RESUMO
BACKGROUND: Spinal cord injuries (SCI) lead to functional alteration with important consequences such as motor and sensory disorders. The repair strategies developed to date remain ineffective. The adipose tissue-derived stromal vascular fraction (SVF) is composed of a cocktail of cells with trophic, pro-angiogenic and immunomodulatory effects. Numerous therapeutic benefits were shown for tissue reconstitution, peripheral neuropathy and for the improvement of neurodegenerative diseases. Here, the therapeutic efficacy of SVF on sensorimotor recovery after an acute thoracic spinal cord contusion in adult rats was determined. METHOD: Male Sprague Dawley rats (n = 45) were divided into 3 groups: SHAM (without SCI and treatment), NaCl (animals with a spinal lesion and receiving a saline injection through the dura mater) and SVF (animals with a spinal lesion and receiving a fraction of fat removed from adipocytes through the dura mater). Some animals were sacrificed 14 days after the start of the experiment to determine the inflammatory reaction by measuring the interleukin-1ß, interleukin-6 and Tumor Necrosis Factor-α in the lesion area. Other animals were followed once a week for 12 weeks to assess functional recovery (postural and locomotor activities, sensorimotor coordination). At the end of this period, spinal reflexivity (rate-dependent depression of the H-reflex) and physiological adjustments (ventilatory response to metabosensitive muscle activation following muscle fatigue) were measured with electrophysiological tools. RESULTS: Compared to non-treated animals, results indicated that the SVF reduced the endogenous inflammation and increased the behavioral recovery in treated animals. Moreover, H-reflex depression and ventilatory adjustments to muscle fatigue were found to be comparable between SHAM and SVF groups. CONCLUSION: Our results highlight the effectiveness of SVF and its high therapeutic potential to improve sensorimotor functions and to restore the segmental sensorimotor loop and the communication between supra- and sub-lesional spinal cord regions after traumatic contusion.
Assuntos
Traumatismos da Medula Espinal , Fração Vascular Estromal , Ratos , Masculino , Animais , Ratos Sprague-Dawley , Autoenxertos , Traumatismos da Medula Espinal/terapia , Traumatismos da Medula Espinal/patologia , Medula Espinal/patologia , Tecido Adiposo , Recuperação de Função FisiológicaRESUMO
Traumatic spinal cord injuries (SCIs) often result in sensory, motor, and vegetative function loss below the injury site. Although preclinical results have been promising, significant solutions for SCI patients have not been achieved through translating repair strategies to clinical trials. In this study, we investigated the effective potential of mechanically activated lipoaspirated adipose tissue when transplanted into the epicenter of a thoracic spinal contusion. Male Sprague Dawley rats were divided into three experimental groups: SHAM (uninjured and untreated), NaCl (spinal cord contusion with NaCl application), and AF (spinal cord contusion with transplanted activated human fat). Pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α) were measured to assess endogenous inflammation levels 14 days after injury. Sensorimotor recovery was monitored weekly for 12 weeks, and gait and electrophysiological analyses were performed at the end of this observational period. The results indicated that AF reduced endogenous inflammation post-SCI and there was a significant improvement in sensorimotor recovery. Moreover, activated adipose tissue also reinstated the segmental sensorimotor loop and the communication between supra- and sub-lesional spinal cord regions. This investigation highlights the efficacy of activated adipose tissue grafting in acute SCI, suggesting it is a promising therapeutic approach for spinal cord repair after traumatic contusion in humans.
