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1.
Front Oncol ; 13: 1226202, 2023.
Article in English | MEDLINE | ID: mdl-37854673

ABSTRACT

Introduction: Human Papillomavirus (HPV) is the primary risk factor for the development of anal intraepithelial neoplasia (AIN) and is a leading risk factor for anogenital squamous cell carcinoma (ASCC). Despite common shared risk factors for both HPV and syphilis, co-infection is not well documented, and the role of syphilitic infection in HPV-associated AIN and ASCC potentiation is not defined. Case description/methods: A 72-year-old single male presented with complaints of mild rectal pain and intermittent rectal bleeding. A flexible sigmoidoscopy was performed, and a firm 4.5cm x 3cm perianal mass was detected and superficially biopsied. Pathology findings demonstrated evidence of a high grade squamous intraepithelial lesion (HGSIL, AIN II/III/AIS) with viral cytopathic effect, consistent with HPV infection. Much of the biopsied lesion showed acanthotic squamous mucosa with intraepithelial neutrophils and abundant submucosal plasma cells, suggesting possible syphilitic involvement. Subsequent immunohistochemical staining for p16 as a surrogate marker for HPV was positive, as was an immunohistochemical stain for spirochetes, supportive of co-infection with Treponema pallidum pallidum (T. pallidum), the causative agent in venereal syphilis. The patient was referred to an infectious disease specialist for syphilitic infection and was treated with penicillin with surprisingly complete resolution of the lesion. EUAs were performed 2- and 3-months following treatment without lesion recurrence. However, one year following diagnosis, a flexible sigmoidoscopy revealed a 5 mm recurrent HPV-related low-grade AIN 1 lesion at the dentate line. Discussion: Resolution of the lesion by antibiotic treatment for syphilitic infection suggested that co-infection by T. pallidum may potentiate HPV-associated squamous cell carcinoma based on histological findings. Findings from this case, as well as a review of bacterial involvement and potentiation in various cancers, are reviewed here. Such findings offer new insight regarding the role of STI-associated bacteria and HPV co-infection in the establishment of AIN and may additionally propose new treatment modalities for ASCC.

2.
J Laryngol Otol ; 136(7): 632-634, 2022 Jul.
Article in English | MEDLINE | ID: mdl-34991758

ABSTRACT

OBJECTIVE: Advice to patients following grommet insertion and waterproofing can vary from clinician to clinician. A laboratory based experiment was performed to determine at what depth water contamination would occur through various grommet tubes. METHODS: A novel experimental ear model was developed using an artificial tympanic membrane and ventilation tubes. Water contamination was identified using an effervescent solid that reacts when in contact with water. Measures of dispersion were used to describe the results. RESULTS: The average depth of water contamination was: 19.64 mm (range = 11-33 mm, standard deviation = 5.55 mm) using a Shepard grommet; 20.84 mm (range = 18-26 mm, standard deviation = 1.97 mm) with a titanium grommet; and 21.36 mm (range = 18-33 mm, standard deviation = 3.03 mm) using a T-tube. Water contamination was possible at depths of 11-33 mm. The average pressure at water effervescent activation was 0.20 kPa. CONCLUSION: Submersion underwater at any depth with grommets is likely to lead to middle-ear contamination. These findings are concordant with clinical studies.


Subject(s)
Immersion , Middle Ear Ventilation , Ear, Middle , Humans , Middle Ear Ventilation/methods , Tympanic Membrane , Water
3.
Biomaterials ; 279: 121187, 2021 12.
Article in English | MEDLINE | ID: mdl-34678648

