Effects of robotic guidance on the coordination of locomotion

BACKGROUND

Functional integration of motor activity patterns enables the production of coordinated movements, such as walking. The activation of muscles by weightened summation of activation signals has been demonstrated to represent the spatiotemporal components that determine motor behavior during walking. Exoskeleton robotic devices are now often used in the rehabilitation practice to assist physical therapy of individuals with neurological disorders. These devices are used to promote motor recovery by providing guidance force to the patients. The guidance should in principle lead to a muscle coordination similar to physiological human walking. However, the influence of robotic devices on locomotor patterns needs still to be characterized. The aim of this study was to analyze the effect of force guidance and gait speed on the modular organization of walking in a group of eight healthy subjects.

METHOD

A group of healthy subjects walked on a treadmill with and without robotic aiding at speeds of 1.5, 2.0 and 2.5 Km/h. The guidance force was varied between 20%, 40%, 70% and 100% level of assistance. EMG recordings were obtained from seven leg muscles of the dominant leg and kinematic and kinetic features of the knee and hip joints were extracted.

RESULTS

Four motor modules were sufficient to represent the variety of behavioral goals demanded during robotic guidance, with similar relationships between muscle patterns and biomechanical parameters across subjects, confirming that the low-dimensional and impulsive control of human walking is maintained using robotic force guidance. The conditions of guidance force and speed that maintained correct and incorrect (not natural) modular control were identified.

CONCLUSION

In neurologically intact subjects robotic-guided walking at various force guidance and speed levels does not alter the basic locomotor control and timing. This allows the design of robotic-aided rehabilitation strategies aimed at the modulation of motor modules, which are altered in stroke.

An empirical model of erythemal ultraviolet radiation in the city of Valencia, Spain

This paper presents an improved empirical model that predicts ultraviolet erythemal radiation (UVER) and considers all aspects of atmospheric conditions in Valencia, Spain. The analyzed model is a potential function whose dependent variable is UVER radiation and independent variables are the clearness index and slant ozone column. A potential regression function with all the information contributed a small coefficient of determination and one chose to use a regression potential-exponential mathematical form which improved the coefficient of similar determination. A study was carried out on the influence of season on the regression parameters. This was found to be considerable due to the clearness index. The convergence between the values calculated by the model and the experimental values was analyzed using the mean bias error (MBE) and mean absolute bias error (MABE) statistical parameters. The clearness index and ozone column intervals were analyzed and found to give an improved prediction of the UVER clearness index using regression analysis. Also, a sensitivity analysis was performed on the regression coefficients and parameters. It is important to study the effects of UVER radiation predicted by the model on human health or on agriculture crop growth and yield.

Non-tuberculous mycobacteria in wild boar (Sus scrofa) from Southern Spain: epidemiological, clinical and diagnostic concerns

Non-tuberculous mycobacteria (NTM) are widely distributed in the environment, particularly in wet soil, marshland, rivers or streams, but also are causative agents of a wide variety of infections in animals and humans. Little information is available regarding the NTM prevalence in wildlife and their effects or significance in the bovine tuberculosis (bTB) epidemiology and diagnosis. This research shows the most frequently NTM isolated in lymph nodes of wild boar (Sus scrofa) from southern Spain, relating the NTM presence with the individual characteristics, the management of animals and the possible misdiagnosis of Mycobacterium bovis in concurrent infections. A total of 219 NTM isolates were obtained from 1249 wild boar mandibular lymph nodes sampled between 2007 and 2011. All but 75 isolates were identified by the PCR-restriction analysis-hsp65, and a partial sequencing of the 16S rDNA was carried out to identify the rest of the isolates. Results showed that Mycobacterium chelonae was the most frequently isolated NTM specie (133 isolates, 60.7%), followed by Mycobacterium avium (24 isolates, 11%). No relation was found regarding sex, body condition and management, but M. chelonae was more frequently detected in adults, whereas M. avium was more prevalent in subadults. The high NTM prevalence observed in the studied wild boar populations could make difficult the bTB diagnostic.

Similarity of muscle synergies in human walking and cycling: preliminary results

Recent investigations on how the Motor System coordinates different tasks in humans have indicated that a low-dimensional structure of muscle synergies is sufficient to explain specific spatiotemporal components underlying such behaviors. In this work, we tested the hypothesis that pedaling and walking share common modular features by using the muscle synergies paradigm. Seven healthy subjects walked on a treadmill at their maximum speed and also cycled in an ergometer, set at the same walking cadence. EMG activity was recorded from 10 muscles of the most dominant leg. A Non-Negative Matrix Factorization algorithm was applied to extract synergies. Four synergies were sufficient to explain 90% of the EMG variability during walking and cycling. There were statistically significant correlations (higher than 71%) across similar synergies for each task (walking and pedaling). These preliminary results support the hypothesis of modular control across different human motor tasks and may indicate that some synergies are shared amongst different rhythmic movements.

