Cellular processes involved in human epidermal cells exposed to extremely low frequency electric fields.

We observed on different tissues and organisms a biological response after exposure to pulsed low frequency and low amplitude electric or electromagnetic fields but the precise mechanism of cell response remains unknown. The aim of this publication is to understand, using bioinformatics, the biological relevance of processes involved in the modification of gene expression. The list of genes analyzed was obtained after microarray protocol realized on cultures of human epidermal explants growing on deepidermized human skin exposed to a pulsed low frequency electric field. The directed acyclic graph on a WebGestalt Gene Ontology module shows six categories under the biological process root: "biological regulation", "cellular process", "cell proliferation", "death", "metabolic process" and "response to stimulus". Enriched derived categories are coherent with the type of in vitro culture, the stimulation protocol or with the previous results showing a decrease of cell proliferation and an increase of differentiation. The Kegg module on WebGestalt has highlighted "cell cycle" and "p53 signaling pathway" as significantly involved. The Kegg website brings out interactions between FoxO, MAPK, JNK, p53, p38, PI3K/Akt, Wnt, mTor or NF-KappaB. Some genes expressed by the stimulation are known to have an exclusive function on these pathways. Analyses performed with Pathway Studio linked cell proliferation, cell differentiation, apoptosis, cell cycle, mitosis, cell death etc. with our microarrays results. Medline citation generated by the software and the fold change variation confirms a diminution of the proliferation, activation of the differentiation and a less well-defined role of apoptosis or wound healing. Wnt and DKK functional classes, DKK1, MACF1, ATF3, MME, TXNRD1, and BMP-2 genes proposed in previous publications after a manual analysis are also highlighted with other genes after Pathway Studio automatic procedure. Finally, an analysis conducted on a list of genes characterized by an accelerated regulation after extremely low frequency pulsed stimulation also confirms their role in the processes of cell proliferation and differentiation. Bioinformatics approach allows in-depth research, without the bias of pre-selection, on cellular processes involved in a huge gene list.

Statistical validation of the acceleration of the differentiation at the expense of the proliferation in human epidermal cells exposed to extremely low frequency electric fields.

An acceleration of differentiation at the expense of proliferation is observed in our previous publications and in the literature after exposure of various biological models to low frequency and low-amplitude electric and electromagnetic fields. This observation is related with a significant modification of genes expression. We observed and compared over time this modification. This study use microarray data obtained on epidermis cultures harvested from human abdominoplasty exposed to ELF electric fields. This protocol is repeated with samples collected on three different healthy patients. The sampling over time allows comparison of the effect of the stimulus at a given time with the evolution of control group. After 4 days, we observed a significant difference of the genes expression between control (D4C) and stimulated (D4S) (p < 0.05). On the control between day 4 and 7, we observed another group of genes with significant difference (p < 0.05) in their expression. We identify the common genes between these two groups and we select from them those expressing no difference between stimulate at 4 days (D4S) and control after 7 days (D7C). The same analysis was performed with D4S-D4C-D12C and D7S-D7C-D12C. The lists of genes which follow this pattern show acceleration in their expressions under stimulation appearing on control at a later time. In this list, genes such as DKK1, SPRR3, NDRG4, and CHEK1 are involved in cell proliferation or differentiation. Numerous other genes are also playing a function in mitosis, cell cycle or in the DNA replication transcription and translation.

Adverse reactions and events related to musculoskeletal allografts: reviewed by the World Health Organisation Project NOTIFY.

