Five-year stability in associations of health-related quality of life measures in community-dwelling older adults: the Rancho Bernardo Study

Ó The Author(s) 2010. This article is published with open access at Springerlink.com Objective This study examines the five-year stability of the association of SF-12 and SF-6D scores with scores on the longer SF-36 and its domains in community-dwelling older men and women. Methods Participants were 653 men and 917 women aged 50 and older who completed mailed surveys of HRQOL (1995, 2000). SF-36 physical (PCS) and mental (MCS) component scores, domain scores; SF-12 PCS and MCS scores; and SF-6D scores were computed. Results Average age in 1995 was 68.2 ± 10.7 for men and 69.8 ± 11.3 for women. In 1995 and 2000, men had significantly higher scores on all measures (P’s \ 0.001). All three authors have contributed to the conception and design of the work and data analysis plan, interpretation of the data, and preparing the manuscript for publication. The second and third authors were in charge of the acquisition of subjects. The first author conducted the data analysis and wrote the first draft which was revised by the second and third authors. All authors were involved with the data in a manner substantial enough to take public responsibility for it. All authors believe the manuscript represents valid work and have reviewed the final version of the manuscript and approve of it for publication

MRI of the kidney—state of the art

Ultrasound and computed tomography (CT) are modalities of first choice in renal imaging. Until now, magnetic resonance imaging (MRI) has mainly been used as a problem-solving technique. MRI has the advantage of superior soft-tissue contrast, which provides a powerful tool in the detection and characterization of renal lesions. The MRI features of common and less common renal lesions are discussed as well as the evaluation of the spread of malignant lesions and preoperative assessment. MR urography technique and applications are discussed as well as the role of MRI in the evaluation of potential kidney donors. Furthermore the advances in functional MRI of the kidney are highlighted

Assessment of selected B cells populations in the workers of X-ray departments

Objectives: Workers of X-ray departments are occupationally exposed to long-term low levels of ionizing radiation (LLIR), which may affect their humoral immunity. The aim of the study was to assess the influence of LLIR on the number and proportion of B cells (CD19+), B1 cells (CD5+CD19+) and memory B cells (CD27+CD19+) in peripheral blood of such workers. Materials and Methods: In the study group of 47 X-ray departments workers and the control group consisting of 38 persons, the number and percentage of CD19+, CD5+CD19+, CD27+CD19+ cells as well as CD5+CD19+/CD19+ and CD27+CD19+/CD19+ cell ratios were assessed using flow cytometry. Additionally, the study group was divided into 2 groups by the length of employment below and over 15 years and analysis adjusted for age and smoking habit was performed. Results: The total number of CD19+ cells showed significant increase in the group of workers in comparison with the persons from the control group, whereas the percentage of CD5+CD19+ cells as well as CD27+CD19+/CD19+ and CD5+CD19+/CD19+ cell ratios were lower. Percentage, number of CD5+CD19+ cells and CD5+CD19+/CD19+ cell ratio were significantly lower in the workers with length of employment longer than 15 years in comparison with those employed below 15 years. Moreover, we found positive associations between the number of CD19+ cells and employment as well as smoking habit, whereas the number of CD5+CD19+ cells was positively associated with cigarette smoking alone. Percentage of CD5+CD19+ cells as well as CD5+CD19+/CD19+ and CD27+CD19+/CD19+ cell ratios were negatively correlated with employment. Conclusions: The study suggests association between the suppressive influence of low level ionizing radiation on circulating in peripheral blood, especially of B1 cells as well as of memory B cells, in workers of X-ray units, which is adverse in relation to microbiological threat

Kontrastmittelfreie quantitative Messung der Perfusion der Unterschenkelmuskulatur mittels MR-Spektroskopie-basierter Arterial Spin Labeling (ASL) Technik: FAIR-PRESS

