Young Volunteers Research Articles

Total body water percentage and 3rd space water are novel risk factors for training-related lower extremity muscle injuries in young males

PurposeTo identify the risk factors for training-related lower extremity muscle injuries in young males by a non-invasive method of body composition analysis. MethodsA total of 282 healthy young male volunteers aged 18 – 20 years participated in this cohort study. Injury location, degree, and injury rate were adjusted by a questionnaire based on the overuse injury assessment methods used in epidemiological studies of sports injuries. The occurrence of training injuries is monitored and diagnosed by physicians and treated accordingly. The body composition was measured using the BodyStat QuadScan 4000 multifrequency Bio-impedance system at 5, 50, 100 and 200 kHz to obtain 4 impedance values. The Shapiro-Wilk test was used to check whether the data conformed to a normal distribution. Data of normal distribution were shown as mean ± SD and analyzed by t-test, while those of non-normal distribution were shown as median (Q1, Q3) and analyzed by Wilcoxon rank sum test. The receiver operator characteristic curve and logistic regression analysis were performed to investigate risk factors for developing training-related lower extremity injuries and accuracy. ResultsAmong the 282 subjects, 78 (27.7%) developed training injuries. Lower extremity training injuries revealed the highest incidence, accounting for 23.4% (66 cases). These patients showed higher percentages of lean body mass (p = 0.001), total body water (TBW, p = 0.006), extracellular water (p = 0.020) and intracellular water (p = 0.010) as well as a larger ratio of basal metabolic rate/total weight (p = 0.006), compared with those without lower extremity muscle injuries. On the contrary, the percentage of body fat (p = 0.001) and body fat mass index (p = 0.002) were lower. Logistic regression analysis showed that TBW percentage > 65.35% (p = 0.050, odds ratio = 3.114) and 3rd space water > 0.95% (p = 0.045, odds ratio = 2.342) were independent risk factors for lower extremity muscle injuries. ConclusionTBW percentage and 3rd space water measured with bio-impedance method are potential risk factors for predicting the incidence of lower extremity muscle injuries in young males following training.

Acute effects of energy drink consumption on microvascular reactivity in young male volunteers at rest: a randomized trial.

Energy drinks are nonalcoholic beverages whose main ingredients are sugar, taurine, and caffeine. The consumption of energy drinks is increasing worldwide, but only a few conflicting studies have investigated the vascular effects of energy drinks in young adults. The aim of this study was to evaluate microvascular reactivity before and after energy drinks consumption in young healthy male volunteers. This was a cross-sectional prospective study. Microvascular reactivity signals were evaluated in the skin of the forearm using laser speckle contrast imaging with acetylcholine (ACh) iontophoresis before and 90 and 180 min after the randomized consumption of one ED or the same volume of water (control), followed by a postocclusive reactive hyperemia (PORH) test. Thirty-two volunteers were evaluated (age: 25.4±4.3 years). Energy drink consumption prevented the rest-induced reduction in cutaneous vascular conductance over time that was observed in the control group. In the control group, there were significant reductions in microvascular vasodilation at 90 and 180 min compared to baseline (P=0.004), but this was not the case in the energy drink group (P=0.76). Our results demonstrated that the reduction in microvascular conductance associated with prolonged immobility can be prevented by the consumption of one energy drink, highlighting the vasodilator effects of this beverage in young individuals at rest. The between-study variability in terms of the brand of energy drinks and the ingested volume, as well as the method of vascular evaluation and the inclusion criteria, may explain the discrepancies among previous studies on the vascular effects of energy drinks.

