Bone From Blood: Characteristics and Clinical Implications of Circulating Osteogenic Progenitor (COP) Cells

Circulating osteogenic progenitor (COP) cells are a population of cells in the peripheral blood with the capacity for bone formation, as well as broader differentiation into mesoderm-like cells in vitro. Although some of their biological characteristics are documented in vitro, their role in diseases of the musculoskeletal system remains yet to be fully evaluated. In this review, we provide an overview of the role of COP cells in a number of physiological and pathological conditions, as well as identify areas for future research. In addition, we suggest possible areas for clinical utilization in the management of musculoskeletal diseases. © 2020 American Society for Bone and Mineral Research (ASBMR).     

Comparison of body’s center of mass motion relative to center of pressure between treadmill and over-ground walking

Treadmills have been used in rehabilitation settings to provide convenient protocols and continuous monitoring of movement over multiple cycles at well-controlled speeds for gait and balance training. However, the potential differences in the movement control may affect the translation of the training outcomes to real life over-ground walking (OW). The similarities and differences in the balance control between treadmill walking (TW) and OW have largely been unexplored. The current study bridged the gap by comparing the motions of the body’s center of mass (COM) relative to the center of pressure (COP) between TW and OW, in terms of the COM-COP inclination angle (IA) and its rate of change (RCIA). The movement of the COM and COP separately were quite different between OW and TW, but when describing the COM motion relative to the COP, the COM motions became similar qualitatively with similar butterfly patterns. However, significantly increased peak values in themediolateral RCIA and greater ranges of mediolateral IA were found during TW (p < 0.004). In the sagittal plane, the posterior velocity of the belt led to an anterior RCIA (posterior RCIA in OW) with increasing anterior IA during early double-limb support phase, and reduced posterior RCIA (p < 0.009) with an increased anterior IA (p < 0.001) during the remainder of the phase. These differences between TW and OW may have to be taken into account in future designs of strategies to optimize the translation of treadmill gait training outcomes into real life over-ground walking.     

A High-Intensity Multicomponent Agility Intervention Improves Parkinson Patients’ Clinical and Motor Symptoms

Objective

To determine the effects of a high-intensity exercise therapy using sensorimotor and visual stimuli on nondemented Parkinson disease (PD) patients’ clinical symptoms, mobility, and standing balance.

Balance Control and Energetics of Powered Exoskeleton-Assisted Sit-to-Stand Movement in Individuals With Paraplegic Spinal Cord Injury

Objective

To quantify the effects of initial hip angle and angular hip velocity settings of a lower-limb wearable robotic exoskeleton (WRE) on the balance control and mechanical energy requirements in patients with paraplegic spinal cord injuries (SCIs) during WRE-assisted sit-to-stand (STS).

着鞋类型和步速对膝关节载荷的影响

目的探讨着鞋类型(裸足、普通鞋、极简鞋)与步行速度(快步走、常速行走)对膝关节生物力学指标的影响,为科学健身提供理论参考。方法采用Vicon三维运动捕捉系统、Kisler三维测力台同步采集10名男性在裸足、穿着不同鞋常速行走与快步走时下肢运动生物力学指标。采用双因素(2种行走方式×3种着鞋类型)重复测量方差分析对各指标进行统计分析。结果相对于快步走,常速行走时足底压力中心(center of pressure,COP)向外偏移较大,额状面膝关节力臂、膝关节内收外力矩和第1峰值负载率均较小,但额状面膝关节冲量矩较大;相对于穿着普通跑鞋,裸足或穿着极简鞋时,步幅变小,COP向外偏移较大,额状面膝关节力臂、膝关节内收外力矩、第1峰值负载率和额状面膝关节冲量矩较小。结论为降低额状面膝关节冲量矩以及峰值负载率,建议着极简鞋采用小步幅进行快步走锻炼。     

Silicone Oil-Free Polymer Syringes for the Storage of Therapeutic Proteins

Prefilled syringes are a popular choice for the delivery of biopharmaceuticals. However, glass syringes might not be the optimal primary packaging material for all biopharmaceuticals. There is evidence that the necessary lubricant silicone oil in glass syringes can interact with proteins and can be shed from the surface into the product solution. In recent years, silicone oil-free polymer syringes were developed. Despite several advantages, however, a major shortcoming of these polymer systems is their relatively high gas permeability, which might be a limitation for the storage of oxygen sensitive biopharmaceuticals. So far, no long-term protein stability studies regarding such polymer systems have been published. In this study, 2 therapeutic proteins were stored in glass syringes and in silicone oil-free polymer syringes. In addition, polymer syringes stored in nitrogen-filled aluminum pouches or covered with oxygen-tight labels were included. Similar chemical protein stability was achieved at 4°C for all syringes. However, in contrast to the polymer syringes, high particle counts were observed in the glass syringes. Polymer syringes stored in nitrogen-filled aluminum pouches presented a promising alternative for the storage of biopharmaceuticals as they do not expose patients to silicone oil and silicone oil-protein aggregates.     