ABSTRACT

In recent decades, an increasing number of tissue engineered bone grafts have been developed. However, expensive and laborious screenings in vivo are necessary to assess the safety and efficacy of their formulations. Rodents are the first choice for initial in vivo screens but their size limits the dimensions and number of the bone grafts that can be tested in orthotopic locations. Here, we report the development of a refined murine subcutaneous model for semi-orthotopic bone formation that allows the testing of up to four grafts per mouse one order of magnitude greater in volume than currently possible in mice. Crucially, these defects are also "critical size" and unable to heal within the timeframe of the study without intervention. The model is based on four bovine bone implants, ring-shaped, where the bone healing potential of distinct grafts can be evaluated in vivo. In this study we demonstrate that promotion and prevention of ossification can be assessed in our model. For this, we used a semi-automatic algorithm for longitudinal micro-CT image registration followed by histological analyses. Taken together, our data supports that this model is suitable as a platform for the real-time screening of bone formation, and provides the possibility to study bone resorption, osseointegration and vascularisation.


Subject(s)
Bone Regeneration , Regenerative Medicine , Animals , Biocompatible Materials , Cattle , Mice , Osteogenesis , Tissue Engineering , Tissue Scaffolds
4.
Bone ; 150: 115999, 2021 09.
Article in English | MEDLINE | ID: mdl-33971315

ABSTRACT

During skeletal development most bones are first formed as cartilage templates, which are gradually replaced by bone. If later in life those bones break, temporary cartilage structures emerge to bridge the fractured ends, guiding the regenerative process. This bone formation process, known as endochondral ossification (EO), has been widely studied for its potential to reveal factors that might be used to treat patients with large bone defects. The extracellular matrix of cartilage consists of different types of collagens, proteoglycans and a variety of non-collagenous proteins that organise the collagen fibers in complex networks. Thrombospondin-5, also known as cartilage oligomeric matrix protein (TSP-5/COMP) is abundant in cartilage, where it has been described to enhance collagen fibrillogenesis and to interact with a variety of growth factors, matrix proteins and cellular receptors. However, very little is known about the skeletal distribution of its homologue thrombospondin-4 (TSP-4). In our study, we compared the spatiotemporal expression of TSP-5 and TSP-4 during postnatal bone formation and fracture healing. Our results indicate that in both these settings, TSP-5 distributes across all layers of the transient cartilage, while the localisation of TSP-4 is restricted to the population of hypertrophic chondrocytes. Furthermore, in fractured bones we observed TSP-4 sparsely distributed in the periosteum, while TSP-5 was absent. Last, we analysed the chemoattractant effects of the two proteins on endothelial cells and bone marrow stem cells and hypothesised that, of the two thrombospondins, only TSP-4 might promote blood vessel invasion during ossification. We conclude that TSP-4 is a novel factor involved in bone formation. These findings reveal TSP-4 as an attractive candidate to be evaluated for bone tissue engineering purposes.


Subject(s)
Endothelial Cells , Osteogenesis , Cartilage , Cartilage Oligomeric Matrix Protein , Chondrocytes , Humans , Thrombospondins
5.
J Laryngol Otol ; 135(3): 246-249, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33622427

ABSTRACT

BACKGROUND: Concerns have emerged regarding infection transmission during flexible nasoendoscopy. METHODS: Information was gathered prospectively on flexible nasoendoscopy procedures performed between March and June 2020. Patients and healthcare workers were followed up to assess for coronavirus disease 2019 development. One-sided 97.5 per cent Poisson confidence intervals were calculated for upper limits of risk where zero events were observed. RESULTS: A total of 286 patients were recruited. The most common indication for flexible nasoendoscopy was investigation of 'red flag' symptoms (67 per cent). Forty-seven patients (16 per cent, 95 per cent confidence interval = 13-21 per cent) had suspicious findings on flexible nasoendoscopy requiring further investigation. Twenty patients (7.1 per cent, 95 per cent confidence interval = 4.4-11 per cent) had new cancer diagnoses. Zero coronavirus disease 2019 infections were recorded in the 273 patients. No. 27 endoscopists (the doctors and nurses who carried out the procedures) were followed up.The risk of developing coronavirus disease 2019 after flexible nasoendoscopy was determined to be 0-1.3 per cent. CONCLUSION: The risk of coronavirus disease 2019 transmission associated with performing flexible nasoendoscopy in asymptomatic patients, while using appropriate personal protective equipment, is very low. Additional data are required to confirm these findings in the setting of further disease surges.