The effects of endurance physical exercise with fat-free milk intake as a therapy for metabolic syndrome and/or sarcopenia

Background: Nutrition and exercise are important factors for addressing metabolic syndrome and sarcopenia as they are related to insulin secretion. Proteins, particularly branched-chain amino acids (BCAAs), have insulinotropic effects, while exercise reduces insulin secretion. It is thus important to investigate the effects of protein intake and exercise alone and in combination to determine suitable dietary and exercise therapies for treating metabolic syndrome and sarcopenia. Methods: Eight healthy young adult female volunteers participated in a crossover trial consisting of two 5-day experiments. Days 1 and 2 comprised a body-weight-maintained adjustment period during which the participants consumed control diets (energy, 2,010 kcal; protein, 51.9 g). Days 3 to 5 comprised the treatment period during which the participants consumed experimental diets (energy, 2,010 kcal; protein 82.3 g) containing 402 kcal of fat-free milk, and either performed only normal daily activities (non-Ex) or performed normal daily activities and exercised on a bicycle with an ergometer at a target intensity of about 50% of the maximal oxygen intake, expending 402 kcal of additional energy (Ex). Total urine samples were collected during the daytime (6:45 to 18:45) and nighttime (18:45 to 6:45 the next morning). Fasting blood samples were collected early in the morning before and after the treatment period. Results: Plasma valine, leucine, and BCAA levels were significantly elevated after both the non-Ex and Ex periods. Serum insulin levels were significantly elevated only after the non-Ex period. Urinary C-peptide immunoreactivity excretion levels increased significantly during the non-Ex period, but they decreased significantly during the Ex period. After the Ex period, the serum triglyceride and remnant lipoprotein-cholesterol (RLP-C) levels were significantly decreased. Homeostatic model assessment for insulin resistance (HOMA-IR) and atherosclerosis index (AI) values were slightly, yet significantly, increased after the non-Ex period, but were unchanged after the Ex period. The degree of change (Δ) in the RLP-C level significantly and positively correlated with the Δ HOMA-IR and Δ AI.

Investigation and Analysis of Post-Traumatic Growth in Young Rehabilitation Volunteers with Breast Cancer

Investigation and Analysis of Post-Traumatic Growth in Young Rehabilitation Volunteers with Breast Cancer

Correlation of serum VEGF-C, ANGPTL4, and activin A levels with frailty

BackgroundSecretory factors linked to lymphogenesis, such as vascular endothelial growth factor C (VEGF-C), angiopoietin like protein 4 (ANGPTL4), and activin A (ACV-A), have been recognized as potential markers of chronic inflammatory status and age-related diseases. Furthermore, these factors may also be linked to frailty. The primary objective of this study was to examine the serum VEGF-C, ANGPTL4, and ACV-A levels in young individuals, healthy older individuals, and older individuals with pre-frailty and frailty, and to determine their association with pro-inflammatory factor levels. MethodsWe conducted an observational study, enrolling a total of 210 older individuals and 20 young healthy volunteers. Participants were divided into four groups based on the Freid frailty phenotype: healthy young group, older patients without frailty group, pre-frail older group, and frail older group. Plasma and peripheral blood mononuclear cells (PBMCs) were collected from all four groups. ELISA was used to measure the serum levels of VEGF-C, ANGPTL4, ACV-A, and pro-inflammatory cytokines, while RT-qPCR was used to measure the transcription level of VEGF-C, ANGPTL4 and ACV-A in PBMCs. ResultsIn comparison to healthy young individuals and older participants without frailty, older participants with frailty exhibited lower renal function, higher serum levels and transcription levels of VEGF-C, ANGPTL4, ACV-A, and elevated levels of pro-inflammatory cytokines (CRP, IL-1β, and TNF-α). Multiple linear regression analysis revealed that serum levels of VEGF-C, ANGPTL4, and ACV-A were positively correlated with the frailty index, independent of age, eGFR, and comorbidities. Furthermore, the receiver operating characteristic (ROC) curve analysis demonstrated that serum levels of VEGF-C, ANGPTL4, and ACV-A have great accuracy in predicting frailty. ConclusionElevated serum levels of VEGF-C, ANGPTL4, and ACV-A are associated with frailty status.

Resting muscle tension and trigger points in elite junior short-track athletes and healthy non-athletes: a cross-sectional examination.

