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1.
Am J Kidney Dis ; 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38640994

ABSTRACT

RATIONALE & OBJECTIVE: Reasons for transfer from peritoneal dialysis (PD) to hemodialysis (HD) remain incompletely understood. Among incident and prevalent patients receiving PD, we evaluated the association of clinical factors, including prior treatment with HD, with PD technique survival. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Adults who initiated PD at a Dialysis Clinic, Inc (DCI) outpatient facility between January 1, 2010, and September 30, 2019. EXPOSURE: The primary exposure of interest was timing of PD start, categorized as PD-first, PD-early, or PD-late. Other covariates included demographics, clinical characteristics, and routine laboratory results. OUTCOME: Modality switch from PD to HD sustained for more than 90 days. ANALYTICAL APPROACH: Multivariable Fine-Gray models with competing risks and time-varying covariates, stratified at 9 months to account for lack of proportionality. RESULTS: Among 5,224 patients who initiated PD at a DCI facility, 3,174 initiated dialysis with PD ("PD-first"), 942 transitioned from HD to PD within 90 days ("PD-early"), and 1,108 transitioned beyond 90 days ("PD-late"); 1,472 (28%) subsequently transferred from PD to HD. The PD-early and PD-late patients had a higher risk of transfer to HD as compared with PD-first patients (in the first 9 months: adjusted hazard ratio [AHR], 1.51 [95% CI, 1.17-1.96] and 2.41 [95% CI, 1.94-3.00], respectively; and after 9 months: AHR, 1.16 [95% CI, 0.99-1.35] and AHR, 1.43 [95% CI, 1.24-1.65], respectively). More peritonitis episodes, fewer home visits, lower serum albumin levels, lower residual kidney function, and lower peritoneal clearance calculated with weekly Kt/V were additional risk factors for PD-to-HD transfer. LIMITATIONS: Missing data on dialysis adequacy and residual kidney function, confounded by short PD technique survival. CONCLUSIONS: Initiating dialysis with PD is associated with greater PD technique survival, though many of those who initiate PD-late in their dialysis course still experience substantial time on PD. Peritonitis, lower serum albumin, and lower Kt/V are risk factors for PD-to-HD transfer that may be amenable to intervention. PLAIN-LANGUAGE SUMMARY: Peritoneal dialysis (PD) is an important kidney replacement modality with several potential advantages compared with in-center hemodialysis (HD). However, a substantial number of patients transfer to in-center HD early on, without having experienced the quality-of-life and other benefits that come with sustained maintenance of PD. Using retrospective data from a midsize national dialysis provider, we found that initiating dialysis with PD is associated with longer maintenance of PD, compared with initiating dialysis with HD and a later switch to PD. However, many of those who initiate PD-late in their dialysis course still experience substantial time on PD. Peritonitis, lower serum albumin, and lower small protein removal are other risk factors for PD-to-HD transfer that may be amenable to intervention.

2.
Dev Biol ; 511: 63-75, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38621649

ABSTRACT

Loss of function variations in the dual specificity tyrosine-phosphorylation-regulated kinase 1 A (DYRK1A) gene are associated with craniofacial malformations in humans. Here we characterized the effects of deficient DYRK1A in craniofacial development using a developmental model, Xenopus laevis. Dyrk1a mRNA and protein were expressed throughout the developing head and both were enriched in the branchial arches which contribute to the face and jaw. Consistently, reduced Dyrk1a function, using dyrk1a morpholinos and pharmacological inhibitors, resulted in orofacial malformations including hypotelorism, altered mouth shape, slanted eyes, and narrower face accompanied by smaller jaw cartilage and muscle. Inhibition of Dyrk1a function resulted in misexpression of key craniofacial regulators including transcription factors and members of the retinoic acid signaling pathway. Two such regulators, sox9 and pax3 are required for neural crest development and their decreased expression corresponds with smaller neural crest domains within the branchial arches. Finally, we determined that the smaller size of the faces, jaw elements and neural crest domains in embryos deficient in Dyrk1a could be explained by increased cell death and decreased proliferation. This study is the first to provide insight into why craniofacial birth defects might arise in humans with variants of DYRK1A.