Subject(s)
COVID-19/epidemiology , COVID-19/transmission , Endoscopy/adverse effects , Infection Control/organization & administration , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Infectious Disease Transmission, Patient-to-Professional/statistics & numerical data , Adult , COVID-19/prevention & control , Endoscopy/instrumentation , Female , Humans , Ireland , Male , Patient Selection , Personal Protective Equipment , Prospective Studies , Retrospective Studies , Risk Assessment
6.
Ir Med J ; 114(9): 471, 2021 Oct 21.
Article in English | MEDLINE | ID: mdl-37736744
7.
Phys Rev Lett ; 125(11): 116803, 2020 Sep 11.
Article in English | MEDLINE | ID: mdl-32975997

ABSTRACT

An odd-occupied quantum dot in a Josephson junction can flip transmission phase, creating a π junction. When the junction couples topological superconductors, no phase flip is expected. We investigate this and related effects in a full-shell hybrid interferometer, using gate voltage to control dot-junction parity and axial magnetic flux to control the transition from trivial to topological superconductivity. Enhanced zero-bias conductance and critical current for odd parity in the topological phase reflects hybridization of the confined spin with zero-energy modes in the leads.

8.
Nat Commun ; 11(1): 3212, 2020 Jun 25.
Article in English | MEDLINE | ID: mdl-32587242

ABSTRACT

Majorana zero modes are leading candidates for topological quantum computation due to non-local qubit encoding and non-abelian exchange statistics. Spatially separated Majorana modes are expected to allow phase-coherent single-electron transport through a topological superconducting island via a mechanism referred to as teleportation. Here we experimentally investigate such a system by patterning an elongated epitaxial InAs-Al island embedded in an Aharonov-Bohm interferometer. With increasing parallel magnetic field, a discrete sub-gap state in the island is lowered to zero energy yielding persistent 1e-periodic Coulomb blockade conductance peaks (e is the elementary charge). In this condition, conductance through the interferometer is observed to oscillate in a perpendicular magnetic field with a flux period of h/e (h is Planck's constant), indicating coherent transport of single electrons through the islands, a signature of electron teleportation via Majorana modes.

9.
Biomed Mater ; 15(3): 035017, 2020 04 27.
Article in English | MEDLINE | ID: mdl-32069447

ABSTRACT

Additive manufacturing (AM) techniques have provided many opportunities for the rational design of porous metallic biomaterials with complex and precisely controlled topologies that give rise to unprecedented combinations of mechanical, physical, and biological properties. These favorable properties can be enhanced by surface biofunctionalization to enable full tissue regeneration and minimize the risk of implant-associated infections (IAIs). There is, however, an increasing need to investigate the immune responses triggered by surface biofunctionalized AM porous metals. Here, we studied the immunomodulatory effects of AM porous titanium (Ti-6Al-4V) printed using selective laser melting, and of two additional groups consisting of AM implants surface biofunctionalized using plasma electrolytic oxidation (PEO) with/without silver nanoparticles. The responses of human primary macrophages and human mesenchymal stromal cells (hMSCs) were studied in terms of cell viability, cell morphology and biomarkers of macrophage polarization. Non-treated AM porous titanium triggered a strong pro-inflammatory response in macrophages, albeit combined with signs of anti-inflammatory effects. The PEO treatment of AM porous titanium implants showed a higher potential to induce polarization towards a pro-repair macrophage phenotype. We detected no cytotoxicity against hMSCs in any of the groups. However, the incorporation of silver nanoparticles resulted in strong cytotoxicity against attached macrophages. The results of this study indicate the potential immunomodulatory effects of the AM porous titanium enhanced with PEO treatment, and point towards caution and further research when using silver nanoparticles for preventing IAIs.


