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1.
Methods Mol Biol ; 1397: 81-90, 2016.
Article in English | MEDLINE | ID: mdl-26676129

ABSTRACT

Methods to monitor the status of a graft prior to transplantation are highly desirable to avoid unnecessary surgical interventions and follow-up treatments and to optimize the clinical outcome as delayed graft function may lead to costly and lengthy follow-up treatments or even organ loss. As a promising step in this direction we present a method which combines the use of fine needle biopsies, the staining of living cells with dyes suitable to monitor mitochondrial status/cellular integrity, and live confocal real-time analysis.This approach provides information about the functional and structural intactness of an organ within a few minutes. To confirm the feasibility of this approach, we recently published a pilot study using rodent kidneys. The results demonstrated that this method is suitable to monitor organ damage caused by ischemia or short periods of reperfusion. This procedure required minimal time for sample preparation and data acquisition and is suitable for recording damage resulting from unphysiological stress to the organ.


Subject(s)
Kidney/cytology , Kidney/metabolism , Microscopy, Confocal , Molecular Imaging/methods , Staining and Labeling , Animals , Mice , Microscopy, Confocal/methods , Rats , Staining and Labeling/methods
2.
Transpl Int ; 27(8): 868-76, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24750326

ABSTRACT

Prolonged ischemia (I) times caused by organ procurement and transport are main contributors to a decrease in organ function, which is further enhanced during reperfusion (R). This combined damage, referred to as ischemia-reperfusion injury (IRI), is a main contributor to delayed graft function, which leads to costly and lengthy follow-up treatments or even organ loss. Methods to monitor the status of a graft prior to transplantation are therefore highly desirable to optimize the clinical outcome. Here, we propose the use of fine needle biopsies, which are analyzed by real-time live confocal microscopy. Such a combination provides information about the functional and structural integrity of an organ within a few minutes. To confirm the feasibility of this approach, we obtained fine needle biopsies from rodent kidneys and exposed them to various stress conditions. Following the addition of a range of live stains, biopsies were monitored for mitochondrial function, cell viability, and tissue integrity using confocal live cell imaging. Our data demonstrate that this procedure requires minimal time for sample preparation and data acquisition and is well suitable to record organ damage resulting from unphysiological stress.


Subject(s)
Biopsy, Needle/methods , Kidney/pathology , Microscopy, Confocal/methods , Animals , Humans , Male , Mice , Mice, Inbred C57BL , Rats , Rats, Inbred Lew
3.
Biomed Res Int ; 2013: 975608, 2013.
Article in English | MEDLINE | ID: mdl-24324977

ABSTRACT

Islet transplantation is a valid treatment option for patients suffering from type 1 diabetes mellitus. To assure optimal islet cell quality, specialized islet isolation facilities have been developed. Utilization of such facilities necessitates transportation of islet cells to distant institutions for transplantation. Despite its importance, a clinically feasible solution for the transport of islets has still not been established. We here compare the functionality of isolated islets from C57BL/6 mice directly after the isolation procedure as well as after two simulated transport conditions, static versus rotation. Islet cell quality was assessed using real-time live confocal microscopy. In vivo islet function after syngeneic transplantation was determined by weight and blood sugar measurements as well as by intraperitoneal glucose tolerance tests. Vascularization of islets was documented by fluorescence microscopy and immunohistochemistry. All viability parameters documented comparable cell viability in the rotary group and the group transplanted immediately after isolation. Functional parameters assessed in vivo displayed no significant difference between these two groups. Moreover, vascularization of islets was similar in both groups. In conclusion, rotary culture conditions allows the maintenance of highest islet quality for at least 15 h, which is comparable to that of freshly isolated islets.


Subject(s)
Diabetes Mellitus, Type 1/therapy , Insulin/metabolism , Islets of Langerhans Transplantation , Islets of Langerhans/cytology , Animals , Blood Glucose , Cell Survival , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 1/pathology , Glucose Tolerance Test , Humans , Islets of Langerhans/metabolism , Mice
4.
J Nutr Biochem ; 24(1): 112-7, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22819549

ABSTRACT

Mutual clinical and molecular interactions between iron and glucose metabolism have been reported. We aimed to investigate a potential effect of glucose on iron homeostasis. We found that serum iron concentrations gradually decreased over 180 min after the administration of 75 g of glucose from 109.8 ± 45.4 mg/L to 94.4 ± 40.4 mg/L (P<.001; N=40) but remained unchanged in control subjects receiving tap water (N=21). Serum hepcidin, the key iron regulatory hormone which is mainly derived from hepatocytes but also expressed in pancreatic ß-cells, increased within 120 min after glucose ingestion from 19.7 ± 9.9 nmol/L to 31.4 ± 21.0 nmol/L (P<.001). In cell culture, glucose induced the secretion of hepcidin and insulin into the supernatant of INS-1E cultures, but did not change the amount of hepcidin detectable in the hepatocyte cell culture HepG2. We additionally confirmed the expression of hepcidin in a human islet cell preparation. These results suggest that glucose acts as a regulator of serum iron concentrations, most likely by triggering the release of hepcidin from ß-cells.


