Search

ObjectiveThe objective of this study was to evaluate the efficacy and safety of isotonic and hypotonic intravenous fluids in maintenance fluid therapy for term infants.MethodsThis was a multi-centre, prospective, observational study conducted in 21 participating centres from December 30, 2020, to June 30, 2023. The study included term newborns requiring parenteral fluid therapy for maintenance (NCT04781361). The fluid treatment was divided into two groups based on the concentration of sodium in the parenteral fluid, designated as hypotonic (NaCl 145 mmol/L), and the occurrence of clinically significant changes in sodium levels (∆pNa >0.5 mmol/L/h).ResultsA total of 420 patients from 21 centers were included. The ∆pNa was negative in the hypotonic fluid group and positive in the isotonic fluid group, with a significant difference between the groups [respectively −0.07 ± 0.03 (95% CI: −0.13 to −0.02); 0.04 ± 0.03 (95%CI: −0.02 to 0.09), p = 0.04]. There was no difference between the groups in terms of the development of hypernatremia or a clinically meaningful pNa increase. The hypotonic fluid group had a higher incidence of hyponatremia and a clinically meaningful sodium decrease compared to the isotonic fluid group [7.9% vs. 1.2% (OR:6.5, p:0.03)] and [12.2% vs.4.2% (OR:2.9, p = 0.03)].ConclusionContrary to current understanding, this large-scale study is the first to demonstrate that the use of hypotonic fluids in maintenance fluid therapy for newborns poses a risk of hyponatremia development, whereas isotonic fluid therapy appears safe.

Abstract Background Transient progressive weakness and disability of lower limb during the early stage after TKR will increase the risk of fall, but the superior postoperative strength training mode have not been elucidated for functional restoration. This study aimed to compare whether the isokinetic lower limb training is superior to either isotonic or home isometric exercise during early stage after TKR in older people. Methods A total of 43 recruited old participants (mean age, 68.40 years old) receiving TKR were divided randomly based on the different four-week training modes into three groups including isokinetic, isotonic, and home isometric exercise (control group). The primary outcome was set as functional performance in terms of Timed Up and Go (TUG) test and the secondary outcomes include the peak torque of knee at 60 and 120 degree/ second, Short-Form 36 Health Survey (SF-36), and Western Ontario and McMaster Universities Arthritis index (WOMAC). Results All of the peak torque measurements of the knee improved significantly in both the isokinetic and the isotonic group, but not in the control group. Although isotonic training resulted in more strength gains, a significant enhancement in TUG test was observed in the isokinetic group only (p = 0.003). However, there were no significantly improvement of TUG test after training in other two groups. SF-36 and WOMAC improved after training in all three groups, with no significant difference in the degree of improvement between groups. Conclusion Isokinetic training for 4 weeks following TKR effectively improved all the outcome parameters in this study, including the TUG test, lower limb strength, and functional scores. However, both isokinetic and isotonic training modes could be recommended after TKR because of no significant difference in the degree of improvement between these two groups. Trial registration Clinical trial registration number: NCT02938416. Level of evidence I

Background: Transient progressive weakness and disability of lower limb during the early stage after TKR will increase the risk of fall, but the superior postoperative strength training mode have not been elucidated for functional restoration. This study aimed to compare whether the isokinetic lower limb training is superior to either isotonic or home isometric exercise during early stage after TKR in older people. Methods: A total of 43 recruited old participants (mean age, 68.40 years old) receiving TKR were divided randomly based on the different four-week training modes into three groups including isokinetic, isotonic, and home isometric exercise (control group). The primary outcome was set as functional performance in terms of Timed Up and Go (TUG) test and the secondary outcomes include the peak torque of knee at 60 and 120 degree/ second, Short-Form 36 Health Survey (SF-36), and Western Ontario and McMaster Universities Arthritis index (WOMAC). Results: All of the peak torque measurements of the knee improved significantly in both the isokinetic and the isotonic group, but not in the control group. Although isotonic training resulted in more strength gains, a significant enhancement in TUG test was observed in the isokinetic group only (p = 0.003). However, there were no significantly improvement of TUG test after training in other two groups. SF-36 and WOMAC improved after training in all three groups, with no significant difference in the degree of improvement between groups. Conclusion: Isokinetic training for 4 weeks following TKR effectively improved all the outcome parameters in this study, including the TUG test, lower limb strength, and functional scores. However, both isokinetic and isotonic training modes could be recommended after TKR because of no significant difference in the degree of improvement between these two groups. Trial registration: Clinical trial registration number: NCT02938416. Level of evidence: I [ABSTRACT FROM AUTHOR]

IntroductionQuadriceps weakness after knee surgery is the most common consequence that can have different consequences not only for the knee itself but also for the locomotor system in general. This study aimed to compare the results of isokinetic and isotonic exercise on torque restoration quadriceps on knee surgery.MethodsA sample of 180 subjects was analyzed and divided into two subsamples according to the type of rehabilitation protocol that was implemented. The examined group A-isokinetic consisted of 90 male subjects aged 28.54 ± 4.44 years, with a rehabilitation protocol based on the isokinetic exercise of the quadriceps. The examined group B-isotonic also consisted of 90 male subjects aged 27.93 ± 4.27 years, with a rehabilitation protocol for strengthening the quadriceps that applied an exercise program with additional resistance, i.e., isotonic exercise in the gym. Before the start of the rehabilitation treatment, an initial isokinetic test was performed at an angular speed of 60 °/s in all subjects. After 3 and 6 weeks of rehabilitation treatment, the control tests were performed in the same way as in the initial test.ResultsBased on the values of MANOVA analysis and discriminative analysis, significantly better results of isokinetic tests were found in the examined group A-isokinetic compared with those in the examined group B-isotonic. At the final measurement of group A, 83 respondents (92.2%) were placed in the “biggest” class out of the 90 respondents.ConclusionBased on the obtained research results, we conclude that isokinetic exercise is more effective in terms of physiotherapy of quadriceps hypotrophy after knee surgery.

