Cold stimulation of the oral cavity redistributes blood towards the brain in healthy volunteers

BACKGROUND

The aim of this study was to analyze cold stimulation-induced changes in cerebral and cardiac hemodynamics.

METHODS

Upon ingestion of an ice cube, the changes in resistance index, mean flow velocity and flow index of the middle cerebral arteries (MCA) were assessed using transcranial Doppler sonography. Extracranial duplex sonography was used to measure the mean flow velocity and resistance index of the right internal carotid artery (ICA). The change in mean arterial pressure, heart rate, root mean square of successive differences (RMSSD) and end-tidal carbon dioxide pressure were analyzed additionally. These changes were compared to sham stimulation.

RESULTS

Compared with sham stimulation, cooling of the oral cavity resulted in significant changes in cerebral and cardiac hemodynamics. The cold stimulation decreased the resistance index in the MCA (-4.5% ± 5.4%, p < 0.0001) and right ICA (-6.3% ± 15.6%, p = 0.001). This was accompanied by an increase in mean flow velocity (4.1% ± 8.0%, p < 0.0001) and flow index (10.1% ± 43.6%, p = 0.008) in the MCA. The cardiac effects caused an increase in mean arterial pressure (1.8% ± 11.2%, p = 0.017) and RMSSD (55% ± 112%, p = 0.048), while simultaneously decreasing the heart rate (-4.3% ± 9.6%, p = 0.0001).

CONCLUSION

Cooling of the oral cavity resulted in substantial changes in cerebral and cardiac hemodynamics resulting in a blood flow diversion to the brain.

Neural correlates of metacognition: Disentangling the brain circuits underlying prospective and retrospective second-order judgments through noninvasive brain stimulation

Metacognition encompasses the capability to monitor and control one's cognitive processes, with metamemory and metadecision configuring among the most studied higher order functions. Although imaging experiments evaluated the role of disparate brain regions, neural substrates of metacognitive judgments remain undetermined. The aim of this systematic review is to summarize and discuss the available evidence concerning the neural bases of metacognition which has been collected by assessing the effects of noninvasive brain stimulation (NIBS) on human subjects' metacognitive capacities. Based on such literature analysis, our goal is, at first, to verify whether prospective and retrospective second-order judgments are localized within separate brain circuits and, subsequently, to provide compelling clues useful for identifying new targets for future NIBS studies. The search was conducted following the preferred reporting items for systematic reviews and meta-analyses guidelines among PubMed, PsycINFO, PsycARTICLES, PSYNDEX, MEDLINE, and ERIC databases. Overall, 25 studies met the eligibility criteria, yielding a total of 36 experiments employing transcranial magnetic stimulation and 16 ones making use of transcranial electrical stimulation techniques, including transcranial direct current stimulation and transcranial alternating current stimulation. Importantly, we found that both perspective and retrospective judgments about both memory and perceptual decision-making performances depend on the activation of the anterior and lateral portions of the prefrontal cortex, as well as on the activity of more caudal regions such as the premotor cortex and the precuneus. Combining this evidence with results from previous imaging and lesion studies, we advance ventromedial prefrontal cortex as a promising target for future NIBS studies.

Current advances in engineering meniscal tissues: insights into 3D printing, injectable hydrogels and physical stimulation based strategies

The knee meniscus is the cushioning fibro-cartilage tissue present in between the femoral condyles and tibial plateau of the knee joint. It is largely avascular in nature and suffers from a wide range of tears and injuries caused by accidents, trauma, active lifestyle of the populace and old age of individuals. Healing of the meniscus is especially difficult due to its avascularity and hence requires invasive arthroscopic approaches such as surgical resection, suturing or implantation. Though various tissue engineering approaches are proposed for the treatment of meniscus tears, three-dimensional (3D) printing/bioprinting, injectable hydrogels and physical stimulation involving modalities are gaining forefront in the past decade. A plethora of new printing approaches such as direct light photopolymerization and volumetric printing, injectable biomaterials loaded with growth factors and physical stimulation such as low-intensity ultrasound approaches are being added to the treatment portfolio along with the contemporary tear mitigation measures. This review discusses on the necessary design considerations, approaches for 3D modeling and design practices for meniscal tear treatments within the scope of tissue engineering and regeneration. Also, the suitable materials, cell sources, growth factors, fixation and lubrication strategies, mechanical stimulation approaches, 3D printing strategies and injectable hydrogels for meniscal tear management have been elaborated. We have also summarized potential technologies and the potential framework that could be the herald of the future of meniscus tissue engineering and repair approaches.