Short-track speed skating (short track) is an Olympic sport characterized by a specific body position and counterclockwise movement on the track. Based on previous studies, we hypothesized that athlete body positions employed in this sport could lead to asymmetric overuse disorders of the left lower limb muscles. An increased number of latent trigger points (LTrPs) was confirmed in individual muscles of the overloaded left limb of short-track athletes. This study aimed to compare the number of LTrPs and the level of resting muscle tone between elite junior short-track athletes and healthy non-athletes. The experimental (EXP) group comprised 15 elite short-track junior athletes from the Polish national team and the control (CON) group comprised 15 healthy young volunteers. In both groups, the left leg was tested for (i) the presence of LTrPs and (ii) resting muscle tone (RMT), assessed using surface electromyography in six muscles. The EXP group showed a higher number of LTrPs in the left lower limb, compared with the CON group. The muscle that was most significantly affected in the athletes was the vastus lateralis obliquus [χ 2 (1, N = 30), p < 0.001, V Cramer = 0.71]. This muscle also differed significantly between the groups in terms of the RMT (p = 0.033, Cohen's d = 0.87). Elite short-track junior athletes presented with increased RMT and an increased number of LTrPs in the vastus lateralis oblique muscle, compared with healthy non-athletes.

Comparison of changes in ocular aberrations with accommodation and accommodative facility

Aims/Purpose: This study aimed to analyse whether a relationship exists between subjectively measured monocular Accommodative Facility (AF), the magnitude of the revolution‐symmetric Zernike coefficients C20, C40 and C60, and the objectively measured Accommodative Response (AR).Methods: A total of 66 eyes, from 33 healthy young volunteers (26 women and 10 men) with a mean age of 25.12 ± 3.40 years (range age 20–30) participated in this study. Three measurements were made for each eye with the aberrometer Hartmann‐Shack (IRX3, Imagine Eyes, Orsay, France). The stimulus vergence was increased from 0 to 5 D (near vision) in steps of 0.5 D. The AR for each Zernike coefficient was calculated as the difference between the value at 5 D and the value at 0 D, for 4.0 mm pupil size. Monocular assessment of AF was assessed monocularly and conducted at 40 cm ± 2.00 D flippers. Statistical analysis was performed to determine a relationship between the Zernike coefficients, AR and AF. The coefficient of determination (R‐squared) was calculated to measure the proportional amount of variance.Results: The results showed that the highest values of R‐squared were obtained for the C20 coefficient measured at 5D of accommodation (R2 = 0.196, p &lt; 0.01). Lower values were obtained for C40 and C60. The R‐squared values decreased from 0D (R2 = 0.097, p = 0.10) to 5D (R2 = 0.044, p = 0.60) for C40. However, there was an increase in R‐squared values from 0D (R2 = 0.0081, p = 0.47) to 5D (R2 = 0.058, p = 0.05) for C60.Conclusions: No clear trends were found when comparing the Zernike coefficients C20, C40 and C60, analysed in three stages of accommodative demand compared with the accommodative facility measured.The Zernikes coefficients analysed do not explain the differences in AF in this sample of young adult healthy eyes. However, there was found a trend that deserves further investigation.

A dynamic spatiotemporal model for fall warning and protection.

Early detection of falls is important for reducing fall injuries. However, existing fall detection strategies mostly focus on reducing impact injuries rather than avoiding falls. This study proposed the concept of identifying "Imbalance Point" to warn the body imbalance, allowing sufficient time to recover balance. And if falling cannot be avoided, an impact sign is released by detecting the "Fall Point" prior to the impact. To achieve this goal, motion prediction model and balance recovery model are integrated into a spatiotemporal framework to analyze dynamic and kinematic features of body motion. Eight healthy young volunteers participated in three sets of experiment: Normal trial, Recovery trial and Fall trial. The body motion in the trials was recorded using Microsoft Azure Kinect. The results show that the developed algorithm for Fall Point detection achieved 100% sensitivity and 98.6% specificity, along with an average lead time of 297ms. Moreover, Imbalance Point was successfully detected in all Fall trials, and the average time interval between Imbalance Point and Fall Point was 315ms, longer than reported step reaction time for elderly (approximately 270ms). The experiment results demonstrate that the developed algorithm have great potential for fall warning and protection in the elderly.

The relationship between the oblique sagittal temporomandibular joint disc position and the volume surface area of the condyle in young TMD adults.

