Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 123
Filter
1.
Breast ; 64: 127-133, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35689881

ABSTRACT

PURPOSE: To validate the prognostic role of urokinase-type plasminogen-activator (uPA) and plasminogen activator inhibitor type-1 (PAI-1) protein expression in FFPE archived tumor samples when assessed by immunohistochemistry. PATIENTS AND METHODS: Fresh-frozen, paraffin-embedded (FFPE) samples from 303 postmenopausal women with hormone receptor-positive, early breast cancer were investigated. The patients had received 5 years of endocrine therapy in the prospectively randomized ABCSG-8 trial. Immunohistochemistry for stromal uPA and PAI-1 protein expression was correlated with distant recurrence-free survival (DRFS) and overall survival (OS). RESULTS: We detected stromal uPA in 132 of 297 tumors (44.4%) and stromal PAI-1 expression in 74 out of 299 samples (24.7%). Co-expression of uPA and PAI-1 was present in 48 of 294 (16.3%) cases. Neither uPA nor PAI-1 expression was associated with tumor size, age, nodal status, grading, or quantitative receptor status. Patients whose tumor stroma expressed uPA protein had a significantly shorter DRFS (adjusted HR for relapse: 2.78; 95% CI 1.31-5.93; p = 0.008 Cox regression analysis) than women without uPA expression. No such association was seen for PAI-1 and the uPA/PAI1 ratio. After a median follow-up of 5.6 years, women with uPA-positive tumors demonstrated significantly shorter DRFS (93.3% vs. 84.8%; p < 0.013 log-rank test), and tended to have a worse OS (83.0% vs. 77.3%; p = 0.106) compared to women with uPA negative tumors. CONCLUSION: This independent validation in archived tumor samples from a large prospective randomized trial confirms the clinical utility of stromal uPA evaluation by immunohistochemistry. This provides level 1b evidence for the prognostic role of stromal uPA in women with endocrine-responsive early breast cancer.


Subject(s)
Breast Neoplasms , Urokinase-Type Plasminogen Activator , Breast Neoplasms/pathology , Female , Humans , Immunohistochemistry , Neoplasm Recurrence, Local/drug therapy , Plasminogen Activator Inhibitor 1/analysis , Prognosis , Prospective Studies , Urokinase-Type Plasminogen Activator/metabolism
2.
Breast ; 46: 101-107, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31132475

ABSTRACT

BACKGROUND: To evaluate whether uPA/PAI-1 protein in hormone receptor-positive (HR+) breast tumor can predict prognosis in early breast cancer (BC). METHODS: 606 women with HR + BC who had ≥5 years of endocrine therapy and in whom tumor tissue was available were included in this analysis. Stromal uPA/PAI-1 protein expression was evaluated by immunohistochemistry and correlated with distant recurrence-free survival (DRFS) and overall survival (OS). RESULTS: Stromal uPA was detected in 292/538 tumors (54.3%) while 269/505 samples (53.3%) exhibited stromal PAI-1. Co-expression of both proteins was found in 163/437 (37.3%) samples. Stromal uPA/PAI-1 co-expression was not associated with tumor size, age, nodal status, grading, or receptor status. Tumor stroma with both uPA and PAI-1 protein expression were more likely to have a shorter DRFS (HR: 1.87; 95%CI 1.18-2.96; p = 0.007) and OS (HR: 1.29; 95%CI 0.93-1.80; p = 0.129) than women without uPA/PAI-1 co-expression. After a median follow-up of 10 years, women with uPA/PAI-1-positive tumors experienced a significantly shorter DRFS (86.5% vs 72.4%; p < 0.001) and OS (70.4% vs 58.9%; p = 0.020) compared to women with uPA/PAI-1 negative tumors. CONCLUSION: Stromal co-expression of uPA and PAI-1 in breast cancer predicts poor DRFS and OS in postmenopausal women with HR + early-stage BC who receive endocrine therapy.


