Strategies to recruit plateletpheresis donors from a registry of HLA- typed, unrelated, bone marrow donors

Rising demand for single-donor platelet components–from random donors, to maintain platelet inventories, or from HLA-compatible donors, to support alloimmune platelet-refractory patients–necessitated increasing the size of a community plateletpheresis donor registry. This study compares two strategies for recruiting whole-blood donors into a plateletpheresis program. The whole-blood donors who were asked to participate in this study had recently joined an unrelated bone marrow donor registry and had been HLA-typed as part of that process. An in-person recruitment strategy, which was time-intensive for the apheresis donor coordinator, served as the standard. A by-mail strategy involved the mailing of recruitment materials to marrow-donor registry participants. Marrow-donor registry participants were approached about apheresis participation after they had indicated an interest in the plateletpheresis program by returning a tear-off section of an informational brochure that was sent to them along with their marrow- donor registry materials. A total of 852 marrow-donor registry participants were randomly assigned to one of two recruitment strategies, and the recruitment rates were the same (46%) for both methods. In addition, levels of apheresis participation and attrition rates of donors recruited by either strategy were comparable. Thus, the simple strategy of mailing information about a plateletpheresis program is a very cost-effective method of recruiting donors.     

Patient satisfaction with chiropractic physicians in an independent physicians' association

BACKGROUND: Satisfaction with care is one of the variables that can be used in determining the results of medical care. Patient satisfaction surveys allow managed care plans to determine how well their providers meet certain standards. OBJECTIVE: To determine the level of satisfaction with chiropractic care in a random sample of patients seen by physician members of a chiropractic independent physicians' association. DESIGN: A visit-specific questionnaire was mailed to a random sample of 150 patients from health insurance claims filed in the first two months of 2000. RESULTS: The rate of return was 44%. Various aspects of chiropractic care were given a rating of "excellent" by the following percentage of respondents: Length of time to get an appointment (84.9%); convenience of the office (57.7%); access to the office by telephone (77.3%); length of wait at the office (75.7%); time spent with the provider (74.3%); explanation of what was done during the visit (72.8%); technical skills of the chiropractor (83.3%); and the personal manner of the chiropractor (92.4%). The visit overall was rated as excellent by 83.3% of responders, and 95.5% stated they would definitely recommend the provider to others. CONCLUSION: The study demonstrated a high satisfaction rate among managed-care patients.     

Delivery of B Cell Receptor–internalized Antigen to Endosomes and Class II Vesicles

B cell receptor (BCR)-mediated antigen processing is a mechanism that allows class II–restricted presentation of specific antigen by B cells at relatively low antigen concentrations. Although BCR-mediated antigen processing and class II peptide loading may occur within one or more endocytic compartments, the functions of these compartments and their relationships to endosomes and lysosomes remain uncertain. In murine B cells, at least one population of class II– containing endocytic vesicles (i.e., CIIV) has been identified and demonstrated to be distinct both physically and functionally from endosomes and lysosomes. We now demonstrate the delivery of BCR-internalized antigen to CIIV within the time frame during which BCR-mediated antigen processing and formation of peptide–class II complexes occurs. Only a fraction of the BCR-internalized antigen was delivered to CIIV, with the majority of internalized antigen being delivered to lysosomes that are largely class II negative. The extensive colocalization of BCR-internalized antigen and newly synthesized class II molecules in CIIV suggests that CIIV may represent a specialized subcellular compartment for BCR-mediated antigen processing. Additionally, we have identified a putative CIIV-marker protein, immunologically related to the Igα subunit of the BCR, which further illustrates the unique nature of these endocytic vesicles.The recognition of MHC class II–restricted antigens by antigen-specific T cells requires the proteolytic processing of protein antigens to immunogenic peptides by class II–positive antigen-presenting cells (1, 2). The first step in antigen processing by B cells involves B cell receptor (BCR)¹–mediated internalization of antigen (3–5). BCR-internalized antigen is then proteolytically processed and the resultant peptides preferentially loaded onto newly synthesized class II molecules (6–8) from which the class II– associated invariant chain has been removed by the concerted action of acid proteases and the protein HLA-DM/ H-2M (9). The resultant peptide–class II complexes are then transported to the surface of the B cell.The intracellular compartments where antigen processing occurs have only recently been characterized and there is considerable variation in the intracellular localization of class II molecules among different cell types. Many cells, such as human lymphoblasts and macrophages, sequester much of their class II in lysosomes or lysosome-like structures referred to as the MHC class II–enriched compartment (MIIC; reference 10). Although delivery of BCR-internalized antigen to MIIC has been demonstrated (11), the fate of the antigen delivered to these structures (i.e., complete degradation versus processing and binding to class II molecules) remains unknown.In other professional antigen-presenting cells such as many murine B cell lines, there is little accumulation of class II in lysosomes under normal conditions (12–14). Instead, class II is found in endosomes and endosome-related structures, at least one population of which (class II vesicles [CIIV]) can be purified and physically separated from conventional endocytic and secretory organelles by cell fractionation techniques (14).Although many or all endocytic, class II–containing vesicle populations may host the loading of peptides onto class II molecules, there may be important qualitative differences regarding the subcellular compartments where antigenic peptides are generated and efficiently loaded onto class II molecules. Specifically, although BCR-mediated antigen presentation appears to involve binding of peptide to newly synthesized class II molecules (6–8), presentation of fluid phase proteins by B cells appears to be able to occur via both newly synthesized and recycling class II molecules (7, 8, 15, 16), possibly reflecting differences in the intracellular sites of peptide generation and class II loading.Additionally, not all receptors are equivalent at mediating antigen processing and presentation. In murine B cells, antigen internalized via the transferrin receptor (while presented more efficiently than soluble antigen) is presented 10–100 times less efficiently than the same antigen internalized via the BCR (17). This result may reflect the fact that the transferrin receptor has far more restricted access to intracellular class II compartments in B cells than does the BCR (11). Even more dramatic is the demonstration that a single amino acid substitution in the transmembrane region of the human IgM BCR (huBCR) can completely abolish the ability of this receptor to mediate efficient antigen processing and presentation without affecting BCR-mediated antigen endocytosis and bulk antigen degradation (18, 19). Thus, antigen uptake and degradation is necessary, but not sufficient, for antigen processing and presentation.Thus, it has become important to determine the intracellular compartments to which physiologically important receptors (e.g., the BCR) deliver antigens. In this paper, we demonstrate that, within the time frame during which the intracellular events of BCR-mediated antigen processing are known to occur, BCR molecules and BCR-internalized antigen have access not only to predominantly class II– negative endosome and lysosomes, but also to a novel population of endocytic vesicles that are highly enriched in newly synthesized class II molecules (i.e., CIIV). Moreover, CIIV contain a putative marker protein, immunologically related to the Igα subunit of the BCR, further illustrating the distinct nature of these endocytic vesicles.     