Assuntos
Contusões , Traumatismos da Medula Espinal , Humanos , Ratos , Masculino , Animais , Cloreto de Sódio , Ratos Sprague-Dawley , Traumatismos da Medula Espinal/terapia , Tecido Adiposo , Contusões/terapia , InflamaçãoRESUMO
INTRODUCTION: Identification of the seat features that could improve driving experience is a main issue for automotive companies. OBJECTIVE: Long duration real driving sessions were performed to assess the effect of three seats (soft-S1, firm-S2 and suspended-S3) on perceived discomfort and neuromuscular fatigue (NMF). MATERIALS & METHODS: For each seat, the muscular activity of bilateral Trapezius Descendens (TD), Erector Spinae (ES) and Multifidus (MF) muscles of twenty-one participants was recorded during real driving sessions of 3-hours each lasting approximately 3 hours and following the same itinerary. During each driving session, participants were also regularly asked to self-evaluate their level of whole-body and local discomfort. In addition, an endurance static test (EST) was performed before (ESTpre) and after (ESTpost) each driving session to assess the seat effect on physical capacity. RESULTS: Whole-body discomfort increased with driving time for all seats, but this increase became significant latter for S3. The highest scores of local discomfort occurred for neck and lower back. Contrary to S1 and S2, the duration of ESTpost was not significantly lower compared to ESTpre with the S3. Interestingly, muscular activity of S1 remained stable throughout the driving task which could be attributed to sustained muscular contraction, while muscular recruitment adjustments occurred for S2 and S3 from 1H00 of driving. This muscular compensation concerns mostly the right side for S2 and S3 but with different profiles. On the left side, the muscular adjustments concern only the MF with S2 and the ES with S3. CONCLUSION: Overall, our results demonstrated that S3 could be considered as the most suitable seat to delay discomfort and NMF appearance.
Assuntos
Condução de Veículo , Sistema Musculoesquelético , Fenômenos Fisiológicos do Sistema Nervoso , Humanos , Fatores de TempoRESUMO
During a driving task, the seat-driver interface is particularly influenced by the external environment and seat features. This study compares the effect of two different seats (S1 - soft & S2 - firm) and the effect of visual simulation of different road types (city, highway, mountain, country), on pressure distribution and perceived discomfort during prolonged driving. Twenty participants drove two 3-h sessions (one per seat) on a static simulator. Contact Pressure (CP), Contact Surface (CS), and Seat Pressure Distribution Percentage (SPD%) were analyzed throughout, using two pressure mats positioned on seat cushion and backrest. Whole-body and local discomfort for each body part were rated every 20 min. The softer seat, S1, induced a greater contact surface on cushion and backrest and a lower SPD%, reflecting better pressure distribution. Pressure profiles were asymmetrical for both S1 and S2, with higher CP under left buttock (LBu) and right lower back (RLb) and greater CS under thighs and RLb. Pressure distribution was less homogeneous on mountain and city roads than on monotonous roads (highway and country). Despite the pressure differences between the seats, however, both led to similar increases in perceived whole-body discomfort throughout the driving session. Moreover, the highest discomfort scores were in the neck and the lower back areas, whatever the seat. These findings on pressure variables may have implications for the design of backrests and cushions to ensure more homogeneous pressure distribution, even though this is not shown to minimize perceived driver discomfort.
Assuntos
Condução de Veículo , Sistemas de Proteção para Crianças , Dorso , Desenho de Equipamento , Humanos , PosturaRESUMO
Children with low physical activity and interactions with environment experience atypical sensorimotor development and maturation leading to anatomical and functional disorganization of the sensorimotor circuitry and also to enduring altered motor function. Previous data have shown that postnatal movement restriction in rats results in locomotor disturbances, functional disorganization and hyperexcitability of the hind limb representations in the somatosensory and motor cortices, without apparent brain damage. Due to the reciprocal interplay between the nervous system and muscle, it is difficult to determine whether muscle alteration is the cause or the result of the altered sensorimotor behavior (Canu et al., 2019). In the present paper, our objectives were to evaluate the impact of early movement restriction leading to sensorimotor restriction (SMR) during development on the postural soleus muscle and on sensorimotor performance in rats, and to determine whether changes were reversed when typical activity was resumed. Rats were submitted to SMR by hind limb immobilization for 16 h / day from birth to postnatal day 28 (PND28). In situ isometric contractile properties of soleus muscle, fiber cross sectional area (CSA) and myosin heavy chain content (MHC) were studied at PND28 and PND60. In addition, the motor function was evaluated weekly from PND28 to PND60. At PND28, SMR rats presented a severe atrophy of soleus muscle, a decrease in CSA and a force loss. The muscle maturation appeared delayed, with persistence of neonatal forms of MHC. Changes in kinetic properties were moderate or absent. The Hoffmann reflex provided evidence for spinal hyperreflexia and signs of spasticity. Most changes were reversed at PND60, except muscle atrophy. Functional motor tests that require a good limb coordination, i.e. rotarod and locomotion, showed an enduring alteration related to SMR, even after one month of 'typical' activity. On the other hand, paw withdrawal test and grip test were poorly affected by SMR whereas spontaneous locomotor activity increased over time. Our results support the idea that proprioceptive feedback is at least as important as the amount of motor activity to promote a typical development of motor function. A better knowledge of the interplay between hypoactivity, muscle properties and central motor commands may offer therapeutic perspectives for children suffering from neurodevelopmental disorders.
