Sleep and memory consolidation in aging: A neuroimaging perspective.

Recently acquired information is strengthened and consolidated during sleep. For hippocampus-dependent memory, this process is assumed to occur mainly during slow wave sleep. Changes in sleep patterns in older adults can contribute to the disruption of the consolidation process during sleep and thus lead to cognitive impairment. Current findings suggest that reduced gray matter volume, particularly in frontal areas, Aß and tau accumulation in combination with age-related changes of specific oscillations during sleep may contribute to memory deficits. This non-exhaustive review aims at providing a comprehensive picture of the associations between sleep changes and memory consolidation in aging, mainly based on neuroimaging studies. Overall, data confirm the utmost importance of sleep for healthy aging and the need to develop interventions aiming at improving sleep to reduce cognitive decline observed with advancing age.

[Reanimation de l'extension du pouce par transfert de l'extensor indici proprius chez les enfants atteints de pouce flexus adductus congenital]. / Réanimation de l'extension du pouce par transfert de l'extensor indici proprius chez les enfants atteints de pouce flexus adductus congénital.

Congenital clasped thumb is a rare congenital deformity characterized by a permanent contracture of the thumb metacarpo-phalangeal joint. Surgical option often raise in case of failure of the orthopaedic method. We wanted to evaluate the use of the extensor proprius indici (EPI) tendon to reanimate thumb extension in children affected by congenital clasped thumb. We made a retrospective review of children operated in our center between 2005 and 2019. We operated eight children (twelve hands) over this period: nine were grade I, two grade II and one case grade III (arthrogryposis). Medium age at surgery was 18 months (10 to 23 months). In each case, EPI tendon transfer was realized and sutured to the extensor pollici longus. Children were seen in consultation at six weeks postoperative and then mean follow-up was nineteen months. Seven children (87.5%) had a physiologic thumb extension at six weeks. One case of partial loss of extension on the index was noted. One second time of surgery was necessary to change the course of EPI transfer. At six months postoperative, all children could use their thumb with an extension similar to the opposite thumb. Surgery must be proposed in congenital clasped thumb persistent after at least four months of orthopaedic treatment or in cases of severe deformity. Tendon transfer using EPI must be proposed first given the good functionnal results and low morbidity.

Correlation between magnetic resonance, X-ray imaging alterations and histological changes in an ovine model of age-related disc degeneration.

Sheep are one of the many animal models used to investigate the pathophysiology of disc degeneration and the regenerative strategies for intervertebral disc (IVD) disease. To date, few studies have thoroughly explored ageing of ovine lumbar IVDs. Hence, the objective of the present study was to concomitantly assess the development of spontaneous age-related lumbar IVD degeneration in sheep using X-ray, magnetic resonance imaging (MRI) as well as histological analyses. 8 young ewes (< 48 months old) and 4 skeletally mature ewes (> 48 months old) were included. Disc height, Pfirrmann and modified Pfirrmann grades as well as T2-wsi and T2 times were assessed by X-ray and MRI. The modified Boos score was also determined using histology sections. Pfirrmann (2 to 3) and modified Pfirrmann (2 to 4) grades as well as Boos scores (7 to 13) gradually increased with ageing, while T2-weighted signal intensity (1.18 to 0.75), T2 relaxation time (114.36 to 70.65 ms) and disc height (4.1 to 3.2 mm) decreased significantly. All the imaging modalities strongly correlated with the histology (p < 0.0001). The present study described the suitability of sheep as a model of age-related IVD degeneration by correlation of histological tissue alterations with the changes observed using X-ray and MRI. Given the structural similarities with humans, the study demonstrated that sheep warrant being considered as a pertinent animal model to investigate IVD regenerative strategies without induction of degeneration.

[Median nerve compression in the carpal tunnel in children - a delayed diagnosis. About 20 clinical cases]. / La compression du nerf médian dans le canal carpien chez l'enfant ­ un diagnostic retardé. À propos de 20 cas.