Subject(s)
Antimicrobial Cationic Peptides/metabolism , Glucose/metabolism , Iron/blood , Adult , Animals , Antimicrobial Cationic Peptides/genetics , Cells, Cultured , Female , Glucose/pharmacology , Glucose Tolerance Test , Hepatocytes/drug effects , Hepatocytes/metabolism , Hepcidins , Homeostasis/drug effects , Humans , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism , Insulinoma/drug therapy , Insulinoma/metabolism , Male , Middle Aged , Rats
5.
Islets ; 4(2): 152-7, 2012.
Article in English | MEDLINE | ID: mdl-22627172

ABSTRACT

The setup of an islet isolation facility designed along the rules of good manufacturing practice (GMP) is a technically challenging, cost and time intensive process. ( 1) Consequently, several institutions have decided to perform transplantation of islets isolated at another center with an already standing expertise. Such a solution includes the necessity to transport the isolated islets from the isolation to the transplantation facility. In spite of its importance, an ideal solution for the transport of the isolated human islets has still not been established.   Here, we present an islet transport device suited to transport human islet cells under reproducible conditions and minimized cell stress. The transport simulation of the human islets was performed in a transfused "rotary transport system for islets" termed "ROTi." Besides measuring standard metabolic (LDH, lactate, glucose) and physical parameters (pH, dissolved oxygen and temperature), we used five different live stains in combination with real time live confocal microscopy to document islet quality parameters. As live stains we added tetramethylrhodamine methyl ester, cell permeant acetoxymethylester, propidium iodide, annexin-fitc and fluorescent wheat germ agglutinin, and assessed mitochondrial membrane potentials, calcium levels, cell death, apoptosis or cell morphology, respectively. We compared the viability of human islets after 24 h incubation in the ROTi device to an incubation simulating "standard" shipment of islets in 50 ml tubes. All cell viability parameters studied (mitochondrial membrane potentials, calcium content, apoptosis, cell death as well as cell morphology) documented a significantly better cell viability in the ROTi fraction compared with the simulated "standard" shipment fraction. Besides maintaining islet cell viability, the ROTi bears the advantage of a better reproducibility of islet transport conditions.


Subject(s)
Islets of Langerhans Transplantation/methods , Islets of Langerhans/metabolism , Apoptosis/physiology , Cell Survival/physiology , Glucose/metabolism , Humans , Islets of Langerhans/cytology , Islets of Langerhans/ultrastructure , Islets of Langerhans Transplantation/instrumentation , L-Lactate Dehydrogenase/metabolism , Lactic Acid/metabolism , Membrane Potential, Mitochondrial/physiology , Microscopy, Confocal
6.
PLoS One ; 7(3): e33939, 2012.
Article in English | MEDLINE | ID: mdl-22479483

ABSTRACT

BACKGROUND: Pro-inflammatory, cytotoxic CD4(+)CD28(-) T-cells with known defects in apoptosis have been investigated as markers of premature immuno-senescence in various immune-mediated diseases. In this study we evaluated the influence of polyclonal antilymphocyte globulins (ATG-Fresenius, ATG-F) on CD4(+)CD28(-) T-cells in vivo and in vitro. PRINCIPAL FINDINGS: Surface and intracellular three colour fluorescence activated cell sorting analyses of peripheral blood mononuclear cells from 16 consecutive transplant recipients and short-term cell lines were performed. In vivo, peripheral levels of CD3(+)CD4(+)CD28(-) T-cells decreased from 3.7 ± 7.1% before to 0 ± 0% six hours after ATG-F application (P = 0.043) in 5 ATG-F treated but not in 11 control patients (2.9 ± 2.9% vs. 3.9 ± 3.0%). In vitro, ATG-F induced apoptosis even in CD4(+)CD28(-) T-cells, which was 4.3-times higher than in CD4(+)CD28(+) T-cells. ATG-F evoked apoptosis was partially reversed by the broad-spectrum caspase inhibitor benzyloxycarbonyl (Cbz)-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD-fmk) and prednisolon-21-hydrogensuccinate. ATG-F triggered CD25 expression and production of pro-inflammatory cytokines, and induced down-regulation of the type 1 chemokine receptors CXCR-3, CCR-5, CX3CR-1 and the central memory adhesion molecule CD62L predominately in CD4(+)CD28(-) T-cells. CONCLUSION: In summary, in vivo depletion of peripheral CD3(+)CD4(+)CD28(-) T-cells by ATG-F in transplant recipients was paralleled in vitro by ATG-F induced apoptosis. CD25 expression and chemokine receptor down-regulation in CD4(+)CD28(-) T-cells only partly explain the underlying mechanism.