PURPOSE: The use of bone and connective tissue allografts has grown rapidly and surpassed the use of autografts in many countries. Being of human origin, bone and tendon allografts carry the risk of disease transmission and complications have been reported. As part of the Project NOTIFY led by the World Health Organisation, an effort to improve recognition, reporting, tracking and investigation of adverse outcomes of allografts was initiated, achieving a comprehensive review of associated disease transmission and failures. Those involving the use of musculoskeletal allografts are reported here. A major objective is to involve orthopaedic surgeons in the improvement of the safe use of the musculoskeletal allografts. METHODS: We reviewed the medical literature, requested reports from surgeons in selected professional organisations and informally surveyed tissue bank organisations and selected tissue bank professionals to discover reported and unreported cases of adverse outcomes. We analysed each case to decide the likelihood that the complication was truly allograft related. RESULTS: The efficiency of the procedures involved in bone banking and bone and tendon allograft has improved significantly during the last three decades. The evolution of the incidence of reported adverse reactions and events reflects positively on the safety of transplanted tissues. Cases of bacterial and viral transmission by bone and tendon allografts occurred mainly with those that contained viable cells, were not processed to remove cells, or were not disinfected or sterilised. We documented cases of transmission of human immunodeficiency virus (HIV), hepatitis C virus (HCV), human T-lymphotropic virus (HTLV), unspecified hepatitis, tuberculosis and other bacteria. Reporting of these adverse outcomes has led to corrective actions and has significantly improved the safety of allograft use. However, it is probable that not all cases have been reported and investigated. CONCLUSIONS: Considering the high quality standards achieved in many countries, the best approach for further improvement in the safety of allografts is through a systematic reporting of all serious adverse reactions and events in the context of a global biovigilance programme.

[The Department of Orthopaedics and Traumatology of the University Clinics of Brussels, Erasme Hospital]. / Le Service d'Orthopédie-Traumatologie des Cliniques Universitaires de Bruxelles, hôpital Erasme.

On the occasion of the thirty years since its inauguration, the Department of Orthopaedics and Traumatology of the University Hospital Erasme reviews the milestones of its development. Various original new techniques have been implemented: monitoring of implants using strain gauges, external fixation of the limbs, external minifixation, miniinvasive anterior approach in hip arthroplasty, knee ligamentoplasties, orthopaedic microsurgery and composite tissue allotransplantation. The care of aged patients takes place in close collaboration with the Department of Geriatrics. Two new clinical units have been created, the Unit of Hand and Peripheral Nerve Surgery, and the Centre for Sports. The Department has organized an efficient Bone Bank. The new day care hospital improves the possibilities of ambulatory surgery. The article details as well the activities of teaching and research of the members of the Department.

[The Orthopaedic and Traumatology Research Laboratory]. / Le Laboratoire de Recherche en Orthopédie Traumatologie - LROT.

The history of the Orthopaedics and Traumatology Research Laboratory (LROT) is summarized during the last thirty years. The approach, initially focused on bone biomechanics and strength of materials, underwent a rapid diversification as expressed by the list of research topics: monitoring of bone healing; bone strains measurements for different level of activities including microgravity and prevention of disuse osteoporosis; biological effects of electromagnetic fields; evolution of the viscoelastic properties of the callus during bone healing; improvement of the osteoinductive properties of bone substitutes produced by the Tissues Bank of the University Hospital Erasme; Kashin-Beck disease; SICOT telediagnostic, and biomechanics of threaded implants. Those topics, event the most fundamental ones, have immediate significant clinical applications allowing a decrease of the morbidity and an acceleration of the rehabilitation of the patients. The results show the need of multidisciplinary collaborations coordinated around one autonomous laboratory, able to handle specific protocols requiring a dedicate environment.

[Historical review of the treatment of fractures. Contribution of the Belgian surgery to the origin and development of osteosynthesis]. / Aperçu historique du traitement des fractures. Apport de la chirurgie belge dans la naissance et le développement de l'ostéosynthèse.

The word osteosynthesis was proposed by A. Lambotte in 1904. His definition, given in 1908, is still valid today: "Osteo-synthesis is the artificial contention of the bone fragments of fractures, by special devices acting directly on bones, exposed or not, with the aim to strongly fix them in their original position". The authors review the methods of contention before the invention of osteosynthesis and later the developments of bone fixation techniques. They insist in particular on the durable innovations of various pioneers including A. Lambotte, R. Danis, R. Hoffmann and G. Küntscher. The School of Brussels has been implicated in the developments and conceptualisation of osteo-synthesis.

