Peripheral Nerve Repair: Multimodal Comparison of the Long-Term Regenerative Potential of Adipose Tissue-Derived Cells in a Biodegradable Conduit.

Tissue engineering is a popular topic in peripheral nerve repair. Combining a nerve conduit with supporting adipose-derived cells could offer an opportunity to prevent time-consuming Schwann cell culture or the use of an autograft with its donor site morbidity and eventually improve clinical outcome. The aim of this study was to provide a broad overview over promising transplantable cells under equal experimental conditions over a long-term period. A 10-mm gap in the sciatic nerve of female Sprague-Dawley rats (7 groups of 7 animals, 8 weeks old) was bridged through a biodegradable fibrin conduit filled with rat adipose-derived stem cells (rASCs), differentiated rASCs (drASCs), human (h)ASCs from the superficial and deep abdominal layer, human stromal vascular fraction (SVF), or rat Schwann cells, respectively. As a control, we resutured a nerve segment as an autograft. Long-term evaluation was carried out after 12 weeks comprising walking track, morphometric, and MRI analyses. The sciatic functional index was calculated. Cross sections of the nerve, proximal, distal, and in between the two sutures, were analyzed for re-/myelination and axon count. Gastrocnemius muscle weights were compared. MRI proved biodegradation of the conduit. Differentiated rat ASCs performed significantly better than undifferentiated rASCs with less muscle atrophy and superior functional results. Superficial hASCs supported regeneration better than deep hASCs, in line with published in vitro data. The best regeneration potential was achieved by the drASC group when compared with other adipose tissue-derived cells. Considering the ease of procedure from harvesting to transplanting, we conclude that comparison of promising cells for nerve regeneration revealed that particularly differentiated ASCs could be a clinically translatable route toward new methods to enhance peripheral nerve repair.

Aorto-bronchial and aorto-pulmonary fistulation after thoracic endovascular aortic repair: an analysis from the European Registry of Endovascular Aortic Repair Complications.

OBJECTIVES: To learn upon incidence, underlying mechanisms and effectiveness of treatment strategies in patients with central airway and pulmonary parenchymal aorto-bronchial fistulation after thoracic endovascular aortic repair (TEVAR). METHODS: Analysis of an international multicentre registry (European Registry of Endovascular Aortic Repair Complications) between 2001 and 2012 with a total caseload of 4680 TEVAR procedures (14 centres). RESULTS: Twenty-six patients with a median age of 70 years (interquartile range: 60-77) (35% female) were identified. The incidence of either central airway (aorto-bronchial) or pulmonary parenchymal (aorto-pulmonary) fistulation (ABPF) in the entire cohort after TEVAR in the study period was 0.56% (central airway 58%, peripheral parenchymal 42%). Atherosclerotic aneurysm formation was the leading indication for TEVAR in 15 patients (58%). The incidence of primary endoleaks after initial TEVAR was n = 10 (38%), of these 80% were either type I or type III endoleaks. Fourteen patients (54%) developed central left bronchial tree lesions, 11 patients (42%) pulmonary parenchymal lesions and 1 patient (4%) developed a tracheal lesion. The recognized mechanism of ABPF was external compression of the bronchial tree in 13 patients (50%), the majority being due to endoleak formation, further ischaemia due to extensive coverage of bronchial feeding arteries in 3 patients (12%). Inflammation and graft erosion accounted for 4 patients (30%) each. Cumulative survival during the entire study period was 39%. Among deaths, 71% were attributed to ABPF. There was no difference in survival in patients having either central airway or pulmonary parenchymal ABPF (33 vs 45%, log-rank P = 0.55). Survival with a radical surgical approach was significantly better when compared with any other treatment strategy in terms of overall survival (63 vs 32% and 63 vs 21% at 1 and 2 years, respectively), as well as in terms of fistula-related survival (63 vs 43% and 63 vs 43% at 1 and 2 years, respectively). CONCLUSIONS: ABPF is a rare but highly lethal complication after TEVAR. The leading mechanism behind ABPF seems to be a continuing external compression of either the bronchial tree or left upper lobe parenchyma. In this setting, persisting or newly developing endoleak formation seems to play a crucial role. Prognosis does not differ in patients with central airway or pulmonary parenchymal fistulation. Radical bronchial or pulmonary parenchymal repair in combination with stent graft removal and aortic reconstruction seems to be the most durable treatment strategy.