Physical Stimulation Methods Developed for In Vitro Neuronal Differentiation Studies of PC12 Cells: A Comprehensive Review

PC12 cells, which are derived from rat adrenal pheochromocytoma cells, are widely used for the study of neuronal differentiation. NGF induces neuronal differentiation in PC12 cells by activating intracellular pathways via the TrkA receptor, which results in elongated neurites and neuron-like characteristics. Moreover, the differentiation requires both the ERK1/2 and p38 MAPK pathways. In addition to NGF, BMPs can also induce neuronal differentiation in PC12 cells. BMPs are part of the TGF-β cytokine superfamily and activate signaling pathways such as p38 MAPK and Smad. However, the brief lifespan of NGF and BMPs may limit their effectiveness in living organisms. Although PC12 cells are used to study the effects of various physical stimuli on neuronal differentiation, the development of new methods and an understanding of the molecular mechanisms are ongoing. In this comprehensive review, we discuss the induction of neuronal differentiation in PC12 cells without relying on NGF, which is already established for electrical, electromagnetic, and thermal stimulation but poses a challenge for mechanical, ultrasound, and light stimulation. Furthermore, the mechanisms underlying neuronal differentiation induced by physical stimuli remain largely unknown. Elucidating these mechanisms holds promise for developing new methods for neural regeneration and advancing neuroregenerative medical technologies using neural stem cells.

Interventions Facilitating Recovery of Consciousness Following Traumatic Brain Injury: A Systematic Review

People who experience disorders of consciousness (DoC) following a severe traumatic brain injury (TBI) have complex rehabilitation needs addressed by occupational therapy. To examine the effectiveness of interventions to improve arousal and awareness of people with DoC following a TBI. For this systematic review, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched six databases in collaboration with a research librarian. Twenty-seven studies were included and grouped thematically. Multimodal sensory stimulation, familiar voices telling structured stories, and transcranial direct current stimulation had a moderate level of evidence. Multimodal sensory stimulation had the strongest evidence in support of its use in clinical practice. Occupational therapy practitioners should administer multimodal stimuli frequently as studies reported administering these interventions at least twice daily. Occupational therapy practitioners should incorporate personally relevant, meaningful, salient stimuli into interventions when treating patients with DoC.

Hybrid Therapeutic Device (CUHK-OA-M2) for Relieving Symptoms Induced by Knee Osteoarthritis

The symptoms of knee osteoarthritis (KOA) severely affect the life quality of the elderly population. Low-level laser therapy, heat therapy, and massage therapy are widely used as independent treatments for joint disorders. However, there are very limited reports of a combination of these therapies into an integrated device for KOA so far. This study aims to develop a novel hybrid therapeutic device that can meet various requirements for knee therapy. Our hybrid therapeutic device (CUHK-OA-M2) integrated with low-level laser therapy, heat therapy, and local massage therapy can effectively provide patients with KOA with relief from their clinical symptoms. A pilot test of 50 community-dwelling elderly volunteers with KOA was performed. Finally, 43 volunteers completed two treatment periods (30 days each) and two post-treatment periods (30 days each). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were collected and analyzed after each period. The outputs of the low-level laser, heating, and massage therapies significantly decreased the WOMAC scores in terms of pain, stiffness, function and total WOMAC after two treatment periods (p < 0.05). Although the score increased slightly after the post-treatment period, it was still lower than the baseline, indicating the treatment outcome could last for an extended period. Therefore, our CUHK-OA-M2 device, as an integrated multi-functional hybrid therapeutic device, is therapeutically significant for treating osteoarthritis symptoms on the knee joints of elderly subjects.