OBJECTIVES: The carpal tunnel syndrome is rare in children. We performed a retrospective study of 10 children. The aim is to show that the diagnosis of carpal tunnel syndrome is difficult in children. PATIENTS AND METHODS: We identified all children with median nerve compression in the carpal tunnel between 2010 at 2020, managed in our service. RESULTS: Ten children with 20 hands included. There was different etiologies of carpal tunnel syndrome: 5 lysosomal storage diseases, 4 idiopathic carpal tunnel syndrome, 1 genodermatose, 1 Byler syndrome and 1 VACTERL syndrome. Common presenting symptoms were pain (five patients) and under use of fingers (five patients). Two children had opposition deficit of the thumb. We operated 19 hands. Median age at diagnosis was 4 years and 7 months. One children or 2 hands had a reanimation of opposition by tendinous transfer of flexor digitorum superficialis tendon of the ring finger. All children had a complete regression of the painful symptoms, a use improvement of fingers and recovery of the opposition of the thumb. CONCLUSION: The diagnosis of carpal tunnel syndrome is difficult in children. It is common to be confronted with an advanced clinical symptoms. The atypical symptoms may cause diagnostic delay. Due to the quality of the clinical results obtained, we recommend open carpal tunnel release even when the diagnosis seems delayed. LEVEL OF EVIDENCE: IV.

Negative Pressure Wound Therapy in children: A 25 cases series.

Negative Pressure Wound Therapy is a device applied to a wound that causes local depression. There are a few series showing the effectiveness of this treatment in Pediatric. The objective of this work is to try to clarify the indications in children. This is a retrospective series of 25 children between 2004 and 2019. The inclusion criteria were all children with a wound treated with Negative Pressure Wound Therapy. The characteristics retained were their age, the context of occurrence, the treatment time, the depression applied, the technique of skin covering wound and the average healing time. We included 25 patients. The average age was 8.8 years. The context of the wound occurrence was mainly a road (44%) or a domestic (36%) accident. Substance losses were mainly located in the lower limb (84%). The depression applied was -90mmHg. The healing time was 18.4 days. Thin skin grafting was the main method chosen (88%). No complications related to Negative Pressure Wound Therapy equipment have been identified. Despite the weakness of the literature and the lack of consensus regarding its use, Negative Pressure Wound Therapy is an essential therapy in pediatric. It is a simple and effective technique in children. It can reduce the need for flaps coverage, even in the event of exposure of noble elements. The flaps should not, however, be excluded from the decision-making algorithm, on pain of complications or sequelae.

Long-term behavior of the vascularized fibular free flap for reconstruction of bony defects in children.

OBJECTIVE: Bony resection in children presents a unique reconstructive challenge because of future growth potential. To achieve limb salvage and provide the patient with a functional extremity, vascularized free fibula transfer has become the workhorse for bony reconstruction. The authors present their reconstructive experience using vascularized fibula flaps in a group of pediatric patients. PATIENTS AND METHOD: This is a monocentric, retrospective study of 25 pediatric patients who underwent reconstruction of bony defects with a vascularized fibula flap from 2004 to 2017. Perioperative and long-term complications were noted. Functional outcomes were analyzed. RESULTS: Twenty-five patients with a mean age of 10 years were included. The etiology was tumor for 21 of them and 4 had neurofibromatosis. Median follow-up was 86 months. Overall, survival was 92 percent and flap survival was 100 percent. Perioperative surgical complication rate was 32 percent. The overall union rate was 87 percent following supplemental bone grafting. 67 percent of the lower limb fibula presented hypertrophy, with a mean hypertrophy of 154 percent. Median time to union was 15 months. Leg-length discrepancy was present in 5 patients. Mean Musculoskeletal Tumor Score was 23. CONCLUSION: Vascularized fibula free flap is the ideal material for long bone reconstruction with a definitive result. It allows children with early ambulation, provides good functional outcomes and improve their quality of life.

Management of loss of tissue substance in children's limbs. What are the salient peculiarities? A proposed algorithm.

Loss of tissue substance in children's limbs has the same etiologies and in many cases, the same severity as in adults' limbs, and the means placed at the disposal of a surgeon are likewise comparable. It may nonetheless prove difficult to strategically position the different treatment methods in a decision-making tree. After all, a child presents numerous peculiarities: high quality of vascularization (both microcirculation and macrocirculation), better ability to achieve nerve regeneration and durable bone consolidation and, last but not least, a pronouncedly superior overall functional prognosis. Moreover, a child's future needs to be taken into account ; it is not only cicatrization per se, but also the quality of healing that should dictate therapeutic choices, which will consequently be determined in view of avoiding functional disorders during the growth process. On the basis of their experience and following a review of the literature, the authors have assessed the interest of each relevant technique and drawn up a decision-making tree.