Polymorphisms in DNA-repair genes in a cohort of prostate cancer patients from different areas in Spain: heterogeneity between populations as a confounding factor in association studies

Background: Differences in the distribution of genotypes between individuals of the same ethnicity are an important confounder factor commonly undervalued in typical association studies conducted in radiogenomics. Objective: To evaluate the genotypic distribution of SNPs in a wide set of Spanish prostate cancer patients for determine the homogeneity of the population and to disclose potential bias. Design, Setting, and Participants: A total of 601 prostate cancer patients from Andalusia, Basque Country, Canary and Catalonia were genotyped for 10 SNPs located in 6 different genes associated to DNA repair: XRCC1 (rs25487, rs25489, rs1799782), ERCC2 (rs13181), ERCC1 (rs11615), LIG4 (rs1805388, rs1805386), ATM (rs17503908, rs1800057) and P53 (rs1042522). The SNP genotyping was made in a Biotrove OpenArrayH NT Cycler. Outcome Measurements and Statistical Analysis: Comparisons of genotypic and allelic frequencies among populations, as well as haplotype analyses were determined using the web-based environment SNPator. Principal component analysis was made using the SnpMatrix and XSnpMatrix classes and methods implemented as an R package. Non-supervised hierarchical cluster of SNP was made using MultiExperiment Viewer. Results and Limitations: We observed that genotype distribution of 4 out 10 SNPs was statistically different among the studied populations, showing the greatest differences between Andalusia and Catalonia. These observations were confirmed in cluster analysis, principal component analysis and in the differential distribution of haplotypes among the populations. Because tumor characteristics have not been taken into account, it is possible that some polymorphisms may influence tumor characteristics in the same way that it may pose a risk factor for other disease characteristics. Conclusion: Differences in distribution of genotypes within different populations of the same ethnicity could be an important confounding factor responsible for the lack of validation of SNPs associated with radiation-induced toxicity, especially when extensive meta-analysis with subjects from different countries are carried out.

Collagen (NeuraGen®) nerve conduits and stem cells for peripheral nerve gap repair

Le système nerveux périphérique est responsable de la transmission des impulses motrices, ainsi que de la réception des afférences sensorielles. Les lésions traumatiques des nerfs périphériques conduisent à une impotence fonctionnelle qui peut être dévastant, notamment chez les travailleurs manuels,. La récupération fonctionnelle est donc le but principal dans chirurgie des nerfs périphériques. Malheureusement, une suture directe des moignons nerveux est souvent impossible dans le contexte des traumatismes complexes qui surviennent lors des accidents. La suture nerveuse par interposition d'autogreffe reste le gold standard dans la pratique chirurgicale mais nécessite le sacrifice d'un nerf donneur, avec dysesthésie et possibles douleurs neuropathiques conséquentes. Alternativement, des guides tubulaires pour les nerfs peuvent être utilisées si le gap nerveux est inférieur à 3 cm. Plusieurs guides résorbables en collagène sont approuve en Europe et aux Etas Unis (FDA). Dans cette étude, des conduits de collagène ont été associe a des cellules régénératives (cellules souches adultes) comme stratégie supplémentaire de régénération. Une fois testé le rapport des cellules avec le biomatériau (NeuraGen® nerve guides) in vitro, une étude in vivo dans le rat a été effectuée. Les différents groupes de conduits ont été supplémentés respectivement avec Schwann cells (SC); avec cellules souches adultes dérivées de la moelle épinière, différentiées en cellules "Schwann-like" (dMSC); avec cellules souches adultes dérivées de la graisse, différentiées en cellules "Schwann-like" (dASC). Un groupe de conduits avec du milieu de culture sans cellules a été utilisé comme group control. Les conduits ont été utilisés pour combler un gap de 1cm dans un model de section totale du nerf sciatique chez le rat. Deux semaines post implantation, une analyse immuno-histochimique a été effectuée pour évaluer la régénération axonales et l'infiltration de cellules de Schwann au niveau du conduit. Les cellules ont montré une adhérence efficace aux parois de collagène. En particulier, les cellules de Schwann ont montré une amélioration significative au niveau du sprouting distale. Par contre, aucune différence significative n'a été remarquée entre les groupes pour le sprouting axonale proximal. De plus, si les cellules souches ont montré un pattern de sprouting diffus, les cellules de Schwann ont par contre garanti un cône de croissance typique, associé a une affinité remarquable pour les parois de collagène. NeuraGen® guides pourraient donc être un moyen adapté a l'association avec la thérapie cellulaire en raison de la bonne adhérence des cellules au biomatériau. Des modifications de surface dans le but d'améliorer la performance neurotrophique cellulaire in vivo (e.g. peptides de matrice extracellulaire) pourront être utilisées dans des applications futures.

