A note on the effect of isolation during testing and length of previous confinement on locomotor behaviour during open-field test in dairy calves

This study investigated firstly if confined calves perform more locomotor behaviour when open-field tested in pairs than when tested individually, and secondly if length of confinement affects the build-up of motivation to perform locomotor behaviour. In the first experiment,14 calves were open-field tested on two successive days either individually or as a pair. Calves walked more and performed more locomotor play when tested in pairs, suggesting that it may be appropriate to avoid isolation when aiming to measure the effects of confinement on locomotor behaviour. In the second experiment, in each of three successive weeks, 24 calves had access to an exercise arena for 45 min daily on three successive days either: (i) the first 3 days, (ii) the third, fourth and fifth day, or (iii) the fourth, fifth and sixth day. On the seventh day the calves were released into the arena for 10 min (open-field test). All calves received all three treatments in a Latin square design. Calves performed more locomotor play, and they trotted more after 3 days without access to the arena than after 1 or 0 days, suggesting that in calves the motivation to perform locomotor play and trotting increases with length of confinement.     

Expression of metallothionein in renal tubules of rats exposed to acute and endurance exercise

The induction of exercise-induced apoptosis in not actively involved in exercise organs, such as kidney could be a result of oxidative stress. Metallothionein (MT) exerts a protective effect in the cell against oxidative stress and apoptosis. We have previously demonstrated an increased incidence of apoptosis in distal tubular cells and collecting ducts in rat kidney after acute exercise. The present study was designed to test the hypothesis that MT may play a protective role in rat renal tubules against exercise-induced apoptosis after the acute exercise and regular training. Male Wistar rats were divided into control, acute exercised and 8-wk regularly trained groups. The kidneys were removed after a rest period of 6 h and 96 h. The ultrastructure of renal tubular cells was examined by electron microscopy. Apoptosis was detected in paraffin sections by the TUNEL technique. Expression of MT was examined by immunohistochemistry. The level of lipid peroxidation (thiobarbituric acid reactive substances - TBARS) was assayed in renal tissue homogenates. After acute exercise, the occurrence of apoptosis was restricted to distal tubules and collecting ducts of rat kidney, whereas the proximal tubules remained unaffected. The 8-wk training did not result in increased apoptosis in tubular cell. MT expression was confined exclusively to proximal tubules in all groups. However, it was significantly increased in acutely exercised animals, as compared to control and trained rats. After the 8-wk training, MT expression remained unaltered as compared to the control group. TBARS levels were significantly increased after acute exercise, while after regular training they remained unchanged. A significant correlation between TBARS level and MT expression was demonstrated. The findings could suggest a protective role of MT against oxidative stress and apoptosis in proximal tubular cells.     

Effects of confinement (110 and 240 days) on neuroendocrine stress response and changes of immune cells in men.

The aim of the study was to evaluate the effects of long-term confinement on stress-permissive neuroendocrine and immune responses in humans. Two groups of four male subjects were confined 240 days (group 240) or 110 days (group 110) in two space modules of 100 or 200 m3, respectively. During confinement, none of the volunteers developed psychic stress as could be examined and verified by a current stress test. However, in group 240 but not in group 110, the diurnal rhythm of cortisol secretion was slightly depressed and the urine excretion of norepinephrine significantly increased. The innate part of the immune system became activated as seen by a rise in the number of circulating granulocytes and the enhanced expression of beta2-integrins. In contrast, the ratio of T-helper to T-suppressor cells decreased. All these effects, observed during confinement, were even more pronounced in both groups when values of endocrinological and immunological parameters were compared between before and 1 wk after the end of the confinement period. Hence, return to normal life exerts pronounced effects to a much higher degree, irrespective of how long or under which conditions individuals were confined. Because the delayed-type hypersensitivity skin reaction against recall antigens remained unaffected, it is to be presumed that confinement appears to induce distinct sympathoadrenergic activation and immunological changes but no clinically relevant immunosuppression.     

What do diffusion measurements tell us about membrane compartmentalisation? Emergence of the role of interprotein interactions

The techniques of diffusion analysis based on optical microscopy approaches have revealed a great diversity of the dynamic organisation of cell membranes. For a long period, two frameworks have dominated the way of representing the membrane structure: the membrane skeleton fences and the lipid raft models. Progresses in the methods of data analysis have shed light on the features and consequently the possible origin of membrane domains: Inter-protein interactions play a role in confinement. Innovative developments pushing forward the spatiotemporal resolution limits are currently emerging, which are likely to provide in the future a detailed understanding of the intimate functional dynamic organisation of the cell membrane.     