[Pollicization in the management of congenital hypoplasias and aplasias of the thumb, functional results, about 13 cases]. / Pollicisation dans la prise en charge des hypoplasies et aplasies congénitales du pouce, résultats fonctionnels, à propos de 13 cas.

INTRODUCTION: Pollicization of the index finger as a treatment for aplasia and severe congenital thumb hypoplasia remains a demanding surgical procedure. In aplasias, it is generally well-accepted, less in hypoplasias. However, it is often the only solution to give back to the child the possibilities of a pollici-digital grip, guaranteeing an excellent function of the hand. We decided to evaluate the long-term results of this intervention. MATERIAL AND METHODS: We reviewed all children operated of index pollicization for a congenital aplasia or hypoplasia of the thumb between 2006 and 2018. The evaluation was performed with a specialized reeducator. The analytical and functional characteristics of the neo-thumbs were evaluated, as well as the consequences on the daily life of the child. RESULTS: Thirteen pollicisations were performed on 10 patients. The mean age at surgery was 21 months (10; 43). It was a Blauth stage IIIB in 1 case, IV in 5 cases, and V in 7 cases. Seven children, and eight hands, could be evaluated. The average postoperative follow-up was 6.5 years. The mean age at the examination was 7.7 years (3.3, 12.1). The mean Percival score was 18 out of 22. The adapted video-assisted scoring system had an average score of 11 out of 14. Children described a momentary psychosocial discomfort for 5 of them, and still present in 3 of them. CONCLUSION: The pollicization of the index finger in congenital aplasia or severe hypoplasia (stage IIIB and IV) of the thumb remains for us the only way to create a sensitive thumb, mobile, with satisfactory strength and appearance, and to bring a normal function of the hand. The evaluation of our functional results are good to very good in the majority of patients, and show the benefits give by this intervention.

Fatty acid supplements improve hair coat condition in rhesus macaques.

As captive rhesus macaques often exhibit hair loss, alopecia was quantified and behavior was recorded before, during, and after fatty acid supplementation in six macaques. Fatty acid treatment was associated with a decrease in alopecia and in self-grooming behavior. Therefore, fatty acids may be a viable treatment for alopecia in some captive primates.

[Vascular relationships of the right great splanchnic nerve in the thorax]. / Rapports vasculaires thoraciques du nerf grand splanchnique droit.

AIM: The surgical assumption of responsibility of the pancreatic pain requires either a truncular coelioscopic or radicular neurectomy of greater splanchnic nerves (gsn). The goal of our work is to describe the way and relations of the right gsn which are variable and rarely described. This constitutes an undeniable peroperational hemorrhagic risk during splanchnicectomy. MATERIAL AND METHODS: After a double side thoracotomy and a bilateral sterno-clavicular desarticulation on 15 adult cadaveric subjects preserved by method of Winckler we removed the sterno-costal drill plate as well as the ventral rib arch and proceeded to a mediastinal evisceration of the thorax. Then we respected only the thoracic aorta and the oesophagus, the azygos venous system, the thoracic duct and the thoracic sympathetic chain. In some of the subjects, the azygos vein was injected (after catheterization of its stick) using gelatine coloured with blue paint. We studied the way and vascular relations of the right gsn. We measured the transverse distances between the origin of the gsn on one hand and the longitudinal axes of the azygos vein and the thoracic duct on the other hand. RESULTS: The relations of the right gsn trunk during its way related to the azygos vein in particular its constitutive origin and its affluents: ascending lumbar vein and twelfth intercostal vein. Sometimes the thoracic duct even a lymphatic node was near the gsn in the posterior infra-mediastinal space. A classification of the way and vascular relations of the right gsn in the thorax identified 3 anatomical types. The average distances separating the right gsn on one hand from the azygos vein and the thoracic duct on the other hand were respectively 5.7 mm and 11.2 mm. CONCLUSION: The vascular relations of the right gsn are very variable from one subject to another but primarily venous, sometimes lymphatic. They concerned the great thoracic vessels whose respect is essential in particular at the time of mini-invasive access procedure for a cœlioscopic splanchnicectomy.

