Interspecies difference in liver-specific functions and biotransformation of testosterone of primary rat, porcine and human hepatocyte in an organotypical sandwich culture.

Interspecies difference is an important issue in toxicology research. We compared the potential in vitro metabolism of human, porcine and rat hepatocytes over 2 weeks in culture in an organotypical culture model which reflects the in vivo situation. All three species show similar LDH-rates.

Preoperative electrocardiograms: patient factors predictive of abnormalities.

Background: Age is often the sole criterion for determining the need for preoperative electrocardiograms. However, screening electrocardiograms have not been shown to add value above clinical information. This study was designed to determine whether it is possible to target electrocardiograms ordering to patients most likely to have an abnormality that would affect management and if age alone is predictive of significant electrocardiograms abnormalities.

Excited-state double proton transfer in 1H-pyrazolo[3,4-b]quinoline dimers.

Pyrazoloquinolines are highly fluorescent, both in liquid solutions and in the solid state, which makes them good candidates for various optical devices. The aim of the current work is to understand the photochemical behavior of pyrazolo[3,4-b]quinoline (PQ), which is quite complicated since in n-alkane solvents PQ tends to form strong complexes with protic solvent constituents (often present as minor impurities), as well as dimers. Both types of H-bond complexes were studied systematically by temperature-dependent conventional absorption and fluorescence spectroscopy; the effect of protic solvent constituents was mimicked by varying the ethanol concentration in n-octane in the range from 0.

Out-of-operating room procedures: preprocedure assessment.

Performing an anesthetic in a procedure suite instead of in the operating room can be extremely challenging for the anesthetist. Not only are the procedures performed outside of the operating room becoming increasingly more complex but also patient acuity is increasing. In some cases, the out-of-operating room procedure may be selected as a less risky alternative to an operating room procedure in an extremely high-risk patient.

Improved semiquantitative Western blot technique with increased quantification range.

With the development of new interdisciplinary fields such as systems biology, the quantitative analysis of protein expression in biological samples gains more and more importance. Although the most common method for this is ELISA, Western blot also has advantages: The separation of proteins by size allows the evaluation of only specifically bound protein. This work examines the Western blot signal chain, determines some of the parameters relevant for quantitative analysis and proposes a mathematical model of the reaction kinetics.

Diagnosis, incidence, and outcomes of suspected typhlitis in oncology patients--experience in a tertiary pediatric surgical center in the United Kingdom.

Background: Typhlitis is clinically defined by the triad of neutropenia, abdominal pain, and fever. Radiologic evidence of colonic inflammation supports the diagnosis. We report a single United Kingdom tertiary center experience with management and outcome of typhlitis for 5 years.

Human hepatocyte functions in a crossed hollow fiber membrane bioreactor.

An important challenge in liver tissue engineering is the development of bioartificial systems that are able to favour the liver reconstruction and to modulate liver cell behaviour. A crossed hollow fiber membrane bioreactor was developed to support the long-term maintenance and differentiation of human hepatocytes. The bioreactor consists of two types of hollow fiber (HF) membranes with different molecular weight cut-off (MWCO) and physico-chemical properties cross-assembled in alternating manner: modified polyetheretherketone (PEEK-WC) and polyethersulfone (PES), used for the medium inflow and outflow, respectively.

Needs analysis for the development of a preoperative clinic protocol for perioperative beta-blocker therapy.

Study Objective: To study the development and implementation of a hospital-wide protocol regarding preoperative beta-blocker therapy.

Design: Prospective, observational clinical study.

Setting: Preoperative test center at a university hospital.

Low oxygen expansion improves subsequent chondrogenesis of ovine bone-marrow-derived mesenchymal stem cells in collagen type I hydrogel.

Background/objective: A crucial factor when investigating cartilage tissue engineering using mesenchymal stem cells (MSCs) is their application in large-animal models and preclinical trials. However, in vitro studies using cells of these model organisms must proceed. Considering that oxygen tension is an important parameter for stem cell culture, we investigated the effect of low oxygen tension during the expansion of ovine MSCs on colony-forming unit-fibroblast (CFU-F) formation, senescence and subsequent chondrogenesis in pellet culture and a collagen I hydrogel which is in clinical use for matrix-associated autologous chondrocyte transplantation (MACT).

Present and Future Developments in Hepatic Tissue Engineering for Liver Support Systems : State of the art and future developments of hepatic cell culture techniques for the use in liver support systems.

The liver is the most important organ for the biotransformation of xenobiotics, and the failure to treat acute or acute-on-chronic liver failure causes high mortality rates in affected patients. Due to the lack of donor livers and the limited possibility of the clinical management there has been growing interest in the development of extracorporeal liver support systems as a bridge to liver transplantation or to support recovery during hepatic failure. Earlier attempts to provide liver support comprised non-biological therapies based on the use of conventional detoxification procedures, such as filtration and dialysis.

Intracellular nucleotide pools and ratios as tools for monitoring dedifferentiation of primary porcine hepatocytes in culture.

The effect of two culture configurations (single collagen gel and double collagen gel) and of two hormones (insulin and glucagon) on the differentiated status and the intracellular nucleotide pools of primary porcine hepatocytes was investigated. The objective was to analyze and monitor the current state of differentiation supported by the two culture modes using intracellular nucleotide analysis. Specific intracellular nucleotide ratios, namely the nucleoside triphosphate (NTP) and the uridine (U) ratio were shown to consistently reflect the state of dedifferentiation status of the primary cells in culture affected by the presence of the two hormones insulin and glucagon.

Two compartment model of diazepam biotransformation in an organotypical culture of primary human hepatocytes.

