Surveillance of the recurrence time of the effectiveness of national and region-level quarantines of COVID-19 pandemic in Chile.

The World Health Organization has recommended a range of social and health measures to mitigate the spread of coronavirus disease 2019 (COVID-19), including strategies such as quarantines, border closures, social distancing, and mask usage, among others. Specifically, the Chilean authorities implemented the "step-by-step" plan, built on the concept of dynamic quarantine. Numerous studies have examined the effectiveness of these quarantines in Chile during the pandemic, utilizing data published by the Chilean Ministry of Health. This study's primary aim was to enhance our understanding of quarantine effectiveness in Chile during the pandemic. We accomplished this by analyzing the distributional behavior of the time until the COVID-19 pandemic was deemed under control or not. In our study, we defined an event with two potential outcomes related to the instantaneous reproductive number (Rt), which signifies the time until a change in the event outcome occurs. Importantly, we did not predefine a specific temporal observation unit. These findings allowed us to complement the concept of effective quarantine by considering the dynamics generated by the protocols, such as phase 1 of the quarantine, in achieving natural herd immunity in response to the number of COVID-19 cases and Rt. We assessed the behavior of the mean and median residual lifetime until the initiation of controlled/uncontrolled episodes of the COVID-19 pandemic based on Rt in all regions of Chile. Despite variations in the distribution of residual times for controlled/uncontrolled episodes in different regions, there was a similar observation during the period considered (between March 2020 and March 2021): the mitigation measures did not produce a clear positive effect for controlling the epidemic. The residual times of episodes with Rr,t > 1 were not different from those episodes with Rr,t ≤ 1.

Characterization of Antimicrobial Poly(Lactic Acid)- and Polyurethane-Based Materials Enduring Closed-Loop Recycling with Applications in Space.

Recent studies have shown that astronauts experience altered immune response behavior during spaceflight, resulting in heightened susceptibility to illness. Resources and resupply shuttles will become scarcer with longer duration spaceflight, limiting access to potentially necessary medical treatment and facilities. Thus, there is a need for preventative health countermeasures that can exploit in situ resource utilization technologies during spaceflight, such as additive manufacturing (i.e., 3D printing). The purpose of the current study was to test and validate recyclable antimicrobial materials compatible with additive manufacturing. Antimicrobial poly(lactic acid)- and polyurethane-based materials compatible with 3D printing were assessed for antimicrobial, mechanical, and chemical characteristics before and after one closed-loop recycling cycle. Our results show high biocidal efficacy (>90%) of both poly(lactic acid) and polyurethane materials while retaining efficacy post recycling, except for recycled-state polyurethane which dropped from 98.91% to 0% efficacy post 1-year accelerated aging. Significant differences in tensile and compression characteristics were observed post recycling, although no significant changes to functional chemical groups were found. Proof-of-concept medical devices developed show the potential for the on-demand manufacturing and recyclability of typically single-use medical devices using antimicrobial materials that could serve as preventative health countermeasures for immunocompromised populations, such as astronauts during spaceflight.

Comparison of virtual reality to physical box and blocks on cortical an neuromuscualar activations in young adults.

The purpose of this study was to assess the changes in neural activations when performing the box and block test (BBT) in virtual reality (VR) compared to the physical BBT. Young healthy participants performed three trials of the BBT with their left and right hands in both the VR BBT, using VR hand controllers, and physical BBT conditions. Electromyography sensors were placed on the upper extremity of both arms and functional near-infrared spectroscopy was used to measure motor cortex activations throughout each condition. While a reduction in BBT score and increased wrist extensor neuromuscular activity is exhibited during the VR condition, there is no statistical difference in motor cortex activation between the two BBT conditions. This work provides a basis for exploring cortical and neuromuscular responses to VR in patient populations.

Low Motor Dexterity and Significant Behaviors Following Hospitalized Isolation in Children.

