Production and stability of cultured red blood cells depends on the concentration of cholesterol in culture medium.

The production of cultured red blood cells (cRBC) for transfusion purposes requires large scale cultures and downstream processes to purify enucleated cRBC. The membrane composition, and cholesterol content in particular, are important during proliferation of (pro)erythroblasts and for cRBC quality. Therefore, we tested the requirement for cholesterol in the culture medium during expansion and differentiation of erythroid cultures with respect to proliferation, enucleation and purification by filtration. The low cholesterol level (22 µg/dl) in serum free medium was sufficient to expand (pro)erythroblast cultures. Addition of 2.0 or 5.0 mg/dL of free cholesterol at the start of differentiation induction inhibited enucleation compared to the default condition containing 3.3 mg/dl total cholesterol derived from the addition of Omniplasma to serum free medium. Addition of 5.0 mg/dl cholesterol at day 5 of differentiation did not affect the enucleation process but significantly increased recovery of enucleated cRBC following filtration over leukodepletion filters. The addition of cholesterol at day 5 increased the osmotic resistance of cRBC. In conclusion, cholesterol supplementation after the onset of enucleation improved the robustness of cRBC and increased the yield of enucleated cRBC in the purification process.

Study on the relationship between low back pain and emotional state, sleep and quality of life in postmenopausal women.

OBJECTIVE: The aim of this study was to investigate the incidence of low back pain in the postmenopausal period and the relationship between low back pain and emotional state, sleep and quality of life. METHODS: This cross-sectional study was conducted with 368 postmenopausal women between 40 and 65 years old. The frequency and severity of low back pain were recorded for all participants, as well as depressive symptoms and anxiety, quality of life and sleep quality. RESULTS: 90.2% of the participants reported low back pain. As low back pain severity increased, it was found that depression, anxiety levels, NHP and PSQI total scores increased as well (p= 0.0001). Significant positive correlations were found between pain intensity and outcome measures, except for sleep duration and habitual sleep efficiency (p< 0.01). CONCLUSION: A great majority of women experience postmenopausal low back pain, which causes significant problems that negatively affect their quality of life, emotional state and sleep quality.

Determination of physical parameters associated with self-efficacy in patients with chronic mechanic low back pain.

BACKGROUND: Self-efficacy that is associated with various pain-related disabilities such as chronic low back pain (LBP), should be questioned besides physical assessments. OBJECTIVES: To investigate the physical factors associated with self-efficacy in patients with chronic mechanic LBP. METHODS: One hundred nine patients diagnosed as chronic mechanic LBP (65 females, 44 males) between 20-50 years old were included to this study. The intensity of LBP was assessed by using a 10-cm Visual Analogue Scale. For musculoskeletal fitness measurement; muscle strength, muscle endurance, and flexibility tests were applied. Functional Reach Test for balance evaluation, Self-Efficacy Scale for self-efficacy measurement, Roland-Morris Disability Questionnaire for disability level evaluation were used. RESULTS: We found a moderate negative correlation between self-efficacy and pain intensity (r=-0.506); a negative and strong correlation between self-efficacy and disability level (r=-0.654) (p< 0.05). Self efficacy had a significant association with right (r= 0.265) and left (r= 0.290) lateral side bending flexibility (p< 0.05). According to multiple regression analysis results, it was found that disability level had a significant effect on self-efficacy (ß=-2.014; p< 0.01). CONCLUSIONS: Poor musculoskeletal fitness and pain intensity may cause decreasing self-efficacy but the major determinant of decreased self-efficacy was low-back related disability scores.

Experimental evaluation and model assessment of coexistence of PAOs and GAOs.

The study evaluated the competition and co-existence of PAOs and GAOs in sequencing batch reactor (SBR) systems sustaining enhanced biological phosphorus removal (EBPR). The SBR operation used acetate as the sole external carbon source and covered a wide range of initial COD/P ratios between 6.5 to 25.9 g COD/g P. A mechanistic model, ASMGG, was adopted for this purpose, which basically incorporated model components and processes associated with GAO metabolism and glycogen metabolism of PAOs. Model calibration was successfully performed with the same set of stoichiometric and kinetic coefficients for all the acetate, phosphate, glycogen and PHA profiles obtained in different experiments. Interpretation of experimental results by means of model simulation indicated competition and co-existence of PAOs and GAOs within the EBPR process, numerically assessing the composition of the microbial community sustained and identifying the respective role and function of PAOs and GAOs on the fate of glycogen and PHA.

Modelling and calibration of phosphate and glycogen accumulating organism competition for acetate uptake in a sequencing batch reactor.

This paper improves the modeling of enhanced biological phosphate removal, by introducing the mechanistic description of a mixed culture of glycogen and phosphate accumulating organisms competing for acetate, and glycogen metabolism of the latter. A new process stoichiometry is defined for the mixed culture based upon previously developed metabolic concepts and models. The proposed model is tested with and used for the calibration of experimental data generated by a sequencing batch reactor operated with acetate feeding at a P/Ac ratio of 0.05 mgP mg(-1)COD. The calibration yielded acceptable numerical results for all the model coefficients tested and supported the validity of selected metabolic relationships for process stoichiometry. It also defined conditions that allow the system to sustain glycogen accumulating organisms with significant impact on process behaviour and performance.

Effects of pH and substrate on the competition between glycogen and phosphorus accumulating organisms.

This article evaluates effects of pH and substrate on the competition between glycogen (GAOs) and phosphorus accumulating organisms (PAOs). A sequencing batch reactor system was operated for enhanced biological phosphorus removal (EBPR) with acetate as the sole carbon source and acetate added domestic wastewater at different influent acetate/phosphate ratios. Some batch tests were performed using acetate added domestic wastewater at different influent acetate, phosphate ratios, with different initial pH values of acetate and domestic wastewater mixture. The resulting experimental data supported the presence of GAOs for all tested HAC P ratios, especially under P limiting conditions for acetate as sole carbon source. Strong evidence is observed that acetate added domestic wastewater system had higher PAOs fraction than acetate system as sole source carbon, with using model components, namely substrate uptake, glycogen utilization and P release.