000 m running performance and improved RE 24 h following the 3000 m test. However, no changes on ratings of perceived exertion and metabolic cost with the application of PBMT.

Acute LED irradiation does not change the anaerobic capacity and time to exhaustion during a high-intensity running effort: a double-blind, crossover, and placebo-controlled study : Effects of LED irradiation on anaerobic capacity and performance in running.

The purpose of this study was to investigate the acute effects of photobiomodulation therapy using cluster light-emitting diodes (LEDT; 104 diodes) (wavelength 660 and 850 nm; energy density 1.5 and 4.5 J/cm(2); energy 60 J at each point; total energy delivered 600 J) on alternative maximal accumulated oxygen deficit (MAODALT) and time to exhaustion, during a high-intensity running effort. Fifteen moderately active and healthy males (age 25.1 ± 4.4 years) underwent a graded exercise test and two supramaximal exhaustive efforts at 115 % of the intensity associated with maximal oxygen uptake performed after acute LEDT or placebo irradiation in a double-blind, crossover, and placebo-controlled study design. The MAODALT was assumed as the sum of both oxygen equivalents estimated from the glycolytic and phosphagen metabolism pathways during each supramaximal effort. For the statistical analysis, a paired t test was used to determine differences between the treatments. The significance level was assumed as 95 %. In addition, a qualitative analysis was used to determine the magnitude of differences between groups. No significant differences were found for the values of oxygen equivalents from each energetic metabolism (P ≥ 0.28), for MAODALT values between the LEDT and placebo conditions (P ≥ 0.27), or for time to exhaustion (P = 0.80), except for the respiratory exchange ratio (P = 0.01). The magnitude-based inference of effect size reported only a possibly negative effect of photobiomodulation on MAODALT when expressed in units relative to body mass and on the glycolysis pathway (26 %). In summary, LEDT after a high-intensity running effort did not alter the MAODALT, metabolic energy pathways, or high-intensity running performance.

Síncopes en un paciente con antecedente de radioterapia: la importancia de una valoración global de la afección cardiaca / Syncopes in a patient with a history of radiotherapy: the importance of a comprehensive assessment of cardiac involvement

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Síncopes en un paciente con antecedente de radioterapia: la importancia de una valoración global de la afección cardiaca. Respuesta / Syncopes in a patient with a history of radiotherapy: the importance of a comprehensive assessment of cardiac involvement. Response

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Constant light enhances synchrony among circadian clock cells and promotes behavioral rhythms in VPAC2-signaling deficient mice.

Individual neurons in the suprachiasmatic nuclei (SCN) contain an intracellular molecular clock and use intercellular signaling to synchronize their timekeeping activities so that the SCN can coordinate brain physiology and behavior. The neuropeptide vasoactive intestinal polypeptide (VIP) and its VPAC2 receptor form a key component of intercellular signaling systems in the SCN and critically control cellular coupling. Targeted mutations in either the intracellular clock or intercellular neuropeptide signaling mechanisms, such as VIP-VPAC2 signaling, can lead to desynchronization of SCN neuronal clocks and loss of behavioral rhythms. An important goal in chronobiology is to develop interventions to correct deficiencies in circadian timekeeping. Here we show that extended exposure to constant light promotes synchrony among SCN clock cells and the expression of ~24 h rhythms in behavior in mice in which intercellular signaling is disrupted through loss of VIP-VPAC2 signaling. This study highlights the importance of SCN synchrony for the expression of rhythms in behavior and reveals how non-invasive manipulations in the external environment can be used to overcome neurochemical communication deficits in this important brain system.

[Quantitative patterns in the clinical manifestations of radiation sickness in large laboratory animals exposed to radiation at superlethal doses. Changes in the regulation of cardiovascular system function]. / Kolichestvennye zakonomernosti klinicheskikh proiavlenii luchevoi bolezni u krupnykh laboratornykh zhivotnykh pri vozdeistvii izlucheniia v sverkhletal'nykh dozakh. Izmeneniia v reguliatsii funktsii serdechno-sosudistoi sistemy.

Dog exposure to doses from 39 to 124 Gy results in an increase of heart rate and tension in control of the cardiac rhythm, the extent being dose dependent. An additional physical load on the cardiovascular animals system reveals a high functional control reserves of the cardiovascular system which provides stable functioning even after exposure to the above doses.

[The possibilities for regulating thymus cell activity with the transcerebral use of physical factors]. / Vozmozhnosti reguliatsii aktivnosti kletok timusa pri transtserebral'nom primenenii fizicheskikh faktorov.

The authors discuss experimental findings on physical factors (impulse currents of different frequencies, SHF and IR laser radiation, coherent and non-coherent red light) effect on thymic cell genome in transcerebral exposure in models of some diseases running with immune disorders.

[The combined action of ionizing radiation and stress on antibody formation in mice]. / Sochetannoe vozdeistvie ioniziruiushchei radiatsii i stressa na antitelogenez u myshei.