Subject(s)
Dyrk Kinases , Xenopus Proteins , Xenopus laevis , Animals , Branchial Region/embryology , Branchial Region/metabolism , Craniofacial Abnormalities/genetics , Craniofacial Abnormalities/embryology , Craniofacial Abnormalities/metabolism , Embryo, Nonmammalian/metabolism , Embryo, Nonmammalian/embryology , Gene Expression Regulation, Developmental , Neural Crest/embryology , Neural Crest/metabolism , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Protein-Tyrosine Kinases/metabolism , Protein-Tyrosine Kinases/genetics , Signal Transduction , Xenopus laevis/embryology , Xenopus laevis/metabolism , Xenopus Proteins/metabolism , Xenopus Proteins/genetics
3.
Cells Tissues Organs ; 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38513621

ABSTRACT

INTRODUCTION: Bioprinting, using "bio-inks" consisting of living cells, supporting structures and biological motifs to create customized constructs, is an emerging technique that aims to overcome the challenges of cartilaginous reconstruction of head and neck structures. Several living cell lines and culturing methods have been explored as bio-inks with varying efficacy. Co-culture of primary chondrocytes and stem cells (SCs) is one technique, well established for degenerative joint disease treatment, with potential for use in expanding chondrocyte populations for bio-inks. This study aims to evaluate the techniques for co-culture of primary chondrocytes and SCs for head and neck cartilage regeneration. METHODS: A literature review was performed through OVID/Web of Science/MEDLINE/BIOSIS Previews/Embase. Studies reporting on chondrocytes and SCs in conjunction with co-culture or cartilage regeneration were included. Studies not reporting on findings from chondrocytes/SCs of the head and neck were excluded. Extracted data included cell sources, co-culture ratios and histological, biochemical and clinical outcomes. RESULTS: 15 studies met inclusion criteria. Auricular cartilage was the most common chondrocyte source (n=10), then nasal septum (n=5), articular (n=1) and tracheal cartilage (n=1). Bone marrow was the most common SC source (n=9) then adipose tissue (n=7). Techniques varied, with co-culture ratios ranging from 1:1 to 1:10. All studies reported co-culture to be superior to SC mono-culture by all outcomes. Most studies reported superiority or equivalence of co-culture to chondrocyte mono-culture by all outcomes. When comparing clinical outcomes, co-culture constructs were equivalent to chondrocyte mono-culture in diameter, and equivalent or inferior in wet weight and height. CONCLUSION: Co-culture of primary chondrocytes and SCs is a promising technique for expanding chondrocyte populations, with at least equivalence to chondrocyte mono-culture and superior to SC mono-culture when seeded at the same chondrocyte densities. However, there remains a lack of consensus regarding the optimal cell sources and co-culture ratios.

4.
bioRxiv ; 2024 Jan 14.
Article in English | MEDLINE | ID: mdl-38260562

ABSTRACT

Loss of function mutations in the dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A) gene are associated with craniofacial malformations in humans. Here we characterized the effects of deficient DYRK1A in craniofacial development using a developmental model, Xenopus laevis . Dyrk1a mRNA and protein was expressed throughout the developing head and was enriched in the branchial arches which contribute to the face and jaw. Consistently, reduced Dyrk1a function, using dyrk1a morpholinos and pharmacological inhibitors, resulted in orofacial malformations including hypotelorism, altered mouth shape, slanted eyes, and narrower face accompanied by smaller jaw cartilage and muscle. Inhibition of Dyrk1a function resulted in misexpression of key craniofacial regulators including transcription factors and members of the retinoic acid signaling pathway. Two such regulators, sox9 and pax3 are required for neural crest development and their decreased expression corresponds with smaller neural crest domains within the branchial arches. Finally, we determined that the smaller size of the faces, jaw elements and neural crest domains in embryos deficient in Dyrk1a could be explained by increased cell death and decreased proliferation. This study is the first to provide insight into why craniofacial birth defects might arise in humans with DYRK1A mutations.