Principles of human locomotion: a review

In this article the principles of human locomotion are revisited and reviewed. This has been done in the framework of two European projects, where the elicitation of these mechanisms inform, on the one hand, the design of artificial bipedal walkers (H2R), and on the other hand the design of lower limb exoskeletons (BETTER) for rehabilitation of gait in post-stroke patients. Passive dynamics emerging from the morphology of the human musculoskeletal system, reflexes as stabilization mechanisms, modular control of movement as well as supra-spinal control of gait are reviewed to get insight on how these mechanisms can be used to explain human locomotion.

Obesity and psoriasis: inflammatory nature of obesity, relationship between psoriasis and obesity, and therapeutic implications

Obesity, particularly abdominal obesity, is currently considered a chronic low-grade inflammatory condition that plays an active role in the development of the pathophysiologic phenomena responsible for metabolic syndrome and cardiovascular disease through the secretion of proinflammatory adipokines and cytokines. In recent years clear genetic, pathogenic, and epidemiologic links have been established between psoriasis and obesity, with important implications for health. The relationship between the 2 conditions is probably bidirectional, with obesity predisposing to psoriasis and psoriasis favoring obesity. Obesity also has important implications in the treatment of psoriasis, such as a greater risk of adverse effects with conventional systemic drugs and reduced efficacy and/or increased cost with biologic agents, for which dosage should be adjusted to the patient's weight.

Dermatosurgery: total quality management in a dermatology department

BACKGROUND

Dermatosurgery (DS) is a growing sector in dermatology. Performance measurement is organized worldwide to improve the quality of health care. Clinical audit relies on self-assessment, comparison with guidelines, frames of references and implementation of improvement actions.

OBJECTIVE

To assess the efficiency of our DS department.

METHODS

A clinical audit focusing on the organization of the DS unit, patient routing, continuing medical education and training for students was conducted by two external auditors. After an initial evaluation, improvements were implemented and reassessed 1 year later by the same auditors.

RESULTS

The audit resulted in the implementation of preoperative consultation, improved pre- and postoperative information leaflets for patients, standardizing of surgery reports, earmarking of funds for materials, and patient satisfaction survey. The training of residents was organized.

CONCLUSION

This audit was a driving force for communication among the medical and paramedical teams and helped improve patient care and training of residents in DS. It also highlighted areas needing further improvement.

Motor modules in robot-aided walking

BACKGROUND

It is hypothesized that locomotion is achieved by means of rhythm generating networks (central pattern generators) and muscle activation generating networks. This modular organization can be partly identified from the analysis of the muscular activity by means of factorization algorithms. The activity of rhythm generating networks is described by activation signals whilst the muscle intervention generating network is represented by motor modules (muscle synergies). In this study, we extend the analysis of modular organization of walking to the case of robot-aided locomotion, at varying speed and body weight support level.

METHODS

Non Negative Matrix Factorization was applied on surface electromyographic signals of 8 lower limb muscles of healthy subjects walking in gait robotic trainer at different walking velocities (1 to 3 km/h) and levels of body weight support (0 to 30%).

RESULTS

The muscular activity of volunteers could be described by low dimensionality (4 modules), as for overground walking. Moreover, the activation signals during robot-aided walking were bursts of activation timed at specific phases of the gait cycle, underlying an impulsive controller, as also observed in overground walking. This modular organization was consistent across the investigated speeds, body weight support level, and subjects.

CONCLUSIONS

These results indicate that walking in a Lokomat robotic trainer is achieved by similar motor modules and activation signals as overground walking and thus supports the use of robotic training for re-establishing natural walking patterns.

Nanoscale investigation of AlGaN/GaN-on-Si high electron mobility transistors

AlGaN/GaN HEMTs are devices which are strongly influenced by surface properties such as donor states, roughness or any kind of inhomogeneity. The electron gas is only a few nanometers away from the surface and the transistor forward and reverse currents are considerably affected by any variation of surface property within the atomic scale. Consequently, we have used the technique known as conductive AFM (CAFM) to perform electrical characterization at the nanoscale. The AlGaN/GaN HEMT ohmic (drain and source) and Schottky (gate) contacts were investigated by the CAFM technique. The estimated area of these highly conductive pillars (each of them of approximately 20-50 nm radius) represents around 5% of the total contact area. Analogously, the reverse leakage of the gate Schottky contact at the nanoscale seems to correlate somehow with the topography of the narrow AlGaN barrier regions producing larger currents.