Subject(s)
Antilymphocyte Serum/pharmacology , Apoptosis/drug effects , CD28 Antigens/analysis , CD4-Positive T-Lymphocytes/drug effects , Immunologic Factors/pharmacology , Adult , Antilymphocyte Serum/immunology , Apoptosis/immunology , CD3 Complex , CD4-Positive T-Lymphocytes/immunology , Caspases/metabolism , Cytokines/biosynthesis , Down-Regulation/drug effects , Enzyme Activation/drug effects , Female , Humans , Immunologic Factors/immunology , Inflammation/immunology , Interleukin-2/metabolism , Lymphocyte Depletion , Male , Middle Aged , Organ Transplantation , Receptors, Chemokine/metabolism , Signal Transduction/drug effects , Th1 Cells/drug effects , Th1 Cells/immunology , Transendothelial and Transepithelial Migration/drug effects , Young Adult , fas Receptor/metabolism
7.
Int J Oncol ; 40(1): 40-6, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21879258

ABSTRACT

Pancreatic cancer (PaCa) is the fourth leading cause of cancer deaths in Western societies, with pancreatic ductal adenocarcinomas (PDACs) accounting for >90% of such cases. PDAC is a heterogeneous disease that includes a subset showing overexpression of the secreted glycoprotein Dickkopf-related protein 3 (Dkk-3), a protein shown to be downregulated in various cancers of different tissues. The biological function of Dkk-3 in this subset was studied using the Dkk-3 expressing PANC-1 cell line as a model for PDACs. The influence of Dkk-3 overexpression and knockdown on cellular differentiation and proliferation of PANC-1 was investigated. Confocal microscopy showed that Dkk-3 was expressed in a fraction of PANC-1 cells. While lentiviral-mediated overexpression of DKK3 did not alter cellular proliferation, knockdown of DKK3 resulted in significant reduction of cellular proliferation and concomitant induction of cell cycle inhibitors CDKN2B (p15INK4b), CDKN1A (p21CIP1) and CDKN1B (p27KIP1). In parallel, pancreatic epithelial cell differentiation markers AMY2A, CELA1, CTRB1, GCG, GLB1 and INS were significantly upregulated. PANC-1 cells differentiated using exendin-4 showed analogous induction of cell cycle inhibitors and differentiation markers. Thus, we conclude that Dkk-3 is required to maintain a highly dedifferentiated and consequently proliferative state in PANC-1, indicating a similar function in the Dkk-3 overexpressing subset of PDACs. Therefore, Dkk-3 represents a potential target for the treatment of Dkk-3-positive subtypes of PaCa to drive cells into cell cycle arrest and differentiation.


Subject(s)
Carcinoma, Pancreatic Ductal/pathology , Cell Differentiation/physiology , Intercellular Signaling Peptides and Proteins/physiology , Pancreatic Neoplasms/pathology , Adaptor Proteins, Signal Transducing , Carcinoma, Pancreatic Ductal/genetics , Cell Growth Processes/physiology , Cell Line, Tumor , Chemokines , Cyclin-Dependent Kinase Inhibitor p27/metabolism , Gene Knockdown Techniques , Humans , Intercellular Signaling Peptides and Proteins/biosynthesis , Intercellular Signaling Peptides and Proteins/deficiency , Intercellular Signaling Peptides and Proteins/genetics , Lentivirus/genetics , Microscopy, Fluorescence , Pancreatic Neoplasms/genetics , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/genetics , Real-Time Polymerase Chain Reaction
8.
Transfus Med Hemother ; 37(5): 299-305, 2010.
Article in English | MEDLINE | ID: mdl-21113254