5.
Int J Mol Sci ; 24(13)2023 Jun 21.
Article in English | MEDLINE | ID: mdl-37445640

ABSTRACT

Graphene oxide-based materials (GOBMs) have been widely explored as nano-reinforcements in cementitious composites due to their unique properties. Oxygen-containing functional groups in GOBMs are crucial for enhancing the microstructure of cementitious composites. A better comprehension of their surface chemistry and mechanisms is required to advance the potential applications in cementitious composites of functionalized GOBMs. However, the mechanism by which the oxygen-containing functional groups enhance the response of cementitious composites is still unclear, and controlling the surface chemistry of GOBMs is currently constrained. This review aims to investigate the reactions and mechanisms for functionalized GOBMs as additives incorporated in cement composites. A variety of GOBMs, including graphene oxide (GO), hydroxylated graphene (HO-G), edge-carboxylated graphene (ECG), edge-oxidized graphene oxide (EOGO), reduced graphene oxide (rGO), and GO/silane composite, are discussed with regard to their oxygen functional groups and interactions with the cement microstructure. This review provides insight into the potential benefits of using GOBMs as nano-reinforcements in cementitious composites. A better understanding of the surface chemistry and mechanisms of GOBMs will enable the development of more effective functionalization strategies and open up new possibilities for the design of high-performance cementitious composites.


Subject(s)
Graphite , Graphite/chemistry , Oxygen
6.
Nat Commun ; 13(1): 7800, 2022 12 17.
Article in English | MEDLINE | ID: mdl-36528641

ABSTRACT

The volume, extent and age of Arctic sea ice is in decline, yet winter sea ice production appears to have been increasing, despite Arctic warming being most intense during winter. Previous work suggests that further warming will at some point lead to a decline in ice production, however a consistent explanation of both rise and fall is hitherto missing. Here, we investigate these driving factors through a simple linear model for ice production. We focus on the Kara and Laptev seas-sometimes referred to as Arctic "ice factories" for their outsized role in ice production, and train the model on internal variability across the Community Earth System Model's Large Ensemble (CESM-LE). The linear model is highly skilful at explaining internal variability and can also explain the forced rise-then-fall of ice production, providing insight into the competing drivers of change. We apply our linear model to the same climate variables from observation-based data; the resulting estimate of ice production over recent decades suggests that, just as in CESM-LE, we are currently passing the peak of ice production in the Kara and Laptev seas.


Subject(s)
Climate , Ice Cover , Arctic Regions , Seasons , Oceans and Seas
7.
Polymers (Basel) ; 14(20)2022 Oct 12.
Article in English | MEDLINE | ID: mdl-36297848

ABSTRACT

As the most prevalent structural protein in the extracellular matrix, collagen has been extensively investigated for biofabrication-based applications. However, its utilisation has been impeded due to a lack of sufficient mechanical toughness and the inability of the scaffold to mimic complex natural tissues. The anisotropic alignment of collagen fibres has been proven to be an effective method to enhance its overall mechanical properties and produce biomimetic scaffolds. This review introduces the complicated scenario of collagen structure, fibril arrangement, type, function, and in addition, distribution within the body for the enhancement of collagen-based scaffolds. We describe and compare existing approaches for the alignment of collagen with a sharper focus on electro-compaction. Additionally, various effective processes to further enhance electro-compacted collagen, such as crosslinking, the addition of filler materials, and post-alignment fabrication techniques, are discussed. Finally, current challenges and future directions for the electro-compaction of collagen are presented, providing guidance for the further development of collagenous scaffolds for bioengineering and nanotechnology.

8.
Mater Today Bio ; 15: 100326, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35761844

ABSTRACT

In tissue engineering, foreign body reactions (FBRs) that may occur after the insertion of medical implants are a considerable challenge. Materials currently used in implants are mainly metals that are non-organic, and the lack of biocompatibility and absence of immune regulations may lead to fibrosis after long periods of implantation. Here, we introduce a highly biocompatible hybrid interface of graphene oxide (GO) and collagen type I (COL-I), where the topological nanostructure can effectively inhibit the differentiation of fibroblasts into myofibroblasts. The structure and roughness of this coating interface can be easily adjusted at the nanoscale level through changes in the GO concentration, thereby effectively inducing the polarization of macrophages to the M1 state without producing excessive amounts of pro-inflammatory factors. Compared to nanomaterials or the extracellular matrix as an anti-fibrotic interface, this hybrid bio-interface has superior mechanical strength, physical structures, and high inflammation. Evidenced by inorganic materials such as glass, titanium, and nitinol, GO-COL shows great potential for use in medical implants and cell-material interfaces.