The main objective of this study was to describe the cortical patterns of brain activity during a gross dexterity task and develop a behavioral profile of children experiencing isolation. A cross-sectional assessment was conducted during one visit. Sample: Four pediatric patients who had undergone isolation within a hospital comprised the full data collection. During the collection, participants completed the Box and Blocks Test of gross manual dexterity while undergoing imaging of the motor cortex using functional near-infrared spectroscopy. Participants also completed a Behavioral Assessment System for Children, Third Edition (BASC-3) self-report, which was analyzed along with a parent report to quantify their emotional and social behaviors. All participants displayed lower gross dexterity levels than normative data. Furthermore, three out of the four participants displayed ipsilateral dominance of the motor cortex during the dexterity task. Three of the participants displayed behavioral measures reported within clinically significant or at-risk scores. Clinically significant behavioral scores coupled with lower than expected manual dexterity values and ipsilateral hemispheric dominance indicate that neuroplastic changes can occur in populations undergoing hospitalized isolation. While the impacts of the treatments and isolation in this case cannot be separated, further studies should be conducted to understand these impacts of isolation.

[Relationship between the oxidative profile and the diet diversity index in older adults in an urban-marginal area of Costa Rica]. / Relación entre el perfil oxidativo y el índice de diversidad de la dieta en adultos mayores de una zona urbano-marginal de Costa Rica.

BACKGROUND AND OBJECTIVE: The older we get, the greater the production of reactive oxygen species and therefore the greater the oxidative stress, which is related to the deterioration of the health of older adults. This study analyzed the relationship between the oxidative profile and the dietary diversity index in an urban-marginal population of older adults in Costa Rica. METHODS: Eighty-eight older adults were studied and various markers of oxidative stress, serum glucose levels, lipid profile, and some micronutrients were determined. In addition, the body mass index (BMI) was calculated and the dietary diversity index (DDI) was determined. RESULTS: Lipid peroxidation and DNA oxidation, a mean plasma antioxidant capacity percentage of 39.54±10.67%, which decreased with age, were evidenced. 67% of the participants had alterations in glycemia, 73% had one or more alterations in blood lipid levels, 55% had insufficient vitamin D levels, and 68.6% were overweight. The average IDD was 4.91 points, indicating that the diet was not very diverse. No relationship was found between IDD and nutritional status, between nutritional status and oxidative stress, nor between biochemical variables and oxidative stress. CONCLUSION: The adults studied presented high oxidative stress, a high percentage of overweight, and a low IDD. A higher IDD was associated with a lower blood concentration of MDA and a higher % PAC.

Motor cortical functional connectivity changes due to short-term immobilization of upper limb: an fNIRS case report.

Introduction: A short-term immobilization of one hand affects musculoskeletal functions, and the associated brain network adapts to the alterations happening to the body due to injuries. It was hypothesized that the injury-associated temporary disuse of the upper limb would alter the functional interactions of the motor cortical processes and will produce long-term changes throughout the immobilization and post-immobilization period. Methods: The case participant (male, 12 years old, right arm immobilized for clavicle fracture) was scanned using optical imaging technology of fNIRS over immobilization and post-immobilization. Pre-task data was collected for 3 min for RSFC analysis, processed, and analyzed using the Brain AnalyzIR toolbox. Connectivity was measured using Pearson correlation coefficients (R) from NIRS Toolbox's connectivity module. Results: The non-affected hand task presented an increased ipsilateral response during the immobilization period, which then decreased over the follow-up visits. The right-hand task showed a bilateral activation pattern following immobilization, but the contralateral activation pattern was restored during the 1-year follow-up visit. Significant differences in the average connection strength over the study period were observed. The average Connection strength decreased from the third week of immobilization and continued to be lower than the baseline value. Global network efficiency decreased in weeks two and three, while the network settled into a higher efficient state during the follow-up periods after post-immobilization. Discussion: Short-term immobilization of the upper limb is shown to have cortical changes in terms of activations of brain regions as well as connectivity. The short-term dis-use of the upper limb has shifted the unilateral activation pattern to the bilateral coactivation of the motor cortex from both hemispheres. Resting-state data reveals a disruption in the motor cortical network during the immobilization phase, and the network is reorganized into an efficient network over 1 year after the injury. Understanding such cortical reorganization could be informative for studying the recovery from neurological disorders affecting motor control in the future.

Phantom limb therapy improves cortical efficiency of the sensorimotor network in a targeted muscle reinnervation amputee: a case report.

Targeted muscle reinnervation (TMR) surgery involves the coaptation of amputated nerves to nearby motor nerve branches with the purpose of reclosing the neuromuscular loop in order to reduce phantom limb pain. The purpose of this case study was to create a phantom limb therapy protocol for an amputee after undergoing TMR surgery, where the four main nerves of his right arm were reinnervated into the chest muscles. The goal of this phantom limb therapy was to further strengthen these newly formed neuromuscular closed loops. The case participant (male, 21- years of age, height = 5'8″ and weight = 134 lbs) presented 1- year after a trans-humeral amputation of the right arm along with TMR surgery and participated in phantom limb therapy for 3 months. Data collections for the subject occurred every 2 weeks for 3 months. During the data collections, the subject performed various movements of the phantom and intact limb specific to each reinnervated nerve and a gross manual dexterity task (Box and Block Test) while measuring brain activity and recording qualitative feedback from the subject. The results demonstrated that phantom limb therapy produced significant changes of cortical activity, reduced fatigue, fluctuation in phantom pain, improved limb synchronization, increased sensory sensation, and decreased correlation strength between intra-hemispheric and inter-hemispheric channels. These results suggest an overall improved cortical efficiency of the sensorimotor network. These results add to the growing knowledge of cortical reorganization after TMR surgery, which is becoming more common to aid in the recovery after amputation. More importantly, the results of this study suggest that the phantom limb therapy may have accelerated the decoupling process, which provides direct clinical benefits to the patient such as reduced fatigue and improved limb synchronization.

Warts in pediatric oncology patients: A single-institution retrospective study.

BACKGROUND: Pediatric oncology patients undergoing cancer treatment can often have numerous and recalcitrant cutaneous warts due to their underlying immunosuppression. There are little published data on the optimal management of warts in pediatric oncology patients undergoing active cancer treatment compared to patients having completed treatment. Our objective was to analyze the clinical course of warts treated within this patient population at Boston Children's Hospital over a 10-year period. METHODS: This was a single-institution retrospective study of 72 pediatric oncology patients from 1 September 2011 to 1 September 2021 who were treated for warts at Boston Children's Hospital. All patients had a diagnosis of cutaneous warts with at least one follow-up visit and were receiving active treatment for cancer either during or after concurrent treatment of their warts. We examined the modality and effectiveness of wart treatments while both on and offactive treatment of their cancer. RESULTS: The median age was 12 years (range 4-18). Fifty-four percent of patients were documented to have plantar warts. Sixty percent of patients with a documented number of warts had more than five warts at presentation. For cases in which outcomes were specified, treatment resulted in complete resolution of warts in only 24.0% of patients undergoing active cancer treatment compared to 63.3% of patients not on active treatment. Warts persisted or worsened in 56.0% of patients undergoing active cancer treatment compared to only 13.4% of patients not on active treatment. CONCLUSION: These data may help guide clinicians in evaluating and treating warts in pediatric oncology patients.

Myriad applications of bacteriophages beyond phage therapy.

Bacteriophages are the most abundant biological entity on the planet, having pivotal roles in bacterial ecology, animal and plant health, and in the biogeochemical cycles. Although, in principle, phages are simple entities that replicate at the expense of their bacterial hosts, due the importance of bacteria in all aspects of nature, they have the potential to influence and modify diverse processes, either in subtle or profound ways. Traditionally, the main application of bacteriophages is phage therapy, which is their utilization to combat and help to clear bacterial infections, from enteric diseases, to skin infections, chronic infections, sepsis, etc. Nevertheless, phages can also be potentially used for several other tasks, including food preservation, disinfection of surfaces, treatment of several dysbioses, and modulation of microbiomes. Phages may also be used as tools for the treatment of non-bacterial infections and pest control in agriculture; moreover, they can be used to decrease bacterial virulence and antibiotic resistance and even to combat global warming. In this review manuscript we discuss these possible applications and promote their implementation.

Laterality Index Calculations in a Control Study of Functional Near Infrared Spectroscopy.

Hemispheric dominance has been used to understand the influence of central and peripheral neural damage on the motor function of individuals with stroke, cerebral palsy, and limb loss. It has been well established that greater activation occurs in the contralateral hemisphere to the side of the body used to perform the task. However, there is currently a large variability in calculation procedures for brain laterality when using functional near-infrared spectroscopy (fNIRS) as a non-invasive neuroimaging tool. In this study, we used fNIRS to measure brain activity over the left and right sensorimotor cortices while participants (n = 20, healthy and uninjured) performed left and right-hand movement tasks. Then, we analyzed the fNIRS data using two different processing pipelines (block averaging or general linear model [GLM]), two different criteria of processing for negative values (include all beta values or include only positive beta values), and three different laterality index (LI) formulas. The LI values produced using the block averaging analysis indicated an expected contralateral dominance with some instances of bilateral dominance, which agreed with the expected contralateral activation. However, the inclusion criteria nor the LI formulas altered the outcome. The LI values produced using the GLM analysis displayed a robust left hemisphere dominance regardless of the hand performing the task, which disagreed with the expected contralateral activation but did provide instances of correctly identifying brain laterality. In conclusion, both analysis pipelines were able to correctly determine brain laterality, but processes to account for negative beta values were recommended especially when utilizing the GLM analysis to determine brain laterality.

Dynamometric Strength Profile of Hip Muscles in Youth Soccer Players.

BACKGROUND: Soccer is the most widely practiced sport in the world, demanding high-speed activities such as jumps, sprints and changes of direction. Therefore, having optimal levels of muscle strength improves performance and reduces the injury rate. OBJECTIVES: The objectives of our study were (i) to determine the dynamometric profile of hip muscle strength in young soccer players by position, evaluated at different isokinetic speeds, (ii) to describe the conventional and functional unilateral muscle strength ratios, (iii) to analyze the bilateral balance. METHODS: Thirty-seven male soccer players (age 17.02 ± 0.92 years) participated in the study. Strength assessment was performed with a functional electromechanical dynamometer, and concentric and eccentric strength of abductors, adductors, extensors and hip flexors were measured bilaterally at 0.5 m/s and 1 m/s. RESULTS: For eccentric right hip abduction at 0.5 m/s, defenders are significantly stronger than midfielders (p = 0.013) and stronger than forwards (p = 0.140). For eccentric right hip adduction at 0.5 m/s, defenders are significantly stronger than midfielders (p = 0.005) and stronger than forwards (p = 0.253), as for eccentric right hip adduction at 1 m/s, defenders are significantly stronger than midfielders (p = 0.014) and stronger than forwards (p = 0.084). There is a significant effect for the conventional strength ratio of left abduction/adduction at 1 m/s. The conventional strength ratio of forwards is significantly higher than that of defenders (p = 0.045) and higher than that of midfielders (p = 0.152). CONCLUSIONS: Concentric and eccentric hip strength values differ according to playing position.

Using 3D Printing to Improve Student Education of Complex Anatomy: a Systematic Review and Meta-analysis.

Objective: Additive manufacturing has played an increasingly important role in the field of health care. One of the most recent applications has been the development of 3D printed anatomical models specifically to improve student education. The purpose of this review was to assess the potential for 3D printed models to improve understanding of complex anatomy in undergraduate and medical/professional students. Methods: A systematic review was performed to investigate the different implementations of 3D printed anatomical models in educational curricula. In addition, a meta-analysis was conducted to assess the differences in comprehension between students who received 3D printed models as part of their instruction and those taught with traditional methods. Results: Of the 10 groups included in the meta-analysis, students whose educational experience included a 3D printed model scored roughly 11% better on objective assessments compared to students who did not use such models (Hedge's g = 0.742, p < 0.001). Conclusion: Based on these findings, the use of 3D printed anatomical models as a method of education is likely to improve students' understanding of complex anatomical structures.

Comparison of brain activation and functional outcomes between physical and virtual reality box and block test: a case study.

PURPOSE: Immersive Virtual Reality (VR) systems allow for highly repetitive tasks to be performed within a virtual environment that increases practice in home environments. VR can increase access to rehabilitation by reducing access barriers. However, rehabilitation outcomes between immersive VR systems and conventional physical rehabilitation are not well understood. The purpose of this case study was to assess the use of a custom clinically based VR simulation for testing gross hand dexterity with an individual with chronic stroke. MATERIALS AND METHODS: The participant performed the box and blocks test (BBT) in an immersive VR environment and a physical environment. Three trials of the BBT were performed with their less-affected and affected hands each in both environments while measuring cortical activity using fNIRS. Rests were given between trials and environment conditions. RESULTS: Our results show that there was no statistical difference in the number of blocks moved between the physical and VR BBT for both the affected and less-affected hands. Furthermore, our results also indicate no statistically significant difference between the physical BBT and VR BBT conditions on contralateral motor cortex activation, suggesting that cortical involvement is comparable between physical and VR conditions. CONCLUSIONS: These results suggest that an immersive VR system may be able to elicit functional and motor cortex activations that are comparable to the conventional physical BBT. Importantly, these findings highlights the potential benefits of VR therapy as a remote therapy intervention and/or to increase the effectiveness and practicality of current in-person rehabilitation programs.Implications for rehabilitationThese findings highlight the potential benefits of immersive virtual reality as a remote therapy intervention.Immersive virtual reality use has potential benefits to increase the effectiveness and practicality of current in-person rehabilitation programs.

Comparison of 3D printed anatomical model qualities in acetabular fracture representation.

Background: Acetabular fractures account for 10% of pelvis injuries, which are especially difficult to treat in developing countries with less access to resources. 3D printing has previously been shown to be a beneficial method of surgical planning, however the steep initial costs associated with purchasing a 3D printer may prevent some facilities form utilizing this technique. The purpose of this study was to develop 3D printed models for acetabular surgery using methodologies of varying cost to determine differences in model accuracy and overall quality. Methods: Five acetabular fracture models were developed from de-identified CT data using (I) proprietary and open-source segmentation software and (II) fused deposition modeling (FDM) and stereolithography (SLA) 3D printing methods. The distance between the posterior inferior iliac spine (PIIS) and the ischial spine as well as a unique fracture fragment for each model was compared between the different printing methodologies. The models were then given to 5 physicians and assessed on their overall accuracy compared to traditional 2D images. Results: Printing methodology did not affect the distance from PIIS to ischial spine (P=0.263). However, fracture fragment representation differed across 3D printed models, with the most accurate model produced by the high-end resin-based printer (P=0.007). The survey analysis showed that the low-cost printing methods produced models that were not as accurate in their representation of the fractured region (P=0.008). Conclusions: The differences between models developed using traditional methods and low-cost methods have slight differences but may still provide useful information when developing a surgical plan.

Home intervention for children and adolescents with unilateral trans-radial and partial carpal reduction deficiencies.