Review of hybrid exoskeletons to restore gait following spinal cord injury

Different approaches are available to compensate gait in persons with spinal cord injury, including passive orthoses, functional electrical stimulation (FES), and robotic exoskeletons. However, several drawbacks arise from each specific approach. Orthotic gait is energy-demanding for the user and functionally ineffective. FES uses the muscles as natural actuators to generate gait, providing not only functional but also psychological benefits to the users. However, disadvantages are also related to the early appearance of muscle fatigue and the control of joint trajectories. Robotic exoskeletons that provide joint moment compensation or substitution to the body during walking have been developed in recent years. Significant advances have been achieved, but the technology itself is not mature yet because of many limitations related to both physical and cognitive interaction as well as portability and energy-management issues. Meanwhile, the combination of FES technology and exoskeletons has emerged as a promising approach to both gait compensation and rehabilitation, bringing together technologies, methods, and rehabilitation principles that can overcome the drawbacks of each individual approach. This article presents an overview of hybrid lower-limb exoskeletons, related technologies, and advances in actuation and control systems. Also, we highlight the functional assessment of individuals with spinal cord injury.

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.

Enhancing functional electrical stimulation for emerging rehabilitation robotics in the framework of HYPER project

This paper presents the development of a novel functional electrical stimulation (FES) system. New approaches in emerging rehabilitation robotics propose the use of residual muscular activity or limbs movements during the rehabilitation process of neuromotor. More ambitious projects propose the use of FES systems to restore or compensate motor capabilities by controlling existing muscles or subject limbs. These emerging approaches require more sophisticated FES devices in terms of channels, signals controls and portability. In the framework of HYPER project, such devices are being developed to support the main objective of the project: the development of neurorobots and neuroprosthetics to restore functional motor capabilities in patients who suffered cerebrovascular accidents or spinal cord injury. The presented portable FES system includes novel elec-trostimulator circuits and improved channel switching capacities to enable emerging approaches in rehabilitation robotics.

Proteomic analyses reveal high expression of decorin and endoplasmin (HSP90B1) are associated with breast cancer metastasis and decreased survival

BACKGROUND

Breast cancer is the most common malignancy among women worldwide in terms of incidence and mortality. About 10% of North American women will be diagnosed with breast cancer during their lifetime and 20% of those will die of the disease. Breast cancer is a heterogeneous disease and biomarkers able to correctly classify patients into prognostic groups are needed to better tailor treatment options and improve outcomes. One powerful method used for biomarker discovery is sample screening with mass spectrometry, as it allows direct comparison of protein expression between normal and pathological states. The purpose of this study was to use a systematic and objective method to identify biomarkers with possible prognostic value in breast cancer patients, particularly in identifying cases most likely to have lymph node metastasis and to validate their prognostic ability using breast cancer tissue microarrays.

METHODS AND FINDINGS

Differential proteomic analyses were employed to identify candidate biomarkers in primary breast cancer patients. These analyses identified decorin (DCN) and endoplasmin (HSP90B1) which play important roles regulating the tumour microenvironment and in pathways related to tumorigenesis. This study indicates that high expression of Decorin is associated with lymph node metastasis (p<0.001), higher number of positive lymph nodes (p<0.0001) and worse overall survival (p = 0.01). High expression of HSP90B1 is associated with distant metastasis (p<0.0001) and decreased overall survival (p<0.0001) these patients also appear to benefit significantly from hormonal treatment.

CONCLUSIONS

Using quantitative proteomic profiling of primary breast cancers, two new promising prognostic and predictive markers were found to identify patients with worse survival. In addition HSP90B1 appears to identify a group of patients with distant metastasis with otherwise good prognostic features.

Online assessment of human-robot interaction for hybrid control of walking

Restoration of walking ability of Spinal Cord Injury subjects can be achieved by different approaches, as the use of robotic exoskeletons or electrical stimulation of the user's muscles. The combined (hybrid) approach has the potential to provide a solution to the drawback of each approach. Specific challenges must be addressed with specific sensory systems and control strategies. In this paper we present a system and a procedure to estimate muscle fatigue from online physical interaction assessment to provide hybrid control of walking, regarding the performances of the muscles under stimulation.