9.
iScience ; 25(5): 104207, 2022 May 20.
Article in English | MEDLINE | ID: mdl-35494221

ABSTRACT

In the era of antiretroviral therapy, inflammation is a central factor in numerous HIV-associated comorbidities, such as cardiovascular disease, cognitive impairment, and neuropsychiatric disorders. This highlights the value of developing therapeutics that both reduce HIV-associated inflammation and treat associated comorbidities. Previous research on monoamine oxidase inhibitors (MAOIs) suggests this class of drugs has anti-inflammatory properties in addition to neuropsychiatric effects. Therefore, we examined the impact of deprenyl, an MAOI, on SIV-associated inflammation during acute SIV infection using the rhesus macaque model of HIV infection. Our results show deprenyl decreased both peripheral and CNS inflammation but had no effect on viral load in either the periphery or CNS. These data show that the MAOI deprenyl may have broad anti-inflammatory effects when given during the acute stage of SIV infection, suggesting more research into the anti-inflammatory effects of this drug could result in a beneficial adjuvant for antiretroviral therapy.

10.
Mater Today Bio ; 14: 100253, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35464741

ABSTRACT

Retinal prostheses offer viable vision restoration therapy for patients with blindness. However, a critical requirement for maintaining the stable performance of electrical stimulation and signal transmission is the biocompatibility of the electrode interface. Here, we demonstrated a functionalized electrode-neuron biointerface composed of an annealed graphene oxide-collagen (aGO-COL) composite and neuronal cells. The aGO-COL exhibited an electroactive 3D crumpled surface structure and enhanced the differentiation efficiency of PC-12 â€‹cells. It is integrated into a photovoltaic self-powered retinal chip to develop a biohybrid retinal implant that facilitates biocompatibility and tissue regeneration. Moreover, aGO-COL micropatterns fabricated via 3D bioprinting can be used to create neuronal cell microarrays, which supports the possibility of retaining the high spatial resolution achieved through electrical stimulation of the retinal chip. This study paves the way for the next generation of biohybrid retinal implants based on biointerfaces.

11.
ACS Omega ; 7(7): 5908-5920, 2022 Feb 22.
Article in English | MEDLINE | ID: mdl-35224351

ABSTRACT

Advances in 3D bioprinting allows not only controlled deposition of cells or cell-laden hydrogels but also flexibility in creating constructs that match the anatomical features of the patient. This is especially the case for reconstructing the pinna (ear), which is a large feature of the face and made from elastic cartilage that primarily relies on diffusion for nutrient transfer. The selection of cell lines for reconstructing this cartilage becomes a crucial step in clinical translation. Chondrocytes and mesenchymal stem cells are both studied extensively in the area of cartilage regeneration as they are capable of producing cartilage in vitro. However, such monoculture systems involve unfavorable processes and produce cartilage with suboptimal characteristics. Co-cultures of these cell types are known to alleviate these limitations to produce synergically active chondrocytes and cartilage. The current study utilized a 3D bioprinted scaffold made from combined gelatine methacryloyl and methacrylated hyaluronic acid (GelMA/HAMA) to interrogate monocultures and co-cultures of human septal chondrocytes (primary chondrocytes, PCs) and human bone marrow-derived mesenchymal stem cells (BM-hMSCs). This study is also the first to examine co-cultures of healthy human chondrocytes with human BM-hMSCs encapsulated in GelMA/HAMA bioprinted scaffolds. Findings revealed that the combination of MSCs and PCs not only yielded cell proliferation that mimicked MSCs but also produced chondrogenic expressions that mimicked PCs. These findings suggested that co-cultures of BM-hMSCs and healthy septal PCs can be employed to replace monocultures in chondrogenic studies for cartilage regeneration in this model. The opportunity for MSCs used to replace PCs alleviates the requirement of large cartilage biopsies that would otherwise be needed for sufficient cell numbers and therefore can be employed for clinical applications.