Ziele: Aufgrund der niedrigen Perfusion der Muskulatur am Unterschenkel vor allem in Ruhe ist eine akkurate Messung mittels herkömmlicher MRT-Methoden schwierig. Es wurde nun eine auf der volumenselektiven 1H-Spektroskopie basierte ASL-Sequenz zur Messung der Unterschenkelperfusion getestet. Methode: Die Sequenz kombiniert die lokalisierte Spektroskopie-Technik (PRESS) mit einer „pulsed ASL“ Methode, der Flow-sensitive Alternating Inversion Recovery (FAIR). Zur Bestimmung des in das Untersuchungsvolumen einströmenden Blutes wurden sowohl Spektren nach globalem Inversionspuls als auch nach lokalem Inversionspuls aufgenommen und subtrahiert. Die Differenz im Wasserpeak der beiden nacheinander aufgenommenen Spektren ist proportional zur Gewebeperfusion des aquirierten Voxels. Die Messung erfolgte an 6 gesunden Probanden mittels eines 3 T MRT. Die Messungen im M. Tibialis anterior und im M. Soleus wurden in Ruhe sowie nach Manschetten-induzierter Hyperämie durchgeführt. Die Voxelgröße betrug 20×20×10mm. Andere wichtige Sequenzparameter waren: TR=1800ms, TE=39ms, TI=1200ms. Absolute Perfusionswerte wurden unter Annahme zusätzlicher Parameter (lambda=0.9ml/g, T1blut=1600ms, T1muskel=1400ms, Transitdelay=100ms) berechnet. Ergebnis: Die absoluten Perfusionswerte des M. Soleus betrugen in Ruhe 18±5ml/(100g * min) (n=6). Im Musculus Tibialis anterior wurden 15±8ml/(100g * min) gemessen. Nach induzierter Ischämie wurden in der Phase der Hyperämie deutlich erhöhte Perfusionswerte von bis zu 120ml/(100g * min) ermittelt. Schlussfolgerung: Die FAIR-PRESS Methode ist für die Messung der muskulären Perfusion sowohl in Ruhe als auch bei post-ischämischer Hyperämie geeignet

A comparison of emulsifiers for the formation of oil-in-water emulsions: Stability of the emulsions within 9 h after production and MR signal properties.

Objective: To provide a basis for the selection of suitable emulsifiers in oil-in-water emulsions used as tissue analogs for MRI experiments. Three different emulsifiers were investigated with regard to their ability to stabilize tissue-like oil-in-water emulsions. Furthermore, MR signal properties of the emulsifiers themselves and influences on relaxation times and ADC values of the aqueous phase were investigated. Materials and methods: Polysorbate 60, sodium dodecyl sulfate (SDS) and soy lecithin were used as emulsifiers. MR characteristics of emulsifiers were assessed in aqueous solutions and their function as a stabilizer was examined in oil-in-water emulsions of varying fat content (10, 20, 30, 40, 50%). Stability and homogeneity of the oil-in-water emulsions were evaluated with a delay of 3 h and 9 h after preparation using T1 mapping and visual control. Signal properties of the emulsifiers were investigated by 1H-MRS in aqueous emulsifier solutions. Relaxometry and diffusion weighted MRI (DWI) were performed to investigate the effect of various emulsifier concentrations on relaxation times (T1 and T2) and ADC values of aqueous solutions. Results: Emulsions stabilized by polysorbate 60 or soy lecithin were stable and homogeneous across all tested fat fractions. In contrast, emulsions with SDS showed a significantly lower stability and homogeneity. Recorded T1 maps revealed marked creaming of oil droplets in almost all of the emulsions with SDS. The spectral analysis showed several additional signals for polysorbate and SDS. However, lecithin remained invisible in 1H-MRS. Relaxometry and DWI revealed different influences of the emulsifiers on water: Polysorbate and SDS showed only minor effects on relaxation times and ADC values of aqueous solutions, whereas lecithin showed a strong decrease in both relaxation times (r1,lecithin = 0.11 wt.%−1 s−1, r2,lecithin = 0.57 wt.%−1 s−1) and ADC value (Δ(ADC)lecithin = − 0.18 × 10–3 mm2/s⋅wt.%) with increasing concentration. Conclusion: Lecithin is suggested as the preferred emulsifier of oil-in-water emulsions in MRI as it shows a high stabilizing ability and remains invisible in MRI experiments. In addition, lecithin is suitable as an alternative means of adjusting relaxation times and ADC values of water

Soy lecithin: A beneficial substance for adjusting the ADC in aqueous solutions to the values of biological tissues.