Rehabilitation of gait after stroke: a review towards a top-down approach

This document provides a review of the techniques and therapies used in gait rehabilitation after stroke. It also examines the possible benefits of including assistive robotic devices and brain-computer interfaces in this field, according to a top-down approach, in which rehabilitation is driven by neural plasticity.The methods reviewed comprise classical gait rehabilitation techniques (neurophysiological and motor learning approaches), functional electrical stimulation (FES), robotic devices, and brain-computer interfaces (BCI).From the analysis of these approaches, we can draw the following conclusions. Regarding classical rehabilitation techniques, there is insufficient evidence to state that a particular approach is more effective in promoting gait recovery than other. Combination of different rehabilitation strategies seems to be more effective than over-ground gait training alone. Robotic devices need further research to show their suitability for walking training and their effects on over-ground gait. The use of FES combined with different walking retraining strategies has shown to result in improvements in hemiplegic gait. Reports on non-invasive BCIs for stroke recovery are limited to the rehabilitation of upper limbs; however, some works suggest that there might be a common mechanism which influences upper and lower limb recovery simultaneously, independently of the limb chosen for the rehabilitation therapy. Functional near infrared spectroscopy (fNIRS) enables researchers to detect signals from specific regions of the cortex during performance of motor activities for the development of future BCIs. Future research would make possible to analyze the impact of rehabilitation on brain plasticity, in order to adapt treatment resources to meet the needs of each patient and to optimize the recovery process.

Measurement of the depth of maximum of extensive air showers above 10{18} eV

We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

[Adverse reactions during biological therapy for psoriasis: results of a survey of the Spanish Psoriasis Group]

BACKGROUND

Biologic therapies have been a major breakthrough in the treatment of psoriasis because they are more selective and have a better short-term and medium-term safety profile. There are reliable data to support both the efficacy and the safety of these drugs. However, it is always useful to report the clinical experience of dermatologists who are experts in the use of biologic agents to treat psoriasis, particularly with regard to their safety.

MATERIAL AND METHODS

We present the results of a survey administered to the members of Spanish Psoriasis Group and based on a series of questions referring to the clinical safety of these agents. A total of 988 patients treated with efalizumab, infliximab, etanercept, and adalimumab were reported by 15 members of the group.

RESULTS

There was a particularly high proportion of reactions (34%) to infliximab infusions. Blood test abnormalities were detected in 13.25% of patients and infections in 12.24%, with one case of pulmonary tuberculosis. Attention is drawn to the adverse effects profile of efalizumab: de novo arthritis in 5.8% and rebound in 20.9% of patients.

CONCLUSION

The safety data provided by our study should be taken into account in view of the large number of patients recruited by dermatologists experienced in the use of this type of therapy.

[Spanish evidence-based guidelines on the treatment of moderate-to-severe psoriasis with biologic agents]

Psoriasis vulgaris is an inflammatory skin disease that is generally chronic and that affects between 1 % and 2 % of the population in industrialized Western countries. It is associated with a marked decline in quality of life. A wide range of treatments are currently available, although surveys conducted before the advent of biologic agents reflected a strong degree of dissatisfaction with the treatments then available. Extensive scientific evidence has been gathered on the safety of biologic agents, and this has led to a review of the role of systemic treatment in general and has allowed new therapeutic goals and strategies to be contemplated in patients with moderate-to-severe psoriasis. In this new situation, there is a need for Spanish guidelines on the treatment of moderate-to-severe psoriasis with biologic agents, drafted by consensus among specialists and ratified by the Spanish Psoriasis Group of the Spanish Academy of Dermatology and Venereology (AEDV). These guidelines should be evidence-based with regard to the pharmacologic characteristics, mechanism of action, administration route and regimen, efficacy, contraindications, adverse effects, and cost estimates of biologic agents approved for the treatment of moderate-to severe psoriasis in Spain.