The risk of being fearful or fearless of falls in older people: an empirical validation

PURPOSE: To investigate the risk of being fearful or fearless of falls in older people. METHODS: Using a force plate, postural control in different sensory and rhythmic conditions was measured in 263 community-dwelling older people. Other assessments included fear of falling, and handgrip strength. Fall incidence was assessed at baseline and during a one-year follow-up period. RESULTS: Logistic regression analysis revealed that increased lateral sway in near-tandem stance with eyes open (OR = 5.33; p < 0.01) and a worse performance on anteroposterior rhythmic weight shifts (OR = 0.65; p < 0.05) were related to falls. Univariate analyses revealed that older people with inappropriate high fear of falling according to their fall incidence had worse balance capacities on the rhythmic weight shifts (p < 0.05) but had similar static balance and physical capacities. Older people with inappropriate low fear of falling had a better hand grip (p < 0.05) but equally worse balance capacities than the comparison group. CONCLUSIONS: The results indicate the importance of lateral stability in relation to falls. They also suggest a substantial impact of inappropriate fear of falling on physical performance. Inappropriate high fear of falling may result in worse performance during dynamic balance tests, whereas older people with inappropriate low fear seem to overrate their capacities because of higher strength.     

Managing Paratonia in Persons With Dementia: Short-term Effects of Supporting Cushions and Harmonic Techniques

ObjectivesParatonia, a form of hypertonia typically seen in dementia, is often associated with difficulties in positioning and daily care. No evidence-based therapy or clinical guideline for management is available. In this study, the short-term effect of harmonic techniques (HT) and supporting cushions (SC) on paratonia was explored.DesignThis was a multicenter interventional clinical trial with AB/BA crossover design. Each intervention (SC or HT) was subsequently implemented over 1 week in each of the participants.Setting and participantsThe study included 22 participants with moderate to severe paratonia from 9 different nursing homes in Flanders, Belgium.MethodsMeasurements of biceps brachii and rectus femoris muscle tone (MyotonPRO), maximal elbow and knee extension (goniometer), and pain (Pain Assessment Checklist for Seniors With Limited Ability to Communicate) were performed on 3 different days within 1 week. The effect of HT on nursing care was evaluated with the Pain Assessment Checklist for Seniors With Limited Ability to Communicate and visual analog scale ratings of discomfort items.ResultsAfter 30 minutes of positioning with SC, participants had lower biceps brachii muscle tone (P = .041) and higher maximal elbow extension (P = .006) than without SC. After a 30-minute session of HT, a significant increase in biceps brachii muscle tone (P = .032) and maximal extension of elbow (P < .001) and knee (P = .028) was found. Pain (P = .003) and discomfort (P = .001 to P = .019) during morning care were significantly lower when care was preceded by 30 minutes of HT.Conclusions/ImplicationsThis explorative study revealed beneficial short-term effects on range of motion for both SC and HT and a positive effect of SC on upper limb muscle tone. Beneficial effects of HT were found on resident's pain and caregiver's discomfort during care. The results of the present study are encouraging and can contribute to the development of evidence-based interventions for paratonia.