Copyright of Sport & Tourism Central European Journal / Sport i Turystyka Srodkowoeuropejskie Czasopismo Naukowe is the property of Jan Dlugosz University in Czestochowa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Maintaining an adequate fluid balance is crucial during extended physical activity. It is currently unknown how drinking an isotonic medinilla speciosa beverage affects the autonomic regulation of heart function during and after exercise. The purpose of this study is to examine how drinking isotonic beverages affects heart rate variability (HRV) during and after intense exercise. A maximal exercise test to assess protocol loading, a control group, and an experimental group were all carried out by twenty-one young man (19.3 ± 1.2 years) over the course of three distinct protocols, with a 48-hour break in between each stage. The protocol called for 10 minutes of rest with the subject lying down, 90 minutes of treadmill work at 70% of one's maximum oxygen uptake, and 60 minutes of rest in the dorsal decubitus position. In the control group, no rehydration beverages could be consumed. No matter the level of hydration, alterations in the sympathetic nervous system (SNS) and the parasympathetic nervous system (PSNS) were seen, showing an increase in the former and a reduction in the latter. Hydration with isotonic solutions during recovery causes considerable alterations in cardiac autonomic regulation, hastening the recovery of the linear HRV index. Exerciseinduced HRV was not significantly impacted by isotonic hydration, however it does speed up the recovery of linear indices after exercise. [ABSTRACT FROM AUTHOR]

Underlying the dawn of humanity was primarily the search for food and access to drinking water. Over the course of civilization, there has been a significant increase in drinking water quality. By the average of the nutritional standards, the daily water demand is 2.5 L (also including liquid products such as tea, coffee, or soup). However, it is worth noticing that the need is strictly individual for each person and depends on two major factors, namely, epidemiological (sex, age state of health, lifestyle, and diet) and environmental (humidity and air temperature). Currently, our diet is more and more often enriched with isotonic drinks, functional drinks, or drinks bearing the hallmarks of health-promoting products. As a result, manufacturing companies compete to present more interesting beverages with complex compositions. This article will discuss both the composition of functional beverages and their impact on health. [ABSTRACT FROM AUTHOR]

Fatigue in muscles is a reason for the low skill performance of soccer players so this study sought to find out the effect of the quadriceps muscle fatigue resulting from an isotonic contraction on some kinematic variables and the accuracy of soccer players’ execution of the corner kick. A test for the accuracy of the corner kick and the leg press exercise was used on a sample of 8 international soccer players, and their means were as follows: age: 26.8 ± 2.3 years, height: 174 ± 12 cm, mass: 71 ± 6 kg, training age: 14.6 ± 1.8 years. The performance of the corner kick test was videotaped by three cameras and Kinovea program for kinematic analysis was used. The results showed a negative effect of the quadriceps muscle fatigue after isotonic contractions on kinematic variables and on the accuracy of corner kicks. The study results point to the necessity of enhancing the ability of soccer players in terms of endurance of muscle strength in the quadriceps muscle to the highest possible extent due to the importance of that element in their skillful performance, including the accuracy of the implementation of corner kicks.

Introduction: Muscle synergy is regarded as a motor control strategy deployed by the central nervous system (CNS). Clarifying the modulation of muscle synergies under different strength training modes is important for the rehabilitation of motor-impaired patients. Methods: To represent the subtle variation of neuromuscular activities from the smaller forearm muscles during wrist motion, we proposed to apply muscle synergy analysis to preprocessed high-density electromyographic data (HDEMG). Here, modulation of muscle synergies within and across the isometric and isotonic training modes for strengthening muscles across the wrist were investigated. Surface HDEMGs were recorded from healthy subjects (N = 10). Three different HDEMG electrode configurations were used for comparison and validation of the extracted muscle synergies. The cosine of principal angles (CPA) and the Euclidian distance (ED) between synergy vectors were used to evaluate the intra- and inter-mode similarity of muscle synergies. Then, how the activation coefficients modulate the excitation of specific synergy under each mode was examined by pattern recognition. Next, for a closer look at the mode-specific synergies and the synergies shared by the two training modes, k-means clustering was applied. Results: We observed high similarity of muscle synergies across different tasks within each training mode, but decreased similarity of muscle synergies across different training modes. Both intra- and intermode similarity of muscle synergies were consistently robust to electrode configurations regardless of the similarity metric used. Discussion: Overall, our findings suggest that applying muscle synergy analysis to HDEMG is feasible, and that the traditional muscle synergies defined by whole-muscle components may be broadened to include sub-muscle components represented by the HDEMG channels. This work may lead to an appropriate neuromuscular analysis method for motor function evaluation in clinical settings and provide valuable insights for the prescription of rehabilitation training therapies. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to evaluate the efficacy and safety of isotonic and hypotonic intravenous fluids in maintenance fluid therapy for term infants., Methods: This was a multi-centre, prospective, observational study conducted in 21 participating centres from December 30, 2020, to June 30, 2023. The study included term newborns requiring parenteral fluid therapy for maintenance (NCT04781361). The fluid treatment was divided into two groups based on the concentration of sodium in the parenteral fluid, designated as hypotonic (NaCl <130 mmol/L) and isotonic (NaCl = 130-154 mmol/L). The primary outcomes were the change in mean plasma sodium (pNa) levels per hour (∆pNa mmol/L/h), the incidence of hyponatremia (pNa <135 mmol/L) and hypernatremia (pNa >145 mmol/L), and the occurrence of clinically significant changes in sodium levels (∆pNa >0.5 mmol/L/h)., Results: A total of 420 patients from 21 centers were included. The ∆pNa was negative in the hypotonic fluid group and positive in the isotonic fluid group, with a significant difference between the groups [respectively -0.07 ± 0.03 (95% CI: -0.13 to -0.02); 0.04 ± 0.03 (95%CI: -0.02 to 0.09), p  = 0.04]. There was no difference between the groups in terms of the development of hypernatremia or a clinically meaningful pNa increase. The hypotonic fluid group had a higher incidence of hyponatremia and a clinically meaningful sodium decrease compared to the isotonic fluid group [7.9% vs. 1.2% (OR:6.5, p:0.03)] and [12.2% vs.4.2% (OR:2.9, p  = 0.03)]., Conclusion: Contrary to current understanding, this large-scale study is the first to demonstrate that the use of hypotonic fluids in maintenance fluid therapy for newborns poses a risk of hyponatremia development, whereas isotonic fluid therapy appears safe., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ozkan, Duman, Tuzun, Narter, Akyildiz, Altuncu, Satar, Ozdemir, Kurt, Tugcu, Konak, Uygun, Yilmaz Semerci, Dikmen, Baysal, Zeybek, Kostekci, Sahin, Tutal, Anik, Buyuktiryaki, Karagol, Tunç, Colak, Cetin, Orman, Olukman, Deveci, Sarici, Cakir and Keskinoglu.)

