A Method to Evaluate Fetal Erythropoiesis from Postnatal Survival of Fetal RBCs

Fetal RBCs are produced during a period of very rapid growth and stimulated erythropoiesis under hypoxic intrauterine conditions. Fetal RBC life span varies with gestational age (GA) and is shorter than that in healthy adults. Due to the special kinetic properties of life span-based survival of human RBCs, a mathematical model-based kinetic analysis of the survival of fetal RBCs shortly after birth provides a unique opportunity to “look backward in time” to evaluate fetal erythropoiesis. This work introduces a novel method that utilizes postnatal in vivo RBC survival data collected within 2 days after birth to study both nonsteady-state (non-SS) in utero RBC production and changing fetal RBC life span over time. The effect of changes in erythropoiesis rate and RBC life span and the effect of multiple postnatal phlebotomies on the RBC survival curves were investigated using model-based simulations. This mathematical model, which considers both changes in the rate of erythropoiesis and RBC life span and which accurately accounts for the confounding effect of multiple phlebotomies, was applied to survival curves for biotin-labeled RBCs from ten anemic very low birth weight preterm infants. The estimated mean fetal RBC production rate scaled by body weight was 1.07 × 10⁷ RBCs/day g, and the mean RBC life span at birth was 52.1 days; these values are consistent with reported values. The in utero RBC life span increased at a rate of 0.51 days per day of gestation. We conclude that the proposed mathematical model and its implementation provide a flexible framework to study in utero non-SS fetal erythropoiesis in newborn infants.KEY WORDS: cord blood RBCs, fetal erythropoiesis, fetal RBC life span, fetal RBC production, red blood cells     

The segway personal transporter as an alternative mobility device for people with disabilities: a pilot study

Sawatzky B, Denison I, Langrish S, Richardson S, Hiller K, Slobogean B. The Segway Personal Transporter as an alternative mobility device for people with disabilities: a pilot study.

Objectives

To determine the functional measures that best correlate with the skill levels of people with disabilities who operate a Segway Personal Transporter, and—using a qualitative analysis—to explore subjects’ experience with the Segway.

Design

A prospective study encompassing 3 training sessions with the Segway to correlate subjects’ functional ability (eg, cognition, balance, mobility, muscle strength) with their skill level on the device.

Setting

A provincial adult rehabilitation center.

Participants

Twenty-three subjects (age range, 19−65y) with a wide range of disabilities (eg, multiple sclerosis, spinal cord injury, amputation) who could walk at least 6m with or without assistance.

Interventions

Not applicable.

Main Outcome Measures

Segway Task Assessment, Berg Balance Scale, and Timed Up & Go test.

Results

No correlation was found because all participants successfully completed the final Segway Task Assessment, regardless of scores on functional assessments.

Conclusions

The Segway is a useful device for a broad range of populations with functional disabilities. Subjects found the Segway easy to use and were excited about its potential as an assistive device for use in their communities.     

Long‐term follow‐up of tailored behavioural treatment and exercise based physical therapy in persistent musculoskeletal pain: A randomized controlled trial in primary care

This study examined long‐term effects of a tailored behavioural treatment protocol (TBT), as compared with an exercise based physical therapy protocol (EBT). One‐hundred and twenty‐two patients who, due to persistent musculoskeletal pain, consulted physical therapists in primary care were originally randomized to either of the two conditions. Follow‐up assessments two‐year post‐treatment were completed by 65 participants. According to per‐protocol analyses, short‐term effects were maintained in both groups for the primary outcome, pain‐related disability. The TT‐group reported lower disability levels compared with the EBT‐group. Intention‐to‐treat analyses (ITT) conveyed similar results. Secondary outcomes of pain intensity, pain control, and functional self‐efficacy were maintained over the 2‐year post‐treatment, but previous group differences were levelled out according to the most conservative method of ITT. Fear of movement/(re)injury increased in the EBT‐group, and EBT participants reported higher fear of movement/(re)injury two years post‐treatment compared to TT. The study supports tailoring of treatments in concordance with patients’ needs and preferences of activity goals and functional behavioural analyses including predictors of pain‐related disability, for successful immediate outcomes and their maintenance in the long run. Exercise‐based treatments resulted in somewhat smaller immediate treatment effects but had similar maintenance of effects over the 2‐year follow‐up period.     

Effects of estrogenic compounds on immunoglobulin production by mouse splenocytes

The effects of culture medium and serum components on immunoglobulin (Ig) production by mouse splenocytes were examined. In this study, we showed that culture medium containing charcoal-dextran-treated fetal bovine serum (CDFBS) supported Ig production more efficiently than culture medium containing FBS. In addition, RPMI 1640 medium supported Ig production more efficiently than Dulbecco modified Eagle medium. In addition, an increase in medium IgA production was observed with the increase in both CDFBS and FBS concentrations, whereas an increase in IgM level was observed in the presence of 5% and 10% FBS and 10% CDFBS. Dose-dependent effects of estrogenic compounds on Ig production were also examined. We found that 17beta-estradiol induced increases in IgM and IgE levels, but diethylstilbestrol enhanced only the IgE level. On the other hand, tamoxifen and bisphenol A enhanced medium IgM level at physiological concentrations. Among flavonoids, daidzein enhanced IgM and IgE levels at concentrations above 10 microM, and genistein induced a decrease in IgM level and an increase in IgE level at concentrations above 10 microm. In addition, quercetin and luteolin enhanced medium IgE level at all concentrations tested, whereas IgA, IgG, and IgM levels were not affected. These results suggest that environmental estrogens affect Ig production of mouse Splenocytes in a complex and class-specific manner.