[Evolution of the biomechanical principle of osteosynthesis]. / Evolution du principe biomécanique des techniques d'ostéosynthèse.

Through the technological evolution of the medical devices used for the treatment of bone fractures, two main concepts are in opposition: the internal rigid and the external elastic fixations. For forty years, the limitation due to the mechanical resistance of the materials have determined the various methods of treatment of fractures and influenced the comprehension of the physiopathology of bone healing. Two main figures of the Belgian orthopaedics and traumatology, Robert Danis and Franz Burny, had a determinant impact in this evolution.

[The Tissue Bank of the University Hospital Erasme]. / La Banque de Tissus de l'Hôpital Universitaire Erasme.

The evolution of the Tissue Bank belonging to the University Hospital Erasme is summarized during its 13 years of experience. In parallel with this evolution, the important modifications of the legislation, the selection criteria and the bone graft processing are reported. The significant improvement of the safety of the allograft related to the risk of infection is also mentioned. In constant progression, the ongoing research within the BTE studies the osteogenic activity of the graft, mostly of bone demineralized matrix.

[Effects of electric and electromagnetic fields on cell differentiation and application in orthopedic and trauma surgery]. / Effets des champs électriques et électromagnétiques sur la différenciation cellulaire et leur intérêt en chirurgie orthopédique et traumatologique.

The discovery of the dynamic electrical properties of bone is at the origin of the therapeutical application of the electromagnetic fields in Orthopaedics and Traumatology. The first empirical treatment of non-union, fresh fractures and osteonecroses allowed the observation of several effects which, without justifying a systematic clinical application, encouraged further fundamental research. The results of this work realized during 35 years are summarized in the present article. After exposure to specific electromagnetic fields, we observed a modification of the DNA activity and an increased production of RNA. During enchondral ossification, the amount of acid GAGS increased faster and the ossification of the primary ossification point is accelerated. On fresh fractures, the rigidity of the callus increased faster. Finally, the microarrays analyses show an upregulation of mRNA involved in cellular differentiation and proliferation. The mRNA responsible of the production of BMP-2 is significantly increased, explaining the main results observed after the expense of experimental models of the bond tissues. All the observed results are in favour of an acceleration of the cellular differentiation at the expense of the proliferation.

Effects of physical environment on the evolution of Kashin-Beck disease in Tibet.

In previous studies we observed a proximo-distal gradient of lesion frequencies along the limb, with the distal joints being the most often affected. This suggests an associated effect of environmental factors on the most exposed joints. On a population of 820 children (mean age 13 years) of endemic areas distributed in groups of healthy and severity stages I to III of KBD (Kashin-Beck disease), the effects of different working activities were studied. Heavy work like that of a ploughman were compared to light physical work, e.g. school children, and exposure to cold and history of frostbite were also considered. The most severe stages, II and III, were present in 72% of the ploughman vs. 29% of the schoolchildren, 70% of the shepherds vs. 30% (p < 0.001) of the schoolchildren, and in 65% of the shepherds working in winter vs. 40% of those working in the other seasons (p < 0.001). In the group with history of frostbite, 58% present the severest stages vs. 40% without (p < 0.001). The results confirm a highly significant relation between microtrauma and cold and the severity of the KBD alterations.

[Validation of a new in vivo measurement method to measure subsidence of a cemented Exeter femoral stem]. / Validation d'une méthode de mesure de l'enfoncement d'un implant fémoral cimenté de type Exeter.