Background: Rebuilding the strength of the quadriceps as soon as possible after total knee replacement (TKR) is important so as to restore gait stability. To date, there are no standard postoperative strength training programs during the early recovery stage after TKR. Purpose: To compare the therapeutic effects between isokinetic and isotonic strengthening in patients after TKR. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: From April 2018 to August 2020, 37 patients met the inclusion criteria and were randomly assigned to perform either 4-week isokinetic or isotonic strength training programs. Other components of the rehabilitation program were kept the same between the 2 groups. All cases were evaluated by the Timed Up and Go (TUG) test, peak torque of knee extension and flexion (60 and 120 deg/s), 36-item Short Form Health Survey (SF-36), and Western Ontario and McMaster Universities Arthritis Index (WOMAC). Results: After undergoing a 4-week strength training regimen, significant improvements in the TUG test were noted in both groups; however, the time improvement in the isotonic group did not reach the minimal detectable change. All peak torque measurements improved in the isokinetic group but not in the isotonic group for knee flexion at 60 deg/s. The pain subdomain, physical domain, mental domain, total SF-36 score, and WOMAC index all improved significantly in both groups after training. Both training groups improved significantly in peak torque of knee strength, TUG test, and functional scores, but the differences between isokinetic and isotonic training were not statistically significant. Conclusion: The study findings showed that a 4-week strengthening exercise program in the early postoperative stage, involving either isokinetic or isotonic training, resulted in significant improvements in patients undergoing TKR. Registration: NCT02938416 (ClinicalTrials.gov identifier). [ABSTRACT FROM AUTHOR]

Nowadays, the sector of isotonic beverages has developed its market based on fruit juices that provide a sports drink with antioxidant and biological activities in addition to their principal role of rehydration and replacement of minerals and carbohydrates during physical exercise. Consumption of grape juice is increasing worldwide because of its sensory characteristics and nutritional value. It contains mainly water, sugars, organic acids, and phenolic compounds. Phenolic compounds play a major role in prevention of various diseases through their biological activities linked to antioxidant, anti-inflammation, anticancer, anti-aging, antimicrobial, and cardioprotective properties. Several studies have demonstrated that grape juice is able to improve performances of antioxidant activity, protect against oxidative damage, and reduce inflammation during sports activities. Polyphenol content also provides a great sensory profile, mainly color which is an important indicator for consumers when choosing beverage products. The contribution of grape juice through its nutritional value and sensory properties makes it an alternative for the development of a new isotonic drink that will be a novel and healthy product in the field of healthy beverages.

Background: Lateral epicondylitis (LE) is the most common chronic musculoskeletal conditions of the upper extremity with pain and wrist extension disability. The tendon which is most affected is the extensor carpi radialis brevis (ECRB). Previous study evaluated the effect of taping technique on patient with LE, but no study investigated the changes of electromyography (EMG) on ECRB when using dynamic taping (DT) technique. Objects: The aim of this study was to investigate the effect of DT technique using dynamic tape on muscle activity of ECRB during wrist isometric extension, isotonic extension and flexion. Methods: Twenty-one healthy subjects volunteered to participate in this study. Subjects were instructed to perform wrist isometric extension, isotonic extension and flexion without and with DT on origin area of ECRB. Wrist isometric extension was performed at 75%, 50% and 25% (%maximal voluntary contraction force), respectively, based on maximum contraction force. Isotonic extension and flexion test used dumbbell. EMG data was collected from ECRB. Results: EMG of ECRB were statistically significant decrease in wrist isotonic extension after DT (p < 0.05). Significant increase in wrist isometric extension during 25% and 50% force task (p < 0.05). Conclusion: This study applied DT technique to suppress the wrist extensor muscles in 21 healthy adults in their twenties. Change in muscle activity was compared in the ECRB muscle during wrist isometric extension, isotonic extension and flexion task. Based on the results of this study, the DT technique applied to the wrist and forearm area can reduce the load on the wrist extensors when the wrist performs various movements during daily life movements or repetitive tasks, and by using these effects, excessive stress is applied to tennis elbow patients.

Underlying the dawn of humanity was primarily the search for food and access to drinking water. Over the course of civilization, there has been a significant increase in drinking water quality. By the average of the nutritional standards, the daily water demand is 2.5 L (also including liquid products such as tea, coffee, or soup). However, it is worth noticing that the need is strictly individual for each person and depends on two major factors, namely, epidemiological (sex, age state of health, lifestyle, and diet) and environmental (humidity and air temperature). Currently, our diet is more and more often enriched with isotonic drinks, functional drinks, or drinks bearing the hallmarks of health-promoting products. As a result, manufacturing companies compete to present more interesting beverages with complex compositions. This article will discuss both the composition of functional beverages and their impact on health.