Bioactive Porous Particles as Biological and Physical Stimuli for Bone Regeneration

Even though bony defects can be recovered to their original condition with full functionality, critical-sized bone injuries continue to be a challenge in clinical fields due to deficiencies in the scaffolding matrix and growth factors at the injury region. In this study, we prepared bone morphogenetic protein-2 (BMP-2)-loaded porous particles as a bioactive bone graft for accelerated bone regeneration. The porous particles with unique leaf-stacked morphology (LSS particles) were fabricated by a simple cooling procedure of hot polycaprolactone (PCL) solution. The unique leaf-stacked structure in the LSS particles provided a large surface area and complex release path for the sufficient immobilization of BMP-2 and sustained release of BMP-2 for 26 days. The LSS was also recognized as a topographical cue for cell adhesion and differentiation. In in vitro cell culture and in vivo animal study using a canine mandible defect model, BMP-2-immobilized LSS particles provided a favorable environment for osteogenic differentiation of stem cells and bone regeneration. In vitro study suggests a dual stimulus of bone mineral-like (leaf-stacked) structure (a physical cue) and continuously supplied BMP-2 (a biological cue) to be the cause of this improved healing outcome. Thus, LSS particles containing BMP-2 can be a promising bioactive grafting material for effective new bone formation.

Animal models for epileptic foci localization, seizure detection, and prediction by electrical impedance tomography

Surgical resection of lesions and closed-loop suppression are the two main treatment options for patients with refractory epilepsy whose symptoms cannot be managed with medicines. Unfortunately, failures in foci localization and seizure prediction are constraining these treatments. Electrical impedance tomography (EIT), sensitive to impedance changes caused by blood flow or cell swelling, is a potential new way to locate epileptic foci and predict seizures. Animal validation is a necessary research process before EIT can be used in clinical practice, but it is unclear which among the many animal epilepsy models is most suited to this task. The selection of an animal model of epilepsy that is similar to human seizures and can be adapted to EIT is important for the accuracy and reliability of EIT research results. This study provides an overview of the animal models of epilepsy that have been used in research on the use of EIT to locate the foci or predict seizures; discusses the advantages and disadvantages of these models regarding inducement by chemical convulsant and electrical stimulation; and finally proposes optimal animal models of epilepsy to obtain more convincing research results for foci localization and seizure prediction by EIT. The ultimate goal of this study is to facilitate the development of new treatments for patients with refractory epilepsy. This article is categorized under: Neuroscience > Clinical Neuroscience Psychology > Brain Function and Dysfunction.

Effectiveness of Somatosensory Stimulation for the Lower Limb and Foot to Improve Balance and Gait after Stroke: A Systematic Review

This systematic review’s purpose was to evaluate the effectiveness of lower-limb and foot somatosensory stimulation to improve balance and gait post-stroke. PRISMA reporting guidelines were followed. Included studies: randomized controlled trials (RCTs), published in English with ethical approval statement. Studies of conditions other than stroke, functional electrical stimulation, and interventions eliciting muscle contraction, were excluded. AgeLine, AMED, CINAHL PLUS, EMBASE, EMCARE MEDLINE, PEDro, PsycARTICLES, PsycINFO, SPORTDiscus, Web of Science and Cochrane central register of controlled trials were searched from 1 January 2002 to 31 March 2022. Two authors independently screened results, extracted data and assessed study quality using Cochrane Risk of Bias 2 tool; 16 RCTs (n = 638) were included. Four studies showed a medium or large standardized between-group effect size (Cohen’s d) in favor of somatosensory stimulation, in relation to: customized insoles (d = 0.527), taping (d = 0.687), and electrical stimulation (two studies: d = 0.690 and d = 1.984). Although limited by study quality and heterogeneity of interventions and outcomes, with only one study’s results statistically significant, several interventions showed potential for benefit, exceeding the minimally important difference for gait speed. Further research with larger trials is required. This unfunded systematic review was registered with PROSPERO (number CRD42022321199).

Infant stimulation reduces weight loss and increases breastfeeding: a randomized controlled trial

OBJECTIVES

The study aimed to measure the effect of auditory, tactile, visual, and vestibular (ATVV) stimulation therapy on sucking effectiveness (SE), infant-feeding mode, weight, height, and head circumference (HC) of full-term infants.