Assuntos
Retroalimentação Sensorial/fisiologia , Elevação dos Membros Posteriores/efeitos adversos , Atividade Motora/fisiologia , Músculo Esquelético/fisiopatologia , Animais , Feminino , Masculino , Movimento/fisiologia , Atrofia Muscular/patologia , Ratos , Ratos Sprague-DawleyRESUMO
Experimental stress paradigms have been little used in the sport psychology literature because they are unrelated to the specific sport task. The Trier Social Stress Test (TSST) was used in the present study to investigate its influence on the free-throw performance of skilled basketball players. We also investigated the influence of adopting other-approach goals (i.e., doing well relative to others) on free-throw performance when basketball players were placed in a competition immediately after the TSST, comparatively with a control condition without competition. The results showed that free-throw performance decreased in the control condition, while free-throw performance remained stable when the TSST was followed by a competition. They also highlighted that other-approach goals were significant positive predictors of post-TSST performance in the competition condition but not in the control condition. The TSST may now be used with skilled athletes as an experimental stress paradigm to induce acute stress in the sport domain.
Assuntos
Basquetebol , Objetivos , Atletas , Basquetebol/psicologia , HumanosRESUMO
Prolonged driving under real conditions can entail discomfort linked to driving posture, seat design features, and road properties like whole-body vibrations (WBV). This study evaluated the effect of three different seats (S1 = soft; S2 = firm; S3 = soft with suspension system) on driver's sitting behavior and perceived discomfort on different road types in real driving conditions. Twenty-one participants drove the same 195 km itinerary alternating highway, city, country, and mountain segments. Throughout the driving sessions, Contact Pressure (CP), Contact Surface (CS), Seat Pressure Distribution Percentage (SPD%) and Repositioning Movements (RM) were recorded via two pressure mats installed on seat cushion and backrest. Moreover every 20 minutes, participants rated their whole-body and local discomfort. While the same increase in whole-body discomfort with driving time was observed for all three seats, S3 limited local perceived discomfort, especially in buttocks, thighs, neck, and upper back. The pressure profiles of the three seats were similar for CP, CS and RM on the backrest but differed on the seat cushion. The soft seats (S1 & S3) showed better pressure distribution, with lower SPD% than the firm seat (S2). All three showed highest CP and CS under the thighs. Road type also affected both CP and CS of all three seats, with significant differences appearing between early city, highway and country segments. In the light of these results, automotive manufacturers could enhance seat design for reduced driver discomfort by combining a soft seat cushion to reduce pressure peaks, a firm backrest to support the trunk, and a suspension system to minimize vibrations.