Drug biotransformation is one of the most important parameters of preclinical screening tests for the registration of new drug candidates. Conventional existing tests rely on nonhuman models which deliver an incomplete metabolic profile of drugs due to the lack of proper CYP450 expression as seen in human liver in vivo. In order to overcome this limitation, we used an organotypical model of human primary hepatocytes for the biotransformation of the drug diazepam with special reference to metabolites in both the cell matrix phase and supernatant and its interaction of three inducers (phenobarbital, dexamethasone, aroclor 1254) in different time responses (1, 2, 4, 8, 24 h).

Connected culture of murine hepatocytes and HUVEC in a multicompartmental bioreactor.

A multicompartmental bioreactor was conceived and designed to mimic cross talk between cells in different culture chambers connected only by flow, such that cell-cell interaction is mediated by soluble ligands as occurs in the body. The system was tested with a connected culture of murine hepatocytes and human umbilical vein endothelial cells. Metabolites such as albumin, urea, lactate and viability were monitored during the course of the experiments and compared with monoculture conditions in the bioreactor.

Assessment of risk factors for survival of neonates born after second-trimester PPROM.

Objective: Assess fetal risk factors which impact survival of infants delivered after second-trimester PPROM.

Study Design: Clinical records of 87 patients, who all had second-trimester rupture of membranes between 14+0 and 24+6 weeks of gestation treated January 1998 to July 2005 were reviewed regarding perinatal outcome. This study is based on 25 surviving infants.

Development and validation of a novel bioreactor system for load- and perfusion-controlled tissue engineering of chondrocyte-constructs.

Osteoarthritis is a severe socio-economical disease, for which a suitable treatment modality does not exist. Tissue engineering of cartilage transplants is the most promising method to treat focal cartilage defects. However, current culturing procedures do not yet meet the requirements for clinical implementation.

Enrichment of human beta 1 bri/alpha 6 bri/CD71 dim keratinocytes after culture in defined media.

Stem cell-like keratinocytes are responsible for the high regenerative potential of the skin. For clinical applications using keratinocytes in artificial skin constructs, it is suitable to work with serum-free medium under defined conditions. This is also true for the preceding expansion of the stem cell-like keratinocyte population.

Analysis of stem cell lipids by offline HPTLC-MALDI-TOF MS.

MALDI-TOF MS is traditionally used for "proteomics", but is also a useful tool for lipid analysis. Depending on the applied matrix, however, some lipid classes are more sensitively detected than other ones and this may even lead to suppression effects if complex mixtures are analyzed. Therefore, a previous separation into the individual lipid classes is necessary.

EGF induces coalescence of different lipid rafts.

The suggestion that microdomains may function as signaling platforms arose from the presence of growth factor receptors, such as the EGFR, in biochemically isolated lipid raft fractions. To investigate the role of EGFR activation in the organization of lipid rafts we have performed FLIM analyses using putative lipid raft markers such as ganglioside GM1 and glycosylphosphatidylinositol (GPI)-anchored GFP (GPI-GFP). The EGFR was labeled using single domain antibodies from Llama glama that specifically bind the EGFR without stimulating its kinase activity.

Timing and targeting of cell-based VEGF165 gene expression in ischemic tissue.

Background: Therapeutic angiogenesis has become a key technology in experimental and clinical medicine. Only few data are available on the effects of timing and targeting of therapeutic proteins after cell-based gene transfer. This work investigates such effects after temporary expression of vascular endothelial growth factor 165 (VEGF(165)), the most commonly used angiogenic protein for therapeutic purposes.

TOJ3, a v-jun target with intrinsic oncogenic potential, is directly regulated by Jun via a novel AP-1 binding motif.

The TOJ3 gene was originally identified on the basis of its specific activation in avian fibroblasts transformed by the v-jun oncogene of avian sarcoma virus 17 (ASV17). Overexpression of TOJ3 induces cellular transformation of embryonic avian fibroblasts, revealing an intrinsic oncogenic potential. Transforming activity has also been demonstrated for MSP58, the human homolog of TOJ3, and oncogenic cell transformation by MSP58 is specifically inhibited by the tumor suppressor PTEN.

Gypsins A-D from Gypsophila arabica.

Four new cyclopeptides, named gypsins A-D (1- 4), together with one known oleanane saponin, were isolated from the roots of Gypsophila arabica. The structures of cyclo(-Leu(1)-Pro(2)-Leu(3)-Trp(4)-Pro(5)-Gly(6)-) (1), cyclo(-Leu(1)-Pro(2)-Tyr(3)-Phe(4)-Pro(5)-Gly(6)-) (2), cyclo(-Ala(1)-Pro(2)-Tyr(3)-Leu(4)-Leu(5)-Pro (6)-Pro(7)-Ala(8)-) (3), and cyclo(-Leu(1)-Trp(2)-Pro(3)-Gly(4)-Gly(5)-Ser(6)-Ser(7)-) (4) were elucidated by 1D and 2D NMR spectroscopy including 1D-TOCSY, DQF-COSY, 2D-ROESY, HSQC, and HMBC experiments, as well as ESI tandem mass spectrometric fragmentation analysis and chemical evidence.

Multilineage differentiation potential of human dermal skin-derived fibroblasts.

Dermal skin-derived fibroblasts from rodent and human have been found to exhibit mesenchymal surface antigen immunophenotype and differentiation potential along the three main mesenchymal-derived tissues: bone, cartilage and fat. Human dermal skin-derived mesenchymal stem cells constitute a promising cell source in clinical applications. Therefore, we isolated fibroblastic mesenchymal stem-cell-like cells from human dermis derived from juvenile foreskins, which share a mesenchymal stem cell phenotype and multi-lineage differentiation potential.