Endoscopic epiglottopexy using Lichtenberger's needle carrier to avoid breakdown of repair.

Severe type III laryngomalacia LM is represented by a retroflexed epiglottis that touches the posterior pharyngeal wall and obstructs the laryngeal inlet. Endoscopic epiglottopexy is advised in such cases wherein pexy sutures are passed between the epiglottis and base of tongue. Using conventional needle carriers, it is difficult to pass such sutures that go deep enough into the tongue base. Such a pexy is prone to a break down. We describe a novel technique of placing these glossoepiglottic sutures using the Lichtenberger's needle carrier. We used this technique in three patients with excellent results and report no complications. We propose to use this technique in cases of epiglottic prolapse seen in severe LM and certain hypotonic conditions.

Estimations of topographically correct regeneration to nerve branches and skin after peripheral nerve injury and repair.

Peripheral nerve injury is typically associated with long-term disturbances in sensory localization, despite nerve repair and regeneration. Here, we investigate the extent of correct reinnervation by back-labeling neuronal soma with fluorescent tracers applied in the target area before and after sciatic nerve injury and repair in the rat. The subpopulations of sensory or motor neurons that had regenerated their axons to either the tibial branch or the skin of the third hindlimb digit were calculated from the number of cell bodies labeled by the first and/or second tracer. Compared to the normal control side, 81% of the sensory and 66% of the motor tibial nerve cells regenerated their axons back to this nerve, while 22% of the afferent cells from the third digit reinnervated this digit. Corresponding percentages based on quantification of the surviving population on the experimental side showed 91%, 87%, and 56%, respectively. The results show that nerve injury followed by nerve repair by epineurial suture results in a high but variable amount of topographically correct regeneration, and that proportionally more neurons regenerate into the correct proximal nerve branch than into the correct innervation territory in the skin

Large-scale genomic analyses link reproductive aging to hypothalamic signaling, breast cancer susceptibility and BRCA1-mediated DNA repair.

Menopause timing has a substantial impact on infertility and risk of disease, including breast cancer, but the underlying mechanisms are poorly understood. We report a dual strategy in ∼70,000 women to identify common and low-frequency protein-coding variation associated with age at natural menopause (ANM). We identified 44 regions with common variants, including two regions harboring additional rare missense alleles of large effect. We found enrichment of signals in or near genes involved in delayed puberty, highlighting the first molecular links between the onset and end of reproductive lifespan. Pathway analyses identified major association with DNA damage response (DDR) genes, including the first common coding variant in BRCA1 associated with any complex trait. Mendelian randomization analyses supported a causal effect of later ANM on breast cancer risk (∼6% increase in risk per year; P = 3 × 10(-14)), likely mediated by prolonged sex hormone exposure rather than DDR mechanisms.

Use of a ventricular septal defect occluder for apical closure in transapical aortic valve replacement.

During transapical transcatheter aortic valve replacement (TA-TAVR), the apical closure remains a challenge for the surgeon, having the risk for ventricular tear and massive bleeding. Apical closure devices are already under clinical evaluation, but only a few can lead to a full percutaneous TA-TAVR. We describe the successful use of a 9-mm myocardial occluder (ventricular septal defect occluder) that was used to seal the apex after a standard TA-TAVR (using the Sapien XT 23-mm transcatheter valve and the Ascendra + delivery system). The placement of the nonmodified myocardial occluder was performed through the Ascendra + delivery system, with a very small amount of blood loss and an acceptable sealing of the apical tear. This approach is feasible and represents a further step toward true-percutaneous transapical heart valve procedures. Modified apical occluders are under evaluation in animal models.

Adjuvant Fluorouracil, Leucovorin, and Oxaliplatin in Stage II to III Colon Cancer: Updated 10-Year Survival and Outcomes According to BRAF Mutation and Mismatch Repair Status of the MOSAIC Study.