Assuntos
Sistemas de Proteção para Crianças/efeitos adversos , Dor Lombar/fisiopatologia , Postura Sentada , Vibração/efeitos adversos , Condução de Veículo , Feminino , Humanos , Dor Lombar/etiologia , Masculino , Fatores de TempoRESUMO
Prolonged driving could induce neuromuscular fatigue and discomfort since drivers have little opportunity to adjust their position. However, better car seat design could play a major role in limiting these effects. This study compared the effect of two different seats (S - soft and F - firm) on neuromuscular fatigue and driver's perceived discomfort during prolonged driving, also assessing the effect of different road types on neuromuscular activity. Twenty participants performed two 3-h driving sessions, one for each seat, on a static simulator. Every 20 min, participants self-evaluated their level of whole-body and individual body-area discomfort. Surface electromyography (sEMG) was recorded for eight muscles including Trapezius descendens (TD), Erector spinae longissimus (ESL), Multifidus (MF), Vastus lateralis (VL) and Tibialis anterior (TA) throughout the driving sessions. Moreover, an endurance static test (EST) was performed prior to and after each driving session. Whole-body discomfort increased with time with both seats, but no difference in discomfort scores was observed between seats throughout the driving sessions. The highest discomfort scores were for neck and lower back areas with both seats. Neuromuscular fatigue was revealed by a shorter endurance time in post-driving EST for both seats. EMG recordings showed different neuromuscular fatigue profiles for the two seats, with earlier onset of fatigue for S. Despite the lack of difference in perceived discomfort level, the two seats have different impacts: the softness of S induces greater activity of the lower back muscles, while F offers greater support for the lower back.
Assuntos
Condução de Veículo/psicologia , Músculos do Dorso/fisiopatologia , Desenho de Equipamento/efeitos adversos , Ergonomia , Fadiga Muscular/fisiologia , Fatores de Tempo , Adulto , Automóveis , Simulação por Computador , Eletromiografia , Humanos , Dor Lombar/etiologia , Cervicalgia/etiologia , Postura SentadaRESUMO
Spinal cord injury is a main health issue, leading to multiple functional deficits with major consequences such as motor and sensitive impairment below the lesion. To date, all repair strategies remain ineffective. In line with the experiments showing that implanted hydrogels, immunologically inert biomaterials, from natural or synthetic origins, are promising tools and in order to reduce functional deficits, to increase locomotor recovery, and to reduce spasticity, we injected into the lesion area, 1 week after a severe T10 spinal cord contusion, a thermoresponsive physically cross-linked poly(N-isopropylacrylamide)-poly(ethylene glycol) copolymer hydrogel. The effect of postinjury intensive rehabilitation training was also studied. A group of male Sprague-Dawley rats receiving the hydrogel was enrolled in an 8 week program of physical activity (15 min/day, 5 days/week) in order to verify if the combination of a treadmill step-training and hydrogel could lead to better outcomes. The data obtained were compared to those obtained in animals with a spinal lesion alone receiving a saline injection with or without performing the same program of physical activity. Furthermore, in order to verify the biocompatibility of our designed biomaterial, an inflammatory reaction (interleukin-1ß, interleukin-6, and tumor necrosis factor-α) was examined 15 days post-hydrogel injection. Functional recovery (postural and locomotor activities and sensorimotor coordination) was assessed from the day of injection, once a week, for 9 weeks. Finally, 9 weeks postinjection, the spinal reflexivity (rate-dependent depression of the H-reflex) was measured. The results indicate that the hydrogel did not induce an additional inflammation. Furthermore, we observed the same significant locomotor improvements in hydrogel-injected animals as in trained saline-injected animals. However, the combination of hydrogel with exercise did not show higher recovery compared to that evaluated by the two strategies independently. Finally, the H-reflex depression recovery was found to be induced by the hydrogel and, albeit to a lesser degree, exercise. However, no recovery was observed when the two strategies were combined. Our results highlight the effectiveness of our copolymer and its high therapeutic potential to preserve/repair the spinal cord after lesion.
RESUMO
Over the recent years, several methods have been experienced to repair injured peripheral nerves. Among investigated strategies, the use of natural or synthetic conduits was validated for clinical application. In this study, we assessed the therapeutic potential of vein guides, transplanted immediately or two weeks after a peroneal nerve injury and filled with olfactory ecto-mesenchymal stem cells (OEMSC). Rats were randomly allocated to five groups. A3 mm peroneal nerve loss was bridged, acutely or chronically, with a 1 cm long femoral vein and with/without OEMSCs. These four groups were compared to unoperated rats (Control group). OEMSCs were purified from male olfactory mucosae and grafted into female hosts. Three months after surgery, nerve repair was analyzed by measuring locomotor function, mechanical muscle properties, muscle mass, axon number, and myelination. We observed that stem cells significantly (i) increased locomotor recovery, (ii) partially maintained the contractile phenotype of the target muscle, and (iii) augmented the number of growing axons. OEMSCs remained in the nerve and did not migrate in other organs. These results open the way for a phase I/IIa clinical trial based on the autologous engraftment of OEMSCs in patients with a nerve injury, especially those with neglected wounds.