Subject(s)
Biocompatible Materials/chemistry , Porosity , Printing, Three-Dimensional , Prostheses and Implants , Titanium/chemistry , Alloys/chemistry , Biomarkers/metabolism , Bone Regeneration , Cell Survival , Cells, Cultured , Humans , Immunomodulation/drug effects , Inflammation , Ions , Lasers , Leukocytes, Mononuclear/cytology , Macrophages/metabolism , Materials Testing , Mesenchymal Stem Cells/cytology , Metal Nanoparticles/chemistry , Monocytes/cytology , Nanoparticles/chemistry , Phenotype , Polyethylene Glycols/chemistry , Silver/chemistry , Stress, Mechanical , Surface Properties
10.
Eur Cell Mater ; 38: 106-122, 2019 09 18.
Article in English | MEDLINE | ID: mdl-31532540

ABSTRACT

in tissue engineering, endochondral ossification (EO) is often replicated by chondrogenically differentiating mesenchymal stromal cells (MSCs) in vitro and achieving bone formation through in vivo implantation. The resulting marrow-containing bone constructs are promising as a treatment for bone defects. However, limited bone formation capacity has prevented them from reaching their full potential. This is further complicated since it is not fully understood how this bone formation is achieved. Acellular grafts derived from chondrogenically differentiated MSCs can initiate bone formation; however, which component within these decellularised matrices contribute to bone formation has yet to be determined. Collagen type X (COLX), a hypertrophy-associated collagen found within these constructs, is involved in matrix organisation, calcium binding and matrix vesicle compartmentalisation. However, the importance of COLX during tissue-engineered chondrogenesis and subsequent bone formation is unknown. The present study investigated the importance of COLX by shRNA-mediated gene silencing in primary MSCs. A significant knock-down of COLX disrupted the production of extracellular matrix key components and the secretion profile of chondrogenically differentiated MSCs. Following in vivo implantation, disrupted bone formation in knock-down constructs was observed. The importance of COLX was confirmed during both chondrogenic differentiation and subsequent EO in this tissue engineered setting.


Subject(s)
Cartilage/metabolism , Chondrogenesis , Collagen Type X/metabolism , Mesenchymal Stem Cells/metabolism , Osteogenesis , Animals , Cartilage/cytology , Cartilage/physiology , Cells, Cultured , Child , Chondrocytes/cytology , Chondrocytes/metabolism , Collagen Type X/genetics , Humans , Mesenchymal Stem Cells/cytology , Mice , Mice, Inbred BALB C , Mice, Nude
11.
Osteoarthritis Cartilage ; 27(12): 1831-1840, 2019 12.
Article in English | MEDLINE | ID: mdl-31536814

ABSTRACT

OBJECTIVE: Synovium contains multipotent progenitor/stromal cells (MPCs) with potential to participate in cartilage repair. Understanding the identity of these MPCs will allow their therapeutic potential to be fully exploited. Hence this study aimed to identify primary synovial MPCs and characterize them in the context of cartilage regeneration. METHODS: Primary MPC/MPC-subset specific markers in synovium were identified by FACS analysis of uncultured cells. MPC-subsets from human synovium obtained from patients undergoing total knee arthroplasty were FACS sorted, cultured, immunophenotyped and chondrogenically differentiated. The anatomical localization of MPCs in synovium was examined using immunohistochemistry. Finally, the presence of these MPC subsets in healthy synovium obtained from human organ donors was examined. RESULTS: A combination of CD45, CD31, CD73 and CD90 can isolate two distinct MPC-subsets in synovium. These MPC-subsets, freshly isolated from synovium, did not express CD45 or CD31, but expressed CD73. Additionally, a sub-population of CD73+ cells also expressed CD90. CD45-CD31-CD73+CD90- cells were significantly more chondrogenic than CD45-CD31-CD73+CD90+ cells in the presence of TGFß1. Interestingly, reduced chondrogenic ability of CD73+CD90+ cells could be reversed by the addition of BMP2, showing discrete chondrogenic factor requirements by distinct cell-subsets. In addition, these MPCs had distinct anatomical localization; CD73 was expressed both in intimal and sub-intimal region while CD90 was enriched in the sub-intimal region. We further demonstrated that these subsets are also present in healthy synovium. CONCLUSIONS: We provide indications that primary MPCs in synovial intima and sub-intima are phenotypically and functionally distinct with different chondrogenic properties.