Current training interventions assessing pediatric functional motor skills do not account for children and adolescents with upper limb reductions who utilize a prosthesis. Prosthesis rejection showed that 1 out of 5 prosthesis users will reject their prosthesis due to lack of durability, lack of function, not meeting the participant's needs, perceived lack of need, and medical restrictions indicating that prosthetic users believed they were more functional without the device. It was hypothesized that an 8-week Home Intervention program will result in significant improvements in gross manual dexterity, bimanual coordination, and the functional activities performed during the program. It was also hypothesized that the novel Prosthesis Measurement of Independent Function (PMIF) score will reflect the Home Intervention performance improvements. Five pediatric participants (ages 5-19 years) with congenital upper limb reductions were fitted with a 3D printed upper extremity prosthesis for their affected limb. Participants then completed the 8-week Home Intervention which included Training activities completed 2×/week for 8 weeks and Non-Training activities completed only at week 1 and week 8. Participant's times were recorded along with each participant receiving a PMIF score ranging from 0 = unable to complete activity, to 7 = complete independence with activity completion. Results showed a decrease in overall averaged activity times amongst all activities. For all activities performed, individual averaged time decreased with the exception of Ball Play which increased over the 8-week intervention period. There was significant interaction for Home Intervention performance with F = 2.904 (p = 0.003). All participants increased their PMIF scores to 7 (complete independence) at the end of the 8 week intervention period. Decreases in time averages and increases in PMIF scores indicate that learning and functional use of the prostheses have occurred amongst the pediatric participants.

Functional performance and patient satisfaction comparison between a 3D printed and a standard transradial prosthesis: a case report.

BACKGROUND: The delay between amputation and prosthesis fitting contributes to the high rate of prosthetic abandonment despite advances in technology. Three-dimensional (3D) printing has allowed for the rapid fabrication of prostheses. Allowing individuals with amputations to interact with a prosthesis shortly after their procedure may reduce rejection chances. The purpose of the current investigation is to compare functional outcomes and patient satisfaction between a standard transradial prosthesis fitted in a clinic with a 3D-printed prosthesis fitted remotely. The standard prosthesis featured a hook terminal device, while the 3D printed prosthesis' terminal device was a functional hand. RESULTS: The main finding of this case study was that the use of a 3D printed arm prosthesis fitted remotely resulted in better functional performance, but lower overall patient satisfaction than the standard arm prosthesis. Use of the 3D printed arm resulted in improved gross manual dexterity as measured by the Box and Block test. The 3D printed prosthesis also allowed improved performance in bimanual coordination. However, the standard-hook device scored higher in patient satisfaction survey results. The patient's concerns with the 3D printed prosthesis were the durability and effectiveness of the device. CONCLUSION: While durability and complex grip patterns remain a concern, the positive attributes of 3D printed prostheses include visual appeal, ease of donning, and customization of parameters to improve upper-limb symmetry offers a promising option to familiarize new amputee patients with the use of a prosthesis. Rapid manufacturing and remote fitting allows 3D printed devices to serve as postoperative transitional devices and may function as definitive devices with minimal loss of functionality if standard clinic-based prostheses are not available. METHODS: The patient was a 59-year-old male with a traumatic transradial amputation of the dominant arm. A 3D printed transradial prosthesis was remotely fitted and manufactured using photogrammetry. Assessments were performed initially with the standard-hook prosthesis and then with the 3D printed device after a 5-week familiarization period. Functional outcomes were evaluated using the Box and Block Test and Bimanual Coordination Tray Test. Patient satisfaction was evaluated using two self-reported questionnaires (the QUEST 2.0 and the modified OPUS).