The present study aims to compare the volume surface area of the condyle, the horizontal condylar axial angle and the disc-condyle angle between temporomandibular disorder (TMD) and asymptomatic volunteers, explore and analyze the relationship between the temporomandibular joint (TMJ) disc position in oblique sagittal plane and the volume surface area of the condyle in young adults with TMD symptoms. 84 young adult volunteers were received TMJ examination by Magnetic Resonance Imaging (MRI) and Cone Beam Computed Tomography (CBCT). TMD and asymptomatic volunteers were 42 each. MRI was used to assess the position of TMJ disc in the oblique sagittal plane with the condyle apex method. CBCT data were used for three-dimensional (3D) reconstruction of condyle and the measurements of the horizontal condylar axial angle and the volume surface area of the condyle. The condylar volume surface area of the TMD group was smaller than that of the asymptomatic group (p < 0.05), the disc condyle angle was larger than that of the asymptomatic group (p < 0.05), and no significant difference was found in the horizontal condylar axial angle (p > 0.05). In terms of correlation, the volume surface area of the condyle were negatively correlated with the position of the articular disc in TMD patients (p < 0.05). This significant negative correlation suggests that the possibility of disc displacement can be considered when poor condylar morphology is found.

Comparison of Spirometric Parameters in different Postures among Young Healthy Volunteers.

Spirometry is the most common pulmonary function tests that specifically measures volume and flow of air during respiration. It helps to identify obstructive and restrictive diseases of the lungs. The alterations of the results in spirometry can happen even in normal health due to change in body postures that alter lung volumes and muscle biomechanics. So, the objective of this study is to determine the effects of change of postures mainly supine, sitting and standing on pulmonary parameters of young healthy volunteers. A cross-sectional analytical study was conducted among young medical students of Maharajgunj Medical Campus in the department of Clinical Physiology. A total of 31 students were selected by convenient sampling technique. Pulmonary parameters: Forced Vital Capacity (FVC), Forced Expiratory Volume in 1st second (FEV1), FEV1/FVC, Peak Expiratory Flow(PEF), EF2575 were collected from spirometry. The spirometry was done in supine, sitting and standing postures and the best value of each posture was selected for the comparison and obtained data were analyzed using repeated measures ANOVA with confidence interval of 95%. The pulmonary parameters recorded in different postures showed that the mean of these variables comparatively increased in standing posture than others with mean FVC 3.98±0.66 L, mean FEV1 3.53±0.55L, mean FEV1/FVC 89.23±5.60%, mean PEF 8.60±1.62L/s and mean PEF2575 4.46±1.08 L/s. The mean comparisons of these pulmonary parameters in supine, sitting and standing postures showed statistically significant differences with P value < 0.05. The pulmonary parameters are affected by body postures. Those parameters are recorded highest during standing posture and lowest during supine posture.

Early mucosal events promote distinct mucosal and systemic antibody responses to live attenuated influenza vaccine

Compared to intramuscular vaccines, nasally administered vaccines have the advantage of inducing local mucosal immune responses that may block infection and interrupt transmission of respiratory pathogens. Live attenuated influenza vaccine (LAIV) is effective in preventing influenza in children, but a correlate of protection for LAIV remains unclear. Studying young adult volunteers, we observe that LAIV induces distinct, compartmentalized, antibody responses in the mucosa and blood. Seeking immunologic correlates of these distinct antibody responses we find associations with mucosal IL-33 release in the first 8 hours post-inoculation and divergent CD8+ and circulating T follicular helper (cTfh) T cell responses 7 days post-inoculation. Mucosal antibodies are induced separately from blood antibodies, are associated with distinct immune responses early post-inoculation, and may provide a correlate of protection for mucosal vaccination. This study was registered as NCT04110366 and reports primary (mucosal antibody) and secondary (blood antibody, and nasal viral load and cytokine) endpoint data.