[Scalp flap pedicled on the posterior auricular artery. Anatomical study and clinical application]. / Lambeau de scalp pédiculé sur l'artère auriculaire postérieure. Étude anatomique et application clinique.

INTRODUCTION: Management of scalps defect is a common subject for reconstructive surgery. The use of local flap is better because of the hairy skin. OBJECTIVE: The auricular posterior artery is often described as an accessory blood supply for the scalp. METHOD: We present an original case of 16×6 cm scalp flap harvested almost in "vascular island" on the right retro-auricular pedicle to cover an occipital wound. RESULTS: We have obtained an effective healing in 20 days. Despite its considerable length, no distal necrosis has occurred. CONCLUSION: Rarely reported in the surgical literature, the posterior auricular vessels are a good blood supply to harvest scalp flap. This procedure adds to overall techniques of reconstructive surgery for scalps defects that plastic surgeons can use.

Liver-on-chip model and application in predictive genotoxicity and mutagenicity of drugs.

Currently, there is no test system, whether in vitro or in vivo, capable of examining all endpoints required for genotoxicity evaluation used in pre-clinical drug safety assessment. The objective of this study was to develop a model which could assess all the required endpoints and possesses robust human metabolic activity, that could be used in a streamlined, animal-free manner. Liver-on-chip (LOC) models have intrinsic human metabolic activity that mimics the in vivo environment, making it a preferred test system. For our assay, the LOC was assembled using primary human hepatocytes or HepaRG cells, in a MPS-T12 plate, maintained under microfluidic flow conditions using the PhysioMimix® Microphysiological System (MPS), and co-cultured with human lymphoblastoid (TK6) cells in transwells. This system allows for interaction between two compartments and for the analysis of three different genotoxic endpoints, i.e. DNA strand breaks (comet assay) in hepatocytes, chromosome loss or damage (micronucleus assay) and mutation (Duplex Sequencing) in TK6 cells. Both compartments were treated at 0, 24 and 45 h with two direct genotoxicants: methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS), and two genotoxicants requiring metabolic activation: benzo[a]pyrene (B[a]P) and cyclophosphamide (CP). Assessment of cytochrome activity, RNA expression, albumin, urea and lactate dehydrogenase production, demonstrated functional metabolic capacities. Genotoxicity responses were observed for all endpoints with MMS and EMS. Increases in the micronucleus and mutations (MF) frequencies were also observed with CP, and %Tail DNA with B[a]P, indicating the metabolic competency of the test system. CP did not exhibit an increase in the %Tail DNA, which is in line with in vivo data. However, B[a]P did not exhibit an increase in the % micronucleus and MF, which might require an optimization of the test system. In conclusion, this proof-of-principle experiment suggests that LOC-MPS technology is a promising tool for in vitro hazard identification genotoxicants.

Arterial supply to the tibial tuberosity: involvement in patellar ligament transfer in children.

PURPOSE: The aims were to study arterial blood supply of the tibial tuberosity, and to evaluate its remaining blood supply after patellar ligament transposition in children. METHODS: The anatomic study was carried out on 15 lower limbs after latex injection, and on two fetuses after diaphanization. RESULTS: Tibial tuberosity was vascularized by an arterial network mainly supplied by anterior tibial recurrent artery. Other arteries from the popliteal artery or its branches were also involved in the tibial tuberosity blood supply. CONCLUSIONS: Our findings confirm the safety of transposition of patellar ligament in children due to dense arterial network supplying tibial tuberosity.

Thoracolumbar spinal fracture in children: Conservative or surgical treatment?

