Despite the clinical success of anti-CD20 monoclonal antibody (mAb) in the treatment of lymphoma, there remains considerable uncertainty about its mechanism of action. Here we show that the ability of mAbs to translocate CD20 into low-density, detergentinsoluble membrane rafts appears to control how effectively they mediate complement lysis of lymphoma cells. In vitro studies using a panel of anti-B-cell mAbs revealed that the anti-CD20 mAbs, with one exception (B1), are unusually effective at recruiting human complement. Differences in complement recruitment could not be explained by the level of mAb binding or isotype but did correlate with the redistribution of CD20 in the cell membrane following mAb ligation. Membrane fractionation confirmed that B1, unlike 1F5 and rituximab, was unable to translocate CD20 into lipid rafts. In addition, we were able to drive B1 and a range of other anti-B-cell mAbs into a detergent-insoluble fraction of the cell by hyper-cross-linking with an F(ab) 2 anti-Ig Ab, a treatment that also conferred the ability to activate lytic complement. Thus, we have shown that an important mAb effector function appears to be controlled by movement of the target molecule into membrane rafts, either because a raft location favors complement activation by mAbs or because rafts are more sensitive to complement

Objective To assess construct validity of the Prosthetic Limb Users Survey of Mobility (PLUS-M), a self-report mobility measure for people with lower limb amputation (LLA). Design Cross-sectional study. Setting Private prosthetic clinics (n=37). Participants Current lower limb prosthesis users (n=199, mean age=55.4±14.3 years, 71.4% male) were assessed before receiving a replacement prosthesis, prosthetic socket, and/or prosthetic knee. Intervention Not applicable. Main Outcome Measure(s) Convergent construct validity was examined using correlations between participants’ PLUS-M T-scores and measures of physical function, mobility, and balance, including the Amputee Mobility Predictor (AMP), Timed Up and Go (TUG), Patient Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF), Prosthesis Evaluation Questionnaire-Mobility Subscale (PEQ-MS), and Activities-Specific Balance Confidence Scale (ABC). Known-groups construct validity was evaluated by comparing differences in PLUS-M T-scores among participants grouped by Medicare Functional Classification Level (MFCL). Results PLUS-M T-scores demonstrated a moderate positive relationship with AMP scores (rho=0.54, p<0.001) and a moderate negative relationship with TUG times (rho=- 0.56, p<0.001). The PLUS-M also showed a strong positive relationship with PEQ-MS scores (rho=0.78, p<0.001), ABC scores (rho=0.81, p<0.001), and PROMIS-PF T-scores (rho=0.81, p<0.001). Significant differences (p<0.05) in PLUS-M T-scores were found among groups of people classified by different MFCLs. Conclusion Study results support validity of the PLUS-M as a self-report measure of prosthetic mobility. Correlations between PLUS-M and measures of physical function, mobility, and balance indicate convergent construct validity. Similarly, significant differences in PLUS-M T-scores across MFCL groups provide evidence of known-groups construct validity. In summary, evidence indicates that PLUS-M has good construct validity among people with LLA.

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Objective To construct profiles of self-reported health indicators to examine differences and similarities between people with lower limb loss (LLL) and a normative sample (hereafter called the norm), and to compare health indicators between subgroups based on level and etiology of limb loss. Design Survey Setting General community Participants Adults with unilateral lower limb loss (n=1091) participated in this study. Eligibility criteria included LLL resulting from trauma or dysvascular complications and regular use of a prosthesis. Interventions Not applicable Main Outcome Measures Patient-Reported Outcomes Measurement Information System 29-item profile (PROMIS-29) version 1.0 measures physical function, pain interference, fatigue, sleep disturbance, anxiety, depression and satisfaction with participation in social roles. The norms are based on 5,239 individuals representative of the U.S. general population in gender, age, race, ethnicity and education. Results People with LLL reported statistically significantly worse physical function, pain interference and satisfaction with participation in social roles and significantly less fatigue than the norm. People with transfemoral (i.e., above-knee) amputation significantly differed from people with transtibial (i.e., below-knee) amputation on physical function. Similarly, people with amputation due to trauma and dysvascular etiology significantly differed on physical function and satisfaction with social roles after adjusting for relevant clinical characteristics. Conclusions People with LLL generally report worse physical function, pain interference and satisfaction with social roles when compared to norm. People with dysvascular amputation reported worse physical function and satisfaction with social roles than people with traumatic amputation. Health indicator profiles are an efficient way of providing clinically meaningful information about numerous aspects of self-reported health in people with LLL.