Subject(s)
Breast Neoplasms/genetics , Breast Neoplasms/mortality , Breast/cytology , Plasminogen Activator Inhibitor 1/metabolism , Urokinase-Type Plasminogen Activator/metabolism , Aged , Antineoplastic Agents, Hormonal/therapeutic use , Biomarkers, Tumor/genetics , Breast Neoplasms/drug therapy , Disease-Free Survival , ErbB Receptors/metabolism , Female , Humans , Immunohistochemistry , Middle Aged , Neoplasm Recurrence, Local/genetics , Postmenopause , Prognosis , Risk Factors , Stromal Cells/metabolism , Treatment Outcome
3.
J Colloid Interface Sci ; 508: 313-322, 2017 Dec 15.
Article in English | MEDLINE | ID: mdl-28843109

ABSTRACT

HYPOTHESIS: ZSM-5 zeolite is an efficient adsorbent for several compounds. However, is a microporous material, and consequently, is little efficient for large dye molecules. In order to make ZSM-5 zeolite a mesoporous material with ability to adsorb dyes, the use of chitin (low-cost biopolymer) as template in the synthesis route can be an alternative. EXPERIMENTS: ZSM-5 zeolites were synthetized using a nucleating gel as structure-directing agent for the material formation, followed by the chitin insertion (or not), homogenization and hydrothermal treatment. The obtained zeolites (ZSM-5 and chitin/ZSM-5) from these different methods were characterized. The potential of ZSM-5 and chitin/ZSM-5 zeolites to adsorb crystal violet dye (CV) was evaluated in batch mode, considering the effects of adsorbent dosage and pH. Equilibrium, thermodynamic and kinetic studies were also performed. FINDINGS: The use of chitin in the synthesis route provided the following improvements on the ZSM-5 structure: (i) the mesopores volume increased from 0.027 (ZSM-5) to 0.142cm3g-1 (chitin/ZSM-5); (ii) the pore diameter increased from 1.97 (ZSM-5) to 22.49nm (chitin/ZSM-5); (iii) the porosity was increased and the crystallinity was decreased. For both, ZSM-5 and chitin/ZSM-5, the CV adsorption was favored with adsorbent dosage of 2.0gL-1 and pH of 7.5. The pseudo-second order model was suitable to represent the adsorption kinetics and, the Langmuir model was adequate to represent the equilibrium. The maximum adsorption capacity increased from 141.8 (ZSM-5) to 1217.3mgg-1 (chitin/ZSM-5). The adsorption was spontaneous, favorable and endothermic.

4.
BMC Cancer ; 16: 628, 2016 08 12.
Article in English | MEDLINE | ID: mdl-27519272

ABSTRACT

BACKGROUND: Overexpression the KCNJ3, a gene that encodes subunit 1 of G-protein activated inwardly rectifying K(+) channel (GIRK1) in the primary tumor has been found to be associated with reduced survival times and increased lymph node metastasis in breast cancer patients. METHODS: In order to survey possible tumorigenic properties of GIRK1 overexpression, a range of malignant mammary epithelial cells, based on the MCF-7 cell line that permanently overexpress different splice variants of the KCNJ3 gene (GIRK1a, GIRK1c, GIRK1d and as a control, eYFP) were produced. Subsequently, selected cardinal neoplasia associated cellular parameters were assessed and compared. RESULTS: Adhesion to fibronectin coated surface as well as cell proliferation remained unaffected. Other vital parameters intimately linked to malignancy, i.e. wound healing, chemoinvasion, cellular velocities / motilities and angiogenesis were massively affected by GIRK1 overexpression. Overexpression of different GIRK1 splice variants exerted differential actions. While GIRK1a and GIRK1c overexpression reinforced the affected parameters towards malignancy, overexpression of GIRK1d resulted in the opposite. Single channel recording using the patch clamp technique revealed functional GIRK channels in the plasma membrane of MCF-7 cells albeit at very low frequency. DISCUSSION: We conclude that GIRK1d acts as a dominant negative constituent of functional GIRK complexes present in the plasma membrane of MCF-7 cells, while overexpression of GIRK1a and GIRK1c augmented their activity. The core component responsible for the cancerogenic action of GIRK1 is apparently presented by a segment comprising aminoacids 235-402, that is present exclusively in GIRK1a and GIRK1c, but not GIRK1d (positions according to GIRK1a primary structure). CONCLUSIONS: The current study provides insight into the cellular and molecular consequences of KCNJ3 overexpression in breast cancer cells and the mechanism upon clinical outcome in patients suffering from breast cancer.