Subject(s)
Cartilage, Articular/physiology , Cell Differentiation/physiology , Chondrogenesis/physiology , Multipotent Stem Cells/metabolism , Osteoarthritis, Knee , Regeneration/physiology , 5'-Nucleotidase/metabolism , Aged , Aged, 80 and over , Case-Control Studies , Cell Adhesion Molecules/metabolism , Female , Flow Cytometry , GPI-Linked Proteins/metabolism , Humans , Immunohistochemistry , Immunophenotyping , Leukocyte Common Antigens/metabolism , Male , Middle Aged , Platelet Endothelial Cell Adhesion Molecule-1/metabolism , Receptors, Chemokine/metabolism , Receptors, Growth Factor/metabolism , Synovial Membrane/cytology , Thy-1 Antigens/metabolism
12.
Eur Cell Mater ; 37: 277-291, 2019 04 10.
Article in English | MEDLINE | ID: mdl-30968944

ABSTRACT

Endochondral ossification (EO) is the process by which the long bones of the body form and has proven to be a promising method in tissue engineering for achieving cell-mediated bone formation. The present review centred on state-of-the-art research pertaining to mesenchymal stem cells (MSCs)-mediated endochondral bone formation, focusing on the role of donor cells, extracellular matrix and host immune cells during tissue-engineered bone formation. Possible research avenues to improve graft outcome and bone output were highlighted, as well as emerging research that, when applied to tissue-engineered bone grafts, offers new promise for improving the likelihood of such grafts transition from bench to bedside.


Subject(s)
Bone Substitutes/therapeutic use , Bone and Bones/metabolism , Extracellular Matrix , Mesenchymal Stem Cells/metabolism , Osteogenesis , Tissue Engineering/methods , Animals , Bone Substitutes/metabolism , Extracellular Matrix/chemistry , Extracellular Matrix/metabolism , Humans
13.
Anesthesiology ; 129(5): 970-988, 2018 11.
Article in English | MEDLINE | ID: mdl-30212413

ABSTRACT

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Structure-activity studies were performed to identify a new neuromuscular blocking agent retaining the ultra-short acting characteristics of gantacurium, including degradation and reversal by L-cysteine, but lacking its histaminoid properties in man. CW 1759-50 has emerged from this program. METHODS: Adduction of CW 1759-50 with L-cysteine was studied by high-performance liquid chromatography and mass spectrometry. Institutional Animal Care and Use Committee-approved comparisons of CW 1759-50 to gantacurium were performed in rhesus monkeys. ED95 for neuromuscular blockade was established. Spontaneous recovery was compared to reversal by L-cysteine in paired studies of boluses or infusions. In addition, changes in mean arterial pressure and heart rate after very large doses of 15 to 60 × ED95 were compared. RESULTS: The half-time of adduction of L-cysteine to CW 1759-50 in vitro was 2.3 min. The ED95 of CW 1759-50 was 0.069 ± 0.02 mg/kg; ED95 of gantacurium was 0.081 ± 0.05 mg/kg (P = 0.006). Duration of action (recovery to 95% twitch height after 98 to 99% blockade) was as follows: CW 1759-50, 8.2 ± 1.5 min; and gantacurium, 7.4 ± 1.9 min; (n = 8 and 9, P = 0.355). Administration of L-cysteine (30 mg/kg) shortened recovery (i.e., induced reversal) from CW 1759-50 after boluses or infusions (P always less than 0.0001). Recovery intervals (5 to 95% twitch) ranged from 6.1 to 6.7 min (and did not differ significantly) after boluses of 0.10 to 0.50 mg/kg, as well as control infusions (P = 0.426 by analysis of variance). Dose ratios comparing changes of 30% in mean arterial pressure or heart rate to ED95 for neuromuscular blockade (ED 30% Δ [mean arterial pressure or heart rate]/ED95) were higher for CW 1759-50 than for gantacurium. CONCLUSIONS: CW 1759-50, similar to gantacurium, is an ultra-short acting neuromuscular blocking agent, antagonized by L-cysteine, in the monkey. The circulatory effects, however, are much reduced in comparison with gantacurium, suggesting a trial in humans.