METHODS

A single-blinded randomized trial with a sample of 107 mother-child dyads. Inclusion criteria were healthy first-time mothers and full-term infants with no known pathological conditions, weighing between 2500 and 4000 grams, and recommendation of exclusive or predominant breastfeeding. The mothers in the experimental group (EG) received training in ATVV stimulation therapy and provided it from birth (first 24 hours of life) until the end of the follow-ups at week 5. The control group (CG) received only standard care that included education on warning signs and basic guidance on breastfeeding. SE, infant-feeding mode, and neonatal growth were measured at weeks 2 and 5.

RESULTS

In contrast to CG infants, the EG infants drank 2.02 cc more human milk in one minute of effective breastfeeding (p=0.002) at week 2 and 5.51 cc more at week 5 (p<0.0001). They showed greater adherence to breastfeeding at week 5 (p=0.025) and gained more weight: 8.35 grams/day (p=0.009) and 4.19 grams/day (p=0.008). HC did not differ between groups, and height difference was statistically significant at week 5 (p=0.025).

CONCLUSIONS

ATVV stimulation therapy has a positive effect on neonatal health as it promotes effective sucking and exclusive breastfeeding, reduces weight loss, and improves neonatal growth.

Using Subthreshold Vibratory Stimulation During Poststroke Rehabilitation Therapy: A Case Series

Subthreshold vibratory stimulation to the paretic wrist has been shown to prime the sensorimotor cortex and improve 2-week upper extremity (UE) therapy outcomes. The objective of this work was to determine feasibility, safety, and preliminary efficacy of the stimulation over a typical 6-week therapy duration. Four chronic stroke survivors received stimulation during 6-week therapy. Feasibility/safety/efficacy were assessed at baseline, posttherapy, and 1-month follow-up. For feasibility, all participants wore the device throughout therapy and perceived the stimulation comfortable/safe. Regarding safety, no serious/moderate intervention-related adverse events occurred. For efficacy, all participants improved in Wolf Motor Function Test and UE use in daily living based on accelerometry and stroke impact scale. Mean improvements at posttherapy/follow-up were greater than the minimal detectable change/clinically important difference and other trials with similar therapy without stimulation. In conclusion, the stimulation was feasible/safe for 6-week use. Preliminary efficacy encourages a larger trial to further evaluate the stimulation as a therapy adjunct.

Amplified Vasodilatation within the Referred Pain Zone of Trigger Points Is Characteristic of Gluteal Syndrome-A Type of Nociplastic Pain Mimicking Sciatica

Gluteal syndrome (GS) mimicking sciatica is a new disease that has been recently recognized and included in the International Classification of Diseases, 11th Revision. The present study examines nociplastic pain involvement in GS and sciatica patients using a new Skorupska protocol (SP) test that provokes amplified vasodilatation in the area of expected muscle-referred pain. A positive test is confirmed if there is (i) a development of autonomic referred pain (AURP) and (ii) an increase in the delta of average temperature (Δ₸°) > 0.3 °C at the end of the stimulation and during the observation SP phases. Chronic GS (n = 20) and sciatica (n = 30) patients were examined. The SP test confirmed muscle-referred pain for (i) all GS patients with 90.6% positive thermograms (Δ₸° 0.6 ± 0.8 °C; maximum AURP 8.9 ± 13.6% (both p < 0.05)) and (ii) those sciatica (n = 8) patients who reported pain sensation during the test with 20.6% positive thermograms (Δ₸° 0.7 ± 0.7 °C; maximum AURP 15.1 ± 17.8% (both p < 0.05)). The remaining sciatica (n = 22) patients did not report pain during the test and presented a Δ₸° decrease and the AURP size below 1%. Conclusion: Amplified vasodilatation suggesting nociplastic pain involvement was confirmed for all GS and sciatica patients who reported painful sensations in the zone typical for gluteus minimus referred pain during the test.

Development and Usability Validation of a Social Robot Platform for Physical and Cognitive Stimulation in Elder Care Facilities

This article shows our work for developing an elder care platform for social interaction and physical and cognitive stimulation using the Pepper robot and Android OS as clients, based on the knowledge acquired on our long-term social robotics research experience. The first results of the user’s acceptance of the solution are presented in this article. The platform is able to provide different services to the user, such as information, news, games, exercises or music. The games, which have a bi-modal way of interacting (speech and a touch screen interface), have been designed for cognitive stimulation based on the items of the mini-mental state examination. The results of the user’s performance are stored in a cloud database and can be reviewed by therapists through a web interface that also allows them to establish customized therapy plans for each user. The platform has been tested and validated, first using adult people and then deployed to an elder care facility where the robot has been interacting with users for a long period of time. The results and feedback received have shown that the robot can help to keep the users physically and mentally active as well as establish an emotional link between the user and the robot.

The role of serotonin in the control of esophageal sensitivity assessed by multimodal stimulation in health

BACKGROUND

Esophageal hypersensitivity is considered an important pathophysiological mechanism in refractory gastroesophageal reflux disease (GERD) patients. Serotonin (5-HT) plays an important role in the regulation of GI (gastrointestinal) secretion, motility and sensitivity. Previous studies found that altered 5-HT availability has no clear effects on esophageal/GI sensations. Our aim was therefore to investigate the role of 5-HT in esophageal sensitivity in healthy volunteers (HV).

METHODS

Esophageal sensitivity to thermal, mechanical, electrical, and chemical stimuli was assessed in 3 different placebo-controlled studies. In the first study, the effect of citalopram (40 mg; 5-HT reuptake inhibitor; intravenous) was investigated (n = 14). In the second study, the effect of buspirone (20 mg; 5HT1A agonist; oral) was investigated (n = 10). In the third study, acute tryptophan depletion (ATD) was used to decrease 5-HT levels to investigate the effect of reduced 5-HT availability on esophageal sensitivity (n = 15).

KEY RESULTS

No difference was observed in esophageal sensitivity after the administration of citalopram or buspirone (all p > 0.06). In contrast, pain perception threshold to chemical stimulation was increased after ATD (p = 0.017, Cohen's d+ = 0.67). No effect was found on the first perception or pain tolerance threshold. ATD had no influence on esophageal sensitivity to thermal, mechanical, and electrical stimulation compared with placebo.

CONCLUSIONS AND INFERENCES

ATD, which induces 5-HT depletion, significantly decreased pain perception threshold during chemical stimulation, without affecting sensitivity to mechanical, thermal, or electrical stimulation. These findings confirm the involvement of 5-HT in the control of esophageal acid sensitivity, but identifying the receptors involved requires more ligands and studies.

Developments in Antibacterial Therapy: Focus on Physical Stimuli Approaches

At present, various antibacterial therapeutic modalities are available in the clinic. However, due to the rampant abuse of antibiotics over the past few decades and the consequent emergence of innumerable drug-resistant strains of bacteria, it is imperative to develop new and effective antibacterial therapeutic strategies. In recent years, the physical stimuli-based approach to antibacterial therapy has aroused much interest as an alternative to antibiotics and has become a major focus of antibacterial research. In this review, the application of different physical stimuli, including electricity, magnetism, light, ultrasound and thermal stimulation, in antibacterial research is critically examined in order to provide new ideas and directions for the further development of antibacterial therapy in clinical dentistry.

The Effect of Sensory Stimulation on Quality of Life of the Elderly and their Self-efficacy for Coping with the Fear of Falling

BACKGROUND

Aging causes major changes that affect the performance of all senses, and as a result, a critical change in the quality of life is expected. Falling and the fear of falling is one of the major health risks that affect the quality of life among elderly, threatening their independent living. This study was conducted to determine the role of sensory stimulation on the quality of life and self-efficacy in coping with fear in the elderly population.

MATERIALS AND METHODS

During this randomized controlled trial, 80 elderly volunteers from healthcare centers were divided into four intervention groups (music, photo album, aromatherapy, and hand massage) and one control group. Data collection was performed using the Older People's Quality of Life Questionnaire and Falls Efficacy Scale-International tools. Data were analyzed using the Statistical Package for the Social Sciences (SPSS) software program, version 16.0.

RESULTS

Comparing the scores of the quality of life and self-efficacy questionnaires, no statistically significant difference was reported among the groups (p < 0.05).

CONCLUSIONS

Sensory stimulation seems to have no impressive effect on the improvement of self-efficacy in coping with the fear of falling and the quality of life in the older population.

