Biomedical subjects

J Bischoff

Publications and source records attributed to J Bischoff.

At least 19 recordsLinked to original sources

PubMed2006

The clinical benefit of pegylated liposomal doxorubicin in patients with metastatic breast cancer previously treated with conventional anthracyclines: a multicentre phase II trial.

This study evaluates the clinical benefit of pegylated liposomal doxorubicin (PLD) in patients with metastatic breast cancer (MBC), previously treated with conventional anthracyclines. Seventy-nine women with MBC previously treated with anthracyclines received PLD 50 mg m(-2) every 4 weeks. All patients were previously treated with chemotherapy and 30% of patients had > or =3 prior chemotherapies for metastatic disease. Patients were considered anthracycline resistant when they had disease progression on anthracycline therapy for MBC or within 6 months of adjuvant therapy. The overall clinical benefit rate (objective response+stable disease > or =24 weeks) was 24% (16.1% in patients with documented anthracycline resistance vs 29% in patients classified as having non-anthracycline-resistant disease). There was no difference with respect to the clinical benefit between patients who received PLD >12 months and those who received PLD < or =12 months since last anthracycline treatment for metastatic disease (clinical benefit 25 vs 24.1%, respectively). Median time to progression and overall survival were 3.6 and 12.3 months, respectively. The median duration of response was 12 months, and the median time to progression in patients with stable disease (any) was 9.5 months. Fourteen patients (17.7%) had a prolonged clinical benefit lasting > or =12 months. In conclusion, PLD was associated with an evident clinical benefit in anthracycline-pretreated patients with MBC.

Adult↗

PubMed2006

[Clinical impact of locoregional hyperthermia in gynecological oncology].

In the last decade progress in gynecological oncology has been achieved mainly by new cytotoxic drugs and advances in radiation technology. For example, the use of taxanes in the primary therapy of ovarian cancers and of combined radio-chemotherapy in cervical cancer has led to significant prolongations of survival. However, in case of relapse most gynaecological malignancies are associated with very poor prognosis. Efficacy of local and systemic therapy can be increased by combining radiotherapy and/or chemotherapy with locoregional hyperthermia (LRH). Increasing the temperature of the target tissue up to 41-43 degrees C leads to local hyperaemia and the tumor tissue becomes more responsive to cytotoxic interventions. In several prospective randomized studies the combination between LRH and radiotherapy was superior to radiotherapy alone in terms of local control (e. g. chest wall recurrence in breast cancer) and has led to longer overall survival in advanced cervical cancer. Platinum derivatives and other cytotoxic drugs have shown synergistic effects with LRH and the combination of both has elicited high response rates in recurrent cervical cancer. In phase-II-clinical trials the newly developed liposomal anthracyclines demonstrated synergistic effects with LRH in patients with refractory ovarian cancer. Our own experience has shown that adding LRH to radio- and/or chemotherapy is well tolerated by the patients. Despite of the fact, that the available data are still preliminary, the inclusion of LRH into multimodal cancer therapy concepts appears to be very promising. Well-designed comparative studies are still needed to evaluate the role of hyperthermia as an adjunct to conventional cancer therapy.

Combined Modality Therapy↗

PubMed2006

[PTHrP and bone sialoprotein as prognostic markers for developing bone metastases in breast cancer patients].

BACKGROUND: Bone metastases belong to the most frequent metastases in breast cancer. Currently there exist no serum markers which allow early detection of bone metastases. PATIENTS AND METHODS: 89 patients with primary breast cancer have been investigated for parathyroid-hormone-related peptide (PTHrP) in the tumour and bone sialoprotein (BSP) in the serum. Both markers have been correlated with classical prognostic factors and survival. RESULTS: The median age of the patients was 56 years. 17 of the 89 patients developed bone metastases and 25 died during the observation period of 5 years. PTHrP correlated significantly with bone metastases free survival (p = 0.0004) and overall survival (p = 0.0005), whereas BSP correlated only with the bone metastases free survival (p = 0.03). Both markers were shown to be independent prognostic factors for the bone metastases free survival in the multivariate analysis. PTHrP was also found to be an independent prognostic factor for the overall survival. CONCLUSION: The investigation of PTHrP could be a prognostic marker for the presence of bone metastases while BSP could be a marker for the early detection of bone metastases.

Biomarkers, Tumor↗

PubMed2003

[Intramedullary stabilisation of metastatic fractures of long bones].

UNLABELLED: Surgical treatment of metastatic fractures of long bones is mostly a palliative one. Intramedullary stabilisation without resection of metastases follows the aim of the palliative therapy concept. PATIENTS AND METHODS: From 01.01.1995 to 30.08.2001 36 manifest and 4 impending long bone fractures were registered in 22 female and 16 male patients, with a mean age of 63 years. In addition, one revision was necessary due to persisting instability after humeral intramedullary bundle nailing. Pathological fractures were found in the humerus (n=11), femoral neck (n=6), per- and subtrochanteric region (n=12), femoral shaft (n=10) and tibia (n=2). Most of them were malignancies of the kidneys (n=13), bronchi (n=7) and breast (n=6). One patient with a solitary metastasis in the humerus received curative treatment by resection, open reduction and internal fixation. All other cases underwent palliative stabilisation. Metastatic lesions of the femoral neck were treated by resection and prosthetic replacement. The remaining fractures were stabilized intramedullarily without resection of metastases or use of bone cement. In 9 cases, a locking nail was implanted in the humerus, and one patient received humeral bundle nailing. In the lower extremities, we used a classic-nail or gamma-nail in 15 and a locking nail in 8 cases. Two moribund patients did not undergo surgery. RESULTS: No intraoperative complications occurred. 63 % of the patients with stabilisation of the leg were able to walk at the time of discharge. The mean survival time (Kaplan-Meier) of patients after palliative operation amounted to 161.5 days (95 % CI 92.7; 230.3). We found 6 postoperative complications: temporary palsy of the radial nerve (n=1), soft tissue infection (n=1), dislocation of the nail (n=2), loosening of the distal locking screw (n=1), proceeding osteolysis with high fracture risk (n=1). CONCLUSION: Intramedullary stabilisation without resection of metastases using locking nails meets the requirements of palliative therapy. This procedure is less invasive and allows early weight bearing.

