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Abstract: In this study, we examined the effects of cryoprotectant, freezing and thawing, and adenovirus (Adv) transduction on the viability, transgene expression, phenotype, and function of human dendritic cells (DCs). DCs were differentiated from cultured peripheral blood (PB) monocytes following Elutra isolation using granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) for 6days and then transduced using an Adv vector with an IL-12 transgene. Fresh, cryopreserved, and thawed transduced immature DCs were examined for their: 1) cellular concentration and viability; 2) antigenicity using an allogeneic mixed lymphocyte reaction (MLR); 3) phenotype (HLA-DR and CD11c) and activation (CD83); and 4) transgene expression based on IL-12 secretion. Stability studies revealed that transduced DCs could be held in cryoprotectant for as long as 75min at 2–8°C prior to freezing with little effect on their viability and cellularity. Further, cryopreservation, storage, and thawing reduced the viability of the transduced DCs by an average of 7.7%; and had no significant impact on DC phenotype and activation. In summary, cryopreservation, storage, and thawing had no significant effect on DC viability, function, and transgene expression by Adv-transduced DCs. [Copyright &y& Elsevier]

As part of a larger program aiming at assessing transfer and effects of metals in food webs, this work studied the spatial distribution of Cd, Cr, Cu, Pb, and Zn in 101 sub-surface soils, systematically sampled (1 × 1 km regular grid) over a large area around Annaba, the fourth most-populated city of Algeria. Cd and Cr exhibited only one abnormally high value, with all other concentrations being close to pedogeological background. Some places in the centre of the city were polluted by Pb (up to 823 mg kg−1), probably due to aerial deposition from gasoline exhausts. Zn never exceeded regulatory limits over the whole sampling area. Cu was the only element for which a spatial autocorrelation occurred. A spatial interpolation by cokriging allowed the identification of agricultural activities as the main Cu pollution source. Our approach revealed various anthropogenic pollution sources, more efficiently for large-scale patterns than for local abnormalities. [Copyright &y& Elsevier]

Abstract: Two-stage reimplantation using an interval hip prosthesis (spacer) of antibiotic-impregnated bone cement has become a well-accepted method to eradicate infection and prevent limb shortening. However, custom made as well as prefabricated spacers share a weakness of limited strength and hence several fractures of spacers have been observed, even for partial weight bearing. The purpose of this study was therefore to improve the strength of the custom made spacer, used at the Orthopaedic Department of the Saarland University Hospital (Germany). As the material strength of bone cement is limited, several reinforced spacers with a metal core consisting of titanium grade two have been developed and investigated. Loading procedure was close to the ISO 7206/4, though small adaptation was made. An inserted rod of titanium grade two increased the collapse load up to 1000–1300N, but considering a maximum expected load of about three times the body weight, still below the required value. A “full-stem” reinforced spacer, i.e. spacer with a titanium endoskeleton and a minimum of 2–3mm PMMA-coating in order to assure drug release, provides a mobile and functional joint through the treatment course. Those with 8mm thickness of titanium endoskeleton endured up to one million load cycles in a load range of 300–2300N. To give further support for individual cases a meaningful S–N curve for this device was determined. [Copyright &y& Elsevier]

Elastomer O-ring seals are used in many technical applications and their requirements are becoming increasingly challenging for high-pressure applications like hydrogen storage systems. We analyze the performance of such seals at low temperatures and highlight the essential effects of primary leakage. Linear viscoelastic material modeling is described and defined with the help of Dynamic Mechanical Thermal Analysis (DMTA), Time-Temperature Superposition Principle (TTSP), and the shift function of Williams-Landel-Ferry (WLF) by assuming thermo-rheological simple material behavior. Numerical calculations and experimental validation are done for strain-rate dependent uniaxial tensile tests, Temperature Retraction (TR), Compression Set (CS), and specific leakage tests with O-rings. Thanks to Finite Element Analysis (FEA) it is possible to identify the most significant influences on the sealing tightness. Thermal shrinkage and the increasingly limited recovery of elastomer O-rings are mainly responsible for primary leakage at low temperatures and can be enforced by time-temperature dependent stress relaxation and manufacturing tolerances. • The elastomer material 80FVMQ 567 was characterized via several material tests. • Linear viscoelastic material modeling was described in detail (WLF, TTSP, Prony) and implemented in the simulation. • Finite element simulations were validated with key O-Ring experiments at different temperatures. • The generation of primary leakage could be shown with numerical analyses and experiments. • The essential effects of primary leakage were identified and segregated with Finite Element Analyses and experiments. [ABSTRACT FROM AUTHOR]