ABSTRACT

BACKGROUND: Assessment of platelet vitality is important for patients presenting with inherited or acquired disorders of platelet function and for quality assessment of platelet concentrates. METHODS: Herein we combined live stains with intra-vital confocal fluorescence microscopy in order to obtain an imaging method that allows fast and accurate assessment of platelet vitality. Three fluorescent dyes, FITC-coupled wheat germ agglutinin (WGA), tetramethylrhodamine methyl ester perchlorate (TMRM) and acetoxymethylester (Rhod-2), were used to assess platelet morphology, mitochondrial activity and intra-platelet calcium levels. Microscopy was performed with a microlens-enhanced Nipkow spinning disk-based system allowing live confocal imaging. RESULTS: Comparison of ten samples of donor platelets collected before apheresis and platelets collected on days 5 and 7 of storage showed an increase in the percentage of Rhod-2-positive platelets from 3.6 to 47 and finally to 71%. Mitochondrial potential was demonstrated in 95.4% of donor platelets and in 92.5% of platelets stored for 7 days. CONCLUSION: Such fast and accurate visualization of known key parameters of platelet function could be of relevance for studies addressing the quality of platelets after storage and additional manipulation, such as pathogen inactivation, as well as for the analysis of inherited platelet function disorders.

9.
Transplantation ; 90(6): 666-71, 2010 Sep 27.
Article in English | MEDLINE | ID: mdl-20724959

ABSTRACT

BACKGROUND: Risk factors for delayed graft function (DGF) in pancreas transplantation (PTx) and its implications on graft survival are poorly defined. METHODS: Eighty-seven consecutive first-time PTx for type I diabetes performed between January 2003 and December 2007 were retrospectively reviewed. DGF was defined as a reversible need for exogenous insulin beyond postoperative day 10 (DGF group [DGFG]). For statistical analysis, DGFG patients were compared with patients with immediate graft function (control group [CG]). RESULTS: DGF occurred in 16 patients (18.6%). C-peptide levels and DGF were inversely correlated (r=0.24, P=0.03). In univariate analysis, donor cytomegalovirus (CMV)+ antibody status, and D+/R- CMV mismatch were significantly associated with DGF (81.3% vs. CG 52.1%, P=0.029; and 62.5% vs. CG 21.1%, P=0.002, respectively). Compared with University of Wisconsin solution, histidine tryptophan ketoglutarate-preserved grafts displayed higher DGF rates (37.5% vs. CG 12.7%, P=0.030), similar to female recipients (DGFG 68.8% vs. CG 35.2%, P=0.015). On multivariate analysis, a significantly higher DGF incidence was noted in female recipients (DGFG 68.8% vs. CG 35.2%; P=0.03) and in recipients with D+/R- CMV mismatch (DGFG 62.5% vs. CG 21.1%; P=0.03). With a median follow-up of 40.4 months (range 0.7-74.2), graft survival at 5 years did not differ between both groups (94.4% CG vs. 93.8% DGFG; P=0.791). CONCLUSION: This is the first study that identifies CMV mismatch (D+/R-) as an additional risk factor for DGF occurrence in PTx. In this particular cohort, DGF does not seem to affect graft survival.


Subject(s)
Cytomegalovirus Infections/complications , Cytomegalovirus/isolation & purification , Pancreas Transplantation/adverse effects , Adult , Body Mass Index , C-Peptide/blood , C-Reactive Protein/metabolism , Delayed Graft Function/etiology , Diabetes Mellitus, Type 2/surgery , Female , Graft Survival , Humans , Kidney Transplantation/adverse effects , Male , Middle Aged , Pancreas Transplantation/mortality , Regression Analysis , Reoperation/statistics & numerical data , Retrospective Studies , Risk Factors , Survival Rate , Time Factors
10.
Adv Exp Med Biol ; 654: 711-24, 2010.
Article in English | MEDLINE | ID: mdl-20217521

ABSTRACT

Human islet transplantation is one of the three treatment modalities besides the daily administration of exogenous insulin and pancreas transplantation, which can be applied for the treatment of type 1 diabetic patients. Although the metabolic control achieved after islet transplantation is superior compared to exogenous insulin administration, many hurdles remain to be overcome before islet transplantation can be called a routine therapy for type 1 diabetic patients. In contrast to many other therapeutic approaches, proof of principle has been obtained for islet transplantation: As demonstrated in islet autotransplantation, the transplanted islets are not only able to survive in another organ, namely the liver, but also able to retain their functional role, in some patients even for decades. The main challenge for islet allotransplantation is, therefore, to imitate this success, thereby providing type 1 diabetic patients with a cellular therapy lasting for decades and thus circumventing the daily injections of insulin.