Adult↗

PubMed2001

Aortic valve endothelial cells undergo transforming growth factor-beta-mediated and non-transforming growth factor-beta-mediated transdifferentiation in vitro.

Cardiac valves arise from endocardial cushions, specialized regions of the developing heart that are formed by an endothelial-to-mesenchymal cell transdifferentiation. Whether and to what extent this transdifferentiation is retained in mature heart valves is unknown. Herein we show that endothelial cells from mature valves can transdifferentiate to a mesenchymal phenotype. Using induction of alpha-smooth muscle actin (alpha-SMA), an established marker for this process, two distinct pathways of transdifferentiation were identified in clonally derived endothelial cell populations isolated from ovine aortic valve leaflets. alpha-SMA expression was induced by culturing clonal endothelial cells in medium containing either transforming growth factor-beta or low levels of serum and no basic fibroblast growth factor. Cells induced to express alpha-SMA exhibited markedly increased migration in response to platelet-derived growth factor-BB, consistent with a mesenchymal phenotype. A population of the differentiated cells co-expressed CD31, an endothelial marker, along with alpha-SMA, as seen by double-label immunofluorescence. Similarly, this co-expression of endothelial markers and alpha-SMA was detected in a subpopulation of cells in frozen sections of aortic valves, suggesting the transdifferentiation may occur in vivo. Hence, the clonal populations of valvular endothelial cells described here provide a powerful in vitro model for dissecting molecular events that regulate valvular endothelium.

Animals↗

PubMed2001

Increased Tie2 expression, enhanced response to angiopoietin-1, and dysregulated angiopoietin-2 expression in hemangioma-derived endothelial cells.

Infantile hemangiomas are endothelial tumors that grow rapidly in the first year of life and regress slowly during early childhood. Although hemangiomas are well-known vascular lesions, little is known about the mechanisms that cause the excessive endothelial cell proliferation in these most common tumors of infancy. To investigate the molecular basis of hemangioma, we isolated endothelial cells from several proliferative-phase lesions and showed that these cells are clonal and exhibit abnormal properties in vitro (E. Boye, Y. Yu, G. Paranya, J. B. Mulliken, B. R. Olsen, J. Bischoff: Clonality and altered behavior of endothelial cells from hemangiomas. J Clin Invest 2001, 107:745-752). Here, we analyzed mRNA expression patterns of genes required for angiogenesis, including members of the vascular endothelial growth factor (VEGF)/VEGF receptor family and the angiopoietin/Tie family, in hemangioma-derived and normal endothelial cells. KDR, Flt-1, Tie1, Tie2, and angiopoietin-2 (Ang2) were strongly expressed in cultured hemangioma-derived endothelial cells and in hemangioma tissue. In contrast, there was little expression of angiopoietin-1 (Ang1) or VEGF. We found Tie2 mRNA and protein up-regulated with a concomitant increase in cellular responsiveness to Ang1 in most hemangioma-derived endothelial cells. Ang2 mRNA was down-regulated in response to serum in hemangioma-derived endothelial cells, but not in normal endothelial cells, suggesting altered regulation. These findings implicate Tie2 and its ligands Ang1 and Ang2 in the pathogenesis of hemangioma.

Angiopoietin-1↗

PubMed2001

Weekly docetaxel (Taxotere) in patients with metastatic breast cancer.

BACKGROUND: Docetaxel (Taxotere) has demonstrated high antitumour activity in first- and second-line treatment of metastatic breast cancer. This study analysed the efficacy and toxicity of docetaxel given weekly. PATIENTS AND METHODS: Thirty-five patients with metastatic breast cancer received docetaxel, 35 mg/m2 weekly for six weeks, followed by two weeks without treatment. Additional cycles (three weeks' treatment, two weeks' rest) were given until disease progression. All patients had received prior chemotherapy: 32 and 5 patients had received prior anthracycline-containing and taxane-containing regimens, respectively. Docetaxel was administered for a total of 359 doses (median 9. range 6-22). RESULTS: There was one complete response (3%), 11 partial responses (31%), 17 patients with stable disease (49%) and six with disease progression (17%). Overall response rate was 34% (95% confidential interval (95% CI): 18%-51). Median survival was 307 days; median progression-free survival was 2.6 months (range 1.5 to > or = 5.5 months). Three patients showed grade 3 neutropenia. 14 showed grade 3 alopecia, and various grade 1-2 non-haematological toxicities were observed. Treatment was delayed in two patients due to haematotoxicity. and stopped in one patient due to painful nail toxicity. CONCLUSION: Weekly administration of docetaxel at a dose of 35 mg/m2 is effective and of low toxicity in patients with metastatic breast cancer.

Adult↗

PubMed2001

Functional small-diameter neovessels created using endothelial progenitor cells expanded ex vivo.

Arterial conduits are increasