Adult Male Volunteers Research Articles

A structural modeling approach to determine the effects of orthorexia nervosa and social appearance anxiety on healthy lifestyle behaviors in young adults

Aims: The aim of this study is to examine the relationship between orthorexia nervosa (ON) and social appearance anxiety (SAA) and to investigate the effects of these variables on healthy lifestyle behaviors (HLB) in young adults aged 18-30 years. Methods: A total of 408 young adult male and female volunteers, with a mean age of 21.7±2.95 years, participated in this study. A structural model was proposed to examine the effects of SAA and ON on HLB. To assess how well the study variables represented the underlying components, we first evaluated a confirmatory measurement model. Subsequently, we analyzed a structural model that allowed for the examination of multiple regression equations involving several dependent variables. Results: SAA had a negative influence on HLB (std β=-0.673; t-value=-8.425), a significant negative relationship between ON, HLB was also promoted (std β=-0.554; t-value=-9.388). It was determined that there is a positive correlation between SAA, ON which is statistically significant (correlation coefficient=0.830; t-value=10.244). Conclusion: It is concluded that the individuals with high social appearance anxiety do not adopt healthy lifestyle behaviors and are more prone to orthorexia nervosa.

Clinical Assessment of Breast Cancer Resistance Protein (BCRP)-Mediated Drug-Drug Interactions of Sepiapterin with Curcumin and Rosuvastatin in Healthy Volunteers.

Sepiapterin, also known as PTC923 and CNSA-001, is a synthetic form of endogenous sepiapterin being developed as a novel oral treatment for phenylketonuria. Sepiapterin is a natural precursor of tetrahydrobiopterin (BH4) and, when orally administered, is converted to BH4 via the pterin salvage pathway. In vitro studies have demonstrated that both sepiapterin and BH4 are both substrates and inhibitors of the breast cancer resistance protein (BCRP) transporter. This phase I study investigated BCRP-mediated drug-drug interactions of sepiapterin as a victim and as a perpetrator. An open-label, fixed-sequence, four-period, crossover, single-dose study was conducted in adult male and female healthy volunteers (18-55 years of age). In a given treatment period, subjects received a single oral dose of sepiapterin (20 mg/kg), sepiapterin (20 mg/kg) plus curcumin (2 g), rosuvastatin (10 mg), or rosuvastatin (10 mg) plus sepiapterin (60 mg/kg). The pharmacokinetics of sepiapterin, its metabolite BH4, and rosuvastatin were studied, and geometric mean ratios of exposures in the presence and absence of the BCRP inhibitor curcumin or sepiapterin were estimated. The presence of the BCRP c.421C>A polymorphism was evaluated in all subjects. A total of 29 subjects were enrolled and included in the safety analysis. Among them, 26 subjects were included in the pharmacokinetic and drug-drug interaction analyses. Following oral administration20 mg/kg sepiapterin, sepiapterin was rapidly and extensively converted to BH4, and BH4 maximum observed concentration (415.0 ng/mL) was observed 4.95 h (time to maximum observed concentration) post-dose. Sepiapterin maximum observed concentration and area under the concentration-time curve from time 0 to time of the last quantifiable measurement or the last sample collection time (AUClast) were <1% of BH4 values. Coadministration of the BCRP inhibitor curcumin (2 g) increased BH4 maximum observed concentration, AUClast, and area under the concentration-time curve from time 0 extrapolated to infinity by 24%, 21%, and 20%, respectively. When sepiapterin was coadministered with the BCRP substrate rosuvastatin, there was no effect on the pharmacokinetics of rosuvastatin. BCRP c.421C/A carriers (n = 4) had higher plasma exposures of BH4 (1.39 × for AUClast) and rosuvastatin (1.61 × for AUClast) than c.421C/C carriers (n = 22). Greater increases in BH4 exposures (1.33 vs 1.18 for AUClast) were observed in c.421C/A carriers compared with c.421C/C carriers when sepiapterin was coadministered with curcumin. All treatments were well tolerated during the study. Oral coadministration of the BCRP inhibitor curcumin slightly increased the plasma exposure of sepiapterin and its metabolite BH4 in healthy volunteers. This modest increase was deemed not clinically meaningful. Sepiapterin did not alter the pharmacokinetics of the BCRP substrate rosuvastatin.

Pharmacokinetics and bioequivalence of the generic and original dabigatran etexilate after a single dose in healthy volunteers

Aim. To study the comparative pharmacokinetics and confirmation of bioequivalence of the generic (T) and original (R) dabigatran etexilate in healthy volunteers after a single oral dose under fasted conditions.Material and methods. To confirm bioequivalence, an open-label, randomized, replication, crossover, four-step study was conducted to compare the pharmacokinetics and bioequivalence of generic and original dabigatran with a single oral dose 150 mg dabigatran etexilate under fasted conditions in adult healthy male and female volunteers. Sixty-eight subjects participated in the study. During the study, blood plasma samples were taken from volunteers, in which the concentration of total and free dabigatran was determined. Based on the data obtained, pharmacokinetic and statistical analysis was carried out and 90% confidence intervals were calculated for the ratio of mean pharmacokinetic parameters (Сmax, Tmax, AUC0-t, AUC0-∞, AUCt-∞, T1/2, AUCt-∞/AUC0-∞) for total and free dabigatran.Results. The established 90% confidence intervals for the ratio of AUC0-t, AUC0-∞ and Cmax values for total dabigatran were 82,56-96,36% (mean ratio, 89,19%), 82,39-95,90% (mean ratio, 88,89%) and 85,98-99,17% (mean ratio, 92,34%), respectively. The established 90% confidence intervals for the ratio of AUC0-t, AUC0-∞ and Сmax values for free dabigatran were 83,37-98,29% (mean ratio, 90,53%), 82,98-97,33% (mean ratio, 89,87%) and 85,04-99,28% (mean ratio, 91,88%), respectively. For the estimated pharmacokinetic parameters of dabigatran etexilate, 90% confidence intervals ranged from 80-125% for AUC0-t, AUC0-∞ and Cmax. Additional safety analysis was carried out. Generic and original dabigatran were well tolerated by the volunteers. There were no significant differences in vital signs, paraclinical characteristics throughout the study compared with the initial data, as well as significant differences between the drugs in all studied parameters of adverse events.Conclusion. The study showed that generic and original dabigatran are bio­equivalent. In addition, the data obtained indicate that the agents have similar safety profiles.

Generacion de recursos audiovisuales para la realización de medidas antropométricas en adultos mayores

Introduction: Ageing, according to the WHO, results from accumulated molecular and cellular damage, affecting physical and mental health. In Spain, the population aged 65 years and over has increased to 20% in 2022. Nutritional assessment in older adults, crucial for assessing health, uses the MNA questionnaire and anthropometric assessment. Although there are standard protocols for anthropometric measurements in the normal-weight and athletic population, there are no protocols adapted for older adults. The aim of the study is to generate audiovisual teaching resources with specific measurement criteria to improve the knowledge of health professionals and students about anthropometric measurements in older adults. Methodology: Descriptive study on the generation of audiovisual material based on possible and relevant measurements for the anthropometric study of older adults. Photographs and videos were taken of such measurements in an older adult male volunteer. Results: The audiovisual material consists of 13 videos with anthropometric measurements including 3 basic measurements (body mass, Stretch stature and medium arm span), 4 skinfolds (tricipital, bicipital, subscapular and iliac crest), 3 girths (arm relaxed, waist and calf) and 3 lengths (radiale-stylion, heel-knee height and tibiale mediale-sphyrion tibiale). Conclusion: Current manuals do not provide detailed information on the adaptation of the anthropometric measurement protocol to the limitations of older adults, such as spinal deviations or other physical or postural difficulties. Therefore, the audiovisual material created is novel, useful for teaching and learning anthropometric measurements and applicable both in academia and in daily clinical practice.

Pharmacokinetics, Safety, Tolerability, and Immunogenicity of BP02 (Trastuzumab Biosimilar) Compared to EU- and US-Approved Trastuzumab in Healthy Adult Male Volunteers: A Phase 1, Randomized, Double-Blind Study.

This study evaluated the pharmacokinetic (PK) equivalence between BP02 (a proposed trastuzumab biosimilar) and the reference trastuzumab approved in the EU (EU-trastuzumab) and the US (US-trastuzumab). In this phase 1, double-blind, parallel-group trial, 111 healthy male volunteers were randomized 1:1:1 to receive a single 6-mg/kg intravenous infusion of BP02, EU-trastuzumab, or US-trastuzumab and were evaluated for 78days. Serum drug concentration-time data were analyzed by non-compartmental methods. The PK similarity of BP02 to the two reference products, and between EU-trastuzumab and US-trastuzumab, was determined using the standard 80-125% bioequivalence criteria. Baseline demographics for the 111 subjects with evaluable pharmacokinetics were similar across all treatment groups. PK profiles were similar for the three products. The 90% confidence intervals (CIs) for the ratios of area under the serum concentration-time curve (AUC) from the time of dosing to infinity (AUC0-inf), AUC from the time of dosing until the time of the last quantifiable concentration (AUC0-t), and peak serum concentration of trastuzumab (Cmax) were within 80% to 125% for all three pairwise comparisons. Adverse events (AEs) were similar across all arms, with treatment-related AEs reported by 73.0%, 73.0%, and 89.2% of the subjects in the BP02, EU-trastuzumab, and US-trastuzumab groups, respectively. The most common AEs were headache, infusion-related reactions, and upper-respiratory-tract infections. Four subjects-three in the US-trastuzumab group and one in the BP02 group-discontinued the study due to AEs. All post-dose samples except for two tested negative for anti-drug antibodies. This study demonstrates the PK similarity among BP02, EU-trastuzumab, and US-trastuzumab. The safety and immunogenicity profiles observed for the three products in this study are consistent with previous reports for trastuzumab. ANZCTR number: ACTRN12621000573853.

Expanding the Frontiers of nail product evaluation: Novel application of differential scanning calorimetry (DSC) for assessing crosslinking density and predicting nail brittleness and flexibility.

While modern industry advancements have expanded nail beautification options, scientific literature primarily focuses on nail biology and medicine, with limited attention on cosmetic treatments. This study aimed to investigate human nail denaturation properties, including gender impact, blending nails to enlarge the sample pool, nail sensitization through bleaching, and active effectiveness testing. The objective was to understand the DSC and bending fatigue relationship, and define the consumer relevance of the DSC test. Nail clippings were collected from adult female and male volunteers. The wet DSC was employed to validate sample preparation, explore the effects of gender, and assess the potential of using blended nails for claims substantiation testing. Nails were sensitized through bleaching using hydrogen peroxide. The effects were confirmed through DSC and nail flexure tests. Furthermore, the ability of actives to address concerns related to nail softness and brittleness was assessed using these techniques. The results confirmed the viability of equilibrating nails in water for up to 14 h as a standardized testing method. The denaturation temperature results were independent of gender and suitable for claims substantiation testing. Blending nails from different sources did not yield significant variations in denaturation properties. A preliminary study suggested that cadaver nails should be used with caution because they exhibited differences in denaturation temperature, influenced by the sampling location. Bending fatigue tests highlighted the significance of humidity, with higher humidity conditions (80%) enhancing nail flexibility and providing better resolution for claims substantiation. Sensitizing the nails with hydrogen peroxide induced alterations in both DSC and bending fatigue results. Proof-of-principle studies demonstrated an elevation in denaturation temperature and a decrease in the number of cycles to break, indicating a nail-hardening effect when formaldehyde was applied. The use of a nail softener led to an enhancement in nail fatigue resistance due to a notable reduction in nail crosslinking density. The measurement of crosslinking density proved to be a sensitive tool for assessing the effects of cosmetic treatments on nails, particularly in predicting outcomes related to nail brittleness and flexibility.

LSD increases sleep duration the night after microdosing

Microdosing psychedelic drugs at a level below the threshold to induce hallucinations is an increasingly common lifestyle practice. However, the effects of microdosing on sleep have not been previously reported. Here, we report results from a Phase 1 randomized controlled trial in which 80 healthy adult male volunteers received a 6-week course of either LSD (10 µg) or placebo with doses self-administered every third day. Participants used a commercially available sleep/activity tracker for the duration of the trial. Data from 3231 nights of sleep showed that on the night after microdosing, participants in the LSD group slept an extra 24.3 min per night (95% Confidence Interval 10.3–38.3 min) compared to placebo—with no reductions of sleep observed on the dosing day itself. There were no changes in the proportion of time spent in various sleep stages or in participant physical activity. These results show a clear modification of the physiological sleep requirements in healthy male volunteers who microdose LSD. The clear, clinically significant changes in objective measurements of sleep observed are difficult to explain as a placebo effect. Trial registration: Australian New Zealand Clinical Trials Registry: A randomized, double-blind, placebo-controlled trial of repeated microdoses of lysergic acid diethylamide (LSD) in healthy volunteers; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=381476; ACTRN12621000436875.

(031) Bioequivalence Studies of Sildenafil Citrate Orodispersible Film Administered With and Without Water versus Viagra Film-Coated Tablets in Healthy Adult Male Volunteers

Abstract Introduction Orodispersible film (ODF) formulation offers ease of use, convenience of administration, and other advantages, especially for patients who have difficulty in swallowing or are on liquid restriction compared with conventional oral formulations for the treatment of erectile dysfunction. Objective These studies compared the bioequivalence of 50 mg sildenafil citrate ODF formulation (test drug) with the marketed 50 mg sildenafil citrate film-coated tablet (FCT) (Viagra; Pfizer, New York, NY) (reference drug), with and without water in 2 randomized cross-over studies. Methods Two randomized cross-over studies were conducted. The first study explored the bioequivalence of test drug administered with and without water compared with the reference drug with water. The second study investigated the bioequivalence of test drug, without water, compared with the reference drug with water. 42 healthy adult male volunteers started the first study and only 40 completed. While 80 subjects who were enrolled completed the second study. All the 120 subjects from both the studies were included for pharmacokinetic and bioequivalence analysis. All volunteers fasted for 10 hours pre-dose. A 1-day washout period between doses was observed. Blood samples were collected at regular intervals both before (up to 120 minutes before dosing) and after dosing (at different intervals up to 14 hours) dosing stages. Statistical analyses on pharmacokinetic parameters were performed. Safety and tolerability for both the formulations were evaluated. Results In the first study, bioequivalence was demonstrated for sildenafil citrate ODF administered with water when compared with the Viagra FCT. The ratios of adjusted geometric means (90% confidence interval (CI)) were maximum plasma concentration: 1.02 (94.91–108.78) and area under the plasma concentration-time curve: 1.09 (104.49–113.21) for sildenafil citrate ODF administered with water vs Viagra FCT. These ratios were within the bioequivalence acceptance range of 80% to 125%, indicating that the bioequivalence criteria were met. The pharmacokinetic parameters for the second study also demonstrated bioequivalence for sildenafil citrate ODF when administered without water compared with Viagra FCT. The ratios of adjusted geometric means (90% CI) were maximum plasma concentration: 1.02 (95.47–109.36) and area under the plasma concentration-time curve: 1.06 (103.42–108.40) for sildenafil citrate ODF administered without water vs Viagra FCT. Adverse events in both the studies occurred at similar rates for the 2 formulations and were mild in intensity and were expected from the known safety profile. Conclusions Sildenafil citrate ODF administered with and without water met bioequivalence criteria compared with Viagra FCT administered with water under fasted conditions in healthy adult male volunteers. These results suggest that the new ODF formulation can be used interchangeably with the marketed FCT formulation. Therefore, the new ODF formulation can be used as a suitable alternative to the conventional oral solid dosage form for the treatment of ED. Disclosure Yes, this is sponsored by industry/sponsor: Viatris Inc. Clarification: Industry initiated, executed and funded study. Any of the authors act as a consultant, employee or shareholder of an industry for: Viatris Inc.

How far does feedback on oral malodor assessment influence the decision to quit smoking?

A retrospective, uncontrolled, questionnaire-based, pre-post study involving adult male smoker volunteers who were invited to attend a one-day smoking cessation event at their workplace. To assess the effect of feedback on motivation for smoking cessation using oral-malodor measurements. At baseline, the participants attended a brief video presentation regarding various oral health-specific effects of smoking, joined a group introduction to smoking-cessation aids, and were given questionnaires that inquired information about smoking status including type, daily consumption, and duration. Subsequently, respiratory function and oral-malodor assessment were conducted using exhaled and oral cavity air, respectively. To measure oral-malodor, hydrogen sulfide, methyl mercaptan, and dimethyl sulfide concentrations were determined. Participants' intention for smoking cessation was evaluated through questionnaire before and after the event, classifying their intentions as aiming to quit within the next month, within the next 6 months, or having no intention to quit smoking. Immediate feedback on respiratory function and oral malodor measurements was provided by medical and dental blinded examiners, respectively. A total of 241 men, aged 20-54 years, were enrolled and included:169 (70.1%) exclusive cigarette smokers, 39 (16.2%) exclusive heated-tobacco product users, and 33 (13.7%) users of both. Prior to the health event, 8.7%, 17.0%, and 74.3% of smokers expressed intentions to quit within the next month, the next 6 months, or had no intention to quit, respectively. After the event, the corresponding percentages shifted to 17.8%, 26.6%, and 55.6%. In multivariable logistic regression analysis, the association with intention to quit in the next month was significant only for methyl mercaptan concentration in oral cavity air, with an adjusted odds ratio (AOR) of 4.24 (95% CI: 1.52-11.84; p = 0.006). Sensitivity analysis revealed that this association was concentration-dependent. On the other hand, higher daily tobacco consumption (≥ 15 pieces) was significantly associated with less likely intention to quit in the next 6 months (AOR = 0.37; 95% CI: 0.15-0.92, p = 0.032). Feedback on oral malodor measurement may support the motivation of men to quit smoking within the next month, rather than waiting for the next 6 months.

Biomechanical Analysis of a Newly Proposed Surgical Combination (MIS Screw-Rod System for Indirect Decompression+ Interspinous Fusion System for long Term Spinal Stability) in Treatment of Lumbar Degenerative Diseases

ObjectiveThe aim of this study is to analyze the biomechanical stability of a newly proposed surgical combination (minimally invasive surgery of screw-rod system for indirect decompression+ interspinous fusion system for long term spinal stability) in treatment of lumbar degenerative diseases Materials and methodsThe three-dimensional CT image data of an adult healthy male volunteer was selected. An intact model of L4/5 was further established and validated by using Mimic and 3-matic, 3D slicer, abaqus, Python. Four surgical models were constructed. The biomechanical stability among these surgical modes was compared and analyzed using finite element analysis. ResultsThe maximum von mises on fixation system in surgical models 2 and 3 exhibited comparable values. This finding suggested that the increase in interspinous fusion did not result in a significant elevation in maximum von mises on fixation system. Compared with the third surgical model, the fourth model, which received less average von mises experienced by the screw in contact with both cancellous and cortical bone. The findings indicated that the inclusion of facet joint fusion in surgical procedures might not be necessary to increase the average von Mises stress experienced by the screw in contact with both cancellous and cortical bone. ConclusionThe biomechanical stability of the newly proposed surgical combination (MIS screw-rod for indirect decompression + interspinous fusion for long term spinal stability technique) was not lower than that of the other surgical combination groups, and it might not be necessary to perform facet joint fusion during the surgery.

The frequency of sarcopenia in haemophilia patients: Effects on musculoskeletal health and functional performance.

In patients with haemophilia A, chronic arthropathy develops over time as a result of recurrent joint bleeds, which leads to restricted mobility and disability in the affected joints. There are limited studies in the literature evaluating sarcopenia in patients with haemophilia. The present study aims to determine the prevalence of sarcopenia in severe haemophilia-A patients and to evaluate musculoskeletal health and functional performance. Thirty haemophilia-A patients and 26 adult male volunteers were enrolled in the study. For detection of sarcopenia, the appendicular skeletal muscle mass (ASM) obtained by bioelectrical impedance analysis (BIA) was divided by height squared (m2 ) to obtain the appendicular skeletal muscle mass index (ASMI) value. The thighs of both lower extremities were measured using the Modified Sonographic Tight Adjustment Ratio (STAR) method, which was obtained by adding the bilateral rectus femoris and vastus intermedius muscle thicknesses measured by ultrasound. Hand and quadriceps muscle strength (MS) were measured with a dynamometer. Physical performance was determined using the walking speed (WS), timed up-and-go test (TUGT), 5-repetition sit-to-stand test (5RSTS), and 6-min walk test (6MWT). Haemophilia Joint Health Score (HJHS) and Haemophilia Early Arthropathy Detection-Ultrasonography (HEAD-US) were also used to assess the musculoskeletal system. According to the modified STAR values calculated based on body mass index, sarcopenia was present in 15 (50%) of 30 patients. However, based on the ASMI-BIA values, sarcopenia was present in only two (6.6%) patients. A weak correlation was found between ASMI and HJHS, HEAD-US, WS, TUGT, and hand MS (left), while a moderate correlation was found with knee MS (right), knee MS (left), and 5RSTS. A strong correlation was found between the modified STAR score and HEAD-US, HJHS, knee MS (left), 5RSTS, TUGT, and WS, while a moderate correlation was found with hand MS (left), hand MS (right), and knee MS (right). This study showed muscle loss, joint mobility restrictions, and decreased functional capacity in haemophilia patients and demonstrated the presence of sarcopenia in these patients. The STAR measurement method showed stronger relationships with MS and functional performance values than ASMI measurements in terms of evaluating sarcopenia.

Effects of Dual Tasks Including Gum Chewing on Prefrontal Cortex Activity.

The purpose of this study was to examine the effects on prefrontal cortex (PFC) activity of listening to pleasant sounds (PS) while walking, gum chewing (GCh), or performing the dual task of walking and gum chewing at the same time (walking + GCh). A total of 11 healthy adult male volunteers participated in the study (mean age: 29.54±3.37). The block design of the trial consisted of a 30-sec rest, a 60-sec task (target task or control task), and a 30-sec rest. There were three target task conditions: walking, GCh, and the dual task. All of these were performed while listening to PS. The control condition was rest (no exercise) while listening to PS. The outcomes measured and measurements used were PFC activity using two-channel near-infrared spectroscopy and participant self-evaluation of the pleasantness of the experience using the visual analogue scale (VAS). Compared to the control condition, there was significantly greater PFC activation during the GCh and the walking + GCh tasks. Compared to the control condition, GCh and walking + GCh showed significantly greater activation on the VAS measure. In conclusion, listening to PS while GCh or walking + GCh increases PFC activity in the lower central region and induces positive emotional change.

Investigation of the Validity and Reliability of Two Smart Bands Selected That Count Steps at Different Walking Speed

Whether activity monitor smart wristbands that have become widespread can accurately estimate the step count while walking is a matter of curiosity. The current study aims to analyze the validity and reliability of step count (SC) estimation at normal walking and fast walking pace under controlled conditions of two selected smart wristbands of the leading wearable device vendors, Xiaomi (Mi4) and Huawei (H4). Twenty healthy adult male and twenty healthy adult female were included in the study and analyzed separately. The mean age of male and female participants was 22.25 and 21.62 years, with BMI values of 24.22 kg/m2 and 21.42 kg/m2, respectively. The above-ground walking protocol consisted of four separate five-minute tests: Normal Walking Test, Normal Walking Retest, Fast Walking Test, and Fast Walking Retest. In the study, the analyses were performed by using activity monitor measurements and criterion measurements (the number of steps determined from video recordings), compatibility of test-retest measurement values, error indicators (MPE and MAPE), Intraclass Correlation Coefficients (ICC), and Bland-Altman limits of agreement. According to the current study results, it was revealed that the MAPE values recorded for Mi4 and H4 smart wristbands for both normal and fast walking pace in male and female participants were &amp;lt;5%, which was deemed excellent. According to all analyses, the H4 device was found to be valid and reliable, but according to ICC and Pearson Correlation analyses, the Mi4 device was not found to be valid and reliable at fast walking pace.

Finite element analysis and a pilot study of different fixation constructs for Danis-Weber A and B lateral malleolus fractures

BackgroundDisplaced lateral malleolus fractures are typically stabilised through open reduction and internal fixation. The biomechanically and clinically efficacy of locking plates and lag screws, particularly in Weber A and B distal fibular fractures remains a subject of contention. This study examines two locking plate designs for lateral malleolus fractures, evaluating their performance with and without interfragmentary screws using finite element models.MethodsUtilising CT images of a healthy adult male volunteer, a three-dimensional finite element model was constructed. The Fibula-specific Flank Multiaxial Locking Anatomic Plate (FMLP) and the Conventional Locking Plate (CLP) were subjected to stabilisation, both with and without an interfragmentary screw, mimicking the Danis-Weber A and B lateral malleolus oblique fracture fixation. Loads of 140 N and 70 N, equivalent to 20% of the body weight, were applied to simulate the single-leg and two-leg standing conditions in the axial direction. The von Mises stress (VMS) distributions and element displacements were subsequently analyzed.ResultsIn the Danis-Weber A fracture model group, the FMLP with an interfragmentary screw fixation exhibited the lowest peak VMS values: 51.9 MPa in the fibula, 89.0 MPa in the plate, and 61.3 MPa in the screws for simulating single-leg conditions. Under two-leg standing conditions, these peak VMS values decreased to 25.9 MPa in the fibula, 44.5 MPa in the plate, and 30.6 MPa in the screws, respectively. Furthermore, the overall structural peak displacements during single-leg standing for both Weber-A and B fractures with different implants ranged from 1.61 to 2.54 mm. While standing on two feet, the ranged was from 0.80 to 1.27 mm. An interfragmentary screw at the oblique fracture site resulted in reduced the peak value of VMS in the fibula, plate, screws, consequently decreased the overall structural displacement for FMLP and CLP fixation in lateral malleolus fractures.ConclusionsThe current finite element analysis (FEA) demonstrates that FMLP exhibits superior mechanical characteristics in Danis-Weber A and B lateral malleolus fractures compared to CLP. The inclusion of an interfragmentary screw, combined with locking plate design, enhances stability for simple oblique distal fibular fractures. The FMLP presents itself as potential as an alternative for lateral malleolus fractures from a biomechanical perspective. Nevertheless, further verification of these results is imperative through subsequent clinical studies.

Finite element analysis of artificial ankle elastic improved inserts

To discuss the influence of artificial ankle elastic improved inserts (hereinafter referred to as "improved inserts") in reducing prosthesis micromotion and improving joint surface contact mechanics by finite element analysis. Based on the original insert of INBONE Ⅱ implant system (model A), four kinds of improved inserts were constructed by adding arc or platform type flexible layer with thickness of 1.3 or 2.6 mm, respectively. They were Flying goose type_1.3 elastic improved insert (model B), Flying goose type_2.6 elastic improved insert (model C), Platform type_1.3 elastic improved insert (model D), Platform type_2.6 elastic improved insert (model E). Then, the CT data of right ankle at neutral position of a healthy adult male volunteer was collected, and finite element models of total ankle replacement (TAR) was constructed based on model A-E prostheses by software of Mimics 19.0, Geomagic wrap 2017, Creo 6.0, Hypermesh 14.0, and Abaqus 6.14. Finally, the differences of bone-metal prosthesis interface micromotion and articular surface contact behavior between different models were investigated under ISO gait load. The tibia/talus-metal prosthesis interfaces micromotion of the five TAR models gradually increased during the support phase, then gradually fell back after entering the swing phase. The improved models (models B-E) showed lower bone-metal prosthesis interface micromotion when compared with the original model (model A), but there was no significant difference among models A-E ( P>0.05). The maximum micromotion of tibia appeared at the dome of the tibial bone groove, and the ​​micromotion area was the largest in model A and the smallest in model E. The maximum micromotion of talus appeared at the posterior surface of the central bone groove, and there was no difference in the micromotion area among models A-E. The contact area of the articular surface of the insert/talus prosthesis in each group increased in the support phase and decreased in the swing phase during the gait cycle. Compared with model A, the articular surface contact area of models B-E increased, but there was no significant difference among models A-E ( P>0.05). The change trend of the maximum stress on the articular surface of the inserts/talus prosthesis was similar to that of the contact area. Only the maximum contact stress of the insert joint surface of models D and E was lower than that of model A, while the maximum contact stress of the talar prosthesis joint surface of models B-E was lower than that of model A, but there was no significant difference among models A-E ( P>0.05). The high stress area of the lateral articular surface of the improved inserts significantly reduced, and the articular surface stress distribution of the talus prosthesis was more uniform. Adding a flexible layer in the insert can improve the elasticity of the overall component, which is beneficial to absorb the impact force of the artificial ankle joint, thereby reducing interface micromotion and improving contact behavior. The mechanical properties of the inserts designed with the platform type and thicker flexible layer are better.

Decreased neural drive affects the early rate of force development after repeated burst-like isometric contractions.

The neural drive to the muscle is the primary determinant of the rate of force development (RFD) in the first 50 ms of a rapid contraction. It is still unproven if repetitive rapid contractions specifically impair the net neural drive to the muscles. To isolate the fatiguing effect of contraction rapidity, 17 male adult volunteers performed 100 burst-like (i.e., brief force pulses) isometric contractions of the knee extensors. The response to electrically-evoked single and octet femoral nerve stimulation was measured with high-density surface electromyography (HD-sEMG) from the vastus lateralis and medialis muscles. Root mean square (RMS) of each channel of HD-sEMG was normalized to the corresponding M-wave peak-to-peak amplitude, while muscle fiber conduction velocity (MFCV) was normalized to M-wave conduction velocity to compensate for changes in sarcolemma properties. Voluntary RFD 0-50 ms decreased (d = -0.56, p < 0.001) while time to peak force (d = 0.90, p < 0.001) and time to RFDpeak increased (d = 0.56, p = 0.034). Relative RMS (d = -1.10, p = 0.006) and MFCV (d = -0.53, p = 0.007) also decreased in the first 50 ms of voluntary contractions. Evoked octet RFD 0-50 ms (d = 0.60, p = 0.020), M-wave amplitude (d = 0.77, p = 0.009) and conduction velocity (d = 1.75, p < 0.001) all increased. Neural efficacy, i.e., voluntary/octet force ratio, largely decreased (d = -1.50, p < 0.001). We isolated the fatiguing impact of contraction rapidity and found that the decrement in RFD, particularly when calculated in the first 50 ms of muscle contraction, can mainly be explained by a decrease in the net neural drive.

Finite element analysis of five internal fixation modes in treatment of Day type Ⅱcrescent fracture dislocation of pelvis

To compare the biomechanical differences among the five internal fixation modes in treatment of Day type Ⅱ crescent fracture dislocation of pelvis (CFDP), and find an internal fixation mode which was the most consistent with mechanical principles. Based on the pelvic CT data of a healthy adult male volunteer, a Day type Ⅱ CFDP finite element model was established by using Mimics 17.0, ANSYS 12.0-ICEM, Abaqus 2020, and SolidWorks 2012 softwares. After verifying the validity of the finite element model by comparing the anatomical parameters with the three-dimensional reconstruction model and the mechanical validity verification, the fracture and dislocated joint of models were fixed with S 1 sacroiliac screw combined with 1 LC-Ⅱ screw (S 1+LC-Ⅱ group), S 1 sacroiliac screw combined with 2 LC-Ⅱ screws (S 1+2LC-Ⅱ group), S 1 sacroiliac screw combined with 2 posterior iliac screws (S 1+2PIS group), S 1 and S 2 sacroiliac screws combined with 1 LC-Ⅱ screw (S 1+S 2+LC-Ⅱ group), S 2-alar-iliac (S 2AI) screw combined with 1 LC-Ⅱ screw (S 2AI+LC-Ⅱ group), respectively. After each internal fixation model was loaded with a force of 600 N in the standing position, the maximum displacement of the crescent fracture fragments, the maximum stress of the internal fixation (the maximum stress of the screw at the ilium fracture and the maximum stress of the screw at the sacroiliac joint), sacroiliac joint displacement, and bone stress distribution around internal fixation were observed in 5 groups. The finite element model in this study has been verified to be effective. After loading 600 N stress, there was a certain displacement of the crescent fracture of pelvis in each internal fixation model, among which the S 1+LC-Ⅱ group was the largest, the S 1+2LC-Ⅱ group and the S 1+2PIS group were the smallest. The maximum stress of the internal fixation mainly concentrated at the sacroiliac joint and the fracture line of crescent fracture. The maximum stress of the screw at the sacroiliac joint was the largest in the S 1+LC-Ⅱ group and the smallest in the S 2AI+LC-Ⅱ group. The maximum stress of the screw at the ilium fracture was the largest in the S 1+2PIS group and the smallest in the S 1+2LC-Ⅱ group. The displacement of the sacroiliac joint was the largest in the S 1+LC-Ⅱ group and the smallest in the S 1+S 2+LC-Ⅱ group. In each internal fixation model, the maximum stress around the sacroiliac screws concentrated on the contact surface between the screw and the cortical bone, the maximum stress around the screws at the iliac bone concentrated on the cancellous bone of the fracture line, and the maximum stress around the S 2AI screw concentrated on the cancellous bone on the iliac side. The maximum bone stress around the screws at the sacroiliac joint was the largest in the S 1+LC-Ⅱ group and the smallest in the S 2AI+LC-Ⅱ group. The maximum bone stress around the screws at the ilium was the largest in the S 1+2PIS group and the smallest in the S 1+LC-Ⅱ group. For the treatment of Day type Ⅱ CFDP, it is recommended to choose S 1 sacroiliac screw combined with 1 LC-Ⅱ screw for internal fixation, which can achieve a firm fixation effect without increasing the number of screws.

Body weight reduction by exercise increases the urinary 3-methylhistidine excretion level with relatively positive nitrogen, sodium, and potassium balances when compared to dietary restriction

BackgroundRegarding changes in muscle mass, differences due to types of exercise and/or nutritional interventions, and associations with nutrient balances are still unclear. MethodsTo estimate changes in muscle mass during a body weight loss program using either a diet or exercise regimen, we investigated levels of muscle mass-related indices, and body contents of nitrogen, sodium, and potassium as measured by the balance method. Six healthy young adult male volunteers participated in two 10-day crossover experiments (20 days total). The first 5 days comprised an adjustment period (energy intake, 2656 ± 367 kcal/day (mean ± standard deviation)). During the second 5-day period, the participants either reduced their energy intake to 1770 ± 244 kcal/day (diet regimen) or exercised on a bicycle ergometer to expend 886 ± 122 kcal/day (exercise regimen). ResultsThe nitrogen, sodium, and potassium balances were significantly more positive during the exercise regimen than during the diet regimen. The urinary excretion levels of creatinine, 3-methylhistidine (3-MH), aldosterone, and catecholamines, and the 3-MH/creatinine ratio were significantly increased only during the exercise regimen. ConclusionsThe exercise regimen suppresses the decrease in muscle mass-related indices during body weight loss compared to the diet regimen with a relatively positive state of whole-body protein, sodium, and potassium balances, accompanied by an increase in sympathetic/adrenal cortical functions.

The atherosclerosis index during body weight reduction is improved with exercise

IntroductionBody weight reduction is often used for addressing lifestyle-related diseases, and for slimming down or improving the competitiveness of athletes. It is known that high-density lipoprotein-cholesterol (HDL-C) levels can be increased by habitual exercise, while low-density lipoprotein-cholesterol (LDL-C) levels may not always be decreased by dietary restriction or exercise. We hypothesized that the levels of not only HDL-C, but also LDL-C improve more with body weight reduction by a combined diet-and-exercise regimen than that by a diet-only regimen. Summary of facts and resultsSix healthy young adult male volunteers participated in two 10-day crossover experiments (20 days total). The first 5 days comprised an adjustment period (energy intake, 2521±304kcal/day (mean±standard deviation)). During the second 5-day period, participants either reduced their energy intake to 1261±152kcal/day, or reduced their energy intake to 1891±228kcal/day and exercised on a bicycle ergometer to consume 630±76kcal/day. Decreases in the serum total cholesterol (TC), LDL-C, and apolipoprotein (apo) B levels were significantly larger, and decreases in the HDL-C and apo A1 levels were significantly smaller with the diet-and-exercise regimen than with the diet-only regimen. Consequently, the atherosclerosis index (AI: (TC–HDL-C)/HDL-C ratio) was significantly lower, and the degree of its reduction was significantly larger, after the diet-and-exercise regimen than after the diet-only regimen. ConclusionThese results suggest that reducing the body weight by a combination of diet and exercise has more beneficial effects on cholesterol metabolism, including changes in apo levels, than diet alone in healthy young adults.

The Left ventricular ejection fraction and left ventricular volumes assessed from 99mTC single photon emission tomography technique during stress and rest in relation to age in normal volunteer students.

The heart is subject to structural and functional changes with advancing age. Left ventricular compliance appears to decline with age, which could explain why the elderly have such a high rate of heart failure. Changes in heart function with age are associated with an increased risk of cardiovascular death and morbidity. Various techniques have been used to measure the impact of age on heart structure and function. Subject and methods: The study included 221 healthy adult male and female volunteers (160 females and 61 males, 20–80 years of age). All healthy subjects volunteered to participate in this study. They were classified according to their age. All healthy subjects enrolled in the study underwent myocardial perfusion imaging following the 2-day rest–stress 99mTc sestamibi (GSPECT) protocol. At rest and during stress, end-diastolic volume, end-systolic volume, and ejection fraction using the GSPECT software were assessed both at rest and during stress for comparison. The following parameters were measured: left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), and left ventricular ejection fraction (LVEF). The results show that the change in left ventricular ejection fraction (LVEF) decreased during rest and stress in all age groups. In contrast, the change in left ventricular end-systolic volume (LVESV) increased during stress and rest compared with the left ventricular end-diastolic volume (LVEDV) for all ages. Results show a significant change in EDV, ESV, and EF% (16.49%, 30.35%, -7.49%) with p-value &lt; 0.05 for the groups (20- 49). Also a significant change in EDV, ESV, and EF% (12.13%, 24.86%,-1.62%), respectively, with p-value &lt;0.05. for age range (50-80) years. In conclusion, in people with no cardiac functional or structural problems, the aging process is linked to considerable alterations in left and right ventricular EF, ESV, and EDV. When assessing SPECT with 99mTc investigations, our findings highlight the need to adopt age-adapted data as a reference standard. Keywords: SPECT with 99mTC, Age, Hemodynamics, Rest and Stress