Efectos del autoinjerto hueso-tendón patelar-hueso sobre la posición articular y la fuerza en pacientes con reconstrucción del ligamento cruzado anterior / Effects of bone-patellar tendon-bone autograft on joint position and strength in patients with anterior cruciate ligament reconstruction

RESUMEN: El objetivo del estudio fue comparar el déficit propioceptivo a través del Joint position sense (JPS) y Force steadiness en pacientes con reconstrucción del ligamento cruzado anterior (LCA) injerto hueso-tendón patelar-hueso (HTH) 6 a 12 meses postcirugía. Participaron 15 pacientes (13 hombres y 2 mujeres, 25,5 ± 1,3 años) con reconstrucción de LCA con autoinjerto HTH y 20 personas sin lesión del LCA (19 hombres y 1 mujer, 24,1 ± 0,8 años). Para evaluar la sensación de posición de la articulación de la rodilla se midió la Joint position sense (JPS) en tres rangos: 0°-30°, 31°-60° y 61°-90° y la sensación de fuerza del cuádriceps fue evaluada con la prueba Force steadiness (FS) al 15 % de la contracción voluntaria máxima (CVM), ambas pruebas realizadas 6 a 12 meses post cirugía. Los resultados mostraron que no hubo diferencias estadísticamente significativas en la sensación de la posición articular (JPS 0°-30°) (p=0.564) y 31°-60° (p=0.681), mientras que en el rango 61°-90° (p=0.003) existieron diferencias estadísticamente significativas. En las mediciones de sensación de fuerza del cuádriceps (FS al 15 % CVM) entre los pacientes operados de LCA técnica HTH y el grupo control no hubo diferencias estadísticas (p= 0.987) La sensación de la fuerza del cuádriceps medida con la prueba FS al 15 % CVM no presentaría déficit entre los 6 a 12 meses en pacientes post operados de LCA al ser comparados con sujetos sin lesión ni cirugía de este ligamento. Se concluye que la sensación de la posición articular medida con la prueba JPS en en tres rangos articulares de pacientes con reconstrucción de LCA injerto HTH 6 a 12 meses post cirugía sólo mostró alteraciones en el rango de 61°- 90° al ser comparado con el grupo control, lo cual indica que la sensación de la posición articular presenta un déficit en este rango específico.

SUMMARY: The aim of the study was to compare the proprioceptive deficit through the Joint position sense (JPS) and Force steadiness in patients with anterior cruciate ligament (ACL) bone-patellar tendon-bone graft (PTH) reconstruction 6 to 12 months post-surgery. Fifteen patients (13 men and 2 women, 25.5 ± 1.3 years) with ACL reconstruction with HTH autograft and 20 persons without ACL injury (19 men and 1 woman, 24.1 ± 0.8 years) participated. To assess knee joint position sensation, Joint position sense (JPS) was measured in three ranges: 0°-30°, 31°- 60° and 61°-90° and quadriceps strength sensation was assessed with the Force steadiness (FS) test at 15 % of maximal voluntary contraction (MVC), both tests performed 6 to 12 months post surgery. The results showed that there were no statistically significant differences in joint position sensation (JPS 0°-30°) (p=0.564) and 31°-60° (p=0.681), while in the range 61°-90° (p=0.003) there were statistically significant differences. In the quadriceps strength sensation measurements (FS at 15 % CVM) between the patients operated on ACL HTH technique and the control group there were no statistical differences (p= 0.987). The quadriceps strength sensation measured with the FS test at 15 % CVM would not present a deficit between 6 to 12 months in post- operated ACL patients when compared to subjects without injury or surgery of this ligament. It is concluded that the joint position sensation measured with the JPS test in three joint ranges of patients with ACL reconstruction HTH graft 6 to 12 months post surgery only showed alterations in the range of 61°- 90° when compared to the control group, indicating that the joint position sensation presents a deficit in this specific range.

Changes in Sensorimotor Cortical Activation in Children Using Prostheses and Prosthetic Simulators.

