A Review of the Role of Bioreactors for iPSCs-Based Tissue-Engineered Articular Cartilage

BACKGROUND: Osteoarthritis (OA) is the most common degenerative joint disease without an ultimate treatment. In a search for novel approaches, tissue engineering (TE) has shown great potential to be an effective way for hyaline cartilage regeneration and repair in advanced stages of OA. Recently, induced pluripotent stem cells (iPSCs) have been appointed to be essential stem cells for degenerative disease treatment because they allow a personalized medicine approach. For clinical translation, bioreactors in combination with iPSCs-engineerd cartilage could match patients needs, serve as platform for large-scale patient specific cartilage production, and be a tool for patient OA modelling and drug screening. Furthermore, to minimize in vivo experiments and improve cell differentiation and cartilage extracellular matrix (ECM) deposition, TE combines existing approaches with bioreactors.METHODS: This review summarizes the current understanding of bioreactors and the necessary parameters when they are intended for cartilage TE, focusing on the potential use of iPSCs.RESULTS: Bioreactors intended for cartilage TE must resemble the joint cavity niche. However, recreating human synovial joints is not trivial because the interactions between various stimuli are not entirely understood.CONCLUSION: The use of mechanical and electrical stimulation to differentiate iPSCs, and maintain and test chondrocytes are key stimuli influencing hyaline cartilage homeostasis. Incorporating these stimuli to bioreactors can positively impact cartilage TE approaches and their possibility for posterior translation into the clinics.</p

Clinical management of ovarian small-cell carcinoma of the hypercalcemic type: A proposal for conservative surge

Ovarian small-cell carcinoma of the hypercalcemic type is a rare and highly malignant tumor. In two thirds of the patients, the tumor is associated with asymptomatic paraneoplastic hypercalcemia. The diagnosis may be impeded; the tumor must be distinguished

Discretionary sanctions and rewards in the repeated inspection game

We experimentally investigate a repeated “inspection game” where, in the stage game, an employee can either work or shirk and an employer simultaneously chooses to inspect or not inspect. The unique equilibrium of the stage game is in mixed strategies with positive probabilities of shirking/inspecting while combined payoffs are maximized when the employee works and the employer does not inspect. We examine the effects of allowing the employer discretion to sanction or reward the employee after observing stage game payoffs. When employers have limited discretion, and can only apply sanctions and/or rewards following an inspection, we find that both instruments are equally effective in reducing shirking and increasing joint earnings. When employers have discretion to reward and/or sanction independently of whether they inspect we find that rewards are more effective than sanctions. In treatments where employers can combine sanctions and rewards employers rely mainly on rewards and outcomes closely resemble those of treatments where only rewards are possible

Phosphocreatine interacts with phospholipids, affects membrane properties and exerts membrane-protective effects

A broad spectrum of beneficial effects has been ascribed to creatine (Cr), phosphocreatine (PCr) and their cyclic analogues cyclo-(cCr) and phospho-cyclocreatine (PcCr). Cr is widely used as nutritional supplement in sports and increasingly also as adjuvant treatment for pathologies such as myopathies and a plethora of neurodegenerative diseases. Additionally, Cr and its cyclic analogues have been proposed for anti-cancer treatment. The mechanisms involved in these pleiotropic effects are still controversial and far from being understood. The reversible conversion of Cr and ATP into PCr and ADP by creatine kinase, generating highly diffusible PCr energy reserves, is certainly an important element. However, some protective effects of Cr and analogues cannot be satisfactorily explained solely by effects on the cellular energy state. Here we used mainly liposome model systems to provide evidence for interaction of PCr and PcCr with different zwitterionic phospholipids by applying four independent, complementary biochemical and biophysical assays: (i) chemical binding assay, (ii) surface plasmon resonance spectroscopy (SPR), (iii) solid-state (31)P-NMR, and (iv) differential scanning calorimetry (DSC). SPR revealed low affinity PCr/phospholipid interaction that additionally induced changes in liposome shape as indicated by NMR and SPR. Additionally, DSC revealed evidence for membrane packing effects by PCr, as seen by altered lipid phase transition. Finally, PCr efficiently protected against membrane permeabilization in two different model systems: liposome-permeabilization by the membrane-active peptide melittin, and erythrocyte hemolysis by the oxidative drug doxorubicin, hypoosmotic stress or the mild detergent saponin. These findings suggest a new molecular basis for non-energy related functions of PCr and its cyclic analogue. PCr/phospholipid interaction and alteration of membrane structure may not only protect cellular membranes against various insults, but could have more general implications for many physiological membrane-related functions that are relevant for health and disease

