Combining technologies to create bioactive hybrid scaffolds for bone tissue engineering

Combining technologies to engineer scaffolds that can offer physical and chemical cues to cells is an attractive approach in tissue engineering and regenerative medicine. In this study, we have fabricated polymer-ceramic hybrid scaffolds for bone regeneration by combining rapid prototyping (RP), electrospinning (ESP) and a biomimetic coating method in order to provide mechanical support and a physico-chemical environment mimicking both the organic and inorganic phases of bone extracellular matrix (ECM). Poly(ethylene oxide terephthalate)-poly(buthylene terephthalate) (PEOT/PBT) block copolymer was used to produce three dimensional scaffolds by combining 3D fiber (3DF) deposition, and ESP, and these constructs were then coated with a Ca-P layer in a simulated physiological solution. Scaffold morphology and composition were studied using scanning electron microscopy (SEM) coupled to energy dispersive X-ray analyzer (EDX) and Fourier Tranform Infrared Spectroscopy (FTIR). Bone marrow derived human mesenchymal stromal cells (hMSCs) were cultured on coated and uncoated 3DF and 3DF + ESP scaffolds for up to 21 d in basic and mineralization medium and cell attachment, proliferation, and expression of genes related to osteogenesis were assessed. Cells attached, proliferated and secreted ECM on all the scaffolds. There were no significant differences in metabolic activity among the different groups on days 7 and 21. Coated 3DF scaffolds showed a significantly higher DNA amount in basic medium at 21 d compared with the coated 3DF + ESP scaffolds, whereas in mineralization medium, the presence of coating in 3DF+ESP scaffolds led to a significant decrease in the amount of DNA. An effect of combining different scaffolding technologies and material types on expression of a number of osteogenic markers (cbfa1, BMP-2, OP, OC and ON) was observed, suggesting the potential use of this approach in bone tissue engineerin

A Simulation Study of Missing Data with Multiple Missing X’s

When exploring missing data techniques in a realistic scenario, the current literature is limited: most studies only consider consequences with data missing on a single variable. This simulation study compares the relative bias of two commonly used missing data techniques when data are missing on more than one variable. Factors varied include type of missingness (MCAR, MAR), degree of missingness (10%, 25%, and 50%), and where missingness occurs (one predictor, two predictors, or two predictors with overlap). Using a real dataset, cells are systematically deleted to create various scenarios of missingness so that parameter estimates from listwise deletion and multiple imputation may be compared to the true estimates from the full dataset. Results suggest the multiple imputation works well, even when the imputation model itself is missing data. Accessed 7,222 times on https://pareonline.net from August 12, 2014 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Bibliography of marine biological and fisheries research in Lakshadweep

Bibliography of marine biological and fisheries research in Lakshadwee

Destructive effects of murine arthritogenic antibodies to type II collagen on cartilage explants in vitro

Certain monoclonal antibodies (mAbs) to type II collagen (CII) induce arthritis in vivo after passive transfer and have adverse effects on chondrocyte cultures and inhibit self assembly of collagen fibrils in vitro. We have examined whether such mAbs have detrimental effects on pre-existing cartilage. Bovine cartilage explants were cultured over 21 days in the presence of two arthritogenic mAbs to CII (CIIC1 or M2139), a non-arthritogenic mAb to CII (CIIF4) or a control mAb (GAD6). Penetration of cartilage by mAb was determined by immunofluorescence on frozen sections and correlated with changes to the extracellular matrix and chondrocytes by morphometric analysis of sections stained with toluidine blue. The effects of mAbs on matrix components were examined by Fourier transform infrared microspectroscopy (FTIRM). A possible role of Fc-binding was investigated using F(ab)(2 )from CIIC1. All three mAbs to CII penetrated the cartilage explants and CIIC1 and M2139, but not CIIF4, had adverse effects that included proteoglycan loss correlating with mAb penetration, the later development in cultures of an abnormal superficial cellular layer, and an increased proportion of empty chondrons. FTIRM showed depletion and denaturation of CII at the explant surface in the presence of CIIC1 or M2139, which paralleled proteoglycan loss. The effects of F(ab)(2 )were greater than those of intact CIIC1. Our results indicate that mAbs to CII can adversely affect preformed cartilage, and that the specific epitope on CII recognised by the mAb determines both arthritogenicity in vivo and adverse effects in vitro. We conclude that antibodies to CII can have pathogenic effects that are independent of inflammatory mediators or Fc-binding

Continuous infusion of an agonist of the tumor necrosis factor receptor 2 in the spinal cord improves recovery after traumatic contusive injury.

AimThe activation of the TNFR2 receptor is beneficial in several pathologies of the central nervous system, and this study examines whether it can ameliorate the recovery process following spinal cord injury.MethodsEHD2-sc-mTNFR2 , an agonist specific for TNFR2, was used to treat neurons exposed to high levels of glutamate in vitro. In vivo, it was infused directly to the spinal cord via osmotic pumps immediately after a contusion to the cord at the T9 level. Locomotion behavior was assessed for 6 weeks, and the tissue was analyzed (lesion size, RNA and protein expression, cell death) after injury. Somatosensory evoked potentials were also measured in response to hindlimb stimulation.ResultsThe activation of TNFR2 protected neurons from glutamate-mediated excitotoxicity through the activation of phosphoinositide-3 kinase gamma in vitro and improved the locomotion of animals following spinal cord injury. The extent of the injury was not affected by infusing EHD2-sc-mTNFR2 , but higher levels of neurofilament H and 2', 3'-cyclic-nucleotide 3'-phosphodiesterase were observed 6 weeks after the injury. Finally, the activation of TNFR2 after injury increased the neural response recorded in the cortex following hindlimb stimulation.ConclusionThe activation of TNFR2 in the spinal cord following contusive injury leads to enhanced locomotion and better cortical responses to hindlimb stimulation