[Display omitted] The mechanics of collagenous soft tissues, such as skin, are sensitive to heat. Thus, quantifying and modeling thermo-mechanical coupling of skin is critical to our understanding of skin's physiology, pathophysiology, and its treatment. However, key gaps persist in our knowledge about skin's coupled thermo-mechanics. Among them, we haven't quantified the role of skin's microstructural organization in its response to superphysiological loading. To fill this gap, we conducted a comprehensive set of experiments in which we combined biaxial mechanical testing with histology and two-photon imaging under liquid heat treatment at temperatures ranging from 37 ∘ C to 95 ∘ C lasting between 2 seconds and 5 minutes. Among other observations, we found that unconstrained skin, when exposed to high temperatures, shrinks anisotropically with the principal direction of shrinkage being aligned with collagen's principal orientation. Additionally, we found that when skin is isometrically constrained, it produces significant forces during denaturation that are also anisotropic. Finally, we found that denaturation significantly alters the mechanical behavior of skin. For short exposure times, this alteration is reflected in a reduction of stiffness at high strains. At long exposure times, the tissue softened to a point where it became untestable. We supplemented our findings with confirmation of collagen denaturation in skin via loss of birefringence and second harmonic generation. Finally, we captured all time-, temperature-, and direction-dependent experimental findings in a hypothetical model. Thus, this work fills a fundamental gap in our current understanding of skin thermo-mechanics and will support future developments in thermal injury prevention, thermal injury management, and thermal therapeutics of skin. Our work experimentally explores how skin reacts to being heated. That is, it measures how much skin shrinks, what forces it produces, and how its mechanical properties change; all as a function of temperature, but also of direction and time. Additionally, our work connects these measurements to changes in skin's microscopic make-up. This knowledge is important to our understanding of skin's function and dysfunction, especially during burn injuries or heat-dependent treatments. [ABSTRACT FROM AUTHOR]

Hyponatraemia is a known complication in hospitalised children receiving maintenance intravenous fluid. Several studies have been published to investigate the efficacy and safety of intravenous fluids in children. However, there is still an ongoing debate regarding the ideal solution to be used in the paediatric population. Therefore, the aim of this meta-analysis was to investigate the safety and efficacy of administering isotonic versus hypotonic intravenous maintenance fluid in hospitalised children. An extensive search was undertaken on PubMed, Web of Science, Scopus, ScienceDirect, Google Scholar and Cochrane Library on 28 December 2020. Only randomised controlled trials (RCTs) were included. We used the random-effects model for all analyses. Risk ratio (RR) and mean difference with 95% confidence intervals (CIs) were used for dichotomous and continuous outcomes, respectively. The quality of each study was assessed using the Joanna Briggs Institute critical appraisal tool for RCTs. This study is registered with PROSPERO (CRD42021229067). Twenty-two RCTs with a total of 3795 participants were included. The studies encompassed surgical and medical patients admitted to intensive care unit as well as to general wards. We found that hypotonic fluid significantly increases the risk of hyponatremia at both ≤24 h (RR 0.34; 95% CI: 0.26–0.43, p < 0.00001) and >24 h (RR 0.48; 95% CI: 0.36–0.64, p < 0.00001). Isotonic fluid increases the risk of hypernatraemia at ≤24 h (RR 2.15; 95% CI: 1.24–3.73, p = 0.006). The prevalence of hyponatraemia was also higher in the hypotonic group at both ≤24 h (5.7% vs. 23.3%) and >24 h (6.0% vs. 26.3%). There was no statistically significant difference in the risk of developing adverse outcomes between the two groups. Mean serum and urine sodium as well as serum osmolality/osmolarity was lower in the hypotonic group. Isotonic solution is protective against the development of hyponatraemia while hypotonic solution increases the risk of hyponatraemia. [ABSTRACT FROM AUTHOR]

Continuous flow enteral fluid therapy with isotonic and hypotonic enteral electrolyte solutions are as safe and effective as intravenous fluid therapy. The aim of this study was to carry out a comparative assessment between continuous flow enteral and intravenous (IV) fluid therapy in adult experimentally dehydrated horses. Six experimentally dehydrated adult mares were used in a study carried out in a 6 × 3 crossover design, which each animal received three different treatments (isotonic enteral fluid therapy—EsISO, hypotonic enteral fluid therapy—EsHYPO and intravenous fluid therapy with Lactate Ringer Solution—LR IV, all in continuous flow). Solutions were administered at a rate of 15 mL−1.kg−1.h−1 for 8 h, after 36 h of water and food deprivation. Serum and urinary biochemical assessment; urinary volume, pH and specific gravity; and blood gas analysis were measured at −36, 0, 2, 4, 6, and 8 h. The dehydration period (DP) caused discrete hydroelectrolytic and acid base imbalances. The EsISO, EsHYPO and LR IV increased blood volume. Enteral solutions restored the imbalances yielded by the DP and all treatments increased urine volume. Also, the EsHYPO and LR IV showed no effects in acid base balance, while EsISO showed slightly acidifying effect. The present study certifies the efficacy and safety of isotonic and hypotonic continuous flow enteral fluid therapy in comparison to IV fluid therapy in dehydrated horses.