PURPOSE OF THE STUDY: Total hip arthroplasty has become one of the most common procedures in orthopedic surgery. These patients must nevertheless be followed with care due to the risk of instability. Knowledge of early migration behavior can provide an indirect assessment of implant fixation. The purpose of this work was to develop a new measurement tool for early assessment of the femoral component. MATERIAL AND METHODS: We analyzed the x-rays of ten Exeter stems (Stryker-Howmedica) implanted between 1996 and 2001 using a simple software designed to calculate the vertical subsidence of each implant. The technical precision and inter-observer reproducibility were checked. RESULTS: The software provided a precision of 0.14-0.3 millimeters. The overall precision of the technique was 1.2 millimeters. There was no statistically significant inter-observer variability. We observed a mean subsidence of 1.3+/-0.7 millimeters at six Months, followed by no further migration. DISCUSSION AND CONCLUSION: This new method was found to be reliable. It is useful for identifying implant migration at different bone-cement-implant interfaces. The time course of subsidence appears to be important to determine threshold values for failure. This tool provides an easy-to-use method for both retrospective and prospective analysis. With minor modifications of the software program, this tool can be used for other types of implants.

Protracted systemic changes in bone biology after segmented unloading in the rat.

To investigate whether the decreased bone formation observed in most experimental situations of disuse was caused by an increased inhibition by the bone microenvironment of osteoblast (OB) proliferation, we studied the inhibiting power on ROS 17/2.8 proliferation of the bone marrow extracellular fluid (IPEF) in loaded and unloaded bones of rats submitted to two situations of partial disuse: tail suspension (TS) for 3 days to 2 weeks and around the knee tenectomy (KT) for 2-10 weeks. Histomorphometric parameters and osteoblast precursors dynamics were studied in parallel. Bone volume was lost in the unloaded bones, but not in loaded bones, in both experimental situations. Bone formation was low at early times (7-14 days) in TS rats. However, in KT at later times (4-10 weeks), the osteoblastic index of the unloaded tibia was increased. IPEF was not increased in the unloaded bones 3-7 days after TS. It was decreased later in the course of unloading (after 2 weeks of TS and 2-10 weeks after KT). This decrease was observed in the loaded bones as well. Unexpectedly, we also found that the number of FCFUs was decreased in both loaded and unloaded limbs in TS and KT, and that the yield of cells obtained in primary culture from tibial metaphysis was decreased in both tibiae from KT animals. These data show that an increased IPEF does not play a role in the early inhibition of bone formation responsible for the loss of bone after unloading in the TS model. Its later decrease could be permissive for the increased osteoblastic index observed in the KT model. They also show that, contrary to the usual assumptions, bone biology is changed all over the skeleton after partial unloading, even if the changes result in bone loss in the unloaded bones only. Thus, as yet, unidentified systemic factors probably superimpose on the local factors that control bone volume.

[The orthopedics-traumatology department]. / Le Service d'Orthopédie-Traumatologie.

The Department is involved in clinical and research activities. We pioneered the clinical application of "smart of Orthopaedic implants". The monitoring concept, bringing a high added value, helps in assessing fracture healing or implant fixation. The technique, featuring the 21st century, also requires advanced knowledge in biomaterials. Such implants have been used during the ESA Parabolic Flight Campaigns. These measurements are a prerequisite to establish prevention programs of the bone demineralisation during space flights but also in disuse osteoporosis. The Department is deeply involved in external fixation. In vitro studies of the mechanical insertion and holding parameters of external fixation pins have been performed to produce new implants, which efficiency has been proved by a clinical study. We defined original clinical principles of external fixation as its use in upper limb indications, to maintain microsurgery transplant, preserving devascularization and providing adequate fixation. Our biomechanical approach of the upper limb, now confirmed by others research groups, questioned old clinical concepts. The isokinetic evaluation assesses the dynamic function of articulations, i.e. after arthroplasty, and is also used for medico-legal evaluation. The clinical research touches orthopaedic (or systemic) diseases as algodystrophy, Kienböck disease, Kashing Beck. We conducted a multidisciplinary research on the effect of electromagnetic fields (EMF) on cells differentiation. In addition to possible healing properties, it helps as an objective support to analyse the exposure to the environmental EMF.