[Consensus document on the evaluation and treatment of moderate-to-severe psoriasis. Spanish psoriasis group of the Spanish Academy of Dermatology and Venereology]

The treatment of psoriasis has been revolutionized by the introduction of biologic agents; these agents achieve skin clearance and long-term improvement without the risk of toxicity that has limited use of the classic systemic treatments. The role of systemic treatment in the management of psoriasis is being reviewed on the basis of a large volume of scientific evidence on the efficacy and safety of biologic agents, and new therapeutic goals and strategies are being devised for patients with moderate-to-severe psoriasis. This has led to the need to establish severity criteria that will provide the rationale for the indication of the different systemic agents currently available for the treatment of moderate-to-severe psoriasis, as well as therapeutic goals, efficacy measures, therapeutic strategies, screening protocols, and choice of treatment based on the risk-benefit ratio of the different agents. These criteria must be established through consensus by experienced dermatologists and based on available scientific evidence. The present document reflects the consensus of the Spanish Psoriasis Group on these different issues in the management of moderate-to-severe psoriasis.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

Study of the motion artefacts of skin-mounted inertial sensors under different attachment conditions

A common problem shared by accelerometers, inertial sensors and any motion measurement method based on skin-mounted sensors is the movement of the soft tissues covering the bones. The aim of this work is to propose a method for the validation of the attachment of skin-mounted sensors. A second-order (mass-spring-damper) model was proposed to characterize the behaviour of the soft tissue between the bone and the sensor. Three sets of experiments were performed. In the first one, different procedures to excite the system were evaluated to select an adequate excitation stimulus. In the second one, the selected stimulus was applied under varying attachment conditions while the third experiment was used to test the model. The heel drop was chosen as the excitation method because it showed lower variability and could discriminate between different attachment conditions. There was, in agreement with the model, a trend to increase the natural frequency of the system with decreasing accelerometer mass. An important result is the development of a standard procedure to test the bandwidth of skin-mounted inertial sensors, such as accelerometers mounted on the skin or markers heavier than a few grams.

A new platform based on IEEE802.15.4 wireless inertial sensors for motion caption and assessment

Systems for motion caption and assessment in biomechanics are mostly based on photogrammetry. These systems are restricted to the movement analysis lab and moreover, they are very expensive. New advances in MEMs (Microelectromechanical) and wireless technologies enable inertial sensing as an alternatives for motion caption. This paper presents a wireless inertial sensor including 3 linear accelerometers, 3 gyroscopes and 3 magnetometers. The IMU (inertial measurement unit) includes a IEEE802.15.4 compliant transceiver. The platform expands the frontiers of movement analysis for motion caption in real scenarios like sports and wearable robotics since it does not need structurated labs. Besides the advantages, the cost of the platform is much lower comparing actual photogrammetry systems.

The effectiveness of Iberian protected areas in conserving terrestrial biodiversity

The Iberian Peninsula harbors about 50% of European plant and terrestrial vertebrate species and more than 30% of European endemic species. Despite the global recognition of its importance, the selection of protected areas has been ad hoc and the effectiveness of such choices has rarely been assessed. We compiled the most comprehensive distributional data set of Iberian terrestrial plant and vertebrate species available to date and used it to assess the degree of species representation within existing protected areas. Existing protected areas in Spain and Portugal reasonably represented the plant and animal species we considered (73-98%). Nevertheless, species of some groups (amphibians, reptiles, birds, and gymnosperms) did not accumulate in protected areas at a rate higher than expected by chance (p > 0.05). We determined that to conserve all vertebrate and plant species in the Iberian Peninsula, at least 36 additional areas are needed. Selection of additional areas for conservation would be facilitated if such areas coincided with sites of community importance (SCI) designated under the European Commission Habitats Directive. Additional areas required for full representation of the selected plant and animal species all coincide with SCI in Spain. Nevertheless, the degree of coincidence varies between 0.3% and 74.6%, and there is a possibility that important areas for conservation occur outside the SCI. Our results support the view that current SCI can be used for prioritization of areas for conservation, but a systematic reevaluation of conservation priorities in Spain and Portugal would be necessary to ensure that effective conservation of one of European's most important biodiversity regions is achieved.

Design and validation of a rehabilitation robotic exoskeleton for tremor assessment and suppression

Exoskeletons are mechatronic systems worn by a person in such a way that the physical interface permits a direct transfer of mechanical power and exchange of information. Upper limb robotic exoskeletons may be helpful for people with disabilities and/or limb weakness or injury. Tremor is the most common movement disorder in neurological practice. In addition to medication, rehabilitation programs, and deep brain stimulation, biomechanical loading has appeared as a potential tremor suppression alternative. This paper introduces the robotic exoskeleton called WOTAS (wearable orthosis for tremor assessment and suppression) that provides a means of testing and validating nongrounded control strategies for orthotic tremor suppression. This paper describes in detail the general concept for WOTAS, outlining the special features of the design and selection of system components. Two control strategies developed for tremor suppression with exoskeletons are described. These two strategies are based on biomechanical loading and notch filtering the tremor through the application of internal forces. Results from experiments using these two strategies on patients with tremor are summarized. Finally, results from clinical trials are presented, which indicate the feasibility of ambulatory mechanical suppression of tremor.

