Effect of treadmill gait on bone markers and bone mineral density of quadriplegic subjects

Quadriplegic subjects present extensive muscle mass paralysis which is responsible for the dramatic decrease in bone mass, increasing the risk of bone fractures. There has been much effort to find an efficient treatment to prevent or reverse this significant bone loss. We used 21 male subjects, mean age 31.95 ± 8.01 years, with chronic quadriplegia, between C4 and C8, to evaluate the effect of treadmill gait training using neuromuscular electrical stimulation, with 30-50% weight relief, on bone mass, comparing individual dual-energy X-ray absorptiometry responses and biochemical markers of bone metabolism. Subjects were divided into gait (N = 11) and control (N = 10) groups. The gait group underwent gait training for 6 months, twice a week, for 20 min, while the control group did not perform gait. Bone mineral density (BMD) of lumbar spine, femoral neck, trochanteric area, and total femur, and biochemical markers (osteocalcin, bone alkaline phosphatase, pyridinoline, and deoxypyridinoline) were measured at the beginning of the study and 6 months later. In the gait group, 81.8% of the subjects presented a significant increase in bone formation and 66.7% also presented a significant decrease of bone resorption markers, whereas 30% of the controls did not present any change in markers and 20% presented an increase in bone formation. Marker results did not always agree with BMD data. Indeed, many individuals with increased bone formation presented a decrease in BMD. Most individuals in the gait group presented an increase in bone formation markers and a decrease in bone resorption markers, suggesting that gait training, even with 30-50% body weight support, was efficient in improving the bone mass of chronic quadriplegics.1357136

Non-pharmacological treatments in the stimulation of osteogenesis

Mechanical loads cause bone deformation leading to bone resorption and an increase in local bone formation. However, the stimulus for bone formation depends on the amount and frequency of bone deformation. High calcium intake is required to increase bone formation. There are also non-pharmacological treatments, such as electrical stimulation, low-intensity ultrasound, and laser, which revealed to promote osteogenesis. The article intends to evaluate non-pharmacological, alternative methods which assist in the increase of bone formation or in the osteogenic stimulus. A literature review was carried out for the period between 1982 to 2001.A carga mecânica provoca microdeformações ósseas, que estimulam células osteoblásticas e, conseqüentemente, promovem adaptações nos ossos, muitas vezes relacionadas com uma menor reabsorção óssea e um aumento na formação óssea local. No entanto, o estímulo para formação óssea depende do número e freqüência das deformações aplicadas no osso. Concomitantemente aos estímulos ósseos providos pelas cargas mecânicas, é importante uma dieta rica em cálcio, a qual também beneficia o aumento da massa óssea. Entretanto, existem também outros métodos não farmacológicos, como o ultra-som pulsado de baixa intensidade, a estimulação elétrica e o laser, que já mostraram efeitos positivos na promoção da osteogênese. Assim, realizou-se um levantamento na literatura, no período de 1982 a 2001, sobre esses métodos não farmacológicos com o objetivo de avaliar tais métodos alternativos, que ajudam no aumento da massa óssea ou no estímulo à osteogênese.64765

Emerging Technologies for the Detection of Rabies Virus: Challenges and Hopes in the 21st Century

The diagnosis of rabies is routinely based on clinical and epidemiological information, especially when exposures are reported in rabies-endemic countries. Diagnostic tests using conventional assays that appear to be negative, even when undertaken late in the disease and despite the clinical diagnosis, have a tendency, at times, to be unreliable. These tests are rarely optimal and entirely dependent on the nature and quality of the sample supplied. In the course of the past three decades, the application of molecular biology has aided in the development of tests that result in a more rapid detection of rabies virus. These tests enable viral strain identification from clinical specimens. Currently, there are a number of molecular tests that can be used to complement conventional tests in rabies diagnosis. Indeed the challenges in the 21st century for the development of rabies diagnostics are not of a technical nature; these tests are available now. The challenges in the 21st century for diagnostic test developers are two-fold: firstly, to achieve internationally accepted validation of a test that will then lead to its acceptance by organisations globally. Secondly, the areas of the world where such tests are needed are mainly in developing regions where financial and logistical barriers prevent their implementation. Although developing countries with a poor healthcare infrastructure recognise that molecular-based diagnostic assays will be unaffordable for routine use, the cost/benefit ratio should still be measured. Adoption of rapid and affordable rabies diagnostic tests for use in developing countries highlights the importance of sharing and transferring technology through laboratory twinning between the developed and the developing countries. Importantly for developing countries, the benefit of molecular methods as tools is the capability for a differential diagnosis of human diseases that present with similar clinical symptoms. Antemortem testing for human rabies is now possible using molecular techniques. These barriers are not insurmountable and it is our expectation that if such tests are accepted and implemented where they are most needed, they will provide substantial improvements for rabies diagnosis and surveillance. The advent of molecular biology and new technological initiatives that combine advances in biology with other disciplines will support the development of techniques capable of high throughput testing with a low turnaround time for rabies diagnosis

Novel Vaccines to Human Rabies

Rabies, the most fatal of all infectious diseases, remains a major public health problem in developing countries, claiming the lives of an estimated 55,000 people each year. Most fatal rabies cases, with more than half of them in children, result from dog bites and occur among low-income families in Southeast Asia and Africa. Safe and efficacious vaccines are available to prevent rabies. However, they have to be given repeatedly, three times for pre-exposure vaccination and four to five times for post-exposure prophylaxis (PEP). In cases of severe exposure, a regimen of vaccine combined with a rabies immunoglobulin (RIG) preparation is required. The high incidence of fatal rabies is linked to a lack of knowledge on the appropriate treatment of bite wounds, lack of access to costly PEP, and failure to follow up with repeat immunizations. New, more immunogenic but less costly rabies virus vaccines are needed to reduce the toll of rabies on human lives. A preventative vaccine used for the immunization of children, especially those in high incidence countries, would be expected to lower fatality rates. Such a vaccine would have to be inexpensive, safe, and provide sustained protection, preferably after a single dose. Novel regimens are also needed for PEP to reduce the need for the already scarce and costly RIG and to reduce the number of vaccine doses to one or two. In this review, the pipeline of new rabies vaccines that are in pre-clinical testing is provided and an opinion on those that might be best suited as potential replacements for the currently used vaccines is offered

The Application Of Biomedical Instrumentation For Sensory-motor Recovery And Functional Assessment In Spinal Cord Injured Individuals