Subject(s)
Alternative Splicing , Breast Neoplasms/metabolism , G Protein-Coupled Inwardly-Rectifying Potassium Channels/genetics , G Protein-Coupled Inwardly-Rectifying Potassium Channels/metabolism , Breast Neoplasms/genetics , Cell Adhesion , Cell Proliferation , Female , Gene Expression Regulation, Neoplastic , Humans , MCF-7 Cells , Up-Regulation
5.
Burns ; 40(5): 966-73, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24513133

ABSTRACT

The benefits and risks of singular and repetitive microneedling (1 mm) have not been thoroughly investigated. The aim of this study was to evaluate the benefits and risks of singular and repetitive skin needling with a microneedling device in an animal model with and without skincare. 30 Sprague Dawley rats were randomized to five groups: control, skin-care only (Vitamin A & C), 1× needling 1 mm, 4× needling 1 mm, 4× needling 1 mm with skin-care. All animals were euthanized after 10 weeks. Skin specimens were stained with HE and Masson's trichrome. Additionally, gene expression analysis with microarray technique for various growth factors (TGFß1-3, FGF, EGF, VEGF, TNF-α) and real time reverse transcription PCR for collagen I & III were conducted. We showed that singular microneedling matches and repetitive microneedling sessions superposition epidermal and dermal benefits such as an increase of epidermal thickness (up to 658% increase, p value 0.0008) and dermal connective tissue--even more so when combined with skin-care with vitamin A and C. Juvenile collagen I showed itself up-regulated in all groups, while collagen III was down-regulated. Singular and repetitive PCI with a microneedling device can achieve and supersede the results already shown with medical needling.


Subject(s)
Cicatrix/rehabilitation , Dermis/physiology , Epidermis/physiology , Needles , Regeneration/genetics , Skin Care/methods , Animals , Ascorbic Acid/therapeutic use , Cicatrix/genetics , Cicatrix/pathology , Collagen Type I/genetics , Collagen Type III/genetics , Dermis/metabolism , Dermis/pathology , Epidermis/metabolism , Epidermis/pathology , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Transforming Growth Factor beta/genetics , Vitamin A/therapeutic use , Vitamins/therapeutic use
6.
Br J Cancer ; 110(6): 1614-21, 2014 Mar 18.
Article in English | MEDLINE | ID: mdl-24504363

ABSTRACT

BACKGROUND: MicroRNAs (miRNAs) regulate the biological properties of colorectal cancer (CRC) cells and might serve as potential prognostic factors and therapeutic targets. In this study, we therefore globally profiled miRNAs associated with E-cadherin expression in CRC cells in an attempt to identify miRNAs that are associated with aggressive clinical course in CRC patients. METHODS: Two CRC cell lines (Caco-2 and HRT-18) with different E-cadherin expression pattern were profiled for differences in abundance for more than 1000 human miRNAs using microarray technology. One of the most differentially expressed miRNAs, miR-200a was evaluated for its prognostic role in a cohort of 111 patients and independently validated in 217 patients of the Cancer Genome Atlas data set. To further characterise the biological role of miR-200a expression in CRC, in vitro miR-200a inhibition and overexpression were performed and the effects on cellular growth, apoptosis and epithelial-mesenchymal transition (EMT)-related gene expression were explored. RESULTS: In situ hybridisation specifically localised miR-200a in CRC cells. In both cohorts, a low miR-200a expression was associated with poor survival (P<0.05). Multivariate Cox regression analysis identified low levels of miR-200a expression as an independent prognostic factor with respect to cancer-specific survival (HR=2.04, CI=1.28-3.25, P<0.002). Gain and loss of function assays for miR-200a in vitro led to a significantly differential and converse expression of EMT-related genes (P<0.001.) A low expression of miR-200a was also observed in cancer stem cell-enriched spheroid growth conditions (P<0.05). CONCLUSIONS: In conclusion, our data suggest that low miR-200a expression is associated with poor prognosis in CRC patients. MiR-200a has a regulatory effect on EMT and is associated with cancer stem cell properties in CRC.