Evaluation of Skin Viscoelasticity in Type 1 Neurofibromatosis Patients

Neurofibromatosis type 1 (NF1) is a frequent autosomal dominant disease characterized by cutaneous benign tumors called neurofibromas. Surgery takes an important place in managing these skin disorders. However, skin distensibility and softness of NF1 patients quickly offset the surgical benefit. The aim of this study was to determine the rheological behavior of neurofibromas and compare it with healthy skin in an attempt to comprehend what leads to this phenomenon. Thirty patients were admitted to this study. A group of 24 healthy control subjects was also included. The skin elasticity was assessed by a noninvasive in vivo suction device (Cutometer) including 5 consecutive suctions. The assessments were performed on neurofibroma skin, the supposedly healthy skin around neurofibromas and the healthy skin of control subjects. The extensibility at the first and the fifth traction in NF1 patients (neurofibromas and the supposedly healthy skin around it) was significantly different compared to the healthy skin of control subjects. The viscoelastic parameters obtained from the neurofibromas were significantly different in comparison to those obtained from the supposedly healthy skin of NF1 patients and the healthy skin of control subjects. The rheological profiles of the neurofibromas and the apparent healthy skin of NF1 patients demonstrated a hyperextensibility behavior, but in neurofibromas, the skin was unable to return to its initial position at the end of the stretch.

Prenatal stroke in a neonate heterozygous for factor V Leiden mutation

The authors report an infant with congenital hemiplegia associated to heterozygosity for factor V Leiden. Prenatal stroke in the left cerebral hemisphere was diagnosed by ultrasonography at the 28th week of pregnancy, and followed up until birth. Although neonatal neurologic examination was normal, a moderate right hemiparesis developed along the 1st months of life. Coagulation studies performed in the neonatal period and at the age of 18 months revealed activated protein C resistance due to factor V Leiden mutation (R506Q). There are some previous reports of stroke associated to this mutation in near or at term neonates, but to our knowledge this is the stroke detected at the most early stage of fetal development.

Erbium:Yag laser therapy of lichenoid red tattoo reaction

Delayed reactions caused by red tattoo pigments are often difficult to treat. We report a 31-year-old female patient with a lichenoid reaction to a red tattoo on the right ankle who was successfully treated with five sessions of a surgical Erbium:Yag laser, using several passes in each session. Our work leads us to consider that Er:Yag laser therapy may be an effective and safe treatment for these therapeutically challenging reactions.

Psoriasis, vasculitis and methotrexate

Report on the association of the psoriasis and vasculitis are a very infrequent in the literature. Such an association as been described in extensive psoriasis and arthropathy psoriasis. In this paper we described two cases in which psoriasis, vasculitis and nephropathy are present together. In both cases the association might be produced by methotrexate. In both cases methotrexate is possible uleashing.

Bullous scleroderma-like changes in chronic graft-versus-host disease

Cutaneous graft-versus-host disease (GVHD) is the most common clinical setting for GVHD after bone marrow transplantation. Chronic cutaneous GVHD is categorized according to the type of skin lesions into lichenoid and sclerodermoid variants, but bullous scleroderma-like changes are exceptional. Recently, we studied a patient with these alterations. This is the second case described in the literature.

Nine novel mutations in maturity-onset diabetes of the young (MODY) candidate genes in 22 Spanish families

The aims of this study were to estimate the prevalence of major maturity-onset diabetes of the young (MODY) subtypes in Spanish MODY families and to analyze genotype-phenotype correlations. Twenty-two unrelated pediatric MODY patients and 97 relatives were screened for mutations in the coding region of the glucokinase (GCK), hepatic nuclear factor- HNF-1alpha and HNF4alpha genes using PCR-single strand conformation polymorphism and/or direct sequencing. In families carrying GCK mutations, the influence of genetic defects on fetal growth was investigated by comparing the birth weights of 32 offspring discordant for the mutations. Mutations in MODY genes were identified in 64% of the families. GCK/MODY2 mutations were the most frequently found, in 41%: seven novel (R369P, S411F, M298K, C252Y, Y108C, A188E, and S383L) and 2 already described mutations. Four pedigrees (18%) harbored mutations in the HNF-1alpha/MODY3 gene, including a previously unreported change (R271G). One family (4%) carried a novel mutation in the HNF-4alpha gene (IVS5-2delA), representing the first report of a MODY1 pedigree in the Spanish population. The age at diagnosis was prepubertal in MODY2 index patients and pubertal in MODY3 patients. Overt diabetes was rare in MODY2 and was invariably present in MODY3 index patients. Chronic complications of diabetes were absent in the MODY2 population and were present in more than 40% of all relatives of MODY3. Birth weight was lower in the presence of a GCK fetal mutation when the mutation was of paternal origin. The MODY1 patient was diagnosed at 15 yr of age. She developed intermittent microalbuminuria despite good metabolic control, and severe late-onset complications were common within her family. Mutations in the GCK/MODY2 gene are the most common cause of MODY in our population as recruited from pediatric and adolescent index patients. The inheritance of GCK defects by the fetus results in a reduction of birth weight. Clinical expression of MODY3 and MODY1 mutations, the second and third groups of defects found, was more severe, including the frequent development of chronic complications.