PURPOSE: Spinal thoracolumbar fractures represent 10-14% of pediatric fractures. Most children concerned by such fractures are above 10 years of age. No guidelines presently exist. Analysis of spine pathophysiology and of the various common therapeutic attitudes led us to conduct a review of the different therapeutic approaches in pediatric thoracolumbar fracture. METHODS: A review of the literature was carried out using the Medline and Embase databases with the search-term "pediatric thoracic lumbar spine fractures". RESULTS: The systematic review identified 44 studies, 24 of which were selected, and 19 were included for analysis. Physiological age was categorized on Risser's classification. In Risser 1 with Magerl A1 fracture, surgical treatment was not necessary and functional (rest and analgesics) or conservative treatment (bracing for 6 weeks) was sufficient. In Risser 1 with Magerl A2, A3 or B fracture, conservative treatment (bracing for 3 months) was the first-line option. In Risser 2-4, conservative treatment with bracing for 3 months was possible in the absence of instability, with kyphosis>20° and canal compression>33%; otherwise, treatment should be surgical. Subsequently, in case of onset of secondary instability, surgical treatment can be proposed. We highlight the importance of MRI assessment for diagnosis of thoracolumbar fracture and associated lesions of the intervertebral discs and posterior ligament complex. Children classified as Risser 5 can undergo the same treatment as adults. CONCLUSION: Two main parameters should be assessed in treatment decision-making for thoracolumbar fracture: the Risser scale and the Magerl classification.

A new experimental model of acute osteomyelitis due to methicillin-resistant Staphylococcus aureus in rabbit.

AIMS: To assess the impact of antibiotic therapy on severe osseous infections, animal models of chronic bacterial infections have been developed; however, these models suffer from many experimental limitations. The aim of this work was to develop a new model system in which high levels of bacteria are obtained within femoral bone marrow and bone tissue, and such infections are maintained for at least 14 days. METHODS AND RESULTS: Experimental osteomyelitis was induced in 25 New Zealand white rabbits. A 10(9) CFU ml(-1) suspension of methicillin-resistant Staphylococcus aureus was injected into the knee after bone trepanation. On day 3, surgical debridement was performed to mimic a surgical procedure. Animals were euthanized 1, 2, 3, 9 and 14 days post-inoculation to determine the bacterial counts in marrow and bone, and to evaluate the stability of the infection. Inoculated lesions also were assessed for changes in histological parameters on days 3 and 7 post-inoculation. At days 1, 2, 3, 9 and 14 post-inoculation, we observed 6·50 ± 0·64, 7·30 ± 0·49, 7·82 ± 0·19, 8·00 ± 1·48 and 8·99 ± 0·20 log10 CFU g(-1) in bone marrow and 8·40 ± 0·68, 7·65 ± 0·27, 7·58 ± 0·30, 8·88 ± 0·52 and 8·28 ± 0·39 log10 CFU g(-1) in bone tissue, respectively. No statistical differences in bacterial count were found between bone marrow and bone tissue at any time point. CONCLUSION: This new model of acute osteomyelitis was validated by histological and microbiological changes in the absence of sclerosing agents, and these changes remained stable for 14 days. SIGNIFICANCE AND IMPACT OF THE STUDY: These results describe a new experimental model of acute osteomyelitis and demonstrate its usefulness in assessing the activity of antibacterial agents in vivo soon after bone infection.

Survey of influenza A viruses circulating in wild birds in Canada 2005 to 2007.

A multi-agency, Canada-wide survey of influenza A viruses circulating in wild birds, coordinated by the Canadian Cooperative Wildlife Health Centre, was begun in the summer of 2005. Cloacal swab specimens collected from young-of-year ducks were screened for the presence of influenza A nucleic acids by quantitative, real-time reverse transcription-polymerase chain reaction (RRT-PCR). Specimens that produced positive results underwent further testing for H5 and H7 gene sequences and virus isolation. In addition to live bird sampling, dead bird surveillance based on RRT-PCR was also carried out in 2006 and 2007. The prevalence of influenza A viruses varied depending on species, region of the country, and the year of sampling, but generally ranged from 20% to 50%. All HA subtypes, with the exception of H14 and H15, and all NA subtypes were identified. The three most common HA subtypes were H3, H4, and H5, while N2, N6, and N8 were the three most common NA subtypes. H4N6, H3N2, and H3N8 were the three most common HA-NA combinations. The prevalence of H5 and H7 subtype viruses appears to have a cyclical nature.

US-guided temporomandibular joint injection: Validation of an in-plane longitudinal approach.