Anthropometry and clinical features of Kashin-Beck disease in central Tibet.

We compared two different populations living in central Tibet with the purpose of establishing standard values for different anthropometric parameters in a rural population. Later on, these values were used as references for a similar study on a KBD population. One group (KBD) (n=1,246) came from the endemic areas, and the other group, serving as the control population (n=815), came from non-endemic areas. Both groups included children and adults and were of the Mongoloid type; they were farmers or semi-nomads. Height, weight, segment length, joint perimeter, joint diameter, joint movement were recorded. Also more subjective information such as general feeling of tiredness, rapid fatigue at work, work limitation, joint pain, muscle weakness, muscular atrophy, dwarfism, flatfoot, and waddling gate was also collected. Those variables were compared between the two groups.

The anatomical distribution of radiological abnormalities in Kashin-Beck disease in Tibet.

A radiological study of osteoarticular changes in Kashin-Beck Disease (KBD) was undertaken on the appendicular skeleton in 105 patients with KBD, in 31 healthy subjects living in an endemic area and in 30 healthy subjects living in a non-endemic area. The bone age was delayed in all three populations with no significant difference between the three studied Tibetan populations. Radiological changes occur in 56% of patients with KBD, and are usually bilateral. An analysis of the distribution of lesions shows a proximo-distal gradient. The changes are more common in the distal aspect of the limb and the lower limb is involved more commonly than the upper limb. The foot and ankle are involved in 89.5% of cases. The radiological changes and their distribution might be explained by the hypothesis of inhibition of angiogenesis by mycotoxins, exacerbated by chemical and physical environmental factors.

Histology of Kashin-Beck lesions.

There are few papers in existence describing the histopathology of Kashin-Beck disease. The few existing papers mention chondronecrosis within the epiphyseal primodium and metaphyseal cartilage. In the present study, two series of samples were available for histology: supernumerary fingers removed from young subjects and intra-articular bodies collected in more advanced cases of the disease. The prevailing characteristic of the samples is the absence of vascularisation within the proximal cartilage end plate of the phalanx associated with an alteration of the epiphyseal bone formation. These observations suggest that Kashin-Beck disease could develop from an alteration of the angiogenesis of the metaphyseal cartilage resulting in degeneration with consequent joint dysplasia, which may be associated with a decrease in growth of the diaphyseal bones.

The prevalence of mycotoxins in Kashin-Beck disease.

Mycotoxins are naturally occurring toxic chemical compounds produced by fungi infesting agricultural crops both during their growth and storage. Such secondary metabolites, when ingested, can produce toxic syndromes in humans. As it has been suggested that mycotoxins might be involved in the development of Kashin-Beck disease (KBD), we undertook a survey of barley grains of KBD-affected families and non-affected families in that country. We found, by thin layer chromatography, a hitherto unknown metabolite of Alternaria sp. This was especially common on the barley grains of KBD-affected families.

Effects of physical therapy on patients with Kashin-Beck disease in Tibet.

A clinical trial of physical therapy treatment for patients suffering from Kashin-Beck disease (KBD) has been carried out in Tibet. One-hundred and thirty-five patients with Kashin-Beck disease were allocated to either physical therapy (72 patients) or prescription of multivitamins (63 patients). The patients were followed for 4 years. This study suggested a beneficial effect of physical treatment.

Osteobiology, strain, and microgravity. Part II: studies at the tissue level.

Loading microgravity, and/or defective mechanical strain-forces have important effects on bone cells and bone quality and quantity. The complex mechanisms induced by strain and microgravity on bone cells have been reviewed in Part I of this paper. In Part II, we have considered the data on the alterations induced by unloading and microgravity on the skeleton and the mechanisms that are involved at the tissue level in animals and humans.