Subject(s)
Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 1/therapy , Islets of Langerhans Transplantation/methods , Islets of Langerhans/cytology , Cell Death , Glucose/metabolism , Humans , Insulin/metabolism , Islets of Langerhans/pathology , Microscopy, Confocal/methods , Models, Biological , Pancreas/pathology , Pancreatitis/pathology , Pancreatitis/therapy , Tissue and Organ Procurement/methods , Transplantation, Homologous/methods
11.
J Cell Mol Med ; 14(1-2): 417-25, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19382913

ABSTRACT

Mitochondrial morphology and intracellular organization are tightly controlled by the processes of mitochondrial fission-fusion. Moreover, mitochondrial movement and redistribution provide a local ATP supply at cellular sites of particular demands. Here we analysed mitochondrial dynamics in isolated primary human pancreatic cells. Using real time confocal microscopy and mitochondria-specific fluorescent probes tetramethylrhodamine methyl ester and MitoTracker Green we documented complex and novel patterns of spatial and temporal organization of mitochondria, mitochondrial morphology and motility. The most commonly observed types of mitochondrial dynamics were (i) fast fission and fusion; (ii) small oscillating movements of the mitochondrial network; (iii) larger movements, including filament extension, retraction, fast (0.1-0.3 mum/sec.) and frequent oscillating (back and forth) branching in the mitochondrial network; (iv) as well as combinations of these actions and (v) long-distance intracellular translocation of single spherical mitochondria or separated mitochondrial filaments with velocity up to 0.5 mum/sec. Moreover, we show here for the first time, a formation of unusual mitochondrial shapes like rings, loops, and astonishingly even knots created from one or more mitochondrial filaments. These data demonstrate the presence of extensive heterogeneity in mitochondrial morphology and dynamics in living cells under primary culture conditions. In summary, this study reports new patterns of morphological changes and dynamic motion of mitochondria in human pancreatic cells, suggesting an important role of integrations of mitochondria with other intracellular structures and systems.


Subject(s)
Fluorescent Dyes/metabolism , Microscopy, Confocal , Mitochondria/metabolism , Pancreas/cytology , Cells, Cultured , Humans , Mitochondria/ultrastructure
12.
Transfusion ; 50(2): 400-6, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19804574

ABSTRACT

BACKGROUND: Previous data show improved clot formation after retransfusion of salvaged red blood cells (RBCs). This study was conducted to explore whether such RBCs contain clinically relevant numbers of active residual platelets (PLTs) or exhibit formation of microparticles (MPs). STUDY DESIGN AND METHODS: Thirteen patients undergoing major orthopedic surgery were included in the study, and arterial blood samples from patients and samples from the retransfusion bag were analyzed with various PLT function tests and flow cytometry. RESULTS: With commercial blood cell counters, the numbers of PLTs in the RBC unit were reduced to approximately 25% compared to patients' blood. In contrast, results from flow cytometry showed an 11- to 945-fold reduction in median counts referring to total PLTs and free PLTs. Interestingly, smaller quantities of PLT-derived MPs were found in samples from the retransfusion bag than in patients' arterial blood. Conversely, RBC- and white blood cell-derived MP counts were increased in the retransfusion bag compared to the patient. Rotational thrombelastometry and the Impact-R system (DiaMed) showed a pronounced impairment of PLT ability with regard to adhesion, aggregation, and clot formation. With the use of confocal microscopy, only a few free thrombocytes were detectable among the huge numbers of RBCs. CONCLUSION: Only few free and thus active PLTs are detectable in processed RBCs. It seems very unlikely that these few PLTs can improve clot strength. Nevertheless, the impact of the detected MPs on thrombin generation needs to be clarified in further studies.


Subject(s)
Blood Platelets/physiology , Blood Transfusion, Autologous/methods , Cell-Derived Microparticles , Erythrocytes , Intraoperative Care/methods , Orthopedic Procedures , Adult , Aged , Aged, 80 and over , Blood Coagulation , Blood Loss, Surgical , Female , Flow Cytometry , Humans , Intraoperative Care/instrumentation , Male , Microscopy, Confocal , Middle Aged , Pilot Projects , Platelet Count , Platelet Function Tests , Thrombelastography , Thrombin/biosynthesis , Young Adult
13.
Int J Biochem Cell Biol ; 41(10): 1928-39, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19703655

ABSTRACT

Recent advances in mitochondrial imaging have revealed that in many cells mitochondria can be highly dynamic. They can undergo fission/fusion processes modulated by various mitochondria-associated proteins and also by conformational transitions in the inner mitochondrial membrane. Moreover, precise mitochondrial distribution can be achieved by their movement along the cytoskeleton, recruiting various connector and motor proteins. Such movement is evident in various cell types ranging from yeast to mammalian cells and serves to direct mitochondria to cellular regions of high ATP demand or to transport mitochondria destined for elimination. Existing data also demonstrate that many aspects of mitochondrial dynamics, morphology, regulation and intracellular organization can be cell type-/tissue-specific. In many cells like neurons, pancreatic cells, HL-1 cells, etc., complex dynamics of mitochondria include fission, fusion, small oscillatory movements of mitochondria, larger movements like filament extension, retraction, fast branching in the mitochondrial network and rapid long-distance intracellular translocation of single mitochondria. Alternatively, mitochondria can be rather fixed in other cells and tissues like adult cardiomyocytes or skeletal muscles with a very regular organelle organization between myofibrils, providing the bioenergetic basis for contraction. Adult cardiac cells show no displacement of mitochondria with only very small-amplitude rapid vibrations, demonstrating remarkable, cell type-dependent differences in the dynamics and spatial arrangement of mitochondria. These variations and the cell-type specificity of mitochondrial dynamics could be related to specific cellular functions and demands, also indicating a significant role of integrations of mitochondria with other intracellular systems like the cytoskeleton, nucleus and endoplasmic reticulum (ER).


