Fear of falling: psychometric aspects of Tinetti's Falls Efficacy Scale

In this article we report on the psychometric characteristics of Tinetti's Falls Efficacy Scale. It appears that the scale is homogenous and has good internal consistency. Expected associations with age, gender, physical activity, chronic diseases and history of falls were confirmed. It is concluded that the scale is a reliable and valid instrument to measure fear of falling in performing everyday activities inside the house.     

The interaction between epiphytic algae, a parasitic fungus and Sphagnum as affected by N and P

We report the effects of fertilisation with N and P on the infection of Sphagnum by its fungal parasite Lyophyllum palustre, the expansion of epiphytic algae and the interaction between the latter two from 1998 to 2001. We added 40 kg N ha⁻¹ yr⁻¹ or 3 kg P ha⁻¹ yr⁻¹ in a full factorial design at 4 field sites. In a greenhouse experiment we reinoculated Sphagnum to verify the identity of the fungus and its necrotic effect on Sphagnum .
Lyophyllum palustre was responsible for the necrosis of Sphagnum in our experiments. Adding N induced complete necrosis of Sphagnum cuspidatum by L. palustre , whereas adding P decreased the area of necrotic tissue. Disease severity was related to the N concentration in the Sphagnum capitula. In Sphagnum magellanicum and S. papillosum , infection with L. palustre resulted in defoliation of stem sections. Adding N stimulated the expansion of algae at all sites, reducing the volume of photosynthetic tissue in Sphagnum. The density of the film of algae in the treatments receiving N was a function of the frequency of defoliated Sphagnum stems.
We conclude that infection with parasitic fungi and, in humid environments, the expansion of epiphytic algae, may aggravate the impact of increased N deposition or of other ecosystem disturbances that affect nutrient availability.     

Immunogenicity of dendritic cells pulsed with MAGE3, Survivin and B-cell maturation antigen mRNA for vaccination of multiple myeloma patients

The introduction of autologous stem cell transplantation (SCT) and novel drugs has improved overall survival in multiple myeloma (MM) patients. However, minimal residual disease (MRD) remains and most patients eventually relapse. Myeloma plasma cells express tumor-associated antigens (TAA), which are interesting targets for immunotherapy. In this phase 1 study, we investigated the safety and immunological effects of TAA-mRNA-loaded dendritic cell (DC) vaccination for treatment for MRD in MM after SCT. Mature monocyte-derived DCs were pulsed with keyhole limpet hemocyanin (KLH) and electroporated with MAGE3, Survivin or B-cell maturation antigen (BCMA) mRNA. Twelve patients were vaccinated three times with intravenous (5–22 × 10⁶ DCs) and intradermal vaccines (4–11 × 10⁶ DCs), at biweekly intervals. Immunological responses were monitored in blood and delayed-type hypersensitivity (DTH) biopsies. All patients developed strong anti-KLH T-cell responses, but not KLH antibodies. In 2 patients, vaccine-specific T cells were detected in DTH biopsies. In one patient, we found MAGE3-specific CD4⁺ and CD8⁺ T cells, and CD3⁺ T cells reactive against BCMA and Survivin. In the other patient, we detected low numbers of MAGE3 and BCMA-reactive CD8⁺ T cells. Vaccination was well tolerated with limited toxicity. These findings illustrate that TAA-mRNA-electroporated mature DCs are capable of inducing TAA-T-cell responses in MM patients after SCT.     

The dynamic process of apoptosis analyzed by flow cytometry using Annexin-V/propidium iodide and a modified in situ end labeling technique.

BACKGROUND: To study the apoptotic process in time, we used the following flow cytometric (FCM) techniques: phosphatidylserine (PS) translocation by Annexin-V (AnV), DNA fragmentation by in situ end labeling (ISEL), and propidium iodide (PI) staining. Because PS translocation is assumed to be an early feature of programmed cell death (PCD), we questioned if AnV positivity implies inevitable cell death. METHODS: Apoptosis was induced in Jurkat cells by gamma-irradiation, incubation with camptothecin (CPT), or cytosine beta-D-arabinofuranoside (Ara-C). At different time intervals, PCD was quantified by AnV/PI and ISEL. To analyze the influence of cell handling procedures on PCD, we applied these three FCM techniques on CD34+ bone marrow (BM) stem cells after selection and after a freeze-thaw procedure. Various AnV/PI- CD34+ fractions were cultured in a single-cell single-well (SCSW) assay. RESULTS: Jurkat cells under three different detrimental conditions showed essentially the same pattern of apoptosis in time. Initially developed AnV+/PI- cells subsequently (within 1 h) showed ISEL positivity, after which they turned into AnV+/PI++ cells with even higher levels of ISEL positivity (80-90%). Eventually, they lost some of their PI and ISEL positivity and formed the AnV+/PI+ fraction. Cell handling of CD34+ cells caused high and variable AnV+/PI- fractions (overall range 23-62%). Within total AnV+ and AnV+/PI- populations, only a minority of CD34+ cells showed ISEL positivity (range 4-8% and 0.8-6%, respectively). Different fractions of AnV+/PI- CD34+ cells did have clonogenic capacity. CONCLUSIONS: PCD of cell suspensions in vitro can be followed accurately in time by these three FCM techniques. PS translocation is followed rapidly (within 1 h) by oligo-nucleosomal DNA fragmentation, after which cell (and nuclear) membrane leakage occurs. Detection of PS asymmetry by AnV-fluorescein isothiocyanate (FITC) is not always associated with (inevitable) apoptosis, as can be concluded from the proliferative capacity of AnV+ /PI- CD34+ cells in the SCSW assay.     

