Effects of micro-porosity and local BMP-2 administration on bioresorption of β-TCP and new bone formation

Abstract Background It has been reported that the microporous structure of calcium phosphate (CaP) ceramics is important to osteoconduction. Bone morphogenetic protein-2 (BMP-2) has been shown to be a promising alternative to bone grafting and a therapeutic agent promoting bone regeneration when delivered locally. The aim of this study was to evaluate the effects of micro-porosity within beta-tricalcium phosphate (β-TCP) cylinders and local BMP-2 administration on β-TCP resorption and new bone formation. Methods Bilateral cylindrical bone defects were created in rabbit distal femora, and the defects were filled with β-TCP. Rabbits were divided into 3 groups; defects were filled with a β-TCP cylinder with a total of approximately 60% porosity (Group A: 13.4% micro- and 46.9% macropore, Group B: 38.5% micro- and 20.3% macropore, Group C: the same micro- and macro-porosity as in group B supplemented with BMP-2). Rabbits were sacrificed 4, 8, 12, and 24 weeks postoperatively. Results The number of TRAP-positive cells and new bone formation in group B were significantly greater than those in group A at every period. The amount of residual β-TCP in group C was less than that in group B at all time periods, resulting in significantly more new bone formation in group C at 8 and 12 weeks. The number of TRAP-positive cells in group C was maximum at 4 weeks. Conclusions These results suggest that the amount of submicron microporous structure and local BMP-2 administration accelerated both osteoclastic resorption of β-TCP and new bone formation, probably through a coupling-like phenomenon between resorption and new bone formation

Densified Electrochemical Sensors Based on Local Redox Cycling between Vertically Separated Electrodes in Substrate Generation/Chip Collection and Extended Feedback Modes

A new local redox cycling-based electrochemical (LRC-EC) device integrated with many electrochemical sensors has been developed into a small chip device. The LRC-EC chip device was successfully applied for detection of alkaline phosphatase and horseradish peroxidase activity in substrate generation/chip collection (SG/CC) and extended feedback modes, respectively. The new imaging approach with extended feedback mode was particularly effective for sharpening of the image, because this mode uses feedback signals and minimizes the undesired influence of diffusion. The LRC-EC chip device is considered to be a useful tool for bioanalysis

Predictors of Activities of Daily Living in Intensive Care Unit Survivors: A Propensity Score Matching Analysis

Objectives: Increased long-term impairment is common among intensive care unit (ICU) survivors. However, predictors of activities of daily living (ADL) in ICU survivors are poorly understood. We aimed to focus on the trajectory of physical function and explore the clinical variables that affect ADL at hospital discharge. Methods: We enrolled 411 patients admitted to the ICU from April 2018 to October 2020. Physical function was evaluated at ICU admission, ICU discharge, and hospital discharge. We assessed physical function (grip strength, arm and calf circumference, quadriceps thickness, and Barthel index). Patients were assigned to the high or low ADL group based on their Barthel index at discharge. Propensity score matching analysis was performed to minimize selection biases and differences in clinical characteristics. Results: After matching propensity scores, 114 of the 411 patients (aged 65±15 years) were evaluated. The high ADL group showed better physical function at ICU discharge and hospital discharge than the low ADL group. An overall decreasing trend in muscle mass was observed over time; the rates of decline were lower in the high ADL group than in the low ADL group. The cutoff values for relative changes in calf circumference and quadriceps thickness to predict high ADL were −7.89% (sensitivity: 77.8%, specificity: 55.6%) and −28.1% (sensitivity: 81.0%, specificity: 58.8%), respectively. Conclusions: The relative decreases in calf circumference and quadriceps thickness during hospitalization were lower in patients who maintained their ADL. Assessment of the trajectory of physical function can predict ADL status at hospital discharge among ICU survivors

Cell type-specific transcriptome of Brassicaceae stigmatic papilla cells from a combination of laser microdissection and RNA sequencing

Pollination is an early and critical step in plant reproduction, leading to successful fertilization. It consists of many sequential processes, including adhesion of pollen grains onto the surface of stigmatic papilla cells, foot formation to strengthen pollen-stigma interaction, pollen hydration and germination, and pollen tube elongation and penetration. We have focused on an examination of the expressed genes in papilla cells, to increase understanding of the molecular systems of pollination. From three representative species of Brassicaceae (Arabidopsis thaliana, A. halleri and Brassica rapa) stigmatic papilla cells were isolated precisely by laser microdissection, and cell type-specific gene expression in papilla cells was determined by RNA sequencing. As a result, 17,240, 19,260 and 21,026 unigenes were defined in papilla cells of A. thaliana, A. halleri and B. rapa, respectively, and among these 12,311 genes were common to all three species. Among the17,240 genes predicted in A. thaliana, one-third were papilla specific while approximately half of the genes were detected in all tissues examined. Bioinformatics analysis revealed that genes related to a wide range of reproduction and development functions are expressed in papilla cells, particularly metabolism, transcription, and membrane-mediated information exchange. These results reflect the conserved features of general cellular function and also the specific reproductive role of papilla cells, highlighting a complex cellular system regulated by a diverse range of molecules in these cells. This study provides fundamental biological knowledge to dissect the molecular mechanisms of pollination in papilla cells and will shed light on our understanding of plant reproduction mechanism