Neuronal integration in an abuttingretinas culture system

PURPOSE. Limited integration is consistently observed between subretinal transplants and host retinas. In the current study, an in vitro model system for studying connections forming between two abutting retinas was developed. METHODS. Neuroretinas were dissected from normal wild-type (WT) mice and green fluorescent protein (GFP) transgenic mice (obtained at postnatal days [P]0, P5, or P60), as well as from adult rd mice. Pieces from two different retinas (WT-WT, GFP-WT, GFP-rd) were placed side-by-side (contacting each other at the margins) or overlapping each other in organ cultures for 7 or 12 days. The abutting retinal pieces derived from animals of the same age (P5-P5; P60-P60) or of different ages (P0-P60; P5-P60). Retinal cells and fibers were visualized in wholemount preparations and in cross sections by immunocytochemistry using antibodies against neurofilament (NFϩ), neuronal nitric oxide synthase (NOSϩ), and protein kinase C (PKCϩ) and by GFP fluorescence (GFPϩ). RESULTS. In side-by-side pairs (WT-WT, GFP-WT), numerous horizontal cell fibers (NFϩ) and amacrine cell fibers (NOSϩ) crossed the interface between the two pieces, forming continuous plexiform layers. In overlapping pairs, NFϩ, NOSϩ, and PKCϩ fibers displayed parallel plexiform layers, and no crossover of fibers was observed in any of the pair combinations examined (WT-WT, GFP-WT, GFP-rd). Some integration was seen only in small areas where the structure of both retinal pieces was disrupted at the interface. CONCLUSIONS. The results demonstrate the ability of neurites to extend between abutting retinas and to make appropriate target choices when they are placed side-by-side. However, this ability is limited when they overlap each other, similar to that observed in subretinal transplantation. (Invest Ophthalmol Vis Sci. 2003;44:4936 -4946 ). Prompted by the problem of poor graft-host integration, we developed a modified culture system in which the outgrowth of fibers between two retinal pieces could be analyzed. The system consists of two abutting retinal pieces, placed overlapping each other, which is analogous to the in vivo situation of subretinal transplantation, or side by side. Using specific neuronal markers, we examined in wholemount preparations and in transverse sections, whether neuronal fibers can extend from one retinal piece into the abutting piece. Pairs were formed using retinal pieces derived from 5-day-old (P5) mice and cultured for 7 days, thus encompassing a time window (P5-P12) during which, in normal mouse development, substantial outgrowth of retinal cell processes occurs within the synaptic layers, and synaptic maturation is initiated. 11,12 MATERIALS AND METHODS Animals and Tissue Culture Preparation The experiments were conducted with the approval of the local animal experimentation and ethics committee. Animals were handled according to the guidelines on care and use of experimental animals set forth by the Government Committee on Animal Experimentation at the University of Lund and the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. The organ culture condition has been described in detail. 13 Retinas were dissected from normal mice (C57BL/6), from GFP mice (harboring a transgene consisting of enhanced GFP [EGFP] cDNA under the control of a chicken ␤-actin promoter and a cytomegalovirus enhancer), After the superior and nasal cornea were marked, the eyes were enucleated under sterile conditions and transferred to a dish containing serum-free medium (R16; Invitrogen-Gibco, Gaithersburg, MD). 15 Retinas were dissected from the retinal pigment epithelium (RPE) and from hyaloid vessels. Each retina was cut under fresh medium into four pieces along the superior-inferior and the nasal-temporal axes (Fig