In the face of climate change, water deficit and increasing soil salinity pose an even greater challenge to olive cultivation in the Mediterranean basin. Due to its tolerance to abiotic stresses, wild olive (Olea europaea subsp. europaea var. sylvestris) presents a good candidate in breeding climate-resilient olive varieties. In this study, the early response of the native Croatian wild olive genotype (WOG) to salinity was evaluated and compared with that of well-known cultivars (cv.) Leccino and Koroneiki. Potted olive plants were exposed either to 150 mM NaCl or 300 mM mannitol for 3 weeks to distinguish between the osmotic and ionic components of salt stress. To determine the impact of the plant age on salinity, 1-, 2-, and 3-year-old WOG plants were used in the study. The growth parameters of both the cultivars and WOG of different ages decreased in response to the mannitol treatment. In contrast to cv. Leccino, the NaCl treatment did not significantly affect the growth of cv. Koroneiki or WOG of any age. The contents of Na+ and Cl− were considerably higher in the salt-treated WOG, regardless of age, compared with the cultivars. However, while both treatments significantly reduced the K+ content of cv. Koroneiki, that nutrient was not significantly affected in either cv. Leccino or WOG. Unlike the cultivars and older WOG, the NaCl treatment caused a significant decline of photosynthetic pigments in the 1-year-old WOG. The cultivars and WOG of different ages experienced a similar drop in the chlorophyll a content under the isotonic mannitol treatment. The absence of lipid peroxidation, modulation of superoxide dismutase, and guaiacol peroxidase activity were noted in all WOG ages under both stressors. These data suggest that WOG resilience to salinity is associated with its large leaf capacity for Na+ and Cl− accumulation, K+ retention, and its adaptable antioxidative mechanisms. The results are promising with regard to obtaining a new olive cultivar with better resilience to soil salinity.

In the face of climate change, water deficit and increasing soil salinity pose an even greater challenge to olive cultivation in the Mediterranean basin. Due to its tolerance to abiotic stresses, wild olive (Olea europaea subsp. europaea var. sylvestris) presents a good candidate in breeding climate-resilient olive varieties. In this study, the early response of the native Croatian wild olive genotype (WOG) to salinity was evaluated and compared with that of well-known cultivars (cv.) Leccino and Koroneiki. Potted olive plants were exposed either to 150 mM NaCl or 300 mM mannitol for 3 weeks to distinguish between the osmotic and ionic components of salt stress. To determine the impact of the plant age on salinity, 1-, 2-, and 3-year-old WOG plants were used in the study. The growth parameters of both the cultivars and WOG of different ages decreased in response to the mannitol treatment. In contrast to cv. Leccino, the NaCl treatment did not significantly affect the growth of cv. Koroneiki or WOG of any age. The contents of Na+ and Cl− were considerably higher in the salt-treated WOG, regardless of age, compared with the cultivars. However, while both treatments significantly reduced the K+ content of cv. Koroneiki, that nutrient was not significantly affected in either cv. Leccino or WOG. Unlike the cultivars and older WOG, the NaCl treatment caused a significant decline of photosynthetic pigments in the 1-year-old WOG. The cultivars and WOG of different ages experienced a similar drop in the chlorophyll a content under the isotonic mannitol treatment. The absence of lipid peroxidation, modulation of superoxide dismutase, and guaiacol peroxidase activity were noted in all WOG ages under both stressors. These data suggest that WOG resilience to salinity is associated with its large leaf capacity for Na+ and Cl− accumulation, K+ retention, and its adaptable antioxidative mechanisms. The results are promising with regard to obtaining a new olive cultivar with better resilience to soil salinity. [ABSTRACT FROM AUTHOR]

Background and aims: Increased capillary filtration may paradoxically accelerate vascular refill of both fluid and albumin from the interstitial space, which is claimed to be edema-preventing. We characterized this proposed mechanism, called "interstitial washdown", by kinetic analyses of the hemodilution induced by intravenous infusion of crystalloid fluid during 3 distinct physiological states. Methods: Greater plasma dilution of hemoglobin as compared to albumin during fluid therapy indicated recruitment of albumin, which was compared to the flow of interstitial fluid to the plasma as indicated by population volume kinetic analysis. Data for the comparison were derived from 24 infusions of crystalloid fluid in conscious volunteers, 30 in anesthetized patients, and 31 in patients with ketoacidosis from hyperglycemia. Results: "Interstitial washdown" increased the plasma albumin concentration by between 0.3 and 1.0 g/L in the three series of infusions. The initial albumin concentration in the interstitial fluid returning to the plasma was estimated to between 22 g/L and 29 g/L, which decreased to an average of 50–75% lower during the subsequent 2–3 h. Kinetic simulations show that pronounced washdown was associated with increased capillary filtration (high k12) and, in conscious subjects, with greater plasma and interstitial volume expansion and restricted urine flow. During anesthesia, the main effect was an increase in the non-exchangeable fluid volume ("third-spacing"). Conclusions: Crystalloid fluid accelerates lymphatic flow that moderately increases plasma albumin, but more clearly helps to maintain the intravascular volume. This "interstitial washdown" mechanism becomes exhausted after a few hours. [ABSTRACT FROM AUTHOR]

It is known that high intensity dynamic resistance training which involves eccentric and concentric contractions is one of the effective method for maximizing strength. Although, it is postulated that eccentric and concentric contractions provide different physiological adaptations, previous studies comparing the short-term effects of these two contractions have reported contradictory findings, with some studies reporting greater strength development with eccentric, some with concentric and some with similar within both training (18). Methodological differences may be of critical importance to the reported different findings, when focusing on the underlying reasons for these effects are discussed. The majority of previous studies on this topic have used isokinetic equipment to compare eccentric with concentric training, however there are also several studies which used isotonic method which is the most common type of resistance training. Since the effects of these two methods can form different physiological adaptations (9), it may not be proper to review the studies related to eccentric and concentric comparisons without taking into account training method variable. In isokinetic, contraction velocity can be controlled by the dynamometer however it is hard to standardize the movement velocity of isotonic training. And also previous studies showed that movement velocity of resistance training may affect strength development (11). At this juncture, the aim of this paper was to review the studies investigating eccentric and concentric resistance training and discuss the reported findings by considering methodological differences (training type and movement velocity). Although it was difficult to present certain implications due to only few studies including same methods in terms of contraction types and training methods, some highlights from this paper can be very informative to further studies. One of them is that the effects of eccentric and concentric resistance training might be different according to training types. The effects of movement velocity of resistance training on strength may also be different in terms of isotonic or isokinetic training methods.