Molecular imaging of aging-related 5-hydroxymethylcytosine in cell-free DNA at the single-copy level

In cell-free DNA (cfDNA), 5-hydroxymethylcytosine (5hmC) is a vital epigenetic modification closely related to aging. Although many methods have been developed to quantify 5hmC in DNA extracted from cells, few have been successfully applied to detect 5hmC in cfDNA due to their insufficient sensitivity. In our work, we quantified the ratio of 5hmC modified cfDNA in the circulating blood of volunteers at different ages using an ultrasensitive single-molecule immunofluorescent imaging method. Among the results, the ratio of 5hmC modified cfDNA in the old volunteers was significantly higher than that in the young volunteers. In addition, the sensitivity of this method was greatly improved with the minimal input of 0.5 pg cfDNA, compared to the traditional dot blot assay. Moreover, old volunteers with geriatric syndromes exhibited a significantly higher level of 5hmC in cfDNA than their counterparts without such syndromes. Last, in a single-molecule photobleaching experiment, we demonstrated that the higher ratio of 5hmC modified cfDNA among the old volunteers may result from the enrichment of 5hmC in a single cfDNA strand. Taken together, 5hmC in circulating cfDNA may play multiple roles in aging-related physical changes, especially in geriatric syndromes, and could be a biomarker for evaluating such syndromes.

Re‐evaluating the choice of gamma stimulation frequency for potential treatment of Alzheimer’s disease: Novel invisible spectral flicker evokes gamma responses at various frequencies

AbstractBackgroundWith recent advances in the potential usage of visual gamma stimulation at 40 Hz for treatment of Alzheimer’s disease, there is reason to evaluate the use of other low gamma frequencies. The choice of 40 Hz is based on studies that describe “40 Hz” oscillations with considerable frequency variability. Results are also ambiguous on the acute effects of varying the frequency when stimulating with stroboscopic flicker in the low gamma range (30‐50 Hz). As stroboscopic visual stimulation may also affect adherence in clinical trials due to its inherent flickering, invisible spectral flicker (ISF) was proposed as a more comfortable alternative for entraining 40 Hz. This study investigates the ability of ISF to entrain gamma responses at several frequencies in the range of 36‐44 Hz.MethodTwenty healthy young volunteers were included in an electroencephalography (EEG) experiment (DTU Compute IRB Approval: COMP‐IRB‐2021‐01) with an initial eyes‐open baseline recording followed by a stimulation paradigm using ISF at nine different frequencies (36‐44 Hz, 1 Hz interval) in a randomized complete block design with five blocks. The responses were evaluated as the signal‐to‐noise ratio (SNR) averaged over the O1 and O2 electrodes at the stimulation frequency and analysed using mixed‐effect models with frequency as a fixed factor and subject and block as random factors. All two‐way interactions were included as random factors. Evoked responses were compared to baseline and between frequencies post hoc, correcting for multiple comparisons with Tukey’s method.ResultThe EEG power (Figure 1) showed that stimulus SNR values were significantly higher than baseline for all frequencies (P&lt;.05, see Figure 2), but no stimuli resulted in significantly different SNR. There was significant subject effect (P&lt;&lt;.05), and one subject responded 1‐2 orders of magnitude higher than the others. This suggests higher variability between subjects than frequencies alone.ConclusionOur results indicate that ISF can induce steady‐state visually evoked potentials at several frequencies in the low gamma range of 36‐44 Hz. Across the population of participants, we found no preference or trend for any specific gamma stimulation frequency in the tested range.

PARTICULARITIES OF THE FACTORS THAT INFLUENCE THE INVOLVEMENT OF YOUNG PEOPLE IN VOLUNTEERING ACTIVITIES

The behavior of young people involved in volunteer activities is also the result of society's challenges. Therefore, the management of volunteering activities must focus on the motivation of young volunteers. Identifying the main factors that influence the motivation and frequency of young people's involvement in volunteer activities is one of the solutions that contribute to empowering many volunteers and increasing the involvement of young people in more volunteer projects. Using PLS-SEM, we evaluated how personal attributes (age and education) guide the behavior of young people involved in volunteer activities. The research results indicate that their seriousness and rigor in volunteering activities (regardless of gender) allow young people to experience activities in various fields, contributing to developing personal skills.

Cerebellar somatotopy of the trigemino-cervical complex during nociception.