This study aimed to examine the neural responses of children using prostheses and prosthetic simulators to better elucidate the emulation abilities of the simulators. We utilized functional near-infrared spectroscopy (fNIRS) to evaluate the neural response in five children with a congenital upper limb reduction (ULR) using a body-powered prosthesis to complete a 60 s gross motor dexterity task. The ULR group was matched with five typically developing children (TD) using their non-preferred hand and a prosthetic simulator on the same hand. The ULR group had lower activation within the primary motor cortex (M1) and supplementary motor area (SMA) compared to the TD group, but nonsignificant differences in the primary somatosensory area (S1). Compared to using their non-preferred hand, the TD group exhibited significantly higher action in S1 when using the simulator, but nonsignificant differences in M1 and SMA. The non-significant differences in S1 activation between groups and the increased activation evoked by the simulator's use may suggest rapid changes in feedback prioritization during tool use. We suggest that prosthetic simulators may elicit increased reliance on proprioceptive and tactile feedback during motor tasks. This knowledge may help to develop future prosthesis rehabilitative training or the improvement of tool-based skills.

Use-Dependent Prosthesis Training Strengthens Contralateral Hemodynamic Brain Responses in a Young Adult With Upper Limb Reduction Deficiency: A Case Report.

The purpose of the current case study was to determine the influence of an 8-week home intervention training utilizing a partial hand prosthesis on hemodynamic responses of the brain and gross dexterity in a case participant with congenital unilateral upper-limb reduction deficiency (ULD). The case participant (female, 19 years of age) performed a gross manual dexterity task (Box and Block Test) while measuring brain activity (functional near-infrared spectroscopy; fNIRS) before and after an 8-weeks home intervention training. During baseline, there was a broad cortical activation in the ipsilateral sensorimotor cortex and a non-focalized cortical activation in the contralateral hemisphere, which was non-focalized, while performing a gross manual dexterity task using a prosthesis. After the 8-week home intervention training, however, cortical activation shifted to the contralateral motor cortex while cortical activation was diminished in the ipsilateral hemisphere. Specifically, the oxygenated hemodynamics (HbO) responses increased in the medial aspects of the contralateral primary motor and somatosensory cortices. Thus, these results suggest that an 8-week prosthetic home intervention was able to strengthen contralateral connections in this young adult with congenital partial hand reduction. This was supported by the case participant showing after training an increased flexor tone, increased range of motion of the wrist, and decreased times to complete various gross dexterity tasks. Changes in HbO responses due to the home intervention training follow the mechanisms of use-dependent plasticity and further guide the use of prostheses as a rehabilitation strategy for individuals with ULD.

Low abundance of Mfn2 protein correlates with reduced mitochondria-SR juxtaposition and mitochondrial cristae density in human men skeletal muscle: Examining organelle measurements from TEM images.

The role of mitofusin 2 (Mfn2) in the regulation of skeletal muscle (SM) mitochondria-sarcoplasmic (SR) juxtaposition, mitochondrial morphology, mitochondrial cristae density (MCD), and SM quality has not been studied in humans. In in vitro studies, whether Mfn2 increases or decreases mitochondria-SR juxtaposition remains controversial. Transmission electron microscopy (TEM) images are commonly used to measure the organelle juxtaposition, but the measurements are performed "by-hand," thus potentially leading to between-rater differences. The purposes of this study were to: (1) examine the repeatability and reproducibility of mitochondrial-SR juxtaposition measurement from TEM images of human SM between three raters with different experience and (2) compare the mitochondrial-SR juxtaposition, mitochondrial morphology, MCD (stereological-method), and SM quality (cross-sectional area [CSA] and the maximum voluntary contraction [MVC]) between subjects with high abundance (Mfn2-HA; n = 6) and low abundance (Mfn2-LA; n = 6) of Mfn2 protein. The mitochondria-SR juxtaposition had moderate repeatability and reproducibility, with the most experienced raters showing the best values. There were no differences between Mfn2-HA and Mfn2-LA groups in mitochondrial size, distance from mitochondria to SR, CSA, or MVC. Nevertheless, the Mfn2-LA group showed lower mitochondria-SR interaction, MCD, and VO2max . In conclusion, mitochondrial-SR juxtaposition measurement depends on the experience of the rater, and Mfn2 protein seems to play a role in the metabolic control of human men SM, by regulating the mitochondria-SR interaction.