Effects of recombinant-hemoglobin solutions rHb2.0 and rHb1.1 on blood pressure, intestinal blood flow, and gut oxygenation in a rat model of hemorrhagic shock

The vasoconstriction induced by hemoglobin-based oxygen carriers (HBOCs), mainly a result of nitric oxide (NO) scavenging, until now has limited the application of HBOCs as resuscitation fluids. In this study, we tested the hypothesis that the new modified recombinant-hemoglobin solution rHb2.0, with a 20 to 30 times lesser NO-scavenging rate, would minimize vasoconstriction without adverse effects on microvascular oxygenation. Responses were compared with those to rHb1.1, a recombinant-hemoglobin solution with a wild-type NO-scavenging rate, as well as an oncotically matched albumin solution. In a fixed-pressure (40 mm Hg) rat model of hemorrhagic shock and resuscitation, rHb2.0 and albumin both restored mean arterial pressure (MAP) to baseline values, whereas rHb1.1 increased MAP to 27% above the baseline value. Mesenteric vascular resistance after resuscitation with rHb2.0 was 57% less than that with rHb1.1. rHb2.0 was found to have 55% greater intestinal oxygen delivery (Do2int ) and resulted in a 27% lower oxygen-extraction rate than did rHb1.1 after resuscitation. Intestinal microvascular Po2 , determined on the basis of oxygen-dependent quenching of palladium-porphyrin phosphorescence, revealed no difference between rHb2.0 and rHb1.1. The findings of this study confirm that the well-known pressure effect of HBOCs is caused by their effect on the NO-scavenging rate; recombinant modification of this rate did not increase MAP during resuscitation compared with baseline values. Although systemic vasoconstriction was absent, intestinal vasoconstriction almost negligible, and Do2int greater after resuscitation with rHb2.0, the effect of rHb2.0 on pH, base-excess and microvascular Po2 levels after resuscitation were comparable to those achieved with the use of the albumin solution.     

The development of balance control in children: comparisons of EMG and kinetic variables and chronological and developmental groupings

This cross-sectional study examined electromyographic (EMG) and kinetic variables during reactive balance responses in children grouped according to developmental level as compared with chronological age. Purposes were to explore relationships between the two types of variables and the effectiveness of the two grouping methods. Forty-four children between 9 months and 10 years old were tested for reactive balance control on a moveable platform. Surface electrodes measured EMG activity in the gastrocnemius (GA), hamstrings (HA), paraspinals (PS), tibialis anterior (TA), quadriceps (QA), and abdominal (AB) muscles. Timing and distance of center-of-pressure (COP) movements and peak muscle torques at the ankle, knee, and hip were also examined. Significant relationships and group differences were found between postural muscle activity and both the torque generated in the lower limbs and the timing and distance of COP adjustments employed to restabilize balance. As postural muscle activity increased and became more coordinated in timing, peak torque at the ankle and hip also increased, while the distance of and time to complete COP readjustments decreased. Children in younger/developmentally lower groups had smaller-magnitude and less-synergic muscle activity, lower peak torques, longer times to restabilize the COP, and greater COP paths than older/higher developmental groupings. Grouping by developmental level produced more statistical differences than did grouping by age. The correspondence of GA, HA, and PS muscle activity with COP measures and joint peak torques confirms that these muscles are key contributors to the balance synergy correcting for induced forward sway. Additionally, developmental level appears to be a much better predictor of balance improvement than chronological age.     

A phase II study of a THP-COP regimen for the treatment of elderly patients aged 70 years or older with diffuse large B-cell lymphoma

Pirarubicin (tetrahydropyranyl adriamycin: THP) is an anthracycline drug that reportedly has fewer cardiotoxic effects than doxorubicin. A phase II study was conducted in order to determine the efficacy of a treatment regimen incorporating THP, namely THP-COP in the treatment of elderly patients aged 70 years or older with diffuse large B-cell lymphoma (DLBCL). The treatment regimens for Group A (aged 70-79 years, n = 45) and Group B (aged 80 years or older, n = 16) consisted of cyclophosphamide, THP, vincristine, and prednisolone, repeated six times, every 3 weeks. The complete remission rate was 72.1%. The 5-year survival rate was 38.1%. For elderly patients with favourable prognostic factors, the 5-year survival rate was significantly better at 77.9% compared with 15.6% for patients with poor prognostic factors (p < 0.01). Death associated with the treatment regimen was not observed. We conclude that the THP-COP treatment regimen has fewer side effects and is very effective in the treatment of DLBCL in elderly patients, especially those with favourable prognostic factors. The present findings indicate the necessity of future studies investigating a combination therapy comprised of rituximab and THP-COP for the treatment of elderly patients with CD20-positive DLBCL.