Subject(s)
Cysteine/metabolism , Neuromuscular Blockade/methods , Neuromuscular Blocking Agents/metabolism , Neuromuscular Blocking Agents/pharmacology , Animals , Blood Pressure/drug effects , Heart Rate/drug effects , Humans , Macaca mulatta , Male , Models, Animal
14.
Obes Surg ; 28(10): 2998-3006, 2018 10.
Article in English | MEDLINE | ID: mdl-29948869

ABSTRACT

BACKGROUND: Retrospective studies indicate that acetaminophen iv administration reduces hospital length of stay (LoS) and opiate consumption in patients undergoing bariatric surgery. OBJECTIVE: This study sought to determine whether using acetaminophen iv in morbidly obese subjects undergoing sleeve gastrectomy decreased LoS and total hospital charges as compared to patients receiving saline placebo. SETTING: Single-center university hospital METHODS: Using a randomized, double-blind, placebo-controlled design, subjects were assigned to receive either acetaminophen iv (group A) or saline placebo iv (group P). Data were collected between Jan 1 and Dec 31, 2016. Group A received acetaminophen every 6 h for a total of four doses. The first dose was administered following the induction of general anesthesia; group P received saline iv on the same schedule. Anesthetic management and prophylactic antiemetic regimen were standardized in all subjects. Postoperative pain management consisted of hydromorphone via patient-controlled infusion pump. Primary outcomes include hospital LoS and associated hospital costs. Secondary outcomes include patient satisfaction and postoperative nausea and pain scores. RESULTS: Subject demographics (n = 127) and intraoperative management were similar in the two groups. Across all subjects, median hospital LoS in group A (n = 63) was 1.87 vs. 1.97 days in group P (n = 64) (p = 0.03, Wilcoxon rank-sum test). Postoperatively, daily quality-of-recovery (QoR-15) scores, narcotic consumption, and the use of rescue antiemetics were not significantly different between groups. Median hospital costs were as follows: group A, $12,885 vs. group P, $12,977 (n = 64). CONCLUSIONS: Acetaminophen iv may reduce hospital LoS in subjects undergoing sleeve gastrectomy.


Subject(s)
Acetaminophen , Analgesics, Non-Narcotic , Gastrectomy/adverse effects , Length of Stay/statistics & numerical data , Obesity, Morbid/surgery , Pain, Postoperative/drug therapy , Acetaminophen/administration & dosage , Acetaminophen/therapeutic use , Administration, Intravenous , Analgesics, Non-Narcotic/administration & dosage , Analgesics, Non-Narcotic/therapeutic use , Double-Blind Method , Humans , Intraoperative Period
15.
Eur Cell Mater ; 35: 242-254, 2018 04 26.
Article in English | MEDLINE | ID: mdl-29697853

ABSTRACT

The aim of the current study was to reduce the clinically used supra-physiological dose of bone morphogenetic protein-2 (BMP-2) (usually 1.5 mg/mL), which carries the risk of adverse events, by using a more effective release system. A slow release system, based on an injectable hydrogel composed of BMP-2-loaded recombinant collagen-based microspheres and alginate, was previously developed. Time- and dose-dependent subcutaneous ectopic bone formation within this system and bone regeneration capacity in a calvarial defect model were investigated. BMP-2 doses of 10 µg, 3 µg and 1 µg per implant (50 µg/mL, 15 µg/mL and 5 µg/mL, respectively) successfully induced ectopic bone formation subcutaneously in rats in a time- and dose-dependent manner, as shown by micro-computed tomography (µCT) and histology. In addition, the spatio-temporal control of BMP-2 retention was shown for 4 weeks in vivo by imaging of fluorescently-labelled BMP-2. In the subcritical calvarial defect model, µCT revealed a higher bone volume for the 2 µg of BMP-2 per implant condition (50 µg/mL) as compared to the lower dose used (0.2 µg per implant, 5 µg/mL). Complete defect bridging was obtained with 50 µg/mL BMP-2 after 8 weeks. The BMP-2 concentration of 5 µg/mL was not sufficient to heal a calvarial defect faster than the empty defect or biomaterial control without BMP-2. Overall, this injectable BMP-2 delivery system showed promising results with 50 µg/mL BMP-2 in both the ectopic and calvarial rat defect models, underling the potential of this composite hydrogel for bone regeneration therapies.


Subject(s)
Alginates/chemistry , Bone Morphogenetic Protein 2/administration & dosage , Collagen/chemistry , Injections , Microspheres , Osteogenesis , Transforming Growth Factor beta/administration & dosage , Animals , Bone Morphogenetic Protein 2/pharmacology , Kinetics , Male , Rats, Sprague-Dawley , Recombinant Proteins/administration & dosage , Recombinant Proteins/pharmacology , Skull/diagnostic imaging , Skull/pathology , Time Factors , Transforming Growth Factor beta/pharmacology , X-Ray Microtomography
16.
J Tissue Eng Regen Med ; 12(6): 1530-1540, 2018 06.
Article in English | MEDLINE | ID: mdl-29702747

ABSTRACT

Bone marrow stromal cell (BMSC)-mediated endochondral bone formation may be a promising alternative to the current gold standards of autologous bone transplantation, in the development of novel methods for bone repair. Implantation of chondrogenically differentiated BMSCs leads to bone formation in vivo via endochondral ossification. The success of this bone formation in an allogeneic system depends upon the interaction between the implanted constructs and the host immune system. The current study investigated the effect of chondrogenically differentiated human bone marrow stromal cell (hBMSC) pellets on the maturation and function of dendritic cells (DCs) by directly coculturing bone forming chondrogenic hBMSC pellets and immature or lipopolysaccharide (LPS)-matured DCs in vitro. Allogeneic chondrogenic hBMSC pellets did not affect the expression of CD80, CD86, or HLADR on immature or LPS-matured DCs following 24, 48, or 72 hr of coculture. Furthermore, they did not induce or inhibit antigen uptake or migration of the DCs over time. IL-6 was secreted by allogeneic chondrogenic hBMSC pellets in response to LPS-matured DCs. Overall, this study has demonstrated that maturation of immature DCs was not influenced by allogeneic chondrogenic hBMSC pellets. This suggests that allogeneic chondrogenic hBMSC pellets do not stimulate immunogenic responses from DCs in vitro and are not expected to indirectly activate T cells via DCs. For this reason, allogeneic chondrogenic bone marrow stromal cell pellets are promising candidates for future tissue engineering strategies utilising allogeneic cells for bone repair.


Subject(s)
Cell Differentiation , Chondrogenesis , Dendritic Cells/cytology , Mesenchymal Stem Cells/cytology , CD11c Antigen/metabolism , Humans , Interleukin-6/metabolism , Lipopolysaccharides/pharmacology , Transplantation, Homologous
17.
Phys Rev Lett ; 121(25): 256803, 2018 Dec 21.
Article in English | MEDLINE | ID: mdl-30608825

ABSTRACT

We present measurements of one-dimensional superconductor-semiconductor Coulomb islands, fabricated by gate confinement of a two-dimensional InAs heterostructure with an epitaxial Al layer. When tuned via electrostatic side gates to regimes without subgap states, Coulomb blockade reveals Cooper-pair mediated transport. When subgap states are present, Coulomb peak positions and heights oscillate in a correlated way with magnetic field and gate voltage, as predicted theoretically, with (anti)crossings in (parallel) transverse magnetic field indicating Rashba-type spin-orbit coupling. Overall results are consistent with a picture of overlapping Majorana zero modes in finite wires.