Influence of physical exercise after long-lasting hypodynamia on the morphological parameters of muscle fibers

The purpose of this research was morphometric ultrastructure evaluation of the fibers in muscles taking part in the flight of pigeons forced to exercise after a long period of hypodynamia. It was found that following physical exercise, after 12 and 18 months of mobility limitation, there appeared marked qualitative and quantitative changes: a diminution of the volume fraction and number of mitochondria, increase of smooth sarcoplasmic reticulum and sarcoplasm, and a significant decrease of the number of glycogen granules as compared with those after 18 months hypodynamia. The above described changes were more pronounced in the supracoracoideus than in the pectoralis muscle.     

Hoop Housing for Feeder Pigs Offers a Welfare-Friendly Environment Compared to a Nonbedded Confinement System

Total confinement systems of swine production offer several benefits and costs in terms of animal welfare. Swine raised in total confinement are protected from environmental extremes and predators; however, welfare concerns stem from observations of stereotypic behavior and lameness of pigs, common in some of these systems. Because total confinement systems are expensive to build and maintain compared to less intensive systems, producers have become interested in an inexpensive alternative: hoop structures (Hoop). Open-ended Quonsets shaped like a half cylinder lying on its flat side, the Hoop use bedding to keep the pigs dry and allow this bedding to compost beneath the pigs to keep them warm in winter. This project compared the behavior and physiology of pigs in a nonbedded confinement system (NBCS) with those in the Hoop. Two experiments, 1 in the winter and 1 in the summer, assessed the welfare of pigs based on the incidence of aberrant behavior, physiologic response to handling, incidence of lameness, and the performance of play behavior. Pigs raised in the NBCS performed more aberrant behaviors and less play behavior, had greater plasma cortisol in response to handling (but fewer vocalizations), and a greater incidence of injuries than did the pigs raised in the Hoop. Based on these data, pigs in the Hoop were adjudged to have enhanced welfare as compared to pigs raised in the NBCS. Because the welfare of pigs in the Hoop appears to be greater than the welfare of pigs raised in the NBCS, future research should determine which factors are most important to pigs and then try to incorporate these into production systems.     

Impacto de la pandemia por COVID-19 y el confinamiento estricto de la población en la incidencia de fractura de cadera en España. Una revisión sistemática

Background and objectiveDuring the COVID-19 pandemic, a strict population confinement was decreed in Spain. In a situation of health crisis and health system saturation, knowledge of pathologies whose treatment cannot be delayed is of great importance for the correct management of resources and processes. The objective was to determine the influence of the COVID-19 pandemic and the strict population confinement on hip fracture incidence in Spain.Material and methodSystematic review following the PRISMA guidelines. Search in Pubmed and Chocrane Library on 11/11/2022: hip fracture and COVID-19 and Spain.ResultsSix studies met the inclusion criteria, 50% showed a decrease in the hip fractures incidence during strict population confinement (all in Comunidad de Madrid hospitals), and in the other 50% there were no differences (all in other region hospitals). It was constant that hip fractures, either did not decrease, or decreased much less than the rest of fractures during the period of strict population confinement, increasing their relative number with respect to the total admissions in orthopedic surgery and traumatology.ConclusionsThe behavior of the hip fractures number during the strict population confinement decreed by the COVID-19 pandemic has not been symmetrical in all regions. To design and implement contingency plans in the event of a pandemic situation, these data must be taken into account in order to properly plan material and human resources.     

Muscle metabolism during exercise in dogs after 8-week confinement

Several indicators of muscle metabolism were measured in dogs during exercise following 8 weeks of confinement in cages. Muscle tissue samples were studied at rest and following exercise for adenine nucleotides, creatine phosphate, creatine, glycogen, pyruvate, and lactate. Results indicate that confinement results in less efficient metabolic responses to exercise, decreased muscle glycogen at rest, and changes in the equilibrium between ATP breakdown and resynthesis during exercise.     