At relatively low effort level tasks, surface electromyogram (sEMG) spectral parameters have demonstrated an inconsistent ability to monitor localized muscle fatigue and predict endurance capacity. The main purpose of this study was to assess the potential of the endurance time (Tend) prediction using logarithmic parameters compared to raw data. Ten healthy subjects performed five sets of voluntary isotonic contractions until their exhaustion at 20% of their maximum voluntary contraction (MVC) level. We extracted five sEMG spectral parameters namely the power in the low frequency band (LFB), the mean power frequency (MPF), the high-to-low ratio between two frequency bands (H/L-FB), the Dimitrov spectral index (DSI), and the high-to-low ratio between two spectral moments (H/L-SM), and then converted them to logarithms. Changes in these ten parameters were monitored using area ratio and linear regressive slope as statistical predictors and estimating from onset at every 10% of Tend. Significant correlations (r > 0.5) were found between log(Tend) and the linear regressive slopes in the logarithmic H/L-SM at every 10% of Tend. In conclusion, logarithmic parameters can be used to describe changes in the fatigue content of sEMG and can be employed as a better predictor of Tend in comparison to the raw parameters. [ABSTRACT FROM AUTHOR]

Introduction: Quadriceps weakness after knee surgery is the most common consequence that can have different consequences not only for the knee itself but also for the locomotor system in general. This study aimed to compare the results of isokinetic and isotonic exercise on torque restoration quadriceps on knee surgery., Methods: A sample of 180 subjects was analyzed and divided into two subsamples according to the type of rehabilitation protocol that was implemented. The examined group A-isokinetic consisted of 90 male subjects aged 28.54 ± 4.44 years, with a rehabilitation protocol based on the isokinetic exercise of the quadriceps. The examined group B-isotonic also consisted of 90 male subjects aged 27.93 ± 4.27 years, with a rehabilitation protocol for strengthening the quadriceps that applied an exercise program with additional resistance, i.e., isotonic exercise in the gym. Before the start of the rehabilitation treatment, an initial isokinetic test was performed at an angular speed of 60 °/s in all subjects. After 3 and 6 weeks of rehabilitation treatment, the control tests were performed in the same way as in the initial test., Results: Based on the values of MANOVA analysis and discriminative analysis, significantly better results of isokinetic tests were found in the examined group A-isokinetic compared with those in the examined group B-isotonic. At the final measurement of group A, 83 respondents (92.2%) were placed in the "biggest" class out of the 90 respondents., Conclusion: Based on the obtained research results, we conclude that isokinetic exercise is more effective in terms of physiotherapy of quadriceps hypotrophy after knee surgery., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Nikolić, Obradović, Dimitrijević, Rašković and Dragičević-Cvjetković.)

BACKGROUND AND OBJECTIVE: QTc fluctuations, in rest and exercise lead to arrhythmias and sudden cardiac death. Caffeine is an energy source and it may moderate this bad fluctuation. The purpose of this study was to compare the effect of caffeine on QTc and blood pressure during isometric and isotonic contractions in athletic and non-athletic men. METHODS: in this semi-experimental study, 20 healthy men were randomly selected and placed in two groups of athletes and non-athletes. Pre-test: at first, each subject pressed the dynamometer handle at maximum power for 30s (isometric). After 25 min rest, the isotonic activity was performed in 15 repetitions of 5 seconds. At the end, each subject takes 400 mg of caffeine, and after 60min, the post-test similarly, was repeated as a pre-test. QTc changes and blood pressure were checked before and after the test. FINDINGS: The average weight of individuals was 76±13.93 kg. Caffeine in the athlete group resulted in a decrease in QTc during isometric and isotonic contractions of 11.5 ms and 15ms respectively. But in nonathlete groups, QTc during isometric and isotonic contractions were respectively 0.7ms increase and 4.1 ms decrease. There was no significant correlation between QTc in both groups, but diastolic blood pressure increased significantly (p=0.02). CONCLUSION: The results of the study showed that caffeine consumption had no significant effect on QTc interval but it affected diastolic blood pressure

Hyponatraemia is a known complication in hospitalised children receiving maintenance intravenous fluid. Several studies have been published to investigate the efficacy and safety of intravenous fluids in children. However, there is still an ongoing debate regarding the ideal solution to be used in the paediatric population. Therefore, the aim of this meta-analysis was to investigate the safety and efficacy of administering isotonic versus hypotonic intravenous maintenance fluid in hospitalised children. An extensive search was undertaken on PubMed, Web of Science, Scopus, ScienceDirect, Google Scholar and Cochrane Library on 28 December 2020. Only randomised controlled trials (RCTs) were included. We used the random-effects model for all analyses. Risk ratio (RR) and mean difference with 95% confidence intervals (CIs) were used for dichotomous and continuous outcomes, respectively. The quality of each study was assessed using the Joanna Briggs Institute critical appraisal tool for RCTs. This study is registered with PROSPERO (CRD42021229067). Twenty-two RCTs with a total of 3795 participants were included. The studies encompassed surgical and medical patients admitted to intensive care unit as well as to general wards. We found that hypotonic fluid significantly increases the risk of hyponatremia at both ≤24 h (RR 0.34; 95% CI: 0.26–0.43, p < 0.00001) and >24 h (RR 0.48; 95% CI: 0.36–0.64, p < 0.00001). Isotonic fluid increases the risk of hypernatraemia at ≤24 h (RR 2.15; 95% CI: 1.24–3.73, p = 0.006). The prevalence of hyponatraemia was also higher in the hypotonic group at both ≤24 h (5.7% vs. 23.3%) and >24 h (6.0% vs. 26.3%). There was no statistically significant difference in the risk of developing adverse outcomes between the two groups. Mean serum and urine sodium as well as serum osmolality/osmolarity was lower in the hypotonic group. Isotonic solution is protective against the development of hyponatraemia while hypotonic solution increases the risk of hyponatraemia.