18.
Eur Cell Mater ; 34: 142-161, 2017 09 22.
Article in English | MEDLINE | ID: mdl-28937176

ABSTRACT

With limited autologous and donor bone graft availability, there is an increasing need for alternative graft substitutes. We have previously shown that chondrogenically priming mesenchymal stem cell (MSC) pellets for 28 d in vitro will reproducibly result in endochondral bone formation after in vivo implantation. However, pellet priming time for clinical applications is quite extensive. A micropellet (µpellet)-fibrin construct was developed and coupled, with a shorter priming period, determined by an in vitro time course experiment. In vitro data showed expression of chondrogenic genes and matrix production after 7 d of chondrogenic priming, indicating that briefer priming could possibly be used to induce bone formation in vivo. 7 and 28 d primed pellet, pellet-fibrin and µpellet-fibrin constructs were cultured for in vitro analysis and implanted subcutaneously for 8 weeks into nude mice. µpellet-fibrin constructs, cultured in vitro for 7 or 28 d, produced comparable bone to standard pellets in vivo. MSC-mediated bone formation was achieved following only 7 d of in vitro priming. Bone formation in vivo appeared to be influenced by overall matrix production pre-implantation. Given this short priming time and the injectable nature of the µpellet-fibrin constructs, this approach might be further developed as an injectable bone substitute, leading to a minimally-invasive treatment option, which would allow for tailored filling of bone defects.


Subject(s)
Chondrogenesis , Mesenchymal Stem Cells/metabolism , Osteogenesis , Adult , Animals , Biomarkers/metabolism , Cell Differentiation/drug effects , Cell Shape/drug effects , Chondrogenesis/drug effects , Collagen Type II/metabolism , Extracellular Matrix/drug effects , Extracellular Matrix/metabolism , Female , Fibrin/pharmacology , Gene Expression Regulation/drug effects , Humans , Male , Mesenchymal Stem Cells/drug effects , Mice, Nude , Middle Aged , Osteogenesis/drug effects , Tissue Donors , Up-Regulation/genetics
19.
Phys Rev Lett ; 117(7): 076603, 2016 Aug 12.
Article in English | MEDLINE | ID: mdl-27563982

ABSTRACT

We intercalate a van der Waals heterostructure of graphene and hexagonal boron nitride with Au, by encapsulation, and show that the Au at the interface is two dimensional. Charge transfer upon current annealing indicates the redistribution of the Au and induces splitting of the graphene band structure. The effect of an in-plane magnetic field confirms that the splitting is due to spin splitting and that the spin polarization is in the plane, characteristic of a Rashba interaction with a magnitude of approximately 25 meV. Consistent with the presence of an intrinsic interfacial electric field we show that the splitting can be enhanced by an applied displacement field in dual gated samples. A giant negative magnetoresistance, up to 75%, and a field induced anomalous Hall effect at magnetic fields <1 T are observed. These demonstrate that the hybridized Au has a magnetic moment and suggests the proximity to the formation of a collective magnetic phase. These effects persist close to room temperature.

20.
J Fish Biol ; 88(6): 2303-7, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27245625

ABSTRACT

The present study provides information on length distribution, reproductive biology and diet of Mustelus mosis based on individuals caught in waters off the eastern Arabian Peninsula. Although ageing of vertebral centra was attempted, band pairs were of low clarity and counts could not be confidently assigned.


Subject(s)
Feeding Behavior , Reproduction , Sharks/physiology , Animals , Diet , Female , Indian Ocean , Male , Sexual Maturation , Sharks/growth & development
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