Erosive pustular dermatosis of the scalp after skin grafting

Erosive pustular dermatosis of the scalp is a rare condition of unknown etiology that usually occurs in the elderly and is characterized by pustules that appear on the scalp leading to scarring alopecia. The histopathology is not specific. Its onset has been related with previous trauma on the scalp. Only three cases after skin grafting have been reported. We describe a case of erosive pustular dermatosis of the scalp appearing on a split-thickness skin graft placed after excision of a basal cell carcinoma.

Cloning of tissue-specific genes using serial analysis of gene expression and a novel computational substraction approach

A paradigm of molecular medicine is the identification of functionally specialized genes in the search of defects responsible for human disease. To identify novel genes relevant for thyroid physiology, we applied serial analysis of gene expression (SAGE) and identified 4260 tag sequences that did not match any known gene present in the GenBank database ("no-match" tags). These no-match tags represent still uncharacterized transcripts. Most of them are expected to correspond to housekeeping genes and only a few to genes with a tissue-restricted pattern of expression. To pinpoint the best candidates for tissue-specificity in a large series of tags, we used a computer-based approach. We compared the relative abundance of 80 no match tags in our thyroid SAGE library with the expression level in 14 other SAGE libraries derived from 9 different human tissues. Based on the expression data, we developed the "tissue preferential expression" (TPE) algorithm to discriminate tags expressed specifically in the thyroid. We then selected four tags as preferentially expressed in thyroid. Results were validated by RT-PCR and northern blot on multiple-tissue RNA samples. Finally, the screening of a thyroid cDNA library with expressed sequence tag (EST) sequences related to the selected tags allowed the isolation of four novel thyroid-specific cDNAs. We demonstrate that the computational substraction of SAGE tags by the proposed TPE algorithm is a rapid and reliable way to expedite the cloning of tissue-specific genes through the combined use of SAGE and EST databases.

Stress fracture of the femoral neck in a child. Case report and review of the literature

Fatigue fractures generally appear in normal bone following increased repetitive activity or strenuous exercise, when imbalance occurs between applied force and elastic resistance. Femoral neck fatigue fractures are most common in athletes and young military recruits; such fractures in children with open physes are very rare. This paper reports a fatigue fracture of the femoral neck in an 8-year-old girl presenting with pain in the anterior aspect of the right thigh, of one month duration and without evidence of previous injury. Bed rest and relief of weight bearing are indicated for nondisplaced compression fractures. Surgical treatment is indicated for tension fractures. In most cases, the outcome is favorable, and complications are rarely reported.

Cost evaluation of the medical management of neurofibromatosis 1: a prospective study on 201 patients

Neurofibromatosis 1 (NF1) is associated with many internal complications as well as skin manifestations, and patients may require a variety of medical and surgical interventions. We aimed to assess the medical needs of NF1 patients, and to evaluate the financial cost of the resources used for them in relation to the severity of the disease. We conducted a prospective analysis on a cohort of 201 patients in our referral centre for adults. Severity of the disease was assessed. Therapeutic management was considered as multidisciplinary if it required more than three different specialists. Plastic and dermatological surgery procedures performed were recorded. Hospital costs were computed over a 3-year period and included all hospitalization days, clinic visits and procedures performed in all departments where the patients were admitted. One hundred and thirty-seven patients had at least one out-patient procedure or one hospitalization during the follow-up period. The mean cost per patient per year was pound810 (median 240; range 0-13, 860). Multidisciplinary procedures were more frequent in moderately and severely affected NF1 patients than in milder cases (P < 0. 0001); hence, the costs for moderate and severe cases were higher than for less severe groups (P = 0.005). Plastic and/or dermatological surgery was performed with the same frequency in the different severity groups (71%). Regardless of the presence of serious intractable complications, the patients' priority is for treatment of the disfigurement due to the disease. The management of these patients can be considered relatively inexpensive from the viewpoint of the healthcare system.