Assuntos
Axônios/metabolismo , Locomoção , Transplante de Células-Tronco Mesenquimais , Regeneração Nervosa , Mucosa Olfatória/citologia , Mucosa Olfatória/transplante , Nervo Fibular/lesões , Nervo Fibular/metabolismo , Animais , Modelos Animais de Doenças , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Bainha de Mielina/metabolismo , Tamanho do Órgão , Traumatismos dos Nervos Periféricos/etiologia , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/patologia , Traumatismos dos Nervos Periféricos/terapia , Nervo Fibular/fisiopatologia , RatosRESUMO
In line with experiments showing that implanted hydrogels are promising tools, we designed and injected, after a C2 spinal cord hemisection, a thermoresponsive and thermoreversible physically cross-linked poly(N-isopropylacrylamide)-poly(ethylene glycol) copolymer in order to reduce functional deficits and provide a favorable environment to axotomized axons. Nasal olfactory ecto-mesenchymal stem cells were cultured on the hydrogel in order to verify its biocompatibility. Then, inflammatory reaction (Interleukin-1ß and 6, Tumor Necrosis Factor-α) was examined 15 days post-hydrogel injection. Functional recovery (postural and locomotor activities, muscle strength and tactile sensitivity) was assessed once a week, during 12 weeks. Finally, at 12 weeks post-injection, spinal reflexivity and ventilatory adjustments were measured, and the presence of glial cells and regenerated axons were determined in the injured area. Our results indicate that cells survived and proliferated on the hydrogel which, itself, did not induce an enhanced inflammation. Furthermore, we observed significant motor and sensitive improvements in hydrogel-injected animals. Hydrogel also induced H-reflex recovery close to control animals but no improved ventilatory adjustment to electrically-evoked isometric contractions. Finally, regrowing axons were visualized within the hydrogel with no glial cells colonization. Our results emphasize the effectiveness of our copolymer and its high therapeutic potential to repair the spinal cord after injury.
Assuntos
Hidrogéis/química , Hidrogéis/farmacologia , Traumatismos da Medula Espinal/tratamento farmacológico , Resinas Acrílicas/química , Animais , Axônios/efeitos dos fármacos , Proliferação de Células , Reagentes de Ligações Cruzadas/química , Eletrofisiologia , Feminino , Hidrogéis/administração & dosagem , Injeções Espinhais , Teste de Materiais , Células-Tronco Mesenquimais/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Mielite/tratamento farmacológico , Mielite/patologia , Polietilenoglicóis/química , Ratos Sprague-Dawley , Reflexo/efeitos dos fármacos , Medula Espinal/patologia , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/fisiopatologiaRESUMO
Background and Objectives: Social support may have a stress-buffering effect when an individual is or could be negatively judged by others, but paradoxically may also exacerbate stress. The aim of our study was to examine these findings when social support was provided by a positive or negative evaluative audience composed of familiar and close others (teachers). Design and Methods: 84 men were confronted with the Trier Social Stress Test for Groups through a 3 (negative, positive, no-audience) x 2 (familiar, unfamiliar) experimental design with four measurement points of cortisol levels and state anxiety. We also tested whether closeness with the committee members predicted these variables for the participants in the familiar conditions. Results: Using both a frequentist and a Bayesian approach, familiarity and social support did not have stress-buffering effects (or merely anecdotal effects) on cortisol levels but buffered self-reported anxiety only for the participants faced with a supportive audience composed of familiar persons. Closeness with the experimenters was not a significant predictor of the stress responses. Conclusions: Because these results are preliminary evidence, further investigations into the relations between support provider and recipient during evaluative tasks would be worthwhile to better explain opposing findings found in this growing literature.