Subject(s)
Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Epithelial-Mesenchymal Transition/genetics , MicroRNAs/genetics , Aged , Apoptosis/genetics , Caco-2 Cells , Cell Growth Processes/genetics , Female , Gene Expression , Humans , In Situ Hybridization , Kaplan-Meier Estimate , Male , Middle Aged , Multivariate Analysis , Oligonucleotide Array Sequence Analysis , Prognosis , Retrospective Studies , Transfection
7.
Oncogene ; 32(10): 1316-29, 2013 Mar 07.
Article in English | MEDLINE | ID: mdl-22543582

ABSTRACT

Aggressive cancers often express E-cadherin in cytoplasmic vesicles rather than on the plasma membrane and this may contribute to the invasive phenotype of these tumors. Therapeutic strategies are not currently available that restore the anti-invasive function of E-cadherin in cancers. MDA-MB-231 cells are a frequently used model of invasive triple-negative breast cancer, and these cells express low levels of E-cadherin that is mislocalized to cytoplasmic vesicles. MDA-MB-231 cell lines stably expressing wild-type E-cadherin or E-cadherin fused to glutathione S-transferase or green fluorescent protein were used as experimental systems to probe the mechanisms responsible for cytoplasmic E-cadherin localization in invasive cancers. Although E-cadherin expression partly reduced cell invasion in vitro, E-cadherin was largely localized to the cytoplasm and did not block the invasiveness of the corresponding orthotopic xenograft tumors. Further studies indicated that the glucocorticoid dexamethasone and the highly potent class I histone deacetylase (HDAC) inhibitor largazole cooperated to induce E-cadherin localization to the plasma membrane in triple-negative breast cancers, and to suppress cellular invasion in vitro. Dexamethasone blocked the production of the cleaved form of the CDCP1 (that is, CUB domain-containing protein 1) protein (cCDCP1) previously implicated in the pro-invasive activities of CDCP1 by upregulating the serine protease inhibitor plasminogen activator inhibitor-1. E-cadherin preferentially associated with cCDCP1 compared with the full-length form. In contrast, largazole did not influence CDCP1 cleavage, but increased the association of E-cadherin with γ-catenin. This effect on E-cadherin/γ-catenin complexes was shared with the nonisoform selective HDAC inhibitors trichostatin A (TSA) and vorinostat (suberoylanilide hydroxamic acid, SAHA), although largazole upregulated endogenous E-cadherin levels more strongly than TSA. These results demonstrate that glucocorticoids and HDAC inhibitors, both of which are currently in clinical use, cooperate to suppress the invasiveness of breast cancer cells through novel, complementary mechanisms that converge on E-cadherin.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Breast Neoplasms/drug therapy , Cadherins/metabolism , Dexamethasone/pharmacology , Glucocorticoids/pharmacology , Histone Deacetylase Inhibitors/pharmacology , Animals , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cadherins/biosynthesis , Cadherins/genetics , Cell Line, Tumor , Dexamethasone/administration & dosage , Female , Glucocorticoids/administration & dosage , Histone Deacetylase Inhibitors/administration & dosage , Humans , Mice , Mice, Nude , Neoplasm Invasiveness , Xenograft Model Antitumor Assays
8.
Anaesthesist ; 60(10): 950-62, 2011 Oct.
Article in German | MEDLINE | ID: mdl-21993475

