Transcriptomic analysis of the developing and adult mouse cochlear sensory epithelia

International audienceThe adult mammalian cochlea lacks regenerative ability and the irreversible degeneration of cochlear sensory hair cells leads to permanent hearing loss. Previous data show that early postnatal cochlea harbors stem/progenitor-like cells and shows a limited regenerative/repair capacity. These properties are progressively lost later during the postnatal development. Little is known about the genes and pathways that are potentially involved in this difference of the regenerative/repair potentialities between early postnatal and adult mammalian cochlear sensory epithelia (CSE). The goal of our study is to investigate the transcriptomic profiles of these two stages. We used Mouse Genome 430 2.0 microarray to perform an extensive analysis of the genes expressed in mouse postnatal day-3 (P3) and adult CSE. Statistical analysis of microarray data was performed using SAM (Significance Analysis of Microarrays) software. We identified 5644 statistically significant differentially expressed transcripts with a fold change (FC) >2 and a False Discovery Rate (FDR) ≤0.05. The P3 CSE signature included 3,102 transcripts, among which were known genes in the cochlea, but also new transcripts such as, Hmga2 (high mobility group AT-hook 2) and Nrarp (Notch-regulated ankyrin repeat protein). The adult CSE overexpressed 2,542 transcripts including new transcripts, such as Prl (Prolactin) and Ar (Androgen receptor), that previously were not known to be expressed in the adult cochlea. Our comparative study revealed important genes and pathways differentially expressed between the developing and adult CSE. The identification of new candidate genes would be useful as potential markers of the maintenance or the loss of stem cells and regenerative/repair ability during mammalian cochlear development

Discovery of a novel polymer for human pluripotent stem cell expansion and multilineage differentiation

A scalable and cost-effective synthetic polymer substrate that supports robust expansion and subsequent multilineage differentiation of human pluripotent stem cells (hPSCs) with defined commercial media is presented. This substrate can be applied to common cultureware and used off-the-shelf after long-term storage. Expansion and differentiation of hPSCs are performed entirely on the polymeric surface, enabling the clinical potential of hPSC-derived cells to be realized

Chondroma of the scalp

A 26 year old man, with no specific past or family history, presented with slow growing subcutaneous mass in the right parietal region of about 4 cm. Skin examination revealed a firm subcutaneous nodule that was movable over the underlying bone. Physical examination was not remarkable other than above-described skin lesion. X-rays of the skull (A) and CT scan (B) showed a subcutaneous mass next to the right parietal eminence measuring 17×39 mm and containing calcifications. Surgery resection of the tumor was complete and easy (C). The nodule was not attached to underlying skull. The postoperative course was unremarkable. Histological examination confirmed the diagnosis of soft-tissue chondroma (D). Extraskeletal chondroma is a rare, benign cartilaginous tumor of the soft tissue. It presents as a solitary subcutaneous mass measuring less than 3 cm in diameter that is usually painless and slowly growing. It is most frequently found in the hands and feet of adults in the fourth and fifth decades. Its location in the scalp is exceptional and atypical. Complete excision is recommended for the treatment of extra skeletal chondroma.Pan African Medical Journal 2015; 2

Anévrismes intracrâniens multiples

A 33 years old woman, treated for hypertension on monotherapy for a year, was admitted on emergency for sudden onset headache. Clinical examination revealed a conscious patient, blood pressure= 13/7, with the presence of frank meningeal syndrome, no fever. Cerebral CT showed subarachnoid hemorrhage at the right middle cerebral valley. The arteriography objectified three aneurysmal dilations at the right posterior communicating artery of about 8.3mm, also at the M2 segment of the right middle cerebral arterys of about 4 mm (A) and finally at the left cerebral bifurcation of about 4mm (B). The patient underwent endovascular treatment of the two right aneurysms and was given a three months appointment to secure the aneurysm. The prevalence of intracranial aneurysms in the general population is evaluated from 1 to 5%. Only 15% of these patients have multiple aneurysms and 7% of them have more than four aneurysms. The therapeutic strategy is to first secure the aneurysm bled and subsequently treating other aneurysms according to their size and risk of bleeding.Pan African Medical Journal 2016; 2

Hernie discale cervicale post traumatique

Il s'agit d'un patient de 54 ans, tabagique chronique, victime d'un accident de la voie publique avec réception sur le crane. L'examen clinique trouve un patient conscient, avec tétraparésie à prédominance brachiale (grade C de Frankel) et irritation pyramidale (réflexes ostéotendineux vifs au niveau supérieur et inférieur). Le bilan radiologique initial (radios standards et scanner) était sans particularités. Devant ce tableau clinique, une IRM cervicale a été réalisée et a objectivé une hernie cervicale compressive en C5-C6 avec contusion centromédullaire (A). Le patient a été opéré par voie antérieure avec réalisation d'une discectomie C5-C6 et mise en place d'un greffon iliaque et une plaque cervicale (B). L'évolution postopératoire était favorable ; la déambulation a été possible quatre jours après l'opération. L'hernie discale cervicale posttraumatique est rare (3,8% des traumatismes cervicaux). Quand elle est isolée, les investigations paracliniques peuvent passer à coté de cette lésion et c'est l'IRM qui permet de poser le diagnostic et d'apprécier le degré de compression médullaire et radiculaire.Pan African Medical Journal 2015; 2

Establishment of regeneration and transformation protocols to create hypoalleregenic peanut (Arachis hypogaea) and mustard (Brassica juncea) through genome editing