Subject(s)
Mitochondria/metabolism , Animals , Cytoskeleton/metabolism , Humans , Mitochondria/ultrastructure , Models, Biological , Myocytes, Cardiac/metabolism , Tubulin/metabolism
14.
Cancer Sci ; 100(8): 1414-20, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19493271

ABSTRACT

Dkk-3 is proposed to be a new specific marker for tumor endothelial cells. Here we analyzed the clinical relevance of Dkk-3 expression in pancreas adenocarcinomas and determined its role on endothelial cell growth in vitro. Microvessel density in tumor samples was immunohistochemically determined using Dkk-3 and CD31 as endothelial cell markers, respectively. Based on the median microvessel density as a cut-off point, patients were categorized into high and low microvessel density groups and a correlation with survival and clinical parameters was assessed. Moreover, the role of Dkk-3 expression on chemosensitivity of endothelial cells was analyzed. In contrast to CD31 staining, Dkk-3-positive vessels were found only in tumor tissue and Dkk-3 microvessel density significantly correlated negative with tumor grading. In survival analysis the median survival time was 7 months for patients with Dkk-3 low, and 15 months for Dkk-3 high microvessel density (P = 0.0013). Subset analysis of patients receiving gemcitabine therapy showed that overall survival was significantly decreased in Dkk-3 low tumors than in high tumors (P = 0.009). In Cox regression Dkk-3 emerged as a significant independent parameter (P = 0.024). Dkk-3 overexpression in endothelial cells resulted in significantly enhanced growth inhibition after 5-fluorouracil or gemcitabine treatment compared to control endothelial cells and cancer cell lines. Dkk-3 low microvessel density was associated with tumor progression and worse clinical outcome. Overexpression of Dkk-3 enhanced endothelial cell growth inhibition to chemotherapeutic drugs. Therefore, we suggest that Dkk-3 high microvessel density may help to select patients who may benefit from chemotherapy.


Subject(s)
Adenocarcinoma/pathology , Biomarkers, Tumor/metabolism , Endothelium/metabolism , Intercellular Signaling Peptides and Proteins/metabolism , Pancreatic Neoplasms/pathology , Adaptor Proteins, Signal Transducing , Adenocarcinoma/genetics , Adenoviridae/genetics , Biomarkers, Tumor/genetics , Cell Line, Tumor , Cells, Cultured , Chemokines , Endothelium/pathology , Endothelium, Vascular/cytology , Follow-Up Studies , Gene Expression , Humans , Immunohistochemistry , Intercellular Signaling Peptides and Proteins/genetics , Pancreatic Neoplasms/genetics , Prognosis , Retrospective Studies , Survival Analysis , Time Factors , Transfection , Umbilical Veins/cytology
15.
Tissue Eng Part A ; 15(5): 1063-73, 2009 May.
Article in English | MEDLINE | ID: mdl-18847359

ABSTRACT

The aim of this study was to establish a stand-alone, perfused, rotary cell culture system using small human hepatocytes (SH) for bioartificial liver (BAL) support. SH were grown on cytodex 3 microcarriers (beads) to a maximum density of 1.2 +/- 0.3 x 10(7) cells per mL within 12 days. Size of aggregates formed by up to 15 beads was regulated by rotation speed. Cell function was proven by treatment with ammonia and galactose, and metabolism was analyzed. Treatment strategy was comprised of two phases, namely growth phase and treatment phase. Cells were grown for 6 days and subsequently incubated with ammonia or galactose for 2 days, followed by a 2-day regeneration period and another 2-day treatment phase. Consumption of glucose, release of lactate dehydrogenase, formation of lactate, and production of urea and albumin were determined regularly. Mean galactose consumption was 50 microg per 106 cells per hour, ammonia-induced urea formation was 3.6 microg per 106 cells per hour, and albumin production was 110 ng per 106 cells per hour. All metabolic parameters followed a logarithmic trend and were found to be very stable in the second half of the culture period when cells were treated with ammonia or galactose. Dissolved oxygen (%DO), pH, and temperature were monitored in-stream at intervals of 7 min, and the values were logged. Viability and morphology of cells were monitored via confocal microscopy. Viability was around 95% in controls and 90% during treatment. Promising results were obtained in support of our ongoing efforts to establish a fully autonomous BAL support device utilizing SH as a bridge to transplantation.