[No abstract available]IS7IS11Inst. Syst. Technol. Inf., Control Commun. (INSTICC)De Abreu, D.C., Cliquet Jr., A., Rondina, J.M., Cendes, F., Electrical stimulation during gait promotes increase of muscle cross-sectional area in quadriplegics: A preliminary study (2009) Clin Orthop Relat Res, 467 (2), pp. 553-557. , FebDe Arruda Serra Gaspar, M.I., Cliquet Jr., A., Fernandes Lima, V.M., De Abreu, D.C., Relationship between median nerve somatosensory evoked potentials and spinal cord injury levels in patients with quadriplegia (2009) Spinal Cord, 47 (5), pp. 372-378. , MayBittar, C.K., Cliquet Jr., A., Effects of quadriceps and anterior tibial muscles electrical stimulation on the feet and ankles of patients with spinal cord injuries (2010) Spinal Cord, 48 (12), pp. 881-885. , DecCacho, E.W., De Oliveira, R., Ortolan, R.L., Varoto, R., Cliquet Jr., A., Upper limb assessment in tetraplegia: Clinical, functional and kinematic correlations (2010) Int J Rehabil Res, , Aug 27. [Epub ahead of print]Carvalho, D.C., Cliquet Jr., A., Response of the arterial blood pressure of quadriplegic patients to treadmill gait training (2005) Braz J Med Biol Res, 38 (9), pp. 1367-1373. , SepDe Carvalho, D.C., Cliquet Jr., A., Energy expenditure during rest and treadmill gait training in quadriplegic subjects (2005) Spinal Cord, 43 (11), pp. 658-663. , NovCarvalho, D.C., De Cássia Zanchetta, M., Sereni, J.M., Cliquet Jr., A., Metabolic and cardiorespiratory responses of tetraplegic subjects during treadmill walking using neuromuscular electrical stimulation and partial body weight support (2005) Spinal Cord, 43 (7), pp. 400-405. , JulCarvalho, D.C., Garlipp, C.R., Bottini, P.V., Afaz, S.H., Moda, M.A., Cliquet Jr., A., Effect of treadmill gait on bone markers and bone mineral density of quadriplegic subjects (2006) Braz J Med Biol Res, 39 (10), pp. 1357-1363. , OctCarvalho, D.C., Martins, C.L., Cardoso, S.D., Cliquet Jr., A., Improvement of metabolic and cardiorespiratory responses through treadmill gait training with neuromuscular electrical stimulation in quadriplegic subjects (2006) Artif Organs, 30 (1), pp. 56-63. , JanDe Abreu, D.C.C., Cliquet Jr., A., Rondina, J.M., Cendes, F., Muscle hypertrophy in quadriplegics with combined electrical stimulation and body weight support training (2008) International Journal of Rehabilitation Research, 31 (2), pp. 171-175. , DOI 10.1097/MRR.0b013e3282fc0fa4, PII 0000435620080600000009Ferro, F.P., Gonzalez, H.J.N., Ferreira, D.M., Cliquet Jr., A., Electrical stimulation and treadmill gait in tetraplegic patients: Assessment of its effects on the knee with magnetic resonance imaging (2008) Spinal Cord, 46 (2), pp. 124-128. , DOI 10.1038/sj.sc.3102078, PII 3102078De Medeiros, R.C., Jaccard, A.P., Cliquet Jr., A., Sagittal spinal alignment in paraplegics: A new paradigm for the rehabilitation under neuromuscular electrical stimulation (2010) Spinal Cord, 48 (3), pp. 251-256. , MarVaroto, R., Barbarini, E.S., Cliquet Jr., A., A hybrid system for upper limb movement restoration in quadriplegics (2008) Artif Organs, 32 (9), pp. 725-729. , Se

An Artificial Neural System For Closed Loop Control Of Locomotion Produced Via Neuromuscular Electrical Stimulation

The use of neuromuscular electrical stimulation for restoration of gait in spinal cord injured subjects has been seriously pursued by many investigators for the past 15 years. By and large, however, systems to date require the intervention of a person, be it the patient or an observer, and are restricted to control of stimulation onset and termination. Further, existing systems are not adaptable to environmental and patient variations. This work proposes a system that relies on neural computing to determine proper muscle activation patterns from biomechanical signals. The intelligent system is trained to perform gait under supervision, after which it can be used to control muscle stimulation in an unknown environment. Computer simulations suggest that the best neural architecture for control of gait is a neural network including units corresponding to movement history. Separate networks for the stance and swing phases, respectively, were found to work better than a single neural network trained on the entire gait cycle. The artificial neural device proposed here also includes a voice recognition system that will allow for voluntary locomotion. A safety circuit has been designed to preclude acceptance of unwanted vocal commands in the latter system.19323123

Response of the arterial blood pressure of quadriplegic patients to treadmill gait training

Blood pressure pattern was analyzed in 12 complete quadriplegics with chronic lesions after three months of treadmill gait training. Before training, blood pressure values were obtained at rest, during treadmill walking and during the recovery phase. Gait training was performed for 20 min twice a week for three months. Treadmill gait was achieved using neuromuscular electrical stimulation, assisted by partial body weight relief (30-50%). After training, blood pressure was evaluated at rest, during gait and during recovery phase. Before and after training, mean systolic blood pressures and heart rates increased significantly during gait compared to rest (94.16 ± 5.15 to 105 ± 5.22 mmHg and 74.27 ± 10.09 to 106.23 ± 17.31 bpm, respectively), and blood pressure decreased significantly in the recovery phase (86.66 ± 9.84 and 57.5 ± 8.66 mmHg, respectively). After three months of training, systolic blood pressure became higher at rest (94.16 ± 5.15 mmHg before training and 100 ± 8.52 mmHg after training; P < 0.05) and during gait exercise (105 ± 5.22 mmHg before and 110 ± 7.38 mmHg after training; P < 0.05) when compared to the initial values, with no changes in heart rate. No changes occurred in blood pressure during the recovery phase, with the lower values being maintained. A drop in systolic pressure from 105 ± 5.22 to 86.66 ± 9.84 mmHg before training and from 110 ± 7.38 to 90 ± 7.38 mmHg after training was noticed immediately after exercise, thus resulting in hypotensive symptoms when chronic quadriplegics reach the sitting position from the upright position