ABSTRACT

BACKGROUND: Thoracic epidural analgesia (EDA) is thought to provide cardioprotective effects in patients undergoing noncardiac surgery. The results of two previous meta-analysis showed controversial conclusions regarding the impact of EDA on perioperative survival. The purpose of the present meta-analysis was to evaluate, whether thoracic EDA has the potential to reduce perioperative cardiac morbidity or mortality on the basis of available randomized controlled trials. PATIENTS AND METHODS: A systematic literature search was conducted in medical databases (Med-Line, EBM-Reviews, Embase, Biosis and Biological Abstracts) and relevant clinical trials including patients undergoing noncardiac surgery were evaluated by two independent investigators. All randomized controlled trials investigating the effects of thoracic EDA on perioperative outcome, published from 1980 up to the end of 2008 were included into this quantitative systematic review. Calculations were performed using the statistics program Review Manager 4.1 using a fixed-effects model. RESULTS: Nine studies with a total of 2,768 patients were included in the meta-analysis. Thoracic EDA did not reduce perioperative mortality [odds ratio (Peto OR): 1.08; 95% confidence interval (CI) 0.74-1.58]. Patients receiving thoracic EDA demonstrated a tendency to a lower rate of perioperative myocardial infarction. However, this effect of thoracic EDA did not reach statistical significance (Peto OR: 0.65; 95% CI 0.4-1.05). CONCLUSIONS: The present meta-analysis did not prove any positive influence of thoracic EDA on perioperative in-hospital mortality in patients undergoing noncardiac surgery. Furthermore, it remains questionable if thoracic EDA has the potential to reduce the rate of perioperative myocardial infarction.


Subject(s)
Anesthesia, Epidural , Heart Diseases/prevention & control , Anesthesia, Epidural/adverse effects , Anesthesia, General , Data Interpretation, Statistical , Heart Diseases/mortality , Hospital Mortality , Humans , Myocardial Infarction/epidemiology , Myocardial Infarction/mortality , Odds Ratio , Postoperative Complications/mortality , Randomized Controlled Trials as Topic , Surgical Procedures, Operative , Treatment Outcome
12.
J Plast Reconstr Aesthet Surg ; 64(1): 97-107, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20413357

ABSTRACT

BACKGROUND: Ablative procedures that are used for the improvement of a degenerative process that leads to a loss of skin elasticity and integrity, injure or destroy the epidermis and its basement membrane and lead to fibrosis of the papillary dermis. It was recently shown in clinical and laboratory trials that percutaneous collagen induction (PCI) by multiple needle application is a method for safely treating wrinkles and scars and smoothening the skin without the risk of dyspigmentation. In our study, we describe the effect of PCI on epidermal thickness and the induction of genes relevant for regenerative processes in the skin in a small animal model. METHODS: The purpose of this study in a rat model was to determine the effects of PCI on the skin both qualitatively and quantitatively. The epidermal and dermal changes were observed by histology and immunofluorescence. The changes in gene expression were measured by array analysis for cytokines, such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF)-7, epidermal growth factor (EGF) and extracellular matrix molecules such as collagen type I and type III. RESULTS: The present study showed that PCI with topical vitamins resulted in a 140% increase in epidermal thickness; an increase in gene and protein expression of collagen I, glycosaminoglycans (GAGs) and growth factors such as VEGF, EGF and FGF7. The collagen fibre bundles were increased, thickened, and more loosely woven in both the papillary and reticular dermis. CONCLUSION: We were able to show that PCI modulates gene expression in skin of those genes that are relevant for extracellular matrix remodelling.


Subject(s)
Cicatrix/prevention & control , Collagen/pharmacology , Epidermis/drug effects , Epidermis/physiology , Regeneration/drug effects , Administration, Topical , Animals , Biomarkers/metabolism , Biopsy, Needle , Disease Models, Animal , Epidermis/metabolism , Fluorescent Antibody Technique , Gene Expression Regulation , Humans , Immunohistochemistry , Injections, Intradermal , Male , Random Allocation , Rats , Rats, Sprague-Dawley , Reference Values , Regeneration/physiology , Rejuvenation/physiology , Sensitivity and Specificity , Skin Aging , Skin Care/methods , Vitamin A/pharmacology , Vitamin D/pharmacology
13.
Clin Exp Dermatol ; 35(4): 437-9, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20337652

ABSTRACT

Photoageing is generally treated by ablative procedures that injure the epidermis and basement membrane, and lead to fibrosis of the dermis. Percutaneous collagen induction (PCI) therapy is an alternative treatment for photoaged skin that does not result in clinical signs of dermal fibrosis. In this study, the immediate effects of PCI on the skin were assessed, including the systemic inflammatory response and the production and gene expression of transforming growth factor (TGF) isoforms beta1, beta2 and beta3. Eighty rats were split into four groups: group 1 (n = 24; PCI plus skin care); group 2 (n = 24; skin care only); group 3 (n = 24; PCI only) and group 4 (n = 8; controls). Microarray analysis showed that TGF-beta3, an essential marker for preventing scarring, was upregulated and expressed for 2 weeks postoperatively. PCI might offer a regenerative therapy to improve skin appearance and quality and to improve or even prevent scarring.