A stable and reproducible in vitro regeneration system is necessary for genetic engineering, however, explant responses vary widely between and within species and are highly dependent on the culture conditions. Despite decades of research, plant regeneration is still challenging especially with some plant species referred to as recalcitrant. In this study, we investigated the regeneration and genetic transformation capacities of different lines of peanut (Arachis hypogaea) that is considered recalcitrant and Brown mustard (Brassica juncea) in order to enable editing of the allergens Ara h 1 and Bra J I in peanut and mustard, respectively, via CRISPR/Cas9. Moreover, we demonstrated that, several of the first edited mustard lines displayed reduced or total absence of the Bra J I protein. Firstly, the factors affecting the adventitious shoot regeneration of both plant species were investigated using four peanut lines and six mustard lines from two geographical regions (Europe and India). In both species, shoot regeneration was significantly influenced by the explant type and the genetic make-up of the different lines tested. In mustard, the 5 days old cotyledon explants of all lines showed better responses than hypocotyls regarding adventitious shoot regeneration whereas in peanut the leaflet explants of 5-day-old seedlings exhibited superiority. The combinations of different types of cytokinins and auxins were tested on the explants of both plant species. In all peanut lines, the leaflet explants responded best on medium with 22.19 µM 6-benzylaminopurine (BAP) (+ 2.3 µM kinetin), which was reduced to 7.40 µM BAP after eight weeks, with regeneration rates of 10-89.1% and a mean shoot number per regenerating explant of 1-3.1 shoots. For mustard, the medium containing 8.88 µM BAP, 5.37 µM 1-naphthaleneacetic acid (NAA), and 9.95 µM Silver nitrate (AgNO3) resulted in the highest shoot regeneration rates (58-72% and 65-90% for the European and Indian lines, respectively) as well as the highest shoot numbers per regenerating explant (2.2-2.7 and 2.3-3.0). Furthermore, the effect of different light qualities on shoot regeneration from leaflet explants of the peanut lines was investigated in order to promote shoot induction and elongation. A strong effect of the culture temperature on the regeneration efficiency was observed as different light treatments were connected with different culture temperatures. However, red and blue LEDs could substitute tubular fluorescent lamps without affecting shoot regeneration. In the second step, Agrobacterium-mediated transformation of both plant species was investigated. Transgenic plants carrying large deletions of 566 up to 790 bp as well as indels in the targeted regions especially, indels in all four Bra j I alleles were obtained with the mustard lines tested. Seed viability was investigated in several transgenic mustard lines through in vitro and ex vitro germination. A decrease in seed viability and seed formation was observed in some edited lines, which indicated that the mutation of the major allergen Bra J I in mustard affected seed development. Part of the seeds exhibited aberrant phenotypes that resulted in the rupture of the testa already in the siliques. In contrast, the regenerated shoots from the different transformation experiments with various peanut lines exhibited a lack of transgenicity

Modelling of the physicochemical phenomena in an experiment similar to a gasoline engine

Combustion is a very complex field, since it simultaneously involves several disciplines such as heat transfer, chemistry, turbulence, mass transport etc. In this paper we tried to model a combustion chamber with a geometry close to that of the spark ignition engine. The initial and boundary conditions are well-known. The modeling is based on the approach of calculated probability density function (pdf) in case of turbulent combustion. We used a transport equation for the probability density function similar to the modeling case of the physical and chemical species. Indeed, the theoretical study of this pdf is well developed but its applications remain very limited. In the present paper, the pdf is coupled with a simplified chemistry. This model of combustion was introduced into the KIVA II code in order to simulate the combustion process in a rectangular combustion chamber which is very similar to that of the spark ignition engine (SI). The results found by this model of combustion are compared with the experiment at different operating conditions such as the propane/air equivalence ratio, temperature and pressure. The final results and the conclusions are satisfactory. In this paper, we present only the results relating to a given operation condition with a study of the sensitivity of the flame radius on the equivalence ratio. We believe that the results could be implemented on the case of the spark ignition engine

Successfull management of a cervical oesophageal injury after an anterior cervical approach: a case report

The anterior surgical approach for spinal repair, with or without the insertion of stabilizing hardware, is an established procedure in the management of anterior cervical spine (ACS) pathology. Esophageal injury during this approach is a rare complication that can be life threatening. No treatment protocol has yet been standardized. In addition to conservative measures, several surgical approaches have been presented, ranging from primary repair to reconstruction with local, regional, or distant flaps. The SCM muscle flap, used as reinforcement of a primary suture or as a patch to the lesion is in our opinion an effective treatment for persisting or recurring esophageal fistulae after anterior cervical spine surgery

StemCellNet: an interactive platform for network-oriented investigations in stem cell biology.

Stem cells are characterized by their potential for self-renewal and their capacity to differentiate into mature cells. These two key features emerge through the interplay of various factors within complex molecular networks. To provide researchers with a dedicated tool to investigate these networks, we have developed StemCellNet, a versatile web server for interactive network analysis and visualization. It rapidly generates focused networks based on a large collection of physical and regulatory interactions identified in human and murine stem cells. The StemCellNet web-interface has various easy-to-use tools for selection and prioritization of network components, as well as for integration of expression data provided by the user. As a unique feature, the networks generated can be screened against a compendium of stemness-associated genes. StemCellNet can also indicate novel candidate genes by evaluating their connectivity patterns. Finally, an optional dataset of generic interactions, which provides large coverage of the human and mouse proteome, extends the versatility of StemCellNet to other biomedical research areas in which stem cells play important roles, such as in degenerative diseases or cancer. The StemCellNet web server is freely accessible at http://stemcellnet.sysbiolab.eu