Assuntos
Apoio Social , Estresse Psicológico/prevenção & controle , Ansiedade/etiologia , Ansiedade/psicologia , Humanos , Hidrocortisona/análise , Julgamento , Reconhecimento Psicológico , Saliva/química , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologia , Adulto JovemRESUMO
The single Trier Social Stress Test (TSST) and the TSST for groups (TSST-G) are the most used protocols to experimentally induce psychosocial stress. These tests are based on uncontrollability and social-evaluative threat, inducing psychological and physiological consequences (e.g., anxiety, emotional states, salivary cortisol increases). Many quantitative experimental studies have investigated these stress inducers and these consequences. But, as far as we know, this study is the first to provide a qualitative analysis to access the participants' voices so as to understand the dynamics of their experience throughout the TSST and the TSST-G. This paper outlines a mixed methods approach to the TSST. This approach can help to maximize the information that can be gained from the TSST, which researchers often use without looking more closely at what is qualitatively happening psychologically for participants during the stressor itself. In this way, this protocol is an example of mixed methods, showing the added value of using the enactive phenomenological approach to analyze experimental protocols more deeply. This kind of mixed methods is helpful to access the experience, to understand the actor's point of view, and to analyze in-depth the dynamics of cognitive processes like intentions, perceptions, enacted knowledge, and emotion. The discussion section shows the different uses of a mixed methods protocol, exploiting the enactive phenomenological approach to analyze a protocol or to give a cross vision of the same research subject. This section deals with different existing applications, pointing out some critical steps in this mixed methods approach.
Assuntos
Psicometria , Estresse Psicológico/psicologia , Adulto , Ansiedade/psicologia , Feminino , Humanos , Hidrocortisona/metabolismo , Masculino , Saliva/metabolismo , Estresse Psicológico/metabolismoRESUMO
This study was designed to evaluate the effect of aging on the activity of metabosensitive afferent fibers (thin muscle afferents from group III and IV) and to determine if physical activity performed at old age may influence the afferent discharge. Afferents from tibialis anterior and soleus muscles were recorded on non-exercised rats aged of 3, 6, 12, and 20 months and on animals aged of 12 and 20 months performing a daily incremental treadmill exercise protocol during the last 8 weeks preceding the recordings. Metabosensitive afferent fibers were activated with potassium chloride (KCl) and lactic acid (LA) injections into the blood stream or by muscle electrically-induced fatigue (EIF). Results indicated that aging is associated to a decrease in the magnitude of the responses to chemical injections and EIF. Unfortunately, physical activity did not allow restoring the metabosensitive afferents responses. These results indicate an alteration of the thin afferent fibers with aging and should be taken into account regarding the management of muscle fatigue and potential alterations of exercise pressor reflex (EPR) occurring with aging.
RESUMO
PURPOSE: Previous studies have underlined the benefits of exercise during cancer therapy. However, patients are insufficiently active during treatment. Telehealth is used to encourage people to be active, reducing difficulties and offsetting the lack of infrastructure often reported. We aimed to identify the effects of recommendations and telehealth on the level of physical activity, fatigue, and quality of life. METHODS: Sixty patients suffering from various cancers under treatment were randomized into two groups. Every Sunday, they had to complete online questionnaires: number of steps, MFI-20, and EORTC-QLQ-30. Group R (recommendations) was given encouragement to improve physical activity during 8 weeks, using a recommendation guide, and received a weekly SMS text message for exercise promotion. Group C, without recommendations, was the control group. RESULTS: Two-way ANOVAs for repeated measures did not reveal effect on the number of steps walked over time; however, the results indicated a beneficial effect for group R related to self-reported fatigue (F = 2.686, p = .01) and quality of life (F = 2.431, p = .02). CONCLUSION: Surprisingly, the level of exercise in group R did not significantly increase, but self-reported fatigue and quality of life were improved. This study underlines that inexpensive sharing of time, human, and financial means, through a protocol of physical activity, improves patient health.