The somatotopic organization of the human cerebellum processes somato-motoric input. Its role during pain perception for nociceptive input remains ambiguous. A standardized experimental trigeminal nociceptive input in functional imaging might clarify the role of the cerebellum in trigeminal nociception. Also of interest is the greater occipital nerve, which innervates the back of the head, and can influence the trigeminal perception due to functional coupling within the brainstem, forming the so-called trigemino-cervical complex. In our preregistered study (clinicaltrials.gov: NTC03999060), we stimulated the greater occipital as well as the three main branches of the trigeminal nerve during functional magnetic resonance imaging in two independent cohorts of young healthy volunteers without psychiatric, neurological or pain-related disorders to disentangle overlapping somatotopic cerebellar organization of the nerves innervating the human head. We found a dominant effect of the first trigeminal branch in the cerebellum, underpinning its particular role for headache diseases, and somatotopic representations in bilateral cerebellar lobules I-IV, V, VIIb, VIIIa and Crus I as well as in the brainstem. The study expands the current knowledge on facial and head pain processing by the cerebellum and provides an initial somatotopic map of the trigemino-cervical complex in the human cerebellum with a predominant representation of the first trigeminal branch.

Quantitative study of 3.0T MRI on the thickness of knee joint cartilage in healthy young people

To explore 3.0T MRI accurate measurement of knee cartilage thickness in healthy youth provides reliable anatomical parameters for quantitative diagnosis of osteoarthritis and accurate osteotomy of joint replacement. From January 2013 to December 2013, 30 healthy young volunteers including 14 males and 16 females with an average age of (25.8±2.4) years old ranging from 22 to 33 years were recruited in Changchun, Jilin Province, and a 3.0T MRI scan was performed on the bilateral knee joints of each volunteer. The cartilage thickness was measured on the lateral femoral condyle (LFC), medial femoral condyle (MFC), lateral tibial plateau (LTP) and medial tibial plateau (MTP). In four regions of the knee joint:LFC, MFC, LTP and MTP, whether young men or women, there was no significant difference in cartilage thickness between the left and right knee joints (P>0.05). There were significant differences in knee cartilage thickness between healthy young men and women (P<0.05). In the same sex group, LFC cartilage thickness was thinner in the middle, thicker in front and rear;MFC cartilage thickness was the thinnest in front and gradually thickening from the front to the rear; LTP cartilage thickness was thickest in the middle, second in the rear and thinnest in the front;MTP cartilage thickness was the thinnest in the front, was relatively uniform in the middle and rear and thicker than that in the front. In Northeast China, among healthy adults aged 22 to 33, gender difference may be an important factor in the difference of cartilage thickness in various regions of the knee joint. Regardless of whether male or female healthy young people, the cartilage thickness of the entire knee joint is unevenly distributed, but there is no significant difference in cartilage thickness in the same area between the left and right knee joints.

Young Volunteer Creates Connections With Adult Learners

Young Volunteer Creates Connections With Adult Learners

A Comparative Study on Platelet-Rich Plasma From Elderly Individuals and Young Adults to Treat Pressure Ulcers in Mice

ObjectiveThe aim of the present study was to compare the therapeutic effects of activated platelet-rich plasma (PRP) prepared from elderly individuals and young adults to treat pressure ulcers (PUs), and to accumulate a theoretical basis for allogeneic PRP treatment of PUs in elderly patients. Materials and methodsWhole blood was extracted from elderly individuals aged >65 y and young adult volunteers for PRP preparation, and platelet concentrations in whole blood and PRP were compared. Growth factors released from activated PRP were assayed using the enzyme-linked immunosorbent assay. C57BL/6 mice were divided into three groups: the control saline, elderly-PRP (Group A), and young adult-PRP (Group B). Ischemia-reperfusion injury-induced PUs were established on the backs of mice. PUs were photographed on days 0, 5, and 10 to assess their sizes. Specimens were collected on day 10 and subjected to hematoxylin and eosin and Masson's staining. Immunohistochemical staining for CD31 was conducted to evaluate vascular formation, and cell invasion was assessed using a Transwell assay. The action of PRP on transforming growth factor-beta (TGF-β)-dependent fibroblast activity and epithelial-mesenchymal transition was analyzed using immunofluorescence and Western blotting in vitro. ResultsThe platelet concentrations in whole blood and PRP of young adults were significantly higher than that in elderly individuals. The two PRP treatment groups had similar platelet enrichment coefficients of PRP. After activation, PRP from young adults produced significantly higher levels of platelet-derived growth factor, TGF-β, and vascular endothelial growth factor than PRP from elderly individuals (P < 0.05). The concentrations of platelet-derived growth factor, TGF-β, and vascular endothelial growth factor were positively correlated with the platelet concentrations in whole blood and PRP. The effects of PRP in regulating the expressions of TGF-β, α-smooth muscle actin, vimentin, and E-cadherin were observed in vivo and in vitro. The two PRP treatment groups exhibited better wound healing than the control group, as evidenced by more re-epithelialization, higher collagen content, skin fibrosis, and more blood vessel formation over time. Group B exhibited better wound healing than Group A (P < 0.05). ConclusionPRP exhibits potent wound healing ability in PU therapy, and PRP from young adults is seemingly superior to that from elderly individuals because of a higher concentration of platelets and increased production of growth factors.