12.
Commun Biol ; 5(1): 70, 2022 01 19.
Article in English | MEDLINE | ID: mdl-35046486

ABSTRACT

Pulmonary sequelae following COVID-19 pneumonia have been emerging as a challenge; however, suitable cell sources for studying COVID-19 mechanisms and therapeutics are currently lacking. In this paper, we present a standardized primary alveolar cell culture method for establishing a human alveolar epithelium model that can recapitulate viral infection and cellular plasticity. The alveolar model is infected with a SARS-CoV-2 pseudovirus, and the clinically relevant features of the viral entry into the alveolar type-I/II cells, cytokine production activation, and pulmonary surfactant destruction are reproduced. For this damaged alveolar model, we find that the inhibition of Wnt signaling via XAV939 substantially improves alveolar repair function and prevents subsequent pulmonary fibrosis. Thus, the proposed alveolar cell culture strategy exhibits potential for the identification of pathogenesis and therapeutics in basic and translational research.


Subject(s)
Alveolar Epithelial Cells/virology , COVID-19/physiopathology , Cell Plasticity , Primary Cell Culture/methods , SARS-CoV-2/physiology , Humans , Virus Internalization
13.
Polymers (Basel) ; 14(2)2022 Jan 13.
Article in English | MEDLINE | ID: mdl-35054724

ABSTRACT

Melt-electrowriting (MEW) is an emerging method that combines electrospinning and extrusion printing, allowing the fabrication of micron-scale structures suitable for tissue engineering. Compared to other additive fabrication methods, melt-electro written structures can offer more appropriate substrates for cell culture due to filament size and mechanical characteristics of the fabricated scaffolds. In this study, polycaprolactone (PCL)/graphene composites were investigated for fabrication of micron-size scaffolds through MEW. It was demonstrated that the addition of graphene can considerably improve the processability of PCL to fabricate micron-scale scaffolds with enhanced resolution. The tensile strength of the scaffold prepared from PCL/graphene composite (with only 0.5 wt.% graphene) was proved significantly (by more than 270%), better than that of the pristine PCL scaffold. Furthermore, graphene was demonstrated to be a suitable material for tailoring the degradation process to avoid undesirable bulk degradation, rapid mass loss and damage to the internal matrix of the polymer. The findings of this study offer a promising route for the fabrication of high-resolution scaffolds with micron-scale resolution for tissue engineering.

14.
Acute Med ; 21(4): 205-206, 2022.
Article in English | MEDLINE | ID: mdl-36809453

ABSTRACT

Overuse of corticosteroids is an important problem not only in asthma but also the management of other airways diseases including bronchiectasis and COPD and results in associated risks of serious side effects and irreversible harm. We report a pilot using an in-reach solution to review patients, optimise their care and facilitate early discharge. We discharged >20% of our patients immediately, which is potentially a significant reduction in hospital bed use and, most importantly, through this approach we were able to establish early diagnosis and reduce inappropriate oral corticosteroid use.


Subject(s)
Adrenal Cortex Hormones , Asthma , Humans , Adrenal Cortex Hormones/adverse effects , Disease Progression , Patient Discharge , Patient Care Team
15.
Mater Today Bio ; 13: 100182, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34917923

ABSTRACT

Chronic obstructive pulmonary disease (COPD) is one of the most lethal chronic disease worldwide; however, the establishment of reliable in vitro models for exploring the biological mechanisms of COPD remains challenging. Here, we determined the differences in the expression and characteristics of the autophagic protein LC3B in normal and COPD human small airway epithelial cells and found that the nucleus of COPD cells obviously accumulated LC3B. We next established 3D human small airway tissues with distinct disease characteristics by regulating the biological microenvironment, extracellular matrix, and air-liquid interface culture methods. Using this biomimetic model, we found that LC3B affects the differentiation of COPD cells into basal, secretory, mucous, and ciliated cells. Moreover, although chloroquine and ivermectin effectively inhibited the expression of LC3B in the nucleus, chloroquine specifically maintained the performance of LC3B in cytoplasm, thereby contributing to the differentiation of ciliated cells and subsequent improvement in the beating functions of the cilia, whereas ivermectin only facilitated differentiation of goblet cells. We demonstrated that the autophagic mechanism of LC3B in the nucleus is one factor regulating the ciliary differentiation and function of COPD cells. Our innovative model can be used to further analyze the physiological mechanisms in the in vitro airway environment.