Documentation of clinical outcomes is increasingly expected in delivery of prosthetic services and devices. However, many outcome measures suitable for use in clinical care and research have not been psychometrically tested with prosthesis users. The aim of this study was to determine test-retest reliability, mode-of-administration (MoA) equivalence, standard error of measurement (SEM), and minimal detectable change (MDC) of standardized, self-report instruments that assess constructs of importance to people with lower limb loss. Prosthesis users (n=201) were randomly assigned to groups based on MoA (i.e., paper, electronic, or mixed-mode). Participants completed two surveys 2-3 days apart. Instruments included the Prosthetic Limb Users Survey of Mobility, Prosthesis Evaluation Questionnaire–Mobility Subscale, Activities-Specific Balance Confidence Scale, Quality of Life in Neurological Conditions–Applied Cognition/General Concerns, Patient Reported Outcomes Measurement Information System Profile, and Socket Comfort Score. Intraclass correlation coefficients indicated all instruments are appropriate for group-level comparisons and select instruments are suitable for individual-level applications. Several instruments showed evidence of possible floor and ceiling effects. All were equivalent across MoAs. SEM and MDC were quantified to facilitate interpretation of outcomes and change scores. These results can enhance clinicians' and researchers' ability to select, apply, and interpret scores from instruments administered to prosthesis users.

To date, the plasticity, multipotentiality, and characteristics of progenitor cells from fetal skeletal tissue remain poorly defined. This study has examined cell populations from human fetal femurs in comparison with adult-derived mesenchymal cell populations. Real-time quantitative polymerase chain reaction demonstrated expression of mesenchymal progenitor cell markers by fetal-derived cells in comparison with unselected adult-derived and immunoselected STRO-1-enriched adult populations. Multipotentiality was examined using cells derived from femurs and single-cell clones, culture-expanded from explants, and maintained in basal medium prior to exposure to adipogenic, osteogenic, and chondrogenic conditions. Adipocyte formation was confirmed by Oil Red O lipid staining and aP2 immunocytochemistry, with expression of peroxisome proliferation-activated receptor-␥ detected only in adipogenic conditions. In chondrogenic pellets, chondrocytes lodged within lacunae and embedded within dense proteoglycan matrix were observed using Alcian blue/Sirius red staining and type II collagen immunocytochemistry. Osteogenic differentiation was confirmed by alkaline phosphatase staining and type I collagen immunocytochemistry as well as by gene expression of osteopontin and osteocalcin. Single-cell clonal analysis was used to demonstrate multipotentiality of the fetal-derived populations with the formation of adipogenic, chondrogenic, and osteogenic populations. Mineralization and osteoid formation were observed after culture on biomimetic scaffolds with extensive matrix accumulation both in vitro and in vivo after subcutaneous implantation in severely compromised immunodeficient mice. These studies demonstrate the proliferative and multipotential properties of fetal femur-derived cells in comparison with adult-derived cells. Selective differentiation and immunophenotyping will determine the potential of these fetal cells as a unique alternative model and cell source in the restoration of damaged tissue.

One of the puzzles in cancer predisposition is that women carrying BRCA-1 mutations preferentially develop tumors in epithelial tissues of the breast and ovary. Moreover, sporadic breast tumors contain lower levels of BRCA-1 in the absence of mutations in the BRCA-1 gene. The problem of tissue specificity requires analysis of factors that are unique to tissues of the breast. For example, the expression of estrogen receptor-alpha (ER alpha) is inversely correlated with breast cancer risk, and 90% of BRCA-1 tumors are negative for ER alpha. Here, we show that estrogen stimulates BRCA-1 promoter activity in transfected cells and the recruitment of ER alpha and its cofactor p300 to an AP-1 site that binds Jun/Fos transcription factors. The recruitment of ER alpha/p300 coincides with accumulation in the S-phase of the cell cycle and is antagonized by the antiestrogen tamoxifen. Conversely, we document that overexpression of wild-type p53 prevents the recruitment of ER alpha to the AP-1 site and represses BRCA-1 promoter activity. Taken together, our findings support a model in which an ER alpha/AP-1 complex modulates BRCA-1 transcription under conditions of estrogen stimulation. Conversely, the formation of this transcription complex is abrogated in cells overexpressing p53.

The addition of a concurrent task did not differentially affect walking outcomes in people with and without transfemoral amputation. However, compared to people without limb loss, people with transfemoral amputation adopted a conservative walking strategy. This strategy may reduce the need to concentrate on walking but also contributed to notable gait deviations.