Trunk variability and local dynamic stability during gait after generalized fatigue induced by incremental exercise test in young women in different phases of the menstrual cycle.

The purpose of this study was to identify how generalized fatigue along with hormonal changes throughout the menstrual cycle affects trunk variability and local dynamic stability during gait. General fatigue was induced by an incremental test on a treadmill, and the menstrual cycle was divided into three phases: follicular, ovulatory, and luteal. Twenty-six healthy, young volunteers (aged 18 to 28 years) who did not use oral contraceptives or other hormonal drugs with a regular menstrual cycle participated in the study. They walked on the treadmill for 4 min at the preferred speed, before the incremental test, followed by four sets of 4 min alternating between walking, also at preferred speed, and resting. From trunk kinematic data, the following were extracted: the mean of the standard deviation along strides, as a measure of variability, and the maximum Lyapunov exponent, as a measure of local dynamic stability (LDS). After the incremental test, variability increased, and LDS decreased. However, they showed a tendency to return to the initial value faster in women compared to previous results for men. In the follicular phase, which has less hormonal release, the volunteers had an almost complete recovery in LDS soon after the first rest interval, suggesting that female hormones can interfere with fatigue recovery. Nevertheless, concerning the LDS, it was significantly lower in the luteal phase than in the follicular phase. Women that are not taking oral contraceptives should be aware that they are susceptible to increased gait instabilities in the pre-menstrual phase after strenuous activities.

Effect of Nigella sativa on general health and immune system in young healthy volunteers; a randomized, placebo-controlled, double-blinded clinical trial.

Nigella sativa ( N. sativa) is traditionally used as an immune enhancer in different communities. The aim of this study was to evaluate the effect of N. sativa on immunity related parameters in young healthy subjects. This study was a double blind, randomized, placebo controlled clinical trial. Fifty-two healthy subjects (48 male and 4 female) 18-25 years old were enrolled in the study. They were randomly divided into four groups; the first received charcoal capsules and served as controls and the other three received 0.5, 1 g, and 2 g of powdered N. sativa capsules, respectively. Two blood samples were obtained from all participant, before initiation of the trial and at the end of the four weeks intervention. One sample was used for routine health screening by evaluating liver and renal functions as well as complete blood count and differential. The second sample was used to measure certain cytokines including; IL-1, IL-4, IL-6, IL-10, and TNF. A third and fourth samples were obtained from the last cohort of subjects before and after treatment; the third was used for measuring immunoglobulins and CD profile and the fourth for evaluating certain gene expressions (INF-γ, NF-κ-B, TNF-α, IL-1β, IL-13, IL-8, and IL-6). Only 1 g dose of N. sativa produced a significant elevation in total lymphocyte count, CD3+ and CD4+ counts. One gram N. sativa increased the absolute lymphocyte count from 1850±0.24 to 2170±0.26 (p=0.008), CD3+ from 1184.4±75.60 to 1424±114.51 (p=0.009), and CD4+ from 665.6±141.66 to 841±143.36 (p=0.002). This elevation in T cells was lost by increasing the dose of N. sativa to 2g. The rest of the parameters were not changed significantly in all doses. The results show a promising immunopotentiation effect of N. sativa by elevating helper T cells and the optimum dose for young age group seems to be 1 g.