Hydrographic features off northeast coast and Andaman - Nicobar Islands in relation to demersal finfish resources

Temperature varied from 17.6 to 28.5°C, salinity values from 32.12 to 35.21 x 10"" and dissolved oxygen from 0.8 to 4.41 ml/1. No identifiable relationship could be established between these three parameters and the total fish abundance, probably because the catch was made up of many species having different requirements. Higher abundance of trawl catches was from January to May when bottom water temperature was relatively low. The highest level of abundance of 2764 kg/hr in February 1989 was recorded when the parameters were 26°C, 33.6 x 10" and 2.71 ml/1; and the lowest level of 43.2 kg/hr in July 1988 was when the parameters were 25.3°C, 34.48 x 10'^ and 1.6 ml/1

Performance of a C4F8O Gas Radiator Ring Imaging Cherenkov Detector Using Multi-anode Photomultiplier Tubes

We report on test results of a novel ring imaging Cherenkov (RICH) detection system consisting of a 3 meter long gaseous C4F8O radiator, a focusing mirror, and a photon detector array based on Hamamatsu multi-anode photomultiplier tubes. This system was developed to identify charged particles in the momentum range from 3-70 GeV/c for the BTeV experiment.Comment: 28 pages, 23 figures, submitted to Nuclear Instruments and Method

Hemodialysis Self-management Intervention Randomized Trial (HED-SMART): A Practical Low-Intensity Intervention to Improve Adherence and Clinical Markers in Patients Receiving Hemodialysis

Background: Poor adherence to treatment is common in hemodialysis patients. However, effective interventions for adherence in this population are lacking. Small studies of behavioral interventions have yielded improvements, but clinical effectiveness and long-term effects are unclear. Study Design: Multicenter parallel (1:1) design, blinded cluster-randomized controlled trial. Setting & Participants: Patients undergoing maintenance hemodialysis enrolled in 14 dialysis centers. Intervention: Dialysis shifts of eligible patients were randomly assigned to either an interactive and targeted self-management training program (HED-SMART; intervention; n = 134) or usual care (control; n = 101). HED-SMART, developed using the principles of problem solving and social learning theory, was delivered in a group format by health care professionals over 4 sessions. Outcomes & Measurements: Serum potassium and phosphate concentrations, interdialytic weight gains (IDWGs), self-reported adherence, and self-management skills at 1 week, 3 months, and 9 months postintervention. Results: 235 participants were enrolled in the study (response rate, 44.2%), and 82.1% completed the protocol. IDWG was significantly lowered across all 3 assessments relative to baseline (P < . 0.001) among patients randomly assigned to HED-SMART. In contrast, IDWG in controls showed no change except at 3 months, when it worsened significantly. Improvements in mineral markers were noted in the HED-SMART arm at 3 months (P < . 0.001) and in potassium concentrations (P < . 0.001) at 9 months. Phosphate concentrations improved in HED-SMART at 3 months (P = 0.03), but these effects were not maintained at 9 months postintervention. Significant differences between the arms were found for the secondary outcomes of self-reported adherence, self-management skills, and self-efficacy at all time points. Limitations: Low proportion of patients with diabetes. Conclusions: HED-SMART provides an effective and practical model for improving health in hemodialysis patients. The observed improvements in clinical markers and self-report adherence, if maintained at the longer follow-up, could significantly reduce end-stage renal disease-related complications. Given the feasibility of this kind of program, it has strong potential for supplementing usual care. Trial Registration: Registered at ISRCTN with study number ISRCTN31434033

The effect of brief self-management intervention for hemodialysis patients (HED-SMART) on trajectories of depressive and anxious symptoms

Objective: Depression is often comorbid with End-Stage Renal Disease, and associated with poor adherence and clinical outcomes but course of symptoms is variable. This study sought to describe the long-term trajectories of anxiety and depression in hemodialysis patients, to identify predictors of these trajectories over 12 months and to evaluate the effectiveness of the HEmoDialysis Self-Management Randomized Trial (HED SMART) against usual care on symptoms of anxiety and depression. Methods: A secondary analysis of data from a randomized controlled trial that contrasted HED SMART (n = 101) against usual care (n = 134). Depressive and anxious symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS) at baseline, 1 week and at 3 and 9 months post-intervention. Latent class growth analysis identified trajectories of depression and anxiety, and their sociodemographic and clinical predictors. Results: Symptoms of depression and anxiety over 12 months were characterized by two trajectories: low stable (depression: 55%; anxiety: 59%) with non-clinical levels of distress, and high stable (depression: 45%; anxiety: 41%) with clinical levels of distress. HED SMART predicted significant reductions in depression relative to usual care. A similar trend was noted for anxiety. Younger age, Chinese ethnicity, and more comorbidities were associated with persistent high depression. Younger age and shorter dialysis vintage was associated with persistent high anxiety. Conclusion: A brief self-management intervention designed to support behavioral change can also lead to significant reductions in symptoms of depression and may be of great value for younger HD patients shown to be at greater risk for persistent distress. Trial registration: ISRTN31434033