16.
ESMO Open ; 6(2): 100050, 2021 04.
Article in English | MEDLINE | ID: mdl-33556898

ABSTRACT

BACKGROUND: Approved first-line treatments for patients with BRAF V600-mutant advanced melanoma include nivolumab (a programmed cell death protein 1 inhibitor) plus ipilimumab (a cytotoxic T lymphocyte antigen-4 inhibitor; NIVO+IPI) and the BRAF/MEK inhibitors dabrafenib plus trametinib (DAB+TRAM), encorafenib plus binimetinib (ENCO+BINI), and vemurafenib plus cobimetinib (VEM+COBI). Results from prospective randomized clinical trials (RCTs) comparing these treatments have not yet been reported. This analysis evaluated the relative efficacy and safety of NIVO+IPI versus DAB+TRAM, ENCO+BINI, and VEM+COBI in patients with BRAF-mutant advanced melanoma using a matching-adjusted indirect comparison (MAIC). PATIENTS AND METHODS: A systematic literature review identified RCTs for DAB+TRAM, ENCO+BINI, and VEM+COBI in patients with BRAF-mutant advanced melanoma. Individual patient-level data for NIVO+IPI were derived from the phase III CheckMate 067 trial (BRAF-mutant cohort) and restricted to match the inclusion/exclusion criteria of the comparator trials. Treatment effects for overall survival (OS) and progression-free survival (PFS) were estimated using Cox proportional hazards and time-varying hazard ratio (HR) models. Safety outcomes (grade 3 or 4 treatment-related adverse events) with NIVO+IPI and the comparators were compared. RESULTS: In the Cox proportional hazards analysis, NIVO+IPI showed improved OS compared with DAB+TRAM (HR = 0.53; 95% confidence interval [CI], 0.39-0.73), ENCO+BINI (HR = 0.60; CI, 0.42-0.85), and VEM+COBI (HR = 0.50; CI, 0.36-0.70) for the overall study period. In the time-varying analysis, NIVO+IPI was associated with significant improvements in OS and PFS compared with the BRAF/MEK inhibitors 12 months after treatment initiation. There were no significant differences between NIVO+IPI and BRAF/MEK inhibitor treatment from 0 to 12 months. Safety outcomes favored DAB+TRAM over NIVO+IPI, whereas NIVO+IPI was comparable to VEM+COBI. CONCLUSION: Results of this MAIC demonstrated durable OS and PFS benefits for patients with BRAF-mutant advanced melanoma treated with NIVO+IPI compared with BRAF/MEK inhibitors, with the greatest benefits noted after 12 months.


Subject(s)
Melanoma , Nivolumab , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Humans , Ipilimumab/adverse effects , Melanoma/drug therapy , Melanoma/genetics , Mitogen-Activated Protein Kinase Kinases/therapeutic use , Nivolumab/therapeutic use , Proto-Oncogene Proteins B-raf/genetics
17.
Injury ; 51(12): 2887-2892, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32998823

ABSTRACT

AIMS: Many advocate screw fixation of fractures to the metaphyseal-diaphyseal junction of the fifth metatarsal base, better known as Jones fractures (JF), to facilitate quicker ambulation and return to sport. Maximizing screw parameters based on fifth metatarsal (MT5) anatomy, alongside understanding the anatomic structures compromised by screw insertion, may optimize surgical outcomes. This study aims to (1) correlate the proximity of JF to the peroneus brevis (PB) and plantar fascia (PF) footprints and (2) quantify optimal screw parameters given MT5 anatomy. MATERIALS AND METHODS: 3D CT-scan reconstructions were made of 21 cadaveric MT5s, followed by meticulous mapping of the PB and PF onto the reconstructions. Based on bone length, shape, narrowest intramedullary canal (IMC) diameter, and surrounding anatomy, two traditional debated screw positions were modeled for each reconstruction: (1) an anatomically positioned screw (AP), predicated on maximizing screw length by following the IMC for as long as possible, and (2) a clinically achievable screw (CA), predicated on maximizing screw length without violating the fifth tarso-metatarsal joint or adjacent cuboid bone. Fixation parameters were calculated for all models. RESULTS: The PB and PF extended into the JF site in 29% and 43%, respectively. AP's did not affect PB and PF footprint but required screw entry through the cuboid and fifth tarso-metatarsal joint in all specimens. CA screw entry sites, avoiding the cuboid and fifth tarso-metatarsal joint, partially compromised the PB and PF insertions in 33% and 62% with a median surface loss of 1.6%%(range 0.2-3.2%) and 0.81%%(range 0.05-1.6%), respectively. Mean AP screw length was 64±3.6mm and thread length 49±4.2mm. Mean CA screw length was 48±5.8mm and thread length 28±6.9mm. CONCLUSION: This study underscores the challenges associated with surrounding MT5 anatomy as they relate to optimal JF treatment. Both the extent of JF as well as a clinically achievable positioned screw violate the PB and PF footprints - although the degree to which even partial disruption of these footprints has on outcome remains unclear. To minimize damage to surrounding structures, including the PB and PF footprint, while allowing a screw length approximately two thirds of the metatarsal length, the CA screw position is recommended. This position balances the desire to maximize pull out strength while avoiding cortical penetration or inadvertent fracture site distraction.


Subject(s)
Fractures, Bone , Metatarsal Bones , Tarsal Bones , Bone Screws , Cadaver , Fractures, Bone/diagnostic imaging , Fractures, Bone/surgery , Humans , Metatarsal Bones/diagnostic imaging , Metatarsal Bones/surgery
18.
Int J Mol Sci ; 21(8)2020 Apr 22.
Article in English | MEDLINE | ID: mdl-32331417

ABSTRACT

Retinal prosthesis has recently emerged as a treatment strategy for retinopathies, providing excellent assistance in the treatment of age-related macular degeneration (AMD) and retinitis pigmentosa. The potential application of graphene oxide (GO), a highly biocompatible nanomaterial with superior physicochemical properties, in the fabrication of electrodes for retinal prosthesis, is reviewed in this article. This review integrates insights from biological medicine and nanotechnology, with electronic and electrical engineering technological breakthroughs, and aims to highlight innovative objectives in developing biomedical applications of retinal prosthesis.


Subject(s)
Graphite/chemistry , Nanostructures/chemistry , Nanotechnology , Biocompatible Materials , Humans , Nanotechnology/instrumentation , Nanotechnology/methods , Tissue Engineering , Visual Prosthesis
19.
Gels ; 6(2)2020 Apr 18.
Article in English | MEDLINE | ID: mdl-32325773

ABSTRACT

Hydrogels composed of calcium cross-linked alginate are under investigation as bioinks for tissue engineering scaffolds due to their variable viscoelasticity, biocompatibility, and erodibility. Here, pyrrole was oxidatively polymerized in the presence of sodium alginate solutions to form ionomeric composites of various compositions. The IR spectroscopy shows that mild base is required to prevent the oxidant from attacking the alginate during the polymerization reaction. The resulting composites were isolated as dried thin films or cross-linked hydrogels and aerogels. The products were characterized by elemental analysis to determine polypyrrole incorporation, electrical conductivity measurements, and by SEM to determine changes in morphology or large-scale phase separation. Polypyrrole incorporation of up to twice the alginate (monomer versus monomer) provided materials amenable to 3D extrusion printing. The PC12 neuronal cells adhered and proliferated on the composites, demonstrating their biocompatibility and potential for tissue engineering applications.

20.
J Autism Dev Disord ; 50(12): 4243-4257, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32266683

ABSTRACT

Social stories is a widely used intervention for children on the autism spectrum, particularly within an educational context. To date, systematic reviews and meta analyses of the research evaluating social stories has produced mixed results, often due to a lack of methodological rigour and variability in the development and delivery of the social stories. To address the gap in methodological rigour, a pilot Randomised Control Trial (RCT) was conducted, incorporating a social stories intervention group (n = 9 children on the autism spectrum) and an attentional control group who received a poem (n = 6 children on the autism spectrum) using a digital platform to address variability. Digitally-mediated social stories were found to be effective in producing beneficial changes in behaviour outcomes, which were sustained at a six-week follow up.


Subject(s)
Autistic Disorder/psychology , Autistic Disorder/therapy , Social Adjustment , Autism Spectrum Disorder , Child , Child Development Disorders, Pervasive , Child, Preschool , Female , Humans , Male , Pilot Projects
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