Optimized Preoperative Planning of Double Outlet Right Ventricle Patients by 3D Printing and Virtual Reality:A Pilot Study

OBJECTIVES: In complex double outlet right ventricle (DORV) patients, the optimal surgical approach may be difficult to assess based on conventional two-dimensional (2D) ultrasound (US) and computed tomography (CT) imaging. The aim of this study is to assess the added value of 3D printed and 3D Virtual Reality (VR) models of the heart used for surgical planning in DORV patients, supplementary to the gold standard 2D imaging modalities.METHODS: Five patients with different DORV-subtypes and high-quality CT scans were selected retrospectively. 3D prints and 3D-VR models were created. Twelve congenital cardiac surgeons and paediatric cardiologists, from three different hospitals, were shown 2D-CT first, after which they assessed the 3D print and 3D-VR models in random order. After each imaging method, a questionnaire was filled in on the visibility of essential structures and the surgical plan.RESULTS: Spatial relationships were generally better visualized using 3D methods (3D printing/3D-VR) than in 2D. The feasibility of VSD patch closure could be determined best using 3D-VR reconstructions (3D-VR 92%, 3D print 66%, and US/CT 46%, P &lt; 0.01). The percentage of proposed surgical plans corresponding to the performed surgical approach was 66% for plans based on US/CT, 78% for plans based on 3D printing, and 80% for plans based on 3D-VR visualization.CONCLUSIONS: This study shows that both 3D printing and 3D-VR have additional value for cardiac surgeons and cardiologists over 2D imaging, because of better visualization of spatial relationships. As a result, the proposed surgical plans based on the 3D visualizations matched the actual performed surgery to a greater extent.</p

Creatine homeostasis and protein energy wasting in hemodialysis patients

Muscle wasting, low protein intake, hypoalbuminemia, low body mass, and chronic fatigue are prevalent in hemodialysis patients. Impaired creatine status may be an often overlooked, potential contributor to these symptoms. However, little is known about creatine homeostasis in hemodialysis patients. We aimed to elucidate creatine homeostasis in hemodialysis patients by assessing intradialytic plasma changes as well as intra- and interdialytic losses of arginine, guanidinoacetate, creatine and creatinine. Additionally, we investigated associations of plasma creatine concentrations with low muscle mass, low protein intake, hypoalbuminemia, low body mass index, and chronic fatigue. Arginine, guanidinoacetate, creatine and creatinine were measured in plasma, dialysate, and urinary samples of 59 hemodialysis patients. Mean age was 65 ± 15 years and 63% were male. During hemodialysis, plasma concentrations of arginine (77 ± 22 to 60 ± 19 μmol/L), guanidinoacetate (1.8 ± 0.6 to 1.0 ± 0.3 μmol/L), creatine (26 [16–41] to 21 [15–30] μmol/L) and creatinine (689 ± 207 to 257 ± 92 μmol/L) decreased (all P < 0.001). During a hemodialysis session, patients lost 1939 ± 871 μmol arginine, 37 ± 20 μmol guanidinoacetate, 719 [399–1070] μmol creatine and 15.5 ± 8.4 mmol creatinine. In sex-adjusted models, lower plasma creatine was associated with a higher odds of low muscle mass (OR per halving: 2.00 [1.05–4.14]; P = 0.04), low protein intake (OR: 2.13 [1.17–4.27]; P = 0.02), hypoalbuminemia (OR: 3.13 [1.46–8.02]; P = 0.008) and severe fatigue (OR: 3.20 [1.52–8.05]; P = 0.006). After adjustment for potential confounders, these associations remained materially unchanged. Creatine is iatrogenically removed during hemodialysis and lower plasma creatine concentrations were associated with higher odds of low muscle mass, low protein intake, hypoalbuminemia, and severe fatigue, indicating a potential role for creatine supplementation.ISSN:1479-587

Ethnic differences in the mother-son relationship of incarcerated and non-incarcerated male adolescents in the Netherlands