Assuntos
Exercício Físico/fisiologia , Neoplasias/terapia , Qualidade de Vida/psicologia , Telemedicina/métodos , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Projetos de PesquisaRESUMO
The Trier Social Stress Test (TSST) and its version for groups (TSST-G) are the gold standard for inducing acute psychosocial stress in human experimental settings and have been used in numerous studies since the early 1990s. The TSST and the TSST-G lead to effects on different physiological and psychological markers, such as salivary cortisol, anxiety, and emotional states. These effects were assessed with quantitative methods comparing pre-test and post-test measures with statistical analyses. But to date, no qualitative analyses have been conducted to examine the meaningful experience of participants during the TSST and the TSST-G. This study is the first to conduct qualitative investigations to further clarify the stressful experience of participants confronted with these procedures. Preliminary results showed as expected that the TSST and the TSST-G effectively induced psychosocial stress, with cortisol levels, cognitive anxiety, somatic anxiety, and arousal increases, and with pleasure and dominance decreases. At the qualitative level, the results evidenced that the two theoretically stressful components of the TSST and the TSST-G, namely social-evaluative threat and uncontrollability, were experienced as stress-inducing by the participants. Two case studies confirmed these findings. But the results also showed on one hand that psychosocial stress is a dynamic phenomenon, with important fluctuations throughout the tasks (mainly for the TSST-G); and on the other hand that despite the similar physiological and psychological responses between the TSST and the TSST-G evidenced by the literature, the experience of the participants was both similar and specific. Use of a qualitative method allowed us to provide a complementary point of view to understand the meaningful experience of participants during these stressful procedures, apprehending the dynamic of the subjective stress experience without disrupting it.
Assuntos
Testes Psicológicos , Estresse Psicológico/etiologia , Adolescente , Ansiedade/etiologia , Ansiedade/fisiopatologia , Ansiedade/psicologia , Humanos , Hidrocortisona/metabolismo , Masculino , Testes Psicológicos/normas , Saliva/metabolismo , Comportamento Social , Meio Social , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologia , Adulto JovemRESUMO
The present study was designed to provide an appropriate micro-environment for regenerating axotomized neurons and proliferating/migrating cells. Because of its intrinsic permissive properties, biocompatibility and biodegradability, we chose to evaluate the therapeutic effectiveness of a chitosan-based biopolymer. The biomaterial toxicity was measured through in vitro test based on fibroblast cell survival on thermogelling chitosan lactate hydrogel substrate and then polymer was implanted into a C2 hemisection of the rat spinal cord. Animals were randomized into three experimental groups (Control, Lesion and Lesion + Hydrogel) and functional tests (ladder walking and forelimb grip strength tests, respiratory assessment by whole-body plethysmography measurements) were used, once a week during 10 weeks, to evaluate post-traumatic recoveries. Then, electrophysiological examinations (reflexivity of the sub-lesional region, ventilatory adjustments to muscle fatigue known to elicit the muscle metaboreflex and phrenic nerve recordings during normoxia and temporary hypoxia) were performed. In vitro results indicated that the chitosan matrix is a non-toxic biomaterial that allowed fibroblast survival. Furthermore, implanted animals showed improvements of their ladder walking scores from the 4th week post-implantation. Finally, electrophysiological recordings indicated that animals receiving the chitosan matrix exhibited recovery of the H-reflex rate sensitive depression, the ventilatory response to repetitive muscle stimulation and an increase of the phrenic nerve activity to asphyxia compared to lesioned and nonimplanted animals. This study indicates that hydrogel based on chitosan constitute a promising therapeutic approach to repair damaged spinal cord or may be used as an adjuvant with other treatments to enhance functional recovery after a central nervous system damage. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2004-2019, 2017.