PURPOSE: To test soy lecithin as a substance added to water for the construction of MRI phantoms with tissue-like diffusion coefficients. The performance of soy lecithin was assessed for the useable range of adjustable ADC values, the degree of non-Gaussian diffusion, simultaneous effects on relaxation times, and spectral signal properties. METHODS: Aqueous soy lecithin solutions of different concentrations (0%, 0.5%, 1%, 2%, 3% …, 10%) and soy lecithin-agar gels were prepared and examined on a 3 Tesla clinical scanner at 18.5° ± 0.5°C. Echoplanar sequences (b values: 0-1000/3000 s/mm2 ) were applied for ADC measurements. Quantitative relaxometry and MRS were performed for assessment of T1 , T2 , and detectable spectral components. RESULTS: The presence of soy lecithin significantly restricts the diffusion of water molecules and mimics the nearly Gaussian nature of diffusion observed in tissue (for b values <1000 s/mm2 ). ADC values ranged from 2.02 × 10-3  mm2 /s to 0.48 × 10-3  mm2 /s and cover the entire physiological range reported on biological tissue. Measured T1 /T2 values of pure lecithin solutions varied from 2685/2013 to 668/133 ms with increasing concentration. No characteristic signals of soy lecithin were observed in the MR spectrum. The addition of agar to the soy lecithin solutions allowed T2 values to be well adjusted to typical values found in parenchymal tissue without affecting the soy lecithin-controlled ADC value. CONCLUSION: Soy lecithin is a promising substance for the construction of diffusion phantoms with tissue-like ADC values. It provides several advantages over previously proposed substances, in particular a wide range of adjustable ADC values, the lack of additional 1 H-signals, and the possibility to adjust ADC and T2 values (by adding agar) almost independently of each other

Clonal dissemination of a toxin-A-negative/toxin-B-positive Clostridium difficile strain from patients with antibiotic-associated diarrhea in Poland

Objective. To determine the incidence of toxin-A-negative/toxin-B-positive Clostridium difficile strains and their genetic relatedness in the feces of patients suffering from antibiotic-associated diarrhea (AAD) in Polish hospitals. Methods. C. difficile strains were cultured from patients' stool samples. The present study characterises these strains with respect to their cytopathogenicity on McCoy cells and the absence of toxin A despite a functional toxin B as determined with commercial test kits (Culturette Brand Toxin CD-TCD toxin A test and C. difficile Tox A/B test). In addition, PCR using different primer pairs aiming at non-repeating or repeating regions of the toxin A and B genes were used to confirm the findings. All toxin A-B+strains were genetically characterised by random amplification of polymorphic DNA (RAPD) analysis, PCR ribotyping and, in part, pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments. Results. We here present the presence of 17 toxin A-B+strains among 159 C. difficile strains (11%) isolated from fecal samples from 413 patients with antibiotic-associated diarrhea. All 17 strains possessed the toxin B gene, demonstrated a cytopathogenic effect on the McCoy cells, and were positive in the Tox A/B test. Molecular typing of these 17 C. difficile strains revealed that 7 of 17 (41%) toxin A-/B+C. difficile strains could not be discriminated. It appeared that these strains had a genotype that could not be distinguished from that of a Japanese control strain. Conclusion. Our observations imply that a particular genotype of toxin A-B+C. difficile has spread extensively, not only in Poland but possibly even worldwide