<p>Abstract</p> <p>Background</p> <p>In the Netherlands, youths of Moroccan origin account for a disproportionately large percentage of the population in juvenile justice institutions. Previous research showed that Moroccan adolescents in pre-trial arrest are characterized by less serious offending behavior (i.e., primarily property-based) and lower levels of mental health problems than native Dutch adolescents in pre-trial arrest. To date, little is known about the parent-child relationship of these adolescents. This study examines the mother-son relationships of Moroccan and native Dutch delinquent adolescents and their association with adolescent delinquency.</p> <p>Methods</p> <p>In the present study, differences in the mother-son relationship characteristics between families of incarcerated <it>(N = 129) </it>and non-incarcerated <it>(N = 324) </it>adolescents were examined, and it was analyzed if these differences between incarcerated and non-incarcerated adolescents were the same for Moroccans and native Dutch. Data collection for the incarcerated sample took place from 2006 to 2008. Comparison data were used of interviews conducted with mothers originating from former larger studies in the general Dutch population. Latent Class Analysis was performed in order to identify types of mother-son relationship. Logistic regression analyses were used to identify the relationships between mother-son relationship types, incarceration and ethnicity.</p> <p>Results</p> <p>A three class model of mother-son relationship types was found: a low-conflict mother-son relationship type, a high-conflict mother-son relationship type, and a neglectful mother-son relationship type. Compared to the native Dutch adolescents, Moroccans (both in the incarcerated and non-incarcerated population) more often showed a neglectful mother-son relationship type. For Moroccans, no differences in mother-son relationship types were found between the incarcerated and non-incarcerated adolescents, whereas considerable differences occurred between the native Dutch incarcerated and non-incarcerated adolescents.</p> <p>Conclusions</p> <p>Our findings indicate that mother-son relationship types of incarcerated Moroccan adolescents and non-incarcerated Moroccan adolescents are rather comparable. These findings are in line with previous studies which revealed the less problematic profile of Moroccan adolescents in pre-trial arrest in the Netherlands compared to native Dutch adolescents in pre-trial arrest.</p

Quantitative Microbial Risk Assessment of Contracting COVID-19 Derived from Measured and Simulated Aerosol Particle Transmission in Aircraft Cabins

BACKGROUND: SARS-CoV-2 can be effectively transmitted between individuals located in close proximity to each other for extended durations. Aircraft provide such conditions. Although high attack rates during flights were reported, little was known about the risk levels of aerosol transmission of SARS-CoV-2 in aircraft cabins. OBJECTIVES: The major objective was to estimate the risk of contracting COVID-19 from transmission of aerosol particles in aircraft cabins. METHODS: In two single-aisle and one twin-aisle aircraft, dispersion of generated aerosol particles over a seven-row economy class cabin section was measured under cruise and taxi conditions and simulated with a computational fluid dynamic model under cruise conditions. Using the aerosol particle dispersion data, a quantitative microbial risk assessment was conducted for scenarios with an asymptomatic infectious person expelling aerosol particles by breathing and speaking. Effects of flight conditions were evaluated using generalized additive mixed models. RESULTS: Aerosol particle concentration decreased with increasing distance from the infectious person, and this decrease varied with direction. On a typical flight with an average shedder, estimated mean risk of contracting COVID-19 ranged from 1:3 × 10−3 to 9:0 × 10−2. Risk increased to 7:7 × 10−2 with a super shedder (<3% of cases) on a long flight. Risks increased with increasing flight duration: 2–23 cruise flights of typical duration and 2–10 flights of longer duration resulted in at least 1 case of COVID-19 due to onboard aerosol transmission by one average shedder, and in the case of one super shedder, at least 1 case in 1–3 flights of typical duration cruise and 1 flight of longer duration. DISCUSSION: Our findings indicate that the risk of contracting COVID-19 by aerosol transmission in an aircraft cabin is low, but it will not be zero. Testing before boarding may help reduce the chance of a (super)shedder boarding an aircraft and mask use further reduces aerosol transmission in the aircraft cabin