PURPOSE: The MOSAIC (Multicenter International Study of Oxaliplatin/Fluorouracil/Leucovorin in the Adjuvant Treatment of Colon Cancer) study has demonstrated 3-year disease-free survival (DFS) and 6-year overall survival (OS) benefit of adjuvant oxaliplatin in stage II to III resected colon cancer. This update presents 10-year OS and OS and DFS by mismatch repair (MMR) status and BRAF mutation. METHODS: Survival actualization after 10-year follow-up was performed in 2,246 patients with resected stage II to III colon cancer. We assessed MMR status and BRAF mutation in 1,008 formalin-fixed paraffin-embedded specimens. RESULTS: After a median follow-up of 9.5 years, 10-year OS rates in the bolus/infusional fluorouracil plus leucovorin (LV5FU2) and LV5FU2 plus oxaliplatin (FOLFOX4) arms were 67.1% versus 71.7% (hazard ratio [HR], 0.85; P = .043) in the whole population, 79.5% versus 78.4% for stage II (HR, 1.00; P = .980), and 59.0% versus 67.1% for stage III (HR, 0.80; P = .016) disease. Ninety-five patients (9.4%) had MMR-deficient (dMMR) tumors, and 94 (10.4%) had BRAF mutation. BRAF mutation was not prognostic for OS (P = .965), but dMMR was an independent prognostic factor (HR, 2.02; 95% CI, 1.15 to 3.55; P = .014). HRs for DFS and OS benefit in the FOLFOX4 arm were 0.48 (95% CI, 0.20 to 1.12) and 0.41 (95% CI, 0.16 to 1.07), respectively, in patients with stage II to III dMMR and 0.50 (95% CI, 0.25 to 1.00) and 0.66 (95% CI, 0.31 to 1.42), respectively, in those with BRAF mutation. CONCLUSION: The OS benefit of oxaliplatin-based adjuvant chemotherapy, increasing over time and with the disease severity, was confirmed at 10 years in patients with stage II to III colon cancer. These updated results support the use of FOLFOX in patients with stage III disease, including those with dMMR or BRAF mutation.

Mycoplasma hominis mediastinitis after acute aortic dissection repair.

We report a case of ascending aortic graft infection by an atypical bacteria, Mycoplasma hominis, with mediastinitis, a dreaded complication after cardiac surgery. A 55-year-old patient underwent ascending aorta replacement for acute type A dissection. He developed sternal instability and purulent discharge, requiring sternal wire removal and debridement. Cultures were initially sterile, but showed M. hominis infection after a significant delay and in specific culture media. The patient was treated with doxycycline and moxifloxacine. Cultures became negative and the sternum was closed on the 28th postoperative day after the first debridement. Recovery was favorable, with no signs of infection. Antibiotics were continued for one year. The patient is still asymptomatic 16 months after antibiotic interruption. Atypical organisms should be considered in the differential diagnosis of acute mediastinitis of unknown etiology after routine microbiological investigations.

Variable-stiffness composite panels: Defect tolerance under in-plane tensile loading

Automated Fiber Placement is being extensively used in the production of major composite components for the aircraft industry. This technology enables the production of tow-steered panels, which have been proven to greatly improve the structural efficiency of composites by means of in-plane stiffness variation and load redistribution. However, traditional straight-fiber architectures are still preferred. One of the reasons behind this is related to the uncertainties, as a result of process-induced defects, in the mechanical performance of the laminates. This experimental work investigates the effect of the fiber angle discontinuities between different tow courses in a ply on the un-notched and open-hole tensile strength of the laminate. The influence of several manufacturing parameters are studied in detail. The results reveal that 'ply staggering' and '0% gap coverage' is an effective combination in reducing the influence of defects in these laminates