Fragestellung: Objektive Messung der postoperativen Kniegelenkslaxizität nach Rekonstruktion des vorderen Kreuzbandes mittels zwei nicht-invasiver Messgeräte. Methodik: 52 konsekutive Patienten wurden durchschnittlich 17 Monate nach VKB-SB-Rekonstruktion mittels autologer Patellarsehne nachuntersucht. Die ap-Laxizität wurde mit Hilfe eines neuen Messgerätes (GNRB) mit einer definierten Kraft von 67,89 und 134N gemessen. Die Messung der Rotationsstabilität erfolgte ebenfalls mittels objektivem Messgerät (Rotameter) bei definiertem Drehmoment von 5Nm, 8Nm und 10Nm. Tegner Score, Lysholm Score und IKDC Score wurden eingesetzt, um die gemessenen Ergebnisse der Laxizität mit dem klinischen Ergebnis zu vergleichen. Resultate: Der Pivot shift war negative (33) oder glide (16) in 49 Patienten, negative Lachman tests wurden in 50 Patienten gefunden. Die subjektive Evaluation des IKDC Score zeigte ein A in 44 Patienten, 5 Patienten erreichten ein B und 3 ein C. Der durchschnittliche Lysholm Score betrug 94,5±9,5 Punkte, der durchschnittliche Tegner Score 6,5±1,4 präoperativ und 5,9±1,8 bei der Nachuntersuchung (p=0,003). Im operierten Knie wurde mittels GNRB eine ap-Translation von 2,1±0,7mm bei 67N, 3,1±0,9mm bei 89N und 4,9±1,2mm bei 134N gemessen. Die kontralaterale, nicht operierte Seite zeigte 1,5±0,7mm bei 67N, 2,2±0,8mm bei 89N und 3,6±1,0mm bei 134N. Die durchschnittlichen Seit-zu-Seit-Differenzen (0,6–1,3mm) zeigten zwar signifikante Unterschiede (p<0,05), sie waren jedoch im 2mm-Intervall, welcher im IKDC als normal eingestuft wird. Die Messung der Rotation des operierten Kniegelenkes zeigte bei 5Nm 16,6±8,9° Innenrotation, 33,2±9,5° Außenrotation und 50±12,1° Range (komplette Rotation), die Messung der nicht operierten, kontralateralen Seite zeigte 18,2±9,3° Innenrotation, 31,5±9,4° Außenrotation und 49,8±11,1° für den Range. Bei 8Nm wurden im operierten Knie 26,4±10,1° Innenrotation, 45±10,5° Außenrotation und 71,4±13,7° Range gemessen. Im nicht operierten Knie waren es 28,4±10,6° Innenrotation, 43,9±9,6° Außenrotation und 72,4±13,7° Range. Bei 10Nm wurden auf der operierten Seite 32,2±10,9° Innenrotation, 51,9±11,4° Außenrotation und 84±15,9° Range gemessen. Auf der nicht operierten Seite wurden 34,5±11,9° Innenrotation, 50,9±10,2° Außenrotation und 84,7±16,2° Range ermittelt. Die Unterschiede der tibiofemoralen Rotation zwischen operierter und nicht operierter Seite waren bei allen applizierten Drehmomenten statistisch nicht signifikant (p>0,05). Schlussfolgerung: Die Kniegelenkslaxizität nach Rekonstruktion des VKB kann mit den eingesetzten, nicht-invasiven Messgeräten objektiv quantifiziert werden. Darüber hinaus konnte gezeigt werden, dass sowohl die ap-Laxizität, als auch die Rotationsstabilität mittels Einbündel-VKB-Rekonstruktion wieder hergestellt werden konnte. [Copyright &y& Elsevier]

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