Disturbances in humoral immune response to sheep erythrocytes after separate and combined effect of ionizing radiation (2 and 4 Gy) and stress (swimming for 10 of 60 min) was studied in mice. The increase in sensitivity to stress was found in irradiated mice. Superposition of undulating dynamics of post-stress immunosuppression on dynamics of post-radiation disorder was revealed. This is due to the different mechanisms of disturbances: redistribution of precursors of immunocompetent cells between immune organs in the first case and destruction of cells in the second case.

[The function of the kallikrein-kinin system and the activity of proteinase inhibitors during physical loading and infrared laser irradiation]. / Sostoianie kallikerin-kininovoi sistemy i aktivnost' ingibitorov proteinaz pri fizicheskoi nagruzke i infrakrasnom lazernom obluchenii.

Experiments on 40 male rats were conducted to examine kallikrein-kinin system (KKS) and activity of proteinase activity under stress, impulse infrared laser radiation and their sequence. Infra-red laser radiation following stress prevents activation of KKS provoked by exercise through enhancing antiproteinase potential of blood serum. Thymic mass and activity of thymocyte genome were on the increase.

[The physical work capacity parameters of rodents studied by repeated high-speed swimming following uniform and nonuniform irradiation at high doses]. / Issledovanie parametrov fizicheskoi rabotosposobnosti gryzunov metodom mnogokratnogo skorostnogo plavaniia posle ravnomernogo i neravnomernogo oblucheniia v vysokikh dozakh.

Physical fitness of irradiated (20-200 Gy) mice and rats was estimated by the method of repeated swimming at a fixed distance. Revealed was the reduction adequacy of the two indices, that is the starting time and the fatigue coefficient, the latter being changed more considerably. The dose of 80-100 Gy determined the threshold of the cerebral damage and caused an irreversible decrease in the physical fitness of rodents. The role of exposure of the head in the impairment of the physical fitness of rats has been confirmed by the experiments with some body parts being shielded.

[The mechanism of the neuromotor disorders in the period of the primary reaction to irradiation]. / K mekhanizmu neiromotornykh narushenii perioda pervichnoi reaktsii na obluchenie.

In experiments with dogs it was shown that the impairment of the capacity of fulfilling some actions (e. g. high jumping, equilibration, racing) was maximum 4h after gamma-irradiation with doses of 10 and 40 Gy and did not coincide with vomiting. By shielding body segments it was found that irradiation of abdomen was responsible for the disturbances observed. Novocaine blockade of innervation of abdomen prevented the impairment of the physical capacity, but not vomiting, during the first hours which was indicative of a major role of the reflex mechanism in motor disturbances genesis.

[Cumulated biological effects of microwaves and their reflection in behavior, work capacity, growth of body mass and state of brain neurons]. / Kumuliatsiia biologicheskikh éffektov mikrovoln i ee otrazhenie v povedenii, rabotosposobnosti, priroste massy tela i sostoianii neironov golovnogo mozga.

Albino rats were exposed to 2375 mHz microwaves of 500 microW/cm2 for 169 h. At the time of exposure, the body mass growth diminished, the efficiency and vertical motor activity decreased in exposed animals in comparison with the controls. Three types of radiation-induced damages were found in the brain: chromatolysis, pyknosis, and ischemia. Different brain parts displayed different sensitivity depending on their location in relation to transverse sutures of the skull.

[Indices of RNA metabolism in the brain stem of rats under superlethal exposure to ionizing radiation]. / Nekotorye pokazateli metabolizma RNK v stvole golovnogo mozga krys pri sverkhletal'nom vozdeistvii ioniziruiushchei radiatsii.

A study was made of the content of hnRNA, nuclear poly(A) RNA and biosynthesis of rlnRNA in truncus cerebri of rats divided into 3 groups by the forced swimming test 6-8 min and 60 min after a short-term exposure to sparsely ionizing radiation of 100 Gy. The observed changes in the nuclear RNA metabolism can subsequently lead to the impairment of the synthesis of proteins required for normal functioning of CNS, and to the development of CNS syndrome.

[The dosage thresholds for disordered physical work capacity in mice and rats following irradiation]. / Dozovye porogi narusheniia fizicheskoi rabotosposobnosti myshei i krys posle oblucheniia.

Physical efficiency of mice and rats at early times following irradiation with doses of 35 to 200 Gy was estimated by the muscle endurance and motor coordination indices. A threshold nature of the effects was exhibited at high doses. For instance, as large as 40 Gy was the dose threshold at which stability in the accomplishment of the known operations was impaired; at 70-100 Gy, the accomplishment decreased down to 50% of the initial level, by the 2nd hour after irradiation, with the subsequent partial restoration; 200 Gy was the threshold dose at which the disturbances were irreversible. These values were also similar to those of the threshold doses at which clinical picture of the affection was changed.