Biomedical subjects

Jochen W U Fries

Publications and source records attributed to Jochen W U Fries.

9 recordsLinked to original sources

PubMed2006

Effective engraftment but poor mid-term persistence of mononuclear and mesenchymal bone marrow cells in acute and chronic rat myocardial infarction.

Bone marrow cells are used with promising results for cell therapy after myocardial infarction (MI). We determined the survival and organ distribution of transplanted mononuclear (MNC) or mesenchymal (MSC) bone marrow cells, and the influence of cell type, cell number and application time. MNC and MSC (male Fischer 344 rats) were injected into the border zone of MI (syngeneic females) immediately or 7 days after LAD ligation (10(5) or 10(6) cells, 50 microl). After 0 h, 48 h, 5 days, 3 weeks and 6 weeks, DNA of heart, lung, liver, spleen, kidney, blood, bone marrow, brain and skeletal muscle was isolated and the number of donor cells determined by quantitative real-time PCR with Y-chromosome specific primers (each n>or=4). The percentage of donor-cells in the heart decreased rapidly from 34-80% of injected cells (0 h) to 0.3-3.5% (6 weeks) independent from cell type, number and application time. The absolute number increased after increasing injected cell number (10(6) vs. 10(5)). In the lung, MNC and MSC were found at 0 h (126+/-48 and 140+/-3 per million organ cells), but in liver and kidney, only few. At 48 h and 6 weeks, an increasing number of MNC, but not MSC, were detected in the spleen (6 weeks, 602+/-173 per million organ cells vs. 95+/-50 in the heart, P=0.02). In all other organs, only few or no grafted cells of either cell type were detected at these times. Organ distribution was independent from injection time. The low survival of grafted cells may limit their therapeutic impact, while their distribution to other organs must be considered in all cell therapy applications.

Acute Disease↗

PubMed2006

Engraftment of engineered ES cell-derived cardiomyocytes but not BM cells restores contractile function to the infarcted myocardium.

Cellular cardiomyoplasty is an attractive option for the treatment of severe heart failure. It is, however, still unclear and controversial which is the most promising cell source. Therefore, we investigated and examined the fate and functional impact of bone marrow (BM) cells and embryonic stem cell (ES cell)-derived cardiomyocytes after transplantation into the infarcted mouse heart. This proved particularly challenging for the ES cells, as their enrichment into cardiomyocytes and their long-term engraftment and tumorigenicity are still poorly understood. We generated transgenic ES cells expressing puromycin resistance and enhanced green fluorescent protein cassettes under control of a cardiac-specific promoter. Puromycin selection resulted in a highly purified (>99%) cardiomyocyte population, and the yield of cardiomyocytes increased 6-10-fold because of induction of proliferation on purification. Long-term engraftment (4-5 months) was observed when co-transplanting selected ES cell-derived cardiomyocytes and fibroblasts into the injured heart of syngeneic mice, and no teratoma formation was found (n = 60). Although transplantation of ES cell-derived cardiomyocytes improved heart function, BM cells had no positive effects. Furthermore, no contribution of BM cells to cardiac, endothelial, or smooth muscle neogenesis was detected. Hence, our results demonstrate that ES-based cell therapy is a promising approach for the treatment of impaired myocardial function and provides better results than BM-derived cells.

Animals↗

PubMed2006

First year changes of myocardial lymphatic endothelial markers in heart transplant recipients.

OBJECTIVE: The lymphatic system plays an important role in interstitial fluid balance, lipid metabolism, and immune response. The recent introduction of specific lymphatic endothelial cell markers has made the investigation of lymphangiogenesis under various conditions and from small tissue samples feasible. It was the purpose of the study to investigate the changes of myocardial lymphatic endothelial markers during the first 12 months after heart transplantation and to analyze if a correlation between lymphatic markers and rejection can be found. METHODS: Right ventricular endomyocardial biopsies taken for routine rejection monitoring from 26 heart transplant recipients were investigated. Selected time points were 0.5, 1, 1.5, 6, and 12 months after human heart transplantation (HTX). Immunohistostaining was performed for VEGFR-3, the receptor for lymphangiogenic vascular endothelial growth factors C and D, for LYVE-1, a novel hyaluronan receptor, restricted to lymphatic vessels, and PROX-1, a homeobox gene product, which plays a key role in lymph vessel development and differentiation. RESULTS: Density of VEGFR-3 positive lymphatics did not change during the first 12 months after transplantation. However, in comparison to the 0.5-month biopsy, density of LYVE-1 and PROX-1 positive lymphatics was significantly decreased at 1 month after transplantation (p<0.03) and at the subsequent time points (p<0.01). Patients with only moderate rejection during the first 12 months (ISHLT<IIIa) had a significantly higher density of VEGFR-3 at 0.5 month in comparison to patients with at least one episode of clinically relevant rejection (ISHLT IIIa or worse, p<0.03). CONCLUSION: Myocardial lymphatics show a significant change of endothelial phenotype after transplantation, as demonstrated by significant quantitative changes of lymphatic endothelial marker density. Patients with at least one rejection of ISHLT IIIa or higher had a significantly lower density of VEGFR-3 at 0.5 month after transplantation. The results of this study warrant further investigation on the impact of transplantation on the lymphatic endothelium. The cause-effect relation between rejection and lymphatic endothelium remains to be investigated.