Serial analysis of gene expression as a tool to assess the human thyroid expression profile and to identify novel thyroidal genes

The assessment of the expression profile of normal human thyroid tissue using serial analysis of gene expression (SAGE) generated a collection of 10,994 sequence transcripts (tags). Each tag represented a messenger RNA transcript, and, in total, 6099 different tags could be distinguished. The presence and abundance of thyroid-specific transcripts showed the overall expression profile to be from a normal thyroid cell. The expression level of several transcripts was confirmed on Northern blot. Seventy percent of tags could not be attributed to a known human gene and, therefore, possibly correspond to novel genes putatively involved in thyroid function. The tag sequence generated by the SAGE technique can be used to further characterize these novel genes. In this way, application of the SAGE technique to thyroid tissue gives insight in the expression profile of a normal thyroid gland and provides the information to characterize novel genes involved in thyroid pathology, such as congenital hypothyroidism and thyroid neoplasia.

Complication rates associated with different treatments for mandibular fractures

PURPOSE

This study compared the complication rate with different types of mandibular fracture treatment (maxillomandibular fixation, 2-mm miniplates, 2.4-mm AO plates, and 2.7-mm AO plates).

PATIENTS AND METHODS

A total of 245 patients who presented with 386 fractures were retrospectively analyzed. Patient characteristics, type of fracture, severity of fracture, type of treatment used, and occurrence of complications were recorded. Statistical analysis was used to compare complication rates, fracture severity, and type of treatment.

RESULTS

There were no differences in the complication rates for the different types of treatment. There was a significant correlation (P < .05) between fracture severity and the overall complication rate, postoperative infection, and postoperative malocclusion, but there was no significant correlation between these complications and the type of treatment applied.

CONCLUSION

The occurrence of postoperative complications in the treatment of mandibular fractures is fundamentally related to the severity of the fracture rather than to the type of treatment used.

Malignant fibrous histiocytoma of the scalp. Multidisciplinary treatment

BACKGROUND

Malignant fibrous histiocytomas (MFH) are uncommon in the skin, and even less frequent on the scalp. On the scalp they are often very difficult to excise and it is even more difficult to close the resulting wound.

OBJECTIVE

To review all malignant fibrous histiocytomas diagnosed and treated in our Department during the past 6 years, and to describe the multidisciplinary procedure employed to treat one special case of aggressive malignant fibrous histiocytoma on the scalp that recurred twice.

RESULT

Malignant fibrous histiocytomas represent 0.01% of malignant cutaneous tumors in our area. The immediate results after a multidisciplinary treatment performed on a recurrent malignant fibrous histiocytoma located on the scalp were excellent, but recurrence was observed 6 months later. Two years later we have also treated another case of MFH on the scalp. The same surgical technique was performed, but the patient received high-dose-methotrexate-based neoadjuvant chemotherapy (HD-MTX). One year later, this patient is still alive and no signs of recurrence have been detected.

CONCLUSION

When malignant fibrous histiocytoma occurs on the scalp it must be treated immediately by means of an excision with a large peripheral edge of 2 cm from the visual or CAT limits of the lesion, since the first treatment must be definitive.

RYBP, a new repressor protein that interacts with components of the mammalian Polycomb complex, and with the transcription factor YY1

The products of the Polycomb group (PcG) of genes are necessary for the maintenance of transcriptional repression of a number of important developmental genes, including the homeotic genes. A two-hybrid screen was used to search for putative new members of the PcG of genes in mammals. We have identified a new Zn finger protein, RYBP, which interacts directly with both Ring1 proteins (Ring1A and Ring1B) and with M33, two mutually interacting sets of proteins of the mammalian Polycomb complex. Ring1 binds RYBP and M33 through the same C-terminal domain, whereas the RYBP-M33 interaction takes place through an M33 domain not involved in Ring1 binding. RYBP also interacts directly with YY1, a transcription factor partially related to the product of the Drosophila pleiohomeotic gene. In addition, we show here that RYBP acts as a transcriptional repressor in transiently transfected cells. Finally, RYBP shows a dynamic expression pattern during embryogenesis which initially overlaps partially that of Ring1A in the central nervous system, and later becomes ubiquitous. Taken together, these data suggest that RYBP may play a relevant role in PcG function in mammals.