Ultrasonography of the temporomandibular joint is a non-invasive imaging technic, easy to perform in daily practice. It can be used for diagnosis and to guide intra-articular injections. The objective was to validate a longitudinal in-plane US injection approach of the joint and assess its accuracy. We performed a study in 13 non-embalmed cadavers. The injection was done under real-time US guidance using a needle inserted in-plane with an angulation of 30°and positioned under the capsule until the injection was feasible without resistance. The intra-articular injection was successful in all cases and confirmed by a liquid backflow in 96% of cases. The median duration between skin puncture and the intra-articular injection was 23 seconds. Our technique allows a direct visualization of the needle throughout its course to the joint with a high accuracy. Other studies will be needed to confirm its feasibility and usefulness in patients with TMJ disorders.

Social stability influences the association between adrenal responsiveness and hair cortisol concentrations in rhesus macaques.

Hair cortisol concentrations are increasingly being used in both humans and nonhuman animals as a biomarker of chronic stress. However, many details regarding how hair cortisol concentrations relate to the dynamic activity and regulation of the HPA axis are still unknown. The current study explores 1) how the regulation of the HPA axis in infancy relates to hair cortisol concentrations (HCC) in infancy 2) whether this relationship persists into adulthood under conditions of social stability, and 3) how social instability impacts these relationships. All subjects were rhesus monkeys housed in large social groups at the California National Primate Research Center, and all had participated in a 25-hr. long BioBehavioral Assessment (BBA) at 3-4 months of age when four plasma samples were taken to assess HPA regulation, in particular cortisol responses to 1) 2-hour social separation and relocation, 2) sustained challenge, 3) dexamethasone and 4) ACTH administration. In Study 1, hair samples were collected at the end of the BBA testing from 25 infant rhesus monkeys from 2 different stable social groups. In Study 2, hair samples were obtained at three timepoints from 108 adults from 3 different stable social groups (1 in the Spring/Summer and 2 in the Fall/Winter) to examine the temporal stability of the relationship between HCC and HPA axis regulation. In Study 3, subjects included 31 infants and 33 adults from a single social group experiencing social instability following the same procedures as in Studies 1 and 2. Generalized linear models were used to determine if infants' HPA axis activity and regulation predicted HCC in infancy (Study 1), in adulthood with animals living in stable social conditions (Study 2) or in animals living in an unstable social group (Study 3). Results indicated that for both infants and adults living in stable social groups, HCC are associated with the adrenal response to ACTH in infancy. Samples collected in the winter also had higher HCC than those collected in summer. In the unstable social group, adult hair cortisol levels were higher than in the stable social groups. Additionally, there were no consistent relationships between HCC and infant HPA axis regulation among adults or infants living in a group experiencing social instability. These results suggest that the aspects of the HPA axis that drive HCC may differ depending on context. Under stable, non-stressed conditions there seems to be a trait-like association between adrenal responsivity and HCC in infancy and adulthood. However, this association may be reduced or eliminated under conditions of social stress.

Autosomal dominant spondylocarpotarsal synostosis syndrome: phenotypic homogeneity and genetic heterogeneity.

Spondylocarpotarsal synostosis syndrome (SCT) (OMIM 272460), originally thought to be a failure of normal spine segmentation, is characterized by progressive fusion of vertebras and associates unsegmented bars, scoliosis, short stature, carpal and tarsal synostosis. Cleft palate, sensorineural or mixed hearing loss, joint limitation, clinodactyly, and dental enamel hypoplasia are variable manifestations. Twenty-five patients have been reported. Thirteen affected individuals were siblings from six families and four of these families were consanguineous. In four of those families, Krakow et al. [Krakow et al. (2004) Nat Genet 36:405-410] found homozygosity or compound heterozygosity for mutations in the gene encoding FLNB. This confirmed autosomal recessive inheritance of the disorder. We report on two new patients (a mother and her son) representing the first case of autosomal dominant inheritance. These patients met the clinical and radiological criteria for SCT and did not present any features which could exclude this diagnosis. Molecular analysis failed to identify mutations in NOG and FLNB. SCT is therefore, genetically heterogeneous. Both dominant and autosomal recessive forms of inheritance should be considered during genetic counseling.