Adolescent↗

PubMed2005

Specific occlusion of murine and human tumor vasculature by VCAM-1-targeted recombinant fusion proteins.

BACKGROUND: The tumor vasculature is increasingly recognized as a target for cancer therapy. We developed and evaluated recombinant fusion proteins targeting the coagulation-inducing protein soluble tissue factor (sTF) to the luminal tumor endothelial antigen vascular cell adhesion molecule 1 (VCAM-1, CD106). METHODS: We generated fusion proteins consisting of sTF fused to antibody fragments directed against mouse or human VCAM-1 and characterized them in vitro by flow cytometry, surface plasmon resonance, and two-stage coagulation assays. Their therapeutic effects were tested in three human xenograft tumor models: L540rec Hodgkin lymphoma, Colo677 small-cell lung carcinoma, and Colo677/HDMEC small-cell lung carcinoma with human vasculature. Toxicity was analyzed by histologic examination of organs and determination of laboratory blood parameters. RESULTS: The fusion proteins bound VCAM-1 with nanomolar affinities and had the same coagulation activity as an sTF standard. Xenograft tumor-bearing mice treated with fusion protein (FP) alone or in combination with lipopolysaccharide (FP/L) or doxorubicin (FP/D) exhibited tumor-selective necrosis (L540rec tumors: 74% tumor necrosis [95% confidence interval {CI} = 55% to 93%] with FP/L versus 13% tumor necrosis [95% CI = 4% to 22%] with vehicle; Colo677 tumors: 26% [95% CI = 16% to 36%] with FP versus 8% [95% CI = 2% to 14%] with vehicle); tumor growth delay (Colo677/HDMEC: mean tumor weights after 3 days = 42 mg in FP-treated mice versus 71 mg in vehicle-treated mice, difference = 29 mg, 95% CI = 8 to 100, Mann-Whitney P = .008); and some tumor regressions (one of seven FP-treated Colo677 tumor-bearing mice and two of seven FP/D-treated mice). The fusion protein was well tolerated. CONCLUSIONS: Recombinant tissue factor-based fusion proteins directed against an intraluminal tumor endothelial cell marker induce tumor-selective intravascular coagulation, tumor tissue necrosis, and tumor growth delay.

Angiogenesis Inhibitors↗

PubMed2005

[Non-compaction cardiomyopathy].

Isolated non-compaction of the ventricular myocardium (INVM), also known as left ventricular hypertrabeculation or spongy myocardium, belongs to the "unclassified" cardiomyopathies according to the World Health Organization. The main characteristic of this entity is a prominent trabeculation of the left ventricle with deep intertrabecular recesses communicating with the ventricular cavity. The pathomechanism of INVM is thought to be an arrest in cardiac myogenesis with persistence of embryonic myocardial morphology. The most frequent clinical manifestations include congestive heart failure, ventricular arrhythmias and systemic thromboembolic events. The therapy of INVM comprises standard medical therapy for heart failure.

Cardiomyopathies↗

PubMed2004

Coronary oxygen persufflation for heart preservation in pigs: analyses of endothelium and myocytes.

BACKGROUND: Coronary oxygen persufflation (COP) has been shown to prolong heart preservation time up to 14 hr in a mature pig model, with excellent recovery after orthotopic transplantation. The aim of the present study was to assess the structural, metabolic, and functional myocardial and endothelial integrity after COP in mature pig hearts. METHODS: Cardioplegic arrest was induced by original crystalloid Bretschneider solution (HTK 3h, n=6), modified Bretschneider solution (mHTK+COP, n=6), or University of Wisconsin solution (UW+COP, n=6). Hearts were stored for 3 (HTK 3h) or 14 hr (mHTK+COP, UW+COP) at 0 degrees to 1 degrees C. In addition, COP hearts were persufflated. After heterotopic transplantation and reperfusion for 7 days, hearts were analyzed by light microscopy or electron microscopy for structural injuries. Endothelial function, cardiac enzymes, metabolic parameters, and myocardial water content (MWC) were determined. Six recipient hearts served as controls. RESULTS: Quantitative light microscopic analyses and semiquantitative electron microscopic analyses showed an equal amount of damage in all groups including HTK 3h hearts. No rejection was observed. Substance P induced an equal dilatation in all hearts. Serum levels of cardiac enzymes were similar in all groups, but energy-enriched phosphates were significantly reduced, and MWC was augmented in the HTK 3h hearts and in the UW+COP hearts, in contrast to the mHTK+COP transplants. CONCLUSIONS: The lack of structural defects related to the COP technique, similar endothelial function, and an even better metabolic state of the mHTK+COP hearts versus HTK 3h hearts demonstrate the efficacy of the COP technique for prolongation of myocardial preservation time up to 14 hr.