Assuntos
Quitosana , Hidrogéis , Ácido Láctico , Traumatismos da Medula Espinal , Medula Espinal , Animais , Linhagem Celular , Quitosana/química , Quitosana/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Ácido Láctico/química , Ácido Láctico/farmacologia , Masculino , Camundongos , Ratos , Ratos Sprague-Dawley , Medula Espinal/metabolismo , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/terapiaRESUMO
OBJECTIVE: The purpose of the study was to analyze links between personality, time perspective, and intention to practice physical activity during cancer treatment. METHOD: One hundred forty-three patients participated in survey by questionnaire. Intention to practice physical activity, time perspective using Zimbardo Time Perspective Inventory, and personality with the Big Five Inventory were measured. Structural equation models using Lisrel were developed to examine hypothetical links between the variables. RESULTS: The adjusted model evidenced an excellent fit (comparative fit index = 0.92; root-mean-square error of approximation = 0.076; P = .014). Results showed that intention to practice exercise was positively linked with openness to experience and negatively with present fatalist time perspective. Moreover, conscientiousness and neuroticism were found to be linked with future time perspective, which was positively related with intention to practice physical activity. CONCLUSION: The present exploratory study with patients suffering from cancer underlined the importance of considering jointly time perspective dimensions and personality factors for health behavior recommendations. Based on our results, we propose some reflections on practice to help nurses and physicians increase patient's motivation to be physically active. Taking into account patients' personality and time perspective, we would be able to propose specific awareness messages and offer short interventions to have an impact on patients' motivation to practice.
Assuntos
Atitude Frente a Saúde , Exercício Físico , Comportamentos Relacionados com a Saúde , Neoplasias/terapia , Personalidade , Adulto , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/psicologia , Transtornos da Personalidade , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: Benefits of physical activity during cancer treatment are widely demonstrated, however, most of patients are not active enough. Several studies have analyzed the different variables that would affect the participation to physical activity programs. The aim of our study was to define profiles of patients who agree to participate in a physical activity program in the medical setting according to the hospital structure in which they receive their care, their past and present habits in sports and their temporal perspectives. METHOD: Forty-six patients treated from two different hospitals (regional hospital denoted CLCC; and local hospital denoted CH), completed a survey consisting of a questionnaire on their past and present habits in physical activity, ZTPI and a demographic questionnaire. Patients could decide to participate or not in a physical activity program in the medical community. T-tests and Chi2 were performed to compare the two groups. RESULTS: Chi2 tests have shown that patients cared in CH are significantly more involved in physical activity program than patients cared in CLCC. DISCUSSION: Our study points out that the past and present patient PA (physical activity) has no influence on their accession to a physical activity program, however the type of hospital providing patient care could influence their participation. These results should lead us to rethink about the different forms of communication made around the physical activity programs in medical contexts, and about different practical arrangements proposed according to each health facility.
Assuntos
Exercício Físico , Atividades de Lazer , Neoplasias/terapia , Cooperação do Paciente/estatística & dados numéricos , Inquéritos e Questionários , Fatores Etários , Institutos de Câncer/estatística & dados numéricos , Distribuição de Qui-Quadrado , Escolaridade , Emprego/estatística & dados numéricos , Feminino , Hospitais/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Aposentadoria/estatística & dados numéricos , Estudantes/estatística & dados numéricosRESUMO
Designing three-dimensional tubular materials made of chitosan is still a challenging task. Availability of such forms is highly desired by tissue engineering, especially peripheral nerve tissue engineering. Aiming at this problem, we use an electrodeposition phenomenon in order to obtain chitosan and chitosan-carbon nanotube hydrogel tubular implants. The in vitro biocompatibility of the fabricated structures is assessed using a mouse hippocampal cell line (mHippoE-18). As both implants do not induce significant cytotoxicity, they are next subjected to in vitro degradation studies in the environment simulating in vivo conditions for specified periods of time: 7, 14, and 28 days. The mass loss of implants indicates their stability at the tested time period; therefore, the materials are subcutaneously implanted in Sprague Dawley rats. The explants are collected after 7, 14, and 28 days. The assessment of composition and changes in tissues surrounding the implanted materials is made in respect to surrounding tissue thickness as well as the number of blood vessels, macrophages, lymphocytes, and neutrophils. No symptoms of acute inflammation are noticed at any point in time. The observed regular healing process allows concluding that both chitosan and chitosan-carbon hydrogel tubular implants are biocompatible with high application potential in tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2701-2711, 2016.