A Single Bout of Moderate Aerobic Exercise Improves Motor Skill Acquisition

Long-term exercise is associated with improved performance on a variety of cognitive tasks including attention, executive function, and long-term memory. Remarkably, recent studies have shown that even a single bout of aerobic exercise can lead to immediate improvements in declarative learning and memory, but less is known about the effect of exercise on motor learning. Here we sought to determine the effect of a single bout of moderate intensity aerobic exercise on motor skill learning. In experiment 1, we investigated the effect of moderate aerobic exercise on motor acquisition. 24 young, healthy adults performed a motor learning task either immediately after 30 minutes of moderate intensity running, after running followed by a long rest period, or after slow walking. Motor skill was assessed via a speed-accuracy tradeoff function to determine how exercise might differentially affect two distinct components of motor learning performance: movement speed and accuracy. In experiment 2, we investigated both acquisition and retention of motor skill across multiple days of training. 20 additional participants performed either a bout of running or slow walking immediately before motor learning on three consecutive days, and only motor learning (no exercise) on a fourth day. We found that moderate intensity running led to an immediate improvement in motor acquisition for both a single session and on multiple sessions across subsequent days, but had no effect on between-day retention. This effect was driven by improved movement accuracy, as opposed to speed. However, the benefit of exercise was dependent upon motor learning occurring immediately after exercise–resting for a period of one hour after exercise diminished the effect. These results demonstrate that moderate intensity exercise can prime the nervous system for the acquisition of new motor skills, and suggest that similar exercise protocols may be effective in improving the outcomes of movement rehabilitation programs.     

Plasma cortisol and metabolite level profiles in two isogenic strains of common carp during confinement

A rapid increase in common carp Cyprinus carpio plasma cortisol levels was noted, in two experiments, after 30 mins of a 3 h net confinement, which was sustained while the fish were held in the nets. After release from the nets, cortisol levels returned to control values in 1 h. Plasma glucose and free fatty acid levels were elevated by the confinement. Glucose was increased after 30 min but returned to basal levels after 22 h of recovery while free fatty acids were not elevated until 3 h of confinement and remained high for the duration of the recovery period. After confinement for 3 h, plasma lactate levels were reduced and remained low for a further 1 h. No change in either plasma triglyceride or cholesterol levels were found during the study. Confinement had no effect on haematocrit levels but blood haemoglobin levels were reduced. In both experiments hypochloraemia occurred in response to confinement. However, values returned to pre-confinement levels 22 h after confinement. These results show that rearing isogenic carp strains, under identical conditions, results in a reproducable response to an acute stressor and that these carp respond in a similar manner to other teleost species.     

Effects of confinement stress of variable duration on the growth and microincrement deposition in the otoliths of Oreochromis niloticus(Cichlidae)

The effects of chronic confinement stress (1, 5 and 10 days) and of periodic blood sampling on somatic growth and the structure and growth of otoliths was studied in Oreochromis niloticus . During the study, the plasma concentrations of cortisol were measured at various times during the application of stress: they were significantly higher in confined fish than in control fish (mean ±  s . d . 3·40 ± 0·47 v . 1·26 ± 0·62 ng ml⁻¹, P  < 0·05) up to 5 days after the start of a 10 day stress period. The somatic growth (standard length, L _S, and mass) was affected by the confinement and by the sampling (from 16·21 ± 1·07 to 14·64 ± 1·15 cm for L _S, and from 173·31 ± 33·14 to 110·50 ± 29·48 g for mass). But the confinement masked the effect of the sampling on somatic growth. Tetracycline was injected at the start of the experiment to mark the otoliths, and showed that the short and long duration confinements led to a clear check in the pattern of primary increments in the otoliths. The number of primary increments deposited during the resting periods that followed each period of confinement was always less than the number of days that these periods lasted. No relation was found between the duration of confinement and the structure of the resulting checks. These results suggest that there is a disruption in the laying down of primary increments during periods of confinement resulting in an underestimation of their number compared to the actual number of days of growth. These results call into question the use of otolith primary increments as a means of estimating the age of Nile tilapia that have experienced periods of stress.     

多次短时间快走能提高机体脂肪和能量的消耗

为探讨多次短时间及单次长时间的快走对脂肪代谢与激素反应的影响,以提高鼓励运动的说服力,本研究选择15名健康大学男生为研究对象,进行单次长时间快走运动(SL)(1次×30 min),或多次短时间快走运动(MS)(6次×5 min,每次中间休息30 min)。数据收集后以独立样本t检验和双因素方差分析进行统计检验。研究结果发现:MS在运动后超额摄氧量(EPOC)和恢复期能量消耗显著高于SL,且MS的总摄氧量和总能量消耗(运动期+恢复期)也显著高于SL;而SL在运动结束后甘油浓度显著高于运动前,同时显著高于同期的MS。本研究认为,多次短时间的运动在恢复期的能量消耗显著大于单次长时间的运动,且在恢复期脂肪的消耗也较高,建议不易开展长时间运动的人,可采用多次短时间的运动方式,以增加能量和脂肪的消耗。     

Effects of 10-day confinement on the immune system and psychological aspects in humans.