Adenine Nucleotides↗

PubMed2004

How thrombus model impacts the in vitro study of interventional thrombectomy procedures.

RATIONALE AND OBJECTIVES: Numerous experimental models are used to investigate the effectiveness of thrombectomy devices. We aimed to study the systematic effects of different in vitro thrombus models on the results of experimental thrombectomy and examined how thrombi formed in vitro and ex vivo differ. METHODS: Three variables involved in human in vitro thrombogenesis were investigated: spontaneous or thrombin-induced clotting, age (1 or 5 days old), and storage temperature (4 degrees C or 21 degrees C). The fibrin content of in vitro and fresh or old ex vivo thrombi was measured by histologic studies. Ten experiments were performed with each of 8 different in vitro thrombus types using (1) ultrasound thrombolysis, (2) Oasis thrombectomy, (3) Amplatz thrombectomy, and (4) Straub-Rotarex catheters. Thrombus weight was measured after standardized treatment. RESULTS: The fibrin content was markedly lower in all in vitro than in fresh and old ex vivo thrombi. In vitro thrombus type had no impact on the effectiveness of ultrasound thrombolysis and Amplatz thrombectomy. Thrombogenesis type affected Oasis and Straub-Rotarex catheter use. Storage temperature had a systematic impact on the outcome of Oasis thrombectomies. CONCLUSION: The fibrin content of in vitro thrombi differs substantially from that of fresh and old ex vivo human thrombi. Experimental conditions may systematically impact experimental evaluation of thrombectomy procedures. In vitro thrombi with thrombin-induced thrombogenesis should be favored for use in thrombectomy experiments.

Catheterization↗

PubMed2003

Soluble tissue factor induces coagulation on tumor endothelial cells in vivo if coadministered with low-dose lipopolysaccharides.

OBJECTIVE: This study was performed to evaluate the mechanisms leading to tumor vessel occlusion by tissue factor-based drugs, which are used in vascular targeting approaches for the treatment of malignant tumors. METHODS AND RESULTS: The effects of nontargeted soluble tissue factor were evaluated in vitro and in vivo. Tumor-bearing mice were treated with (1) the extracellular portion of tissue factor (soluble tissue factor), (2) low nontoxic doses of lipopolysaccharides, or (3) a combination thereof. The combination treatment showed the best effects and resulted in selective thrombosis of tumor vessels. On the basis of our data from subsequent in vitro analyses, including surface plasmon resonance measurements and endothelial cell based coagulation assays, we propose a model on how soluble tissue factor, although lacking its membrane anchor, can promote selective tumor vessel occlusion. CONCLUSIONS: To our knowledge, this is the first report to describe the molecular mechanisms of coagulation induction by untargeted soluble tissue factor in vivo. Combination treatments including soluble tissue factor might represent an alternative vascular targeting approach for the treatment of malignant tumors.

Animals↗

PubMed2003

A novel evaluation method for paraffinized human renal biopsies using quantitative analysis of microdissected glomeruli and VCAM-1 as marker of inflammatory mesangial cell activation.

BACKGROUND: In the glomerular mesangium, immunologic and/or infectious activation of the inflammatory, NF-kappaB-mediated signal pathway can induce a progression of already existing mesangial lesions in non-immunologic and immunologic glomerular disease. This progression is preceded by upregulated mesangial gene expression of which the vascular cell adhesion molecule-1, VCAM-1 (vascular cell adhesion molecule-1), is a well-established marker. Its evaluation on minimal tissue such as routinely paraffinized needle core biopsies is not established and needs the development of a novel evaluation method more meaningful than common immunohistology. METHODS: By laser-microdissection, 10 glomeruli/case were isolated from 5 micro m thick tissue slices in a total of 15 cases of mesangial proliferation with different renal diseases (IgA nephropathy, lupus nephritis and mesangial proliferative lesions of unknown aetiology) vs transplant biopsies as negative and TNF alpha-treated cultured human mesangial cells as positive controls. After reverse transcription of isolated RNA, cDNA aliquots were quantified for VCAM-1 expression by real-time PCR using the threshold cycle (C(t)) method, normalized for the housekeeping gene beta-actin, and compared with qualitative RT-PCR results. RESULTS: Unsuspected VCAM-1 transcript steady-state levels could be detected by real-time PCR in agreement with qualitative PCR, while morphologic and immunohistologic analyses were unrevealing. As yields of RNA extraction in femtogram quantities cannot be measured spectrophotometrically, a C(t)-ratio was formed between beta-actin and VCAM-1 per case showing high VCAM-1 expression in lupus nephritis (1.39), and moderate expression in IgA nephropathy (1.08-1.23) vs TNF alpha-treated mesangial cells (0.97-1.23) and negative control cases (0.66-0.68). CONCLUSIONS: This is the first reported gene expression analysis method for routinely paraffininzed human renal biopsies, demonstrating the power of combined laser-microdissection and PCR quantification as novel methods for the evaluation of minimal tissue beyond purely descriptive morphologic analysis.

Biomarkers↗