Differential Effects of Sustained Manual Pressure Stimulation According to Site of Action

Sustained pressure stimulation of the body surface has been used in several physiotherapeutic techniques, such as reflex locomotion therapy. Clinical observations of global motor responses and subsequent motor behavioral changes after stimulation in certain sites suggest modulation of central sensorimotor control, however, the neuroanatomical correlates remain undescribed. We hypothesized that different body sites would specifically influence the sensorimotor system during the stimulation. We tested the hypothesis using functional magnetic resonance imaging (fMRI) in thirty healthy volunteers (mean age 24.2) scanned twice during intermittent manual pressure stimulation, once at the right lateral heel according to reflex locomotion therapy, and once at the right lateral ankle (control site). A flexible modeling approach with finite impulse response basis functions was employed since non-canonical hemodynamic response was expected. Subsequently, a clustering algorithm was used to separate areas with differential timecourses. Stimulation at both sites induced responses throughout the sensorimotor system that could be mostly separated into two anti-correlated subsystems with transient positive or negative signal change and rapid adaptation, although in heel stimulation, insulo-opercular cortices and pons showed sustained activation. In direct voxel-wise comparison, heel stimulation was associated with significantly higher activation levels in the contralateral primary motor cortex and decreased activation in the posterior parietal cortex. Thus, we demonstrate that the manual pressure stimulation affects multiple brain structures involved in motor control and the choice of stimulation site impacts the shape and amplitude of the blood oxygenation level-dependent response. We further discuss the relationship between the affected structures and behavioral changes after reflex locomotion therapy.

Physical Stimulations for Bone and Cartilage Regeneration

A wide range of techniques and methods are actively invented by clinicians and scientists who are dedicated to the field of musculoskeletal tissue regeneration. Biological, chemical, and physiological factors, which play key roles in musculoskeletal tissue development, have been extensively explored. However, physical stimulation is increasingly showing extreme importance in the processes of osteogenic and chondrogenic differentiation, proliferation and maturation through defined dose parameters including mode, frequency, magnitude, and duration of stimuli. Studies have shown manipulation of physical microenvironment is an indispensable strategy for the repair and regeneration of bone and cartilage, and biophysical cues could profoundly promote their regeneration. In this article, we review recent literature on utilization of physical stimulation, such as mechanical forces (cyclic strain, fluid shear stress, etc.), electrical and magnetic fields, ultrasound, shock waves, substrate stimuli, etc., to promote the repair and regeneration of bone and cartilage tissue. Emphasis is placed on the mechanism of cellular response and the potential clinical usage of these stimulations for bone and cartilage regeneration.

Fabrication of Gradient Nanopattern by Thermal Nanoimprinting Technique and Screening of the Response of Human Endothelial Colony-forming Cells

Nanotopography can be found in various extracellular matrices (ECMs) around the body and is known to have important regulatory actions upon cellular reactions. However, it is difficult to determine the relation between the size of a nanostructure and the responses of cells owing to the lack of proper screening tools. Here, we show the development of reproducible and cost-effective gradient nanopattern plates for the manipulation of cellular responses. Using anodic aluminum oxide (AAO) as a master mold, gradient nanopattern plates with nanopillars of increasing diameter ranges [120-200 nm (GP 120/200), 200-280 nm (GP 200/280), and 280-360 nm (GP 280/360)] were fabricated by a thermal imprinting technique. These gradient nanopattern plates were designed to mimic the various sizes of nanotopography in the ECM and were used to screen the responses of human endothelial colony-forming cells (hECFCs). In this protocol, we describe the step-by-step procedure of fabricating gradient nanopattern plates for cell engineering, techniques of cultivating hECFCs from human peripheral blood, and culturing hECFCs on nanopattern plates.

Safety of neuromuscular electrical stimulation among critically ill patients: systematic review

OBJECTIVE

To review the evidence on the safety of neuromuscular electrical stimulation when used in the intensive care unit.

METHODS

A systematic review was conducted; a literature search was performed of the MEDLINE (via PubMed), PEDro, Cochrane CENTRAL and EMBASE databases, and a further manual search was performed among the references cited in randomized studies. Randomized clinical trials that compared neuromuscular electrical stimulation to a control or placebo group in the intensive care unit and reporting on the technique safety in the outcomes were included. Hemodynamic variables and information on adverse effects were considered safety parameters. Articles were independently analyzed by two reviewers, and the data analysis was descriptive.