We investigated the changes in percentages of leukocyte subpopulations, natural killer (NK) cells, CD69-expressing lymphocytes, and psychological aspects in 10 subjects who participated in a 10-day confinement study. Suppression of lymphocyte proliferative reaction and changes in leukocyte distribution are known to occur in space. These responses are similar to those induced by psychological stress. Ground-based confinement studies are suitable for validating the effects of stress arising only due to confinement. Two groups, consisting of five male subjects (ages 20-27 yr, mean 22.8 yr) each, participated in a 10-day confinement study. Blood samples were taken once before, three times during, and once after the confinement and activated with an anti-CD2 agonistic antibody cocktail. The percentages of leukocyte subpopulations, NK (CD45(+)CD56+) cells, and activated lymphocytes (CD45(+)CD69+) were measured by flow cytometric assay. The face scale test was used to measure psychological aspects. The percentage of CD69+ lymphocytes decreased during the period of confinement. This was mostly caused by changes in the ratio between NK and non-NK lymphocytes. The face scale showed that the subjects' moods improved toward the postconfinement period. Consistent with the face scale, the percentages of innate immune cells, such as NK cells and granulocytes, increased during the postconfinement period. We concluded that the changes in the distribution of immune cells caused by stress plays an important role in suppression of proliferative reactivity. The observed physiological reactions were specific to the confined environment, and the stress caused by confinement plays a role in the immune changes observed in space.     

Physiological response in the forearm during and after isometric intermittent handgrip

The aim of the present paper was to study the development of fatigue during isometric intermittent handgrip exercise. Using a handgrip dynamometer, four combinations of contraction-relaxation periods were studied (10 + 10, 10 + 5, 10 + 2 s and continuous contraction) at three contraction intensities (10, 25 and 40% maximum voluntary contraction, MVC). Local blood flow (BF) in the forearm (venous occlusion plethysmography) was followed before, during and after the exercise period. Electromyography (EMG) (frequency analysis) and the perceived effort and pain were recorded during the exercise period. Forearm BF is insufficient even at isometric contractions of low intensity (10% MVC). The results indicate that vasodilating metabolites play an active role for BF in low-intensity isometric contractions. It is shown that maximal BF in the forearm during relaxation periods (25-30 ml.min-1.100 ml-1) is already reached at 25% MVC. Only intermittent exercise at 10% MVC and (10 + 5 s) and (10 + 10 s) at 25% MVC was considered acceptable with regard to local fatigue, which was defined as a switch of local BF to the post-exercise period, a decrease in the number of zero-crossings (EMG) and marked increases in subjective ratings.     

Chronic exercise alters caudal hypothalamic regulation of the cardiovascular system in hypertensive rats

Previous studies have documented a deficit in the GABA neurotransmitter system within the caudal hypothalamus (CH) of spontaneously hypertensive rats (SHR). The reduction in inhibitory influence on this cardiovascular excitatory brain region is associated with an increased neuronal activity and resting blood pressure. The purpose of this study was to determine if chronic treadmill and wheel-running activities alter the ability of the CH to regulate cardiovascular function. SHR were exercised on a treadmill (5 times/wk) at moderate intensity or allowed free access to running wheels (7 days/wk) for a period of 10 wk. Resting blood pressures were obtained before and after the exercise training periods. After the exercise period, rats were anesthetized and microinjection experiments were performed. Treadmill-trained SHR exhibited a significantly blunted developmental rise in resting blood pressure after 10 wk of exercise. A similar yet less marked effect was observed in wheel-run rats. Microinjection of the GABA synthesis inhibitor 3-mercaptopropionic acid (3-MP) into the CH of nonexercised SHR did not produce any change in arterial pressure. In contrast, microinjection of 3-MP into the CH produced significant increases in blood pressure and heart rate in exercised SHR. These results demonstrate that exercise training can alter CH cardiovascular regulation in hypertensive rats and therefore may play a role in increasing cardiovascular health.     

Adaptation of the Main Peripheral Artery and Vein to Long Term Confinement (MARS 500)

Purpose

The objective was to check if 520 days in confinement (MARS 500), may affect the main peripheral arterial diameter and wall thickness and the main vein size.

Method

Common carotid (CC) femoral artery (FA) portal vein (PV), jugular (JG), femoral vein (FV) and tibial vein were assessed during MARS 500 by echography, performed by the subjects. A hand free volumic echographic capture method and a delayed 3D reconstruction software developed by our lab were used for collecting and measuring the vascular parameters.