Subject(s)
Hepatocytes/cytology , Hepatocytes/metabolism , Liver, Artificial , Tissue Engineering/methods , Albumins/metabolism , Cell Aggregation , Cell Count , Cell Culture Techniques/methods , Cell Size , Dextrans , Glucose/metabolism , Humans , L-Lactate Dehydrogenase/metabolism , Microscopy, Confocal , Microspheres , Urea/metabolism
16.
Tissue Eng ; 13(11): 2761-8, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17764400

ABSTRACT

A rotary cell culture system has been established. System quality was determined by observing the stability of the basic parameters of temperature, gas exchange, and pH, and mass transfer (time to equimolarity) between the medium circuit and the 2 cell-containing chambers was investigated. Mass transfer time for urea and several ions was approximately 30 min for the high-fiber-density chamber (HFC) and 50 min for the low-fiber-density chamber (LFC). Exchange of albumin was delayed in both chambers, highlighting the dependence of mass transfer on area of exchange and molecule size. Finally, the ability for cell growth and maintenance was tested. Densities of up to 1.2 x 10(7) immortalized cells per mL at a viability of up to 85% were obtained after 1 week of continuous, non-interfering culture of immortalized cells in the HFC. Human pancreatic islets were also cultivated in the LFC. Confocal analysis using fluorescent dyes showed that the 3-dimensional islet structure was maintained for 1 week. Promising results were obtained, which will further our ongoing efforts toward establishing a mobile cell culture system.


Subject(s)
Rotation , Albumins/metabolism , Cell Culture Techniques/instrumentation , Cell Culture Techniques/methods , Cell Line, Transformed , Cell Survival , Cells, Cultured , Humans , Hydrogen-Ion Concentration , Islets of Langerhans/cytology , Models, Biological , Organ Culture Techniques , Perfusion/methods , Precursor Cell Lymphoblastic Leukemia-Lymphoma/pathology , Temperature , Time Factors , Urea/metabolism
17.
J Gastrointest Surg ; 11(7): 911-7, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17440792

ABSTRACT

Diarrhea is a well-known complication of immunosuppression but is also frequently caused by pathogens such as Clostridium difficile (CD) and rotavirus (RV). Three adult and five pediatric solid organ recipients (SORs) developed diarrhea with simultaneous identification of CD and RV. Rotavirus was identified using an immunochromatografic- or enzyme-linked immunosorbent assay; CD was identified using a rapid immunoassay or enzyme immunoassay. One adult renal, one adult kidney-pancreas, one adult liver, and five pediatric liver recipients were affected. Onset of RV/CD infection ranged from 2 weeks to 4 years posttransplant. All patients presented with enterocolitis causing significant fluid and electrolyte loss. In adults, CD was treated with metronidazole and in children with oral vancomycin. RV infection was treated with fluid/electrolyte replacement. During diarrhea, a significant rise in tacrolimus serum level was noted. All patients cleared CD. One child developed recurrent episodes of RV infection and died from bacterial sepsis; the renal recipient died 6 months posttransplant from myocardial infarction. The remaining six patients are currently alive with well-functioning grafts. Simultaneous infection with CD and RV may lead to severe diarrhea in SORs. Both pathogens should be considered in SOR presenting with diarrhea.


Subject(s)
Clostridioides difficile , Enterocolitis, Pseudomembranous/etiology , Enterocolitis/etiology , Enterocolitis/microbiology , Organ Transplantation/adverse effects , Rotavirus Infections/etiology , Adult , Aged , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged
18.
Surgery ; 141(5): 682-9, 2007 May.
Article in English | MEDLINE | ID: mdl-17462470