Cell kinetics and radiosensitivity of Cercopithecus aethiops sabaceus lymphocytes stimulated by phytohemagglutinin

The use of the BudR-Giemsa technique has shown that the peripheral blood lymphocytes of Cercopithecus aethiops sabaceus display a very fast answer to PHA-stimulation. At 32 h culture time numerous mitoses are already present and at 48 h more than 30% of the dividing cells are in second mitosis. Exposure to X-irradiation results in a higher incidence of unstable aberrations than in human lymphocytes.     

Carbohydrates in Digitalis purpurea at various stages of development

The concentrations of carbohydrates in Digitalis purpurea have been determined at various stages of development. An increase of the carbohydrate content was observed during growth. Glucose was the major carbohydrate component in the leaves and stem, whereas fructose predominated in the inflorescence. The growing tips and other actively growing parts of the plant contained relatively high concentrations of two new compounds.     

Cardiac amyloidosis: the need for early diagnosis

Amyloidosis is a collection of systemic diseases characterised by misfolding of previously soluble precursor proteins that become infiltrative depositions, thereby disrupting normal organ structure and function. In the heart, accumulating amyloid fibrils lead to progressive ventricular wall thickening and stiffness, resulting in diastolic dysfunction gradually progressing to a restrictive cardiomyopathy. The main types of cardiac amyloidosis are amyloid light chain (AL) amyloidosis caused by an underlying plasma cell dyscrasia, amyloid transthyretin (TTR) amyloidosis of wild-type (normal) TTR at older age (ATTRwt) and hereditary or mutant amyloid TTR (ATTRm) in which a genetic mutation leads to an unstable TTR protein. Overall survival is poor once heart failure develops, underlining the need for early referral and diagnosis. Treatment for AL amyloidosis has improved markedly over the last decades, and TTR amyloidosis gene silencers and orally available transthyretin stabilisers are ready to enter the clinical arena after recent positive outcome trials. Novel therapies aiming at fibril degradation with monoclonal antibodies are under investigation. In this review, we focus on ‘red flag’ signs and symptoms, diagnosis and management of cardiac amyloidosis which differs considerably from the general management of heart failure. Only by increasing awareness, prognosis for patients with this devastating disease can be improved.

     

A critical role for prostaglandin E2 in podosome dissolution and induction of high-speed migration during dendritic cell maturation

Dendritic cells (DCs) are professional APCs of the immune system that play a key role in regulating T cell-based immunity. The capacity of DCs to activate T cells depends on their maturation state as well as their ability to migrate to the T cell areas of draining lymph nodes. In this study, we investigated the effects of DC maturation stimuli on the actin cytoskeleton and beta(1) integrin-dependent adhesion and migration. Podosomes, specialized adhesion structures found in immature monocyte-derived DCs as well as myeloid DCs, rapidly dissolve in response to maturation stimuli such as TNF-alpha and PGE(2), whereas the TLR agonist LPS induces podosome dissolution only after a long lag time. We demonstrate that LPS-mediated podosome disassembly as well as the onset of high-speed DC migration are dependent on the production of PGs by the DCs. Moreover, both of these processes are inhibited by Ab-induced activation of beta(1) integrins. Together, these results show that maturation-induced podosome dissolution and loss of alpha(5)beta(1) integrin activity allow human DCs to undergo the transition from an adhesive to a highly migratory phenotype.     

Single-cell image analysis to assess ABC-transporter-mediated efflux in highly purified hematopoietic progenitors

BACKGROUND: Normal and malignant hematopoietic stem cells are characterized by their capacity to actively extrude fluorescent dyes. The contribution of different ATP-binding cassette (ABC) transporters to this phenomenon is largely unknown due to the small stem cell numbers limiting the use of standard methods to assess functional efflux. METHODS: We used epifluorescence microscopy (EFM) in combination with single-cell image analysis to study ABC-transporter-mediated efflux in highly purified, viable, CD34+CD38- cells sorted on an adhesive biolayer. P-glycoprotein and multidrug-resistant protein (MRP)-mediated efflux were quantitated using fluorescent substrates (rhodamine-123 and calcein acetoxymethyl ester [calcein-AM]) and specific inhibitors (verapamil and probenecid, respectively). RESULTS: The feasibility, sensitivity, and reproducibility of rhodamine-123 efflux quantitation using single-cell EFM was shown in cell lines and compared with standard flow cytometric assessment. P-glycoprotein-mediated transport was higher in CD34+CD38- cells than in more differentiated progenitors (mean efflux index = 2.24 +/- 0.35 and 1.14 +/- 0.11, respectively; P = 0.01). P-glycoprotein-mediated transport was the main determinant of the rhodamine "dull" phenotype of these cells. In addition, significant MRP-mediated efflux was demonstrated in CD34+CD38- and CD38+ cells (mean efflux index = 1.42 +/- 0.19 and 1.28 +/- 0.18, respectively). CONCLUSION: The described method is a valuable tool for assessing ABC-transporter-mediated efflux in highly purified single cells. Both P-glycoprotein and MRP-mediated efflux are present in human CD34+CD38- hematopoietic stem cells.