Investigation Of Osteometabolic And Cardio-respiratory Changes Occurring After Gait Training Under Neuromuscular Electric Stimulation In Quadriplegic Patients [investigação Das Alterações Osteo- Metabólicas E Cardio-respiratórias Ocorridas Após O Treinamento De Marcha Sob Estimulação Elétrica Neuromuscular Em Pacientes Tetraplégicos]

This study was aimed to evaluate the effects of gait training with neuromuscular electric stimulation (NMES) on skeletal and cardio-respiratory systems of full quadriplegic patients (C4-C8). Aerobic power (VO2), carbon dioxide production (VCO2), minute ventilation (VE), heart rate (HR), blood pressure (BP), energy consumption, bone markers analysis (osteocalcin, bone alkaline phosphatase, pyridinoline, and deoxypyridinoline) and bone densitometry (DEXA) of the femoral neck and total femur were performed at baseline and six months later. Eleven patients walked on ergometric wake, with NMES and discharge of 60 - 70% of body weight, during six months, twice a week, 20 minutes daily. Ten patients did not perform the gait. Within the gait group, 81.8% showed significant increases of formation markers, of which 72.7% also presented with reduced bone resorption. Within the control group, 20% showed increased bone formation. DEXA results were, in general, opposite to those of bone markers. Cardio-respiratory tests showed a significant increase for VO2 l/min (36%), VCO2 (42.97%), VE (30.48%), SBP mmHg (4.8%) and energy consumption kcal/min (37.68%). In the control group, only VO2 l/min showed a significant increase (26.29%). Gait training with NMES was more efficient in increasing bone formation rates and aerobic power in quadriplegic patients.143141147Whiteneck, G.G., Charlifue, S.W., Frankel, H.L., Fraser, M.H., Gardner, B.P., Gerhart, K.A., Krishnan, K.R., Short, D.J., Mortality, morbidity, and psychosocial outcomes of persons spinal cord injured more than 20 years ago (1992) Paraplegia, 30, pp. 617-630De Barros Filho, T.E., De Oliveira, R.P., Tsanaclis, A.M., De Barros, E.M., Cristante, A.F., Palma, R.M., An experimental model for the transplantation of fetal central nervous system cells to the injured spinal cord in rats (2002) Rev Hosp Clin Fac Med São Paulo, 57, pp. 256-264Garland, D.E., Stewart, C.A., Adkins, R.H., Hu, S.S., Rosen, C., Liotta, F.J., Weinstein, D.A., Osteoporosis after spinal cord injury (1992) J Orthop Res, 10, pp. 371-378Mohr, T., Podenphant, J., Biering-Sorensen, F., Galbo, H., Thamsborg, G., Kjær, M., Increased bone mineral density after prolonged electrically induced cycle training of paralyzed limbs in spinal cord injured man (1997) Calcif Tissue Int, 61, pp. 22-25Figoni, S.F., Exercise responses and quadriplegia (1993) Med Sci Sports Exerc, 25, pp. 433-441Faghri, P.D., Glaser, R.M., Figoni, S.F., Functional electrical stimulation leg cycle ergometer exercise: Training effects on cardiorespiratory responses of spinal cord injured subjects at rest and during submaximal exercise (1992) Arch Phys Med Rehabil, 73, pp. 1085-1093Hannon, R., Blumsohn, A., Naylor, K., Eastell, R., Response of biochemical markers of bone turnover to hormone replacement therapy: Impact of biological variability (1998) J Bone Miner Res, 13, pp. 1124-1133Lekamwasam, S., Lenora, R.S., Effect of leg rotation on hip bone mineral density measurements (2003) J Clin Densitom, 6, pp. 331-336Bloomfield, S.A., Mysiw, W.J., Jackson, R.D., Bone mass and endocrine adaptations to training in spinal cord injured individuals (1996) Bone, 19, pp. 61-68Dawson-Hughes, B., Pharmacologic treatment of postmenopausal osteoporosis (1999) An Official Publication of the American Society for Bone and Mineral Research. Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism. 4th Ed., pp. 283-288. , MJ Favus, editor. Philadelphia: Lippincott-Raven PublishersGoss, F.L., Mcdermott, A., Robertson, R.J., Changes in peak oxygen uptake following computerized functional electrical stimulation in the spinal cord injured (1992) Res Q Exerc Sport, 63, pp. 76-79Mohr, T., Andersen, J.L., Biering-Sorensen, F., Galbo, H., Bangsbo, J., Wagner, A., Kjær, M., Long-term adaptation to electrically induced cycle training in severe spinal cord injured individuals (1997) Spinal Cord, 35, pp. 1-16Dela, F., Mohr, T., Jensen, C.M.R., Haahr, H.L., Secher, N.H., Biering-Sorensen, F., Kjær, Cardiovascular control during exercise: Insights from spinal cord-injured humans (2003) Circulation, 107, pp. 2127-2133Janssen, T.W.J., Dallmeijer, A.J., Veeger, D., Van Der Woude, L.H.V., Normative values and determinants of physical capacity in individuals with spinal cord injury (2002) J Rehabil Res Dev, 39, pp. 29-39Blair, S.N., Kolh, H.W., Pattenbarger, R.S., Clark Jr., D.G., Cooper, K.H., Gibbons, L.W., Physical fitness and all causes of mortality: A prospective study of healthy men and women (1989) J Amer Med Assoc, 262, pp. 2395-240