Results

During the MARS 500 experiment the subjects performed 6 sessions among which 80% of the echographic data were of sufficient quality to be processed. No significant change was found for the Common carotid, Jugular vein, femoral artery, femoral vein, portal vein, and tibial vein diameter. CC and FA IMT (intima media thickness) were found significantly increased (14% to 28% P<0.05) in all the 6 subjects, during the confinement period and also at +2 days after the confinement period, but there was no significant difference 6 month later compare to pre MARS 500.

Conclusion

The experiment confirmed that even untrained to performing echography the subjects were able to capture enough echographic data to reconstruct the vessel image from which the parameters were measured. The increase in both CC and FA IMT should be in relation with the stress generated by the confined environment or absence of solar radiation, as there was no change in gravity, temperature and air in the MARS 500 module, and minor changes in physical exercise and nutrition.     

Profiling of Circulating MicroRNAs after a Bout of Acute Resistance Exercise in Humans

Recent studies have revealed a new aspect of physiological regulation in which microRNAs (miRNAs) play fundamental roles in diverse biological and pathological processes. Furthermore, it was recently discovered that miRNAs are stably secreted into blood and that circulating miRNAs may play important roles in cell–cell communication. Here, we examined whether the circulating miRNA profile is affected by acute resistance exercise. Twelve males performed a resistance exercise session (bench press and leg press), consisting of five sets of 10 repetitions at 70% of maximum strength, with a 1 min rest between sets. Blood samples were taken before exercise, and at 0 and 60 min, 1 day, and 3 days after exercise. The circulating miRNA profile was determined by microarray analysis. Quantitative real-time PCR confirmed that the miR-149* level increased three days after resistance exercise. In contrast, the miR-146a and miR-221 levels decreased three days after resistance exercise. Our findings suggest that circulating miRNA levels change in response to acute resistance exercise, and miRNAs may play important roles in resistance-exercise-induced adaptation.     

Eccentric strain at long muscle length evokes the repeated bout effect

The repeated bout effect (RBE) is a phenomenon characterized by less delayed onset muscle soreness (DOMS) and torque deficit after the second of 2 separate eccentric exercise bouts. Previous investigators have reported that shifting of optimum angle after an initial bout of eccentric exercise mediates the RBE. We hypothesized that an RBE for elbow extensor exercise occurs after an initial bout performed at long (starting position of 50 degrees to an end position of 130 degrees) but not short (starting position of 0 degrees to an end position of 80 degrees) muscle length because strain at long length evokes a shifting of the optimum angle to a longer length. Untrained women performed an initial bout at either long or short length (n = 9 per group) followed 1 week later by a repeated bout (RB) through the full ROM (0-130 degrees). Extensor torque and optimum angle was evaluated before, immediately after, and 2 days after each bout. A mechanical transducer depressed on the triceps brachii quantified DOMS. Torque deficits were 3% and 7% after exercise at short vs. long length, respectively. Two days after the RB, torque deficit was 8% and 1% for those previously exercising at short vs. long length (group x bout, p < 0.05). Greater DOMS (N) was observed after exercise at long (16 +/- 3) vs. short (23 +/- 2) length; whereas greater DOMS occurred for the short-length (17 +/- 2) vs. long (26 +/- 3) group after the RB (group x bout, p < 0.05). Optimum angle shifted to a longer length after exercise at long (+10 +/- 4 degrees) vs. short (+1 +/- 3 degrees) length (group x bout, p < 0.05). After the RB, those exercising previously at short length experienced a shift of +15 +/- 4 degrees (main effect, p < 0.05). The findings of this study indicate that the repetitive strain at long but not short muscle length evokes both immediate and sustained shifts in optimum angle to longer lengths, and that this shifting mediates (r(2) = 0.71) the RBE.     

Healthy Exercise

Persons at any age can substantially improve their fitness for work and play through appropriate exercise training. Considerable evidence indicates that physical activity is valuable for weight control, modifying lipids and improving carbohydrate tolerance. Less rigorous scientific data are available for associated long-term blood pressure and psychological changes with habitual exercise. Strenuous physical activity most likely reduces the incidence of coronary heart disease and the detrimental impact of certain chronic diseases on health. Adverse effects may result from a training program, but the major concern is the susceptibility to cardiovascular events during and immediately after exertion. To achieve optimal benefits with minimal risk, exercise must be carefully prescribed within the context of overall health and training objectives. Taken altogether, a distinct rationale exists for regular vigorous exercise as an integral part of a personal health maintenance program.