Subject(s)
Cicatrix/prevention & control , Collagen/biosynthesis , Rejuvenation/physiology , Skin Aging/physiology , Animals , Gene Expression Regulation/physiology , Male , Needles , Physical Stimulation/instrumentation , Physical Stimulation/methods , Rats , Rats, Sprague-Dawley , Skin/metabolism , Transforming Growth Factor beta/biosynthesis , Transforming Growth Factor beta/genetics
14.
J Phys Condens Matter ; 22(45): 454113, 2010 Nov 17.
Article in English | MEDLINE | ID: mdl-21339600

ABSTRACT

We combine for the first time optical tweezer experiments with the resistive pulse technique based on capillaries. Quartz glass capillaries are pulled into a conical shape with tip diameters as small as 27 nm. Here, we discuss the translocation of λ-phage DNA which is driven by an electrophoretic force through the nanocapillary. The resulting change in ionic current indicates the folding state of single λ-phage DNA molecules. Our flow cell design allows for the straightforward incorporation of optical tweezers. We show that a DNA molecule attached to an optically trapped colloid is pulled into a capillary by electrophoretic forces. The detected electrophoretic force is in good agreement with measurements in solid-state nanopores.


Subject(s)
DNA/chemistry , DNA/ultrastructure , Electrophoresis, Capillary/methods , Molecular Probe Techniques , Nanostructures/chemistry , Nanostructures/ultrastructure , Optical Tweezers , Capillary Action , Porosity , Surface Properties
15.
J Appl Microbiol ; 106(4): 1122-32, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19191965

ABSTRACT

AIMS: To evaluate the GeneDisc multiplex real-time PCR assay for detection of enterohaemorrhagic Escherichia coli (EHEC) O26, O103, O111, O145 and O157 strains. METHODS AND RESULTS: GeneDiscs for detection of genes encoding Shiga toxins (stx), intimins (eae), E. coli O157 (rfbE(O157)) and H7 (fliC(H7)) antigens as well as genes specific for EHEC O26 (wzx(O26)), O103 (wzx(O103)), O111 (wbd1(O111)), O145 (ihp1(O145)) and O157 (ihp1(O157)) were evaluated. The assay was run with native bacteria in 1 h in a GeneDisc Cycler. All genotypes of stx and eae, except stx(2f) and eae-rho, were identified. Escherichia coli strains belonging to O-groups O26, O103, O111, O157 as well as EHEC O145:[H28] strains were specifically detected with this assay. The ihp1(O157) gene was not found specific for EHEC O157. O-rough mutants of EHEC and non-motile EHEC O157 strains were reliably identified with the GeneDisc assay. Two to three colonies of EHEC strains were still detectable in a lawn of 50 000 apathogenic E. coli from agar plates. CONCLUSIONS: The GeneDisc assay is a specific and reliable assay for detection of major EHEC strains. It is robust enough to detect few EHEC colonies in mixed cultures of bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: The assay is promising for its use in EHEC diagnostics and for EHEC monitoring with different kinds of samples.