Background: Non-specific chronic low back pain (NSCLBP) is a prevalent condition that affects 90% of individuals experiencing low back pain. Core stabilization exercises (CSE) stand out as the most commonly employed therapeutic approach for managing NSCLBP. Nevertheless, there remains uncertainty regarding the superior effectiveness between isometric (ISOM) and isotonic (ISOT) types of CSE in the treatment of NSCLBP., Objectives: The primary objective of this study was to compare the efficacy of ISOM and ISOT exercises concerning pain and disability in patients with NSCLBP. Additionally, the study aimed to assess the effectiveness of both ISOM and ISOT in comparison to no intervention concerning these variables in these patients., Methods: This study was a randomized controlled trial that involved 41 men and women experiencing NSCLBP. Participants were randomly allocated to three groups: ISOM CSE (n = 13), ISOT CSE (n = 14), and a waitlist control (n = 14). The exercise training was administered for 40 - 60 minutes three times a week over a period of up to 8 weeks. Pain (assessed using the Visual Analog Scale or VAS) and disability (evaluated through the Oswestry Disability Index or ODI) variables were measured before and after the interventions., Results: Based on the results, there was no significant difference between the 2 exercise groups (ISOM and ISOT) regarding pain and disability. However, the ISOM group demonstrated numerically better results than the ISOT group. Both the ISOM and ISOT groups exhibited a significant decrease in pain levels, with the VAS score decreasing from 5.5 to 2.7 for ISOM and from 5.8 to 3.7 for ISOT, as compared to the control group (P < 0.001 and P = 0.001, respectively). Additionally, the average disability showed a significant improvement in both the ISOM (ODI score from 17 to 11) and ISOT (ODI score from 15.4 to 11) groups compared to the control group (P < 0.001)., Conclusions: Both ISOM and ISOT methods are effective in alleviating pain and disability in patients with NSCLBP. However, there is no significant difference in the benefits between them. Numerically, ISOM exercises were found to be superior. Further studies are needed to obtain a more accurate answer regarding their superiority., Competing Interests: The authors declared no conflict of interest., (Copyright © 2024, Khaledi and Gheitasi.)

At relatively low effort level tasks, surface electromyogram (sEMG) spectral parameters have demonstrated an inconsistent ability to monitor localized muscle fatigue and predict endurance capacity. The main purpose of this study was to assess the potential of the endurance time (Tend) prediction using logarithmic parameters compared to raw data. Ten healthy subjects performed five sets of voluntary isotonic contractions until their exhaustion at 20% of their maximum voluntary contraction (MVC) level. We extracted five sEMG spectral parameters namely the power in the low frequency band (LFB), the mean power frequency (MPF), the high-to-low ratio between two frequency bands (H/L-FB), the Dimitrov spectral index (DSI), and the high-to-low ratio between two spectral moments (H/L-SM), and then converted them to logarithms. Changes in these ten parameters were monitored using area ratio and linear regressive slope as statistical predictors and estimating from onset at every 10% of Tend. Significant correlations (r > 0.5) were found between log(Tend) and the linear regressive slopes in the logarithmic H/L-SM at every 10% of Tend. In conclusion, logarithmic parameters can be used to describe changes in the fatigue content of sEMG and can be employed as a better predictor of Tend in comparison to the raw parameters.

During emergence from general anesthesia, coughing caused by the endotracheal tube frequently occurs and is associated with various adverse complications. In patients undergoing endovascular neurointervention, achieving smooth emergence from general anesthesia without coughing is emphasized since coughing is associated with intracranial hypertension. Therefore, the up-and-down method was introduced to determine the effective effect-site concentration (Ce) of remifentanil to prevent coughing in 50% and 95% (EC50 and EC95) of patients during emergence from sevoflurane anesthesia for endovascular neurointervention. A total of 43 participants, American Society of Anesthesiologists class I or II participants, aged from 20 to 70 years who were undergoing endovascular neurointervention through transfemoral catheter for cerebrovascular disease were enrolled. Using the up-and-down method with isotonic regression, the EC50 and EC95 of remifentanil to prevent coughing during emergence from sevoflurane anesthesia were determined. We also investigated differences of hemodynamic and recovery profiles between the cough suppression group and the cough group. In total, 38 of 43 patients were included for estimation of EC50 and EC95. The EC50 and EC95 of remifentanil to prevent coughing were 1.42 ng/mL (95% confidence interval [CI], 1.28–1.56 ng/mL) and 1.70 ng/mL (95% CI, 1.67–2.60 ng/mL), respectively. There was comparable emergence and recovery data between the cough suppression group (n = 22) and the cough group (n = 16). However, the Ce of remifentanil and total dose of remifentanil were significantly higher in the cough suppression group (P = 0.002 and P = 0.004, respectively). Target-controlled infusion of remifentanil at 1.70 ng/mL could effectively prevent extubation-related coughing in 95% of neurointervention patients, which could ensure smooth emergence. [ABSTRACT FROM AUTHOR]