Molecular genetics of the immotile short tail sperm defect

Hedelmättömyyttä aiheuttavan siittiöiden puolihäntävian molekyyligenetiikka Suomalaisissa Yorkshire karjuissa yleistyi 1990-luvun lopulla autosomaalisesti ja resessiivisesti periytyvä hedelmättömyyttä aiheuttava siittiöiden puolihäntävika (ISTS, immotile short tail sperm). Sairaus aiheuttaa normaalia lyhyemmän ja täysin liikkumattoman siittiön hännän muodostuksen. Muita oireita sairailla karjuilla ei ole havaittu ja emakot ovat oireettomia. Tämän tutkimuksen tarkoituksena oli kartoittaa siittiöiden puolihäntävian aiheuttava geenivirhe ja kehittää DNA-testi markkeri- ja geeniavusteiseen valintaan. Koko genomin kartoituksessa vian aiheuttava alue paikannettiin sian kromosomiin 16. Paikannuksen perusteella kahden geenimerkin haplotyyppi kehitettiin käytettäväksi markkeri-avusteisessa valinnassa. Sairauteen kytkeytyneen alueen hienokartoitusta jatkettiin geenitestin kehittämiseksi kantajadiagnostiikkaan. Vertailevalla kartoituksella oireeseen kytkeytynyt alue paikannettiin 2 cM:n alueelle ihmisen kromosomiin viisi (5p13.2). Tällä alueella sijaitsevia geenejä vastaavista sian sekvensseistä löydetyn muuntelun perusteella voitiin tarkentaa sairauteen kytkeytyneitä haplotyyppejä. Haplotyyppien perusteella puolihäntäoireeseen kytkeytynyt alue rajattiin kahdeksan geenin alueelle ihmisen geenikartalla. Alueelle paikannetun kandidaattigeenin (KPL2) sekvensointi paljasti introniin liittyneen liikkuvan DNA-sekvenssin, Line-1 retroposonin. Tämä retroposoni muuttaa geenin silmikointia siten, että sitä edeltävä eksoni jätetään pois tai myös osa introni- ja inserttisekvenssiä liitetään geenin mRNA tuotteeseen. Molemmissa tapauksissa tuloksena on lyhentynyt KPL2 proteiini. Tähän retroposoni-inserttiin perustuva geenitesti on ollut sianjalostajien käytössä vuodesta 2006. KPL2 geenin ilmenemisen tarkastelu sialla ja hiirellä paljasti useita kudosspesifisiä silmikointimuotoja. KPL2 geenin pitkä muoto ilmenee pääasiassa vain kiveksessä, mikä selittää geenivirheen aiheuttamat erityisesti siittiön kehitykseen liittyvät oireet. KPL2 proteiinin ilmeneminen hiiren siittiön hännän kehityksen aikana ja mahdollinen yhteistoiminta IFT20 proteiinin kanssa viittaavat tehtävään proteiinien kuljetuksessa siittiön häntään. Mahdollisen kuljetustehtävän lisäksi KPL2 saattaa toimia myös siittiön hännän rakenneosana, koska se paikannettiin valmiin siittiön hännän keskiosaan. Lisäksi KPL2 proteiini saattaa myös toimia Golgin laitteessa sekä Sertolin solujen ja spermatidien liitoksissa, mutta nämä havainnot kuitenkin vaativat lisätutkimuksia. Tämän tutkimuksen tulokset osoittavat, että KPL2 geeni on tärkeä siittiön hännän kehitykselle ja sen rakennemuutos aiheuttaa siittiöiden puolihäntäoireen suomalaisilla Yorkshire karjuilla. KPL2 proteiinin ilmeneminen ja paikannus siittiön kehityksen aikana antaa viitteitä proteiinin toiminnasta. Koska KPL2 geenisekvenssi on erittäin konservoitunut, nämä tulokset tuovat uutta tietoa kaikkien nisäkkäiden siittiöiden kehitykseen ja urosten hedelmättömyyteen syihin.

Surgical treatment of hamstring injuries and disorders – the clinical spectrum from chronic tendinopathy to complete rupture

Hamstring muscle injuries and tendon disorders are common, especially in sports. They can be severe and difficult to treat, often resulting in impaired athletic performance and long rehabilitation times. Previous studies considering treatment of these problems are scarce. The current study was designed to investigate the effect of surgery on different types of hamstring muscle injuries and on proximal hamstring tendinopathy. In addition, we wanted to study the typical histopathological findings relating to proximal hamstring tendinopathy. In the study of complete (all three muscles torn) proximal hamstring avulsions (41 patients), our results showed that early operative treatment gives significantly better results than late surgery, and is therefore recommended. Despite this, considerable improvement of symptoms could also be achieved in chronic cases. In the study of partial (one or two muscles torn) proximal hamstring tears (47 patients), we observed that these injuries can cause significant functional deficit and impaired performance in athletes. The main finding was that after surgical repair most of the patients were able to return to their pre-injury level of sports. In the study of distal hamstring tears (18 patients), the results showed that surgical treatment had a good effect in the majority of these cases. In proximal hamstring tendinopathy, the main problem is pain which limits sports. In this study (90 patients), we found that after unsuccessful conservative treatment, surgery was a good treatment option resulting in full return to sports in most cases. In tendinopathic hamstring tendons, the morphological changes of tendinosis were largely identical to those previously described in other common (e.g. Achilles and patellar) tendinopathies. In chronic proximal hamstring avulsions, and also in reoperations, a large defect between distally retracted tendons and the ischial tuberosity may occasionally prevent anatomic reinsertion. We have described a reconstruction method using fascia lata autograft augmentation to be used in these most challenging repairs. This technique was utilized in the treatment of five patients, with encouraging results.