Subject(s)
Enterohemorrhagic Escherichia coli/genetics , Escherichia coli Proteins/genetics , Polymerase Chain Reaction/methods , Shiga Toxins/genetics , Virulence Factors/genetics , Antigens, Bacterial/genetics , Bacterial Typing Techniques , Computer Systems , Enterohemorrhagic Escherichia coli/immunology , O Antigens/genetics , Sensitivity and Specificity , Serotyping
16.
J Chem Phys ; 126(11): 114505, 2007 Mar 21.
Article in English | MEDLINE | ID: mdl-17381218

ABSTRACT

The dynamic structure factor S(Q,omega) of the refractory oxide melts MgAl2O4 and MgAl4O7 is studied by inelastic x-ray scattering with aerodynamic levitation and laser heating. This technique allows the authors to measure simultaneously the elastic response and transport properties of melts under extreme temperatures. Over the wave vector Q range of 1-8 nm-1 the data can be fitted with a generalized hydrodynamic model that incorporates a slow component described by a single relaxation time and an effectively instantaneous fast component. Their study provides estimates of high-frequency sound velocities and viscosities of the Mg-Al-O melts. In contrast to liquid metals, the dispersion of the high-frequency sound mode is found to be linear, and the generalized viscosity to be Q independent. Both experiment and simulation show a weak viscosity maximum around the MgAl4O7 composition.

17.
Handchir Mikrochir Plast Chir ; 36(4): 205-11, 2004 Aug.
Article in German | MEDLINE | ID: mdl-15368145

ABSTRACT

BACKGROUND AND PURPOSE: Reconstruction of tendon tissue is problematic in many cases. Since direct tendon suture is often impossible, major reconstruction with the use of free tendon transplants or tendon transposition is necessary. Important motor units often have to be sacrificed for reconstructive purposes. In this study we investigated whether long tendon-like substitutes can be fabricated in vitro from human mesenchymal stem cells (MSCs) and a collagen type I gel when cultured under cyclic stretching conditions. MATERIAL AND METHODS: MSCs were obtained from bone marrow aspirates of the iliac crest. Cells were suspended in a collagen type I gel and polymerized in a glass-cylinder with defined size. The fabricated tendon substitutes underwent static stretching for 14 days followed by cyclic stretching for 21 days in a special manufactured bioreactor. Non-stretched substitutes served as a control. RESULTS: Macroscopically the stretched tendon substitutes showed an increased opacity and a smoother surface structure compared to the non-stretched control. The stretched substitutes displayed more spindle-shaped, longitudinal orientated cells, a tendon-like organization of the collagen matrix, and a parallel organization of the collagen fibers when stained with Hematoxylin/Eosin and Elastica. CONCLUSION: Long tendon substitutes could be fabricated from MSCs and a collagen type I gel by cyclic stretching and showed tendon-like parallel collagen fibers and spindle-shaped cells. The use of MSCs in combination with adequate scaffold materials has great therapeutic potential for the development of autologous transplantable tendon substitutes.


Subject(s)
Bioreactors , Mesenchymal Stem Cells , Tendons , Tissue Engineering/methods , Bone Marrow , Collagen Type I , Gels , Humans , Ilium , Microscopy , Tendons/transplantation , Time Factors
18.
Zentralbl Chir ; 129 Suppl 1: S113-5, 2004 May.
Article in German | MEDLINE | ID: mdl-15168305

ABSTRACT

BACKGROUND AND PURPOSE: The Vacuum Assisted Closure device (V.A.C.) is commonly used for the treatment of problematic wounds. Furthermore, wound fluid can be easily collected with this device for research purposes. However, there is inadequate information as to whether the measurement of biomoieties of importance to wound healing is affected by the exposure of wound fluid to V.A.C. components, namely Polyurethane-foam and tubing. This study is an attempt to evaluate whether exposure of wound fluid to either V.A.C.-components affects concentrations of transforming growth factor beta 1 (TGF-b1) in wound fluid. MATERIAL AND METHOD: Wound fluid was gathered from five decubital ulcer patients using the foil-technique and was exposed to sterile pieces of the V.A.C. Polyurethane-foam, tubing material or nothing for zero, one or five hours. Saline served as control. The concentration of TGF-b1 was measured using sandwich-ELISA. The resulting data were analyzed using two-way ANOVA, Newman-Keuls and Bonferroni t-Test. RESULTS: The concentration of TGF-b1 decreased significant in all three groups during the five hours of the experiment (p < 0.05). There was no significant decrease in TGF-b1 concentration at any time point in-between the groups. CONCLUSION: From this study, we conclude that wound-fluid collected from the V.A.C.-device via the polyurethane-foam or tubing for purposes of analyzing concentrations of TGF-beta 1 should not be different from fluid collected using the foil technique.