ABSTRACT

BACKGROUND: Although various suture techniques for murine pancreas transplantation have been described, severe limitations have limited their widespread use. We therefore designed a surgical model for cervical heterotopic pancreas transplantation using a cuff technique. METHODS: C57BL6 mice were used as donor and recipient pairs. Recipients were rendered diabetic with streptozotocin and subsequently transplanted. The donor pancreas was isolated using a no-touch technique and then placed in the recipient's cervical region. Vascular anastomoses were completed by pulling the portal vein over the external jugular vein cuff and the donor aortic segment over the carotid cuff and fixed with an 8-0 ligature thereby facilitating a nonsuture technique. To test applicability of this model, graft microcirculation was evaluated by intravital microscopy after prolonged cold ischemia (16 h). RESULTS: The immediate success rate was >90%. Donor operation lasted 40 +/- 5 min; dissection of recipient vessels lasted 20 +/- 4 min. Revascularization time was 4 to 6 min, resulting in a total pancreas ischemia time of 33 +/- 6 min. No thromboembolic complications on the cuff side were observed. Preoperative glucose levels were 518 +/- 59 mg/dl and returned to normal by postoperative day 1 (88 +/- 13 mg/dl). Histology on postoperative days 10 and 30 showed almost normal islet cell and acinar architecture of all grafts. In groups with prolonged cold ischemia, graft microcirculation was significantly reduced and paralleled by increased inflammation, interstitial edema, hemorrhage, acinar vacuolization, and focal areas of necrosis compared with nonischemic controls. CONCLUSIONS: This new model may provide an excellent tool to further investigate the pathophysiology as well as novel therapeutic strategies of preservation, ischemia reperfusion injury, and graft pancreatitis.


Subject(s)
Pancreas Transplantation/methods , Transplantation, Heterotopic/methods , Animals , Blood Glucose , Graft Rejection/diagnosis , Insulin/metabolism , Male , Mice , Mice, Inbred C57BL , Microscopy, Fluorescence/methods , Neck/blood supply , Neck/surgery , Pancreas/metabolism , Pancreas/pathology , Pancreas Transplantation/adverse effects , Pancreatitis/diagnosis , Reperfusion Injury/diagnosis , Transplantation, Heterotopic/adverse effects
19.
Transpl Int ; 20(4): 386-9, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17326780

ABSTRACT

Hemolytic uremic syndrome (HUS) is a rare complication following solid organ transplantation. We report on a patient who underwent renal transplantation using Campath-1H induction and tacrolimus maintenance therapy who developed HUS, which was managed by plasma exchange and switch to Rapamycin. However, graft function could not be restored.


Subject(s)
Antibodies, Monoclonal/adverse effects , Antibodies, Neoplasm/adverse effects , Hemolytic-Uremic Syndrome/chemically induced , Immunosuppressive Agents/adverse effects , Kidney Transplantation/adverse effects , Adult , Alemtuzumab , Antibodies, Monoclonal, Humanized , Hemolytic-Uremic Syndrome/drug therapy , Humans , Male , Plasma Exchange , Sirolimus/therapeutic use , Tacrolimus/therapeutic use
20.
Alcohol Clin Exp Res ; 31(5): 729-36, 2007 May.
Article in English | MEDLINE | ID: mdl-17378920

ABSTRACT

BACKGROUND: Current approaches to support alcohol addict and/or benzodiazepine-treated patients with liver failure include culturing human cells to take over basic metabolic functions for a certain time. METHODS: Small human hepatocytes (SH) were grown in a rotary cell culture system, and their potential to metabolize alcohol and the benzodiazepines oxazepam and diazepam was evaluated. Control experiments were performed with SV40-immortalized HEP cells and cell respective drug-free media. RESULTS: Our results show that SH in rotary culture are able to metabolize ethanol in reasonable amounts compared with evaporation controls (p<0.01). Moreover, SH are also able to metabolize oxazepam and diazepam which proves their ability to perform conjugation and the presence of functional cytochrome P450 enzymes. Basic metabolic activities such as glucose consumption, albumin and urea production are not significantly influenced by the drugs used, which is a precondition for clinical use of these cells. Significantly increased lactate dehydrogenase release indicates enhanced cell death in cultures of SH incubated with either ethanol (p<0.05) or diazepam (p<0.005), but stable viability at or above 90% suggests that cell proliferation is able to keep up with drug-induced cell death. CONCLUSION: Our preliminary study provides evidence that SH are basically suited to support alcohol-abusing and/or benzodiazepine-treated patients undergoing liver failure.


Subject(s)
Alcoholism/metabolism , Alcoholism/therapy , Cell Culture Techniques , Hepatocytes/metabolism , Liver, Artificial , Cell Count , Cell Line , Culture Media , Cytochrome P-450 Enzyme System/metabolism , Diazepam/metabolism , Hepatocytes/transplantation , Humans , Hypnotics and Sedatives/metabolism , L-Lactate Dehydrogenase/metabolism , Lactic Acid/biosynthesis , Liver Diseases, Alcoholic/metabolism , Liver Diseases, Alcoholic/therapy , Microscopy, Confocal , Oxazepam/metabolism , Pilot Projects , Urea/metabolism , Xenobiotics/metabolism
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