High-fat (HF) diets in combination with sedentary lifestyle represent one of the major public health concerns predisposing to obesity and diabetes leading to skeletal muscle atrophy, decreased fiber diameter and muscle mass with accumulation of fat tissue resulting in loss of muscle strength. One strategy to overcome the maleficent effects of HF diet is resistance training, a strategy used to improve muscle mass, reverting the negative effects on obesity-related changes in skeletal muscle. Together with resistance training, supplementation with creatine monohydrate (CrM) in the diet has been used to improve muscle mass and strength. Creatine is a non-essential amino acid that is directly involved in the cross-bridge cycle providing a phosphate group to ADP during the initiation of muscle contraction. Besides its antioxidant and anti-inflammatory effects CrM also upregulates IGF-1 resulting in hyperthophy with an increase in muscle function. However, it is unknown whether CrM supplementation during resistance training would revert the negative effects of high-fat diet on the muscle performance. During 8 weeks we measured muscle performance to climb a 1.1m and 80° ladder with increasing load on trained rats that had received standard diet or high-fat diet, supplemented or not with CrM. We observed that the CrM supplementation up-regulated IGF-1 and phospho-AKT protein levels, suggesting an activation of the IGF1-PI3K-Akt/PKB-mTOR pathway. Moreover, despite the CrM supplementation, HF diet down-regulated several proteins of the IGF1-PI3K-Akt/PKB-mTOR pathway, suggesting that diet lipid content is crucial to maintain or improve muscle function during resistance training. [ABSTRACT FROM AUTHOR]

Isotonic testing and measures of rapid power production are emerging as functionally relevant test methods for detection of muscle aging. Our objective was to assess reliability of rapid velocity and power measures in older adults using the isotonic mode of an isokinetic dynamometer. Sixty-three participants (aged 65 to 82 years) underwent a test-retest protocol with one week time interval. Isotonic knee extension tests were performed at four different loads: 0%, 25%, 50% and 75% of maximal isometric strength. Peak velocity (pV) and power (pP) were determined as the highest values of the velocity and power curve. Rate of velocity (RVD) and power development (RPD) were calculated as the linear slopes of the velocity- and power-time curve. Relative and absolute measures of test-retest reliability were analyzed using intraclass correlation coefficients (ICC), standard error of measurement (SEM) and Bland-Altman analyses. Overall, reliability was high for pV, pP, RVD and RPD at 0%, 25% and 50% load (ICC: .85 - .98, SEM: 3% - 10%). A trend for increased reliability at lower loads seemed apparent. The tests at 75% load led to range of motion failure and should be avoided. In addition, results demonstrated that caution is advised when interpreting early phase results (first 50ms). To conclude, our results support the use of the isotonic mode of an isokinetic dynamometer for testing rapid power and velocity characteristics in older adults, which is of high clinical relevance given that these muscle characteristics are emerging as the primary outcomes for preventive and rehabilitative interventions in aging research. [ABSTRACT FROM AUTHOR]

Background: Growth differentiation factor-15 (GDF-15) is an emerging biomarker for risk stratification in cardiovascular disease. Contrast-induced acute kidney injury (AKI) is an important complication in patients undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI). In this retrospectively observational study, we aimed to determine the role of GDF-15 and the risk of AKI in acute myocardial infarction (AMI) patients. Methods: The medical records of 1195 patients with AMI were reviewed. After exclusion criteria, a total of 751 eligible patients who underwent CAG or PCI were studied. Preoperative clinical parameters including GDF-15 levels were recorded. Multivariate logistic regression analysis was used to identify the risk factors of AKI. Subsequently, to reduce a potential selection bias and to balance differences between the two groups, a propensity score-matched analysis was performed. We recorded the 30-day all-cause mortality of the total study population. Kaplan-Meier analysis was performed to identify the association between short term survival in AMI patients and GDF-15 level. Results: Among 751 enrolled patients, 106 patients (14.1%) developed AKI. Patients were divided into two groups: AKI group (n = 106) and non-AKI group (n = 645). GDF-15 levels were significantly higher in AKI group compared to non-AKI group (1328.2 ± 349.7 ng/L vs. 1113.0 ± 371.3 ng/L, P <0.001). Multivariate logistic regression analyses showed GDF-15 was an independent risk factor of AKI (per 1000 ng/L increase of GDF-15, OR: 3.740, 95% CI: 1.940–7.207, P < 0.001). According to GDF-15 tertiles, patients were divided into three groups. Patients in middle (OR 2.93, 95% CI: 1.46–5.89, P = 0.003) and highest GDF-15 tertile (OR 3.72, 95% CI: 1.87–7.39, P <0.001) had higher risk of AKI compared to patients in the lowest GDF-15 tertile. The propensity score-matched group set comprised of 212 patients. Multivariate logistic regression revealed that GDF-15 is still an independent risk factor for AKI after matching (per 1000 ng/L increase of GDF-15, OR: 2.395, 95% CI: 1.020–5.626, P = 0.045). Based on the Kaplan-Meier analysis, the risk of 30-day all-cause mortality increased in higher GDF-15 tertiles log rank chi-square: 29.895, P <0.001). Conclusion: This suggests that preoperative plasma GDF-15 is an independent risk factor of AKI in AMI patients underwent CAG or PCI. GDF-15 and AKI are associated with poor short term survival of AMI patients. [ABSTRACT FROM AUTHOR]

The constrained partial linear model is fit using a single cone projection, without back-fitting. The cone formulation not only provides effcient computa- tion, but also allows for derivation of convergence rates and inference methods. Conditions for simultaneous root-n convergence of the parameters and optimal convergence for the regression function are given. Hypothesis tests involving the nonlinear regression function, while controlling for the effects of the linear term, use a test statistic whose null distribution is that of a mixture-of-betas random vari- ables, under the normal errors assumption. Inference involving the linear term uses approximate t and F distributions; simulations show these perform well compared to competitors. [ABSTRACT FROM AUTHOR]