RESULTS

The initial search located 1,533 articles, from which only four randomized clinical trials were included. Two studies assessed safety based on hemodynamic variables, and only one study reported an increase in heart rate, respiratory rate and blood lactate, without clinical relevance. The other two studies assessed safety based on reported adverse effects. In one, 15% of patients described a prickling sensation, without any clinically relevant abnormalities. In the other, one patient suffered a superficial burn due to improper parameter configuration.

CONCLUSION

Neuromuscular electrical stimulation is safe for critically ill patients; however, it should be applied by duly trained professionals and with proper evidence-based parameters.

Response characteristics of the cat somatosensory cortex following the mechanical stimulation to non-vital and vital canine

Patients sometimes complain that non-vital teeth after root canal treatment (RCT) are paresthesia compared with vital teeth, and previous psychological studies on the tactile sensibility of non-vital teeth remained controversial. In the present study, intrinsic signal optical imaging, which served as an objective tool, was employed to compare the cortex response characteristics following forces applied to the cat non-vital and vital canines. Based on the evoked cortical responses, the response threshold, signal strength, spatial pattern, temporal dynamics and the preference of force direction, they were not significantly different between vital and non-vital canines. It seemed that the tactile sensibility of vital and non-vital teeth was comparable at the cortical response level, and pulpal receptors were not concerned in tactile function.

Modulation of the sensorimotor system by sustained manual pressure stimulation

In Vojta physiotherapy, also known as reflex locomotion therapy, prolonged peripheral pressure stimulation induces complex generalized involuntary motor responses and modifies subsequent behavior, but its neurobiological basis remains unknown. We hypothesized that the stimulation would induce sensorimotor activation changes in functional magnetic resonance imaging (fMRI) during sequential finger opposition. Thirty healthy volunteers (mean age 24.2) underwent two randomized fMRI sessions involving manual pressure stimulation applied either at the right lateral heel according to Vojta, or at the right lateral ankle (control site). Participants were scanned before and after the stimulation when performing auditory-paced sequential finger opposition with their right hand. Despite an extensive activation decrease following both stimulation paradigms, the stimulation of the heel specifically led to an increase in task-related activation in the predominantly contralateral pontomedullary reticular formation and bilateral posterior cerebellar hemisphere and vermis. Our findings suggest that sustained pressure stimulation of the foot is associated with differential short-term changes in hand motor task-related activation depending on the stimulation. This is the first evidence for brainstem modulation after peripheral pressure stimulation, suggesting that the after-effects of reflex locomotion physiotherapy involve a modulation of the pontomedullary reticular formation.

Biological enhancement of graft-tunnel healing in anterior cruciate ligament reconstruction

The sites where graft healing occurs within the bone tunnel and where the intra-articular ligamentization process takes place are the two most important sites of biological incorporation after anterior cruciate ligament (ACL) reconstruction, since they help to determine the mechanical behavior of the femur-ACL graft-tibia complex. Graft-tunnel healing is a complex process influenced by several factors, such as type of graft, preservation of remnants, bone quality, tunnel length and placement, fixation techniques and mechanical stress. In recent years, numerous experimental and clinical studies have been carried out to evaluate potential strategies designed to enhance and optimize the biological environment of the graft-tunnel interface. Modulation of inflammation, tissue engineering and gene transfer techniques have been applied in order to obtain a direct-type fibrocartilaginous insertion of the ACL graft, similar to that of native ligament, and to accelerate the healing process of tendon grafts within the bone tunnel. Although animal studies have given encouraging results, clinical studies are lacking and their results do not really support the use of the various strategies in clinical practice. Further investigations are therefore needed to optimize delivery techniques, therapeutic concentrations, maintenance of therapeutic effects over time, and to reduce the risk of undesirable effects in clinical practice.

Population response characteristics of intrinsic signals in the cat somatosensory cortex following canine mechanical stimulation

Intrinsic signal optical imaging has been widely used to measure functional maps in various sensory cortices due to better spatial resolution and sensitivity for detecting cortical neuroplasticity. However, application of this technique in dentistry has not been reported. In this study, intrinsic signal optical imaging was used to investigate mechanically driven responses in the cat somatosensory cortex, when punctate mechanical stimuli were applied to maxillary canines. The global signal and its spatial organization pattern were obtained. Global signal strength gradually increased with stimulus strength. There was no significant difference in response strength between contralateral and ipsilateral mechanical stimulation. A slightly greater response was recorded in the sigmoidal gyrus than in the coronal gyrus. The cat somatosensory cortex activated by sensory inputs from mechanical stimulation of canines lacks both topographical and functional organization. It is not organized into columns that represent sensory input from each tooth or direction of stimulation. These results demonstrate that intrinsic signal optical imaging is a valid tool for investigating neural responses and neuroplasticity in the somatosensory cortex that represents teeth.

Skeletal muscle tissue engineering: strategies for volumetric constructs

Skeletal muscle tissue is characterized by high metabolic requirements, defined structure and high regenerative potential. As such, it constitutes an appealing platform for tissue engineering to address volumetric defects, as proven by recent works in this field. Several issues common to all engineered constructs constrain the variety of tissues that can be realized in vitro, principal among them the lack of a vascular system and the absence of reliable cell sources; as it is, the only successful tissue engineering constructs are not characterized by active function, present limited cellular survival at implantation and possess low metabolic requirements. Recently, functionally competent constructs have been engineered, with vascular structures supporting their metabolic requirements. In addition to the use of biochemical cues, physical means, mechanical stimulation and the application of electric tension have proven effective in stimulating the differentiation of cells and the maturation of the constructs; while the use of co-cultures provided fine control of cellular developments through paracrine activity. This review will provide a brief analysis of some of the most promising improvements in the field, with particular attention to the techniques that could prove easily transferable to other branches of tissue engineering.

Updates in biological therapies for knee injuries: bone

Bone is a unique tissue because of its mechanical properties, ability for self-repair, and enrollment in different metabolic processes such as calcium homeostasis and hematopoietic cell production. Bone barely tolerates deformation and tends to fail when overloaded. Fracture healing is a complex process that in particular cases is impaired. Osteoprogenitor cells proliferation, growth factors, and a sound tridimensional scaffold at fracture site are key elements for new bone formation and deposition. Mechanical stability and ample vascularity are also of great importance on providing a proper environment for bone healing. From mesenchymal stem cells delivery to custom-made synthetic scaffolds, many are the biological attempts to enhance bone healing. Impaired fracture healing represents a real burden to contemporary society. Sound basic science knowledge has contributed to newer approaches aimed to accelerate and improve the quality of bone healing.

Efficacy of rapid-rate repetitive transcranial magnetic stimulation in the treatment of depression: a systematic review and meta-analysis

OBJECTIVE

To systematically review the literature pertaining to rapid-rate repetitive transcranial magnetic stimulation (rTMS) compared with sham therapy for the treatment of a major depressive episode in order to arrive at qualitative and quantitative conclusions about the efficacy of rapid-rate rTMS.

METHODS

MEDLINE, the Cochrane Library, the metaRegister of Controlled Trials and abstracts from scientific meetings were searched for the years 1966 until July 2003. The search terms "transcranial magnetic stimulation" and "transcranial magnetic stimulation AND depression" were used. Eighty-seven randomized controlled trials investigating the efficacy of rTMS were referenced on MEDLINE. Nineteen of these involved treatment of a major depressive episode, and these were reviewed. Six met more specific inclusion criteria including the use of rapid-rate stimulation, application to the left dorsolateral prefrontal cortex, evaluation with the 21-item Hamilton Rating Scale for Depression (HAM-D) and use of an intent-to-treat analysis. Scores on the 21-item HAM-D after treatment and standard deviations were extracted from each article for treatment and control subjects. A random-effects model was chosen for the meta-analysis, and the weighted mean difference was used as a summary measure.

RESULTS

Six studies that met the inclusion criteria were identified and included in the meta-analysis. Two of these reported a significantly greater improvement in mood symptoms in the treatment versus the sham group. When combined in the meta-analysis, the overall weighted mean difference was -1.1 (95% confidence interval -4.5 to 2.3), and the results of a test for heterogeneity were not significant (chi2(5) = 5.81, p = 0.33).

CONCLUSIONS

This meta-analysis suggests that rapid-rate rTMS is no different from sham treatment in major depression; however, the power within these studies to detect a difference was generally low. Randomized controlled trials with sufficient power to detect a clinically meaningful difference are required.