110 research outputs found
Cold heparinized lactated ringers with procaine (HeLP) preservation fluid in 266 living donor kidney transplantations
Since the 1960s simple inexpensive cold lactated Ringers with additives has been used for short-term cold preservation of kidneys from living donors. We performed 266 living donor kidney transplantations from January 22, 2003 to October 30, 2006. Donor allografts were recovered laparoscopically and flushed with cold heparin, lactated Ringer's and procaine (HeLP) solution. Warm and cold ischemic times were typically <45 min and <90 min, respectively. The mean follow up was 21.6±12.2 months. There was no delayed graft function. Actuarial 1-year patient and graft survival were 98.6% and 98.1%, respectively. The creatinine at 1 year was 1.46±0.51 mg/dL. The cumulative incidences of acute cellular rejection at 6, 12, 18, and 24 months were 3.0%, 7.1%, 10.2%, and 11.7%. There were no identifiable side effects attributed to the HeLP solution. This study documents the effectiveness of cold HeLP as a flushing and short-term preservation fluid for living donor kidney transplantation with excellent results and significant cost benefit because of its low cost. © 2007 Lippincott Williams & Wilkins, Inc
A semi-analytical approach for the characterization of ordered 3D nano structures using grazing-incidence X-ray fluorescence
Following the recent demonstration of grazing-incidence X-ray fluorescence
(GIXRF) based characterization of the 3D atomic distribution of different
elements and dimensional parameters of periodic nanoscale structures, this work
presents a new computational scheme for the simulation of the angular dependent
fluorescence intensities from such periodic 2D and 3D nanoscale structures. The
computational scheme is based on the dynamical diffraction theory in many-beam
approximation, which allows to derive a semi-analytical solution to the Sherman
equation in a linear-algebraic form. The computational scheme has been used to
analyze recently published GIXRF data measured on 2D Si3N4 lamellar gratings,
as well as on periodically structured 3D Cr nano pillars. Both the dimensional
and structural parameters of these nanostructures have been reconstructed by
fitting numeric simulations to the experimental GIXRF data. Obtained results
show good agreement with nominal parameters used in the manufacturing of the
structures, as well as with reconstructed parameters based on the previously
published finite element method simulations, in case of the Si3N4 grating
Scan Free GEXRF in the Soft X ray Range for the Investigation of Structured Nanosamples
Scan free grazing emission X ray fluorescence spectroscopy GEXRF is an established technique for the investigation of the elemental depth profiles of various samples. Recently it has been applied to investigating structured nanosamples in the tender X ray range. However, lighter elements such as oxygen, nitrogen or carbon cannot be efficiently investigated in this energy range, because of the ineffective excitation. Moreover, common CCD detectors are not able to discriminate between fluorescence lines below 1 keV. Oxygen and nitrogen are important components of insulation and passivation layers, for example, in silicon oxide or silicon nitride. In this work, scan free GEXRF is applied in proof of concept measurements for the investigation of lateral ordered 2D nanostructures in the soft X ray range. The sample investigated is a Si3N4 lamellar grating, which represents 2D periodic nanostructures as used in the semiconductor industry. The emerging two dimensional fluorescence patterns are recorded with a CMOS detector. To this end, energy dispersive spectra are obtained via single photon event evaluation. In this way, spatial and therefore angular information is obtained, while discrimination between different photon energies is enabled. The results are compared to calculations of the sample model performed by a Maxwell solver based on the finite elements method. A first measurement is carried out at the UE56 2 PGM 2 beamline at the BESSY II synchrotron radiation facility to demonstrate the feasibility of the method in the soft X ray range. Furthermore, a laser produced plasma source LPP is utilized to investigate the feasibility of this technique in the laboratory. The results from the BESSY II measurements are in good agreement with the simulations and prove the applicability of scan free GEXRF in the soft X ray range for quality control and process engineering of 2D nanostructures. The LPP results illustrate the chances and challenges concerning a transfer of the methodology to the laborator
Membrane Potential Controls Adipogenic and Osteogenic Differentiation of Mesenchymal Stem Cells
Background: Control of stem cell behavior is a crucial aspect of developmental biology and regenerative medicine. While the functional role of electrophysiology in stem cell biology is poorly understood, it has become clear that endogenous ion flows represent a powerful set of signals by means of which cell proliferation, differentiation, and migration can be controlled in regeneration and embryonic morphogenesis. Methodology/Principal Findings: We examined the membrane potential (Vmem) changes exhibited by human mesenchymal stem cells (hMSCs) undergoing adipogenic (AD) and osteogenic (OS) differentiation, and uncovered a characteristic hyperpolarization of differentiated cells versus undifferentiated cells. Reversal of the progressive polarization via pharmacological modulation of transmembrane potential revealed that depolarization of hMSCs prevents differentiation. In contrast, treatment with hyperpolarizing reagents upregulated osteogenic markers. Conclusions/Significance: Taken together, these data suggest that the endogenous hyperpolarization is a functiona
Inside and out: the activities of senescence in cancer.
The core aspect of the senescent phenotype is a stable state of cell cycle arrest. However, this is a disguise that conceals a highly active metabolic cell state with diverse functionality. Both the cell-autonomous and the non-cell-autonomous activities of senescent cells create spatiotemporally dynamic and context-dependent tissue reactions. For example, the senescence-associated secretory phenotype (SASP) provokes not only tumour-suppressive but also tumour-promoting responses. Senescence is now increasingly considered to be an integrated and widespread component that is potentially important for tumour development, tumour suppression and the response to therapy.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/nrc377
Iscador Qu inhibits doxorubicin-induced senescence of MCF7 cells
Chemotherapy in patients with inoperable or advanced breast cancer inevitably results in low-dose exposure of tumor-cell subset and senescence. Metabolically active senescent cells secrete multiple tumor promoting factors making their elimination a therapeutic priority. Viscum album is one of the most widely used alternative anti-cancer medicines facilitating chemotherapy tolerance of breast cancer patients. The aim of this study was to model and investigate how Viscum album extracts execute additive anti-tumor activity with low-dose Dox using ER + MCF7 breast cancer cells. We report that cotreatment of MCF7 with Viscum album and Dox abrogates G2/M cycle arrest replacing senescence with intrinsic apoptotic program. Mechanistically, this switch was associated with down-regulation of p21, p53/p73 as well as Erk1/2 and p38 activation. Our findings, therefore, identify a novel mechanistic axis of additive antitumor activity of Viscum album and low dose-Dox. In conclusion, ER + breast cancer patients may benefit from addition of Viscum album to low-dose Dox chemotherapy due to suppression of cancer cell senescence and induction of apoptosis
Enzyme in der organischen Synthese Lipase aus Pseudomonas Fluorescens; Acetoacetat Decarboxylase aus Clostridium Acetobutylicum; Nitril Hydratase und Amidase aus Rhodococcus SP. CH5
SIGLEAvailable from TIB Hannover: DW 2162 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
X Ray induced depth profiling of ion implantations into various semiconductor materials
The continuing shrinking of the component dimensions in ULSI technology requires junction depths in the 20-nm regime and below to avoid leakage currents. These ultra shallow dopant distributions can be formed by ultra-low energy (ULE) ion implantation. However, accurate measurement techniques for ultra-shallow dopant profiles are required in order to characterize ULE implantation and the necessary rapid thermal annealing (RTA) processes.</jats:p
- …