Subject(s)
Debridement/instrumentation , Occlusive Dressings , Polyurethanes , Pressure Ulcer/surgery , Suture Techniques/instrumentation , Transforming Growth Factor beta/metabolism , Wound Healing/physiology , Enzyme-Linked Immunosorbent Assay , Equipment Design , Exudates and Transudates/metabolism , Humans , Microcomputers , Surgery, Computer-Assisted/instrumentation , Transforming Growth Factor beta1 , Vacuum
19.
Exp Clin Immunogenet ; 18(2): 96-9, 2001.
Article in English | MEDLINE | ID: mdl-11340298

ABSTRACT

OBJECTIVE: The monoclonal IgG anti-double-stranded (ds) DNA antibody 32B9, obtained from a patient with systemic lupus erythematosus, was found to be encoded by somatically mutated immunoglobulin genes. We examined the input of several somatic mutations into antibody specificity and affinity. METHODS: Five single-chain (sc) Fv fragments [variable domain of the heavy chain (V(H))-linker-variable domain of the light chain (V(L))] derived from 32B9 were constructed and expressed in Escherichia coli. These scFv fragments contained V(H) or V(L) fragments, differing in the somatic mutation pattern. The antigen binding features of the 32B9 IgG were compared with the corresponding scFv fragments, and the binding to DNA of all fragments was analyzed by ELISA. Binding constants to dsDNA were determined by surface plasmon resonance and ELISA. RESULTS: The scFv 32B9 reflected the binding features of the 32B9 IgG. Independently of the somatic mutations, all scFv fragments bound to dsDNA in ELISA. The affinity data indicated that the mutations studied had only a marginal effect on affinity maturation of the 32B9. DISCUSSION: We discuss the approach to constructing scFv fragments as a tool to study autoantibody maturation.


Subject(s)
Antibodies, Antinuclear/immunology , DNA/immunology , Immunoglobulin Fragments/immunology , Immunoglobulin Variable Region/immunology , Antibodies, Antinuclear/genetics , Antigen-Antibody Reactions , Binding Sites, Antibody , Humans , Immunoglobulin Fragments/genetics , Immunoglobulin Variable Region/genetics , Lupus Erythematosus, Systemic/immunology , Mutagenesis, Site-Directed , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology
20.
Waste Manag ; 21(2): 175-84, 2001.
Article in English | MEDLINE | ID: mdl-11220182

ABSTRACT

At the former uranium mining site of Ronneburg, large scale underground and open pit mining for nearly 40 years resulted in a production of about 113,000 tonnes of uranium and about 200 million cubic metres of mine waste. In their present state, these materials cause risks to human health and strong environmental impacts and therefore demand remedial action. The remediation options available are relocation of mine spoil into the open pit and on site remediation by landscaping/contouring, placement of a cover and revegetation. A suitable vegetated cover system combined with a surface water drainage system provides long-term stability against erosion and reduces acid generation thereby meeting the main remediation objectives which are long-term reduction of radiological exposure and contaminant emissions and recultivation. The design of the cover system includes the evaluation of geotechnical, radiological, hydrological, geochemical and ecological criteria and models. The optimized overall model for the cover system has to comply with general conditions as, e.g. economic efficiency, public acceptance and sustainability. Most critical elements for the long-term performance of the cover system designed for the Beerwalde dump are the barrier system and its long-term integrity and a largely self-sustainable vegetation.


Subject(s)
Environmental Pollution/prevention & control , Hazardous Waste , Industrial Waste/prevention & control , Mining , Soil Pollutants, Radioactive/adverse effects , Uranium , Water Pollution, Radioactive/prevention & control , Environmental Monitoring , Environmental Pollution/analysis , Equipment Design , Fresh Water , Germany , Humans , Hydrogen-Ion Concentration , Industrial Waste/analysis , Soil Pollutants, Radioactive/analysis , Trees , Water Pollution, Radioactive/analysis
SELECTION OF CITATIONS
SEARCH DETAIL
...