Effects of quadriceps and anterior tibial muscles electrical stimulation on the feet and ankles of patients with spinal cord injuries

Study design: Controlled clinical test. Objectives: The purpose of this study was to assess the effects of quadriceps and anterior tibial muscles electrical stimulation on the feet and ankles of patients with spinal cord injuries and to compare them with able-bodied individuals and a group of patients who did not undergo neuromuscular electrical stimulation (NMES). Setting: This study was conducted at the Hospital das Clinicas of Unicamp, Campinas, Sao Paulo, Brazil. Methods: Between January and April 2008, 30 patients at the spinal cord injury ambulatory clinic who underwent NMES (group A) were submitted to a clinical and radiographic assessment of their feet and ankles and compared with a spinal cord injury group (group B) who did not undergo NMES and a group of able-bodied individuals (group C). The Kruskal-Wallis test was used to compare all the three groups, and between-group differences (P < 0.05) were investigated with the Mann-Whitney test. Results: The mean mobility of the midfoot and ankle subtalar joint was significantly higher in group C than in groups A and B. Differences in the mean measurements of the profiles of the talocalcaneal and the talus-first metatarsal angles were statistically significant for group A vs the other groups (P = 0.0020, 0.0024, respectively). Foot deformities were found in groups including claw toes and flat feet (group A) and grade I ulcers on the lateral malleolus and calcaneus (group B). Conclusion: Partial-load NMES maintains the feet and ankles in a planted and adequate walking position in patients with spinal cord injuries, a favorable result of new technologies that allows these patients to reacquire independent walking capacity. Spinal Cord (2010) 48, 881-885; doi:10.1038/sc.2010.50; published online 18 May 201

Simple Auto-adaptive Neural Circuit For Control Of Human Gait: A Simulation Based On Back-propagation

The acquisition of connectivity patterns in an artificial, three-layer neural circuit for control of human gait was simulated through a backpropagation algorithm. Input signals for the neural network were equivalent to hip, knee, and ankle angles, and to vertical ground reaction forces during walking. Neural network outputs consisted of signals proportional to the activity of five lower limb muscles. Many network input configurations and connectivity restrictions were tested. Data from normal gait were used for network training. Preliminary testing of network responses in unknown environments was effected by presenting the neural networks with actual pathologic data at the input layer and by later investigating network outputs. Results favored restricted connectivity between middle and output layer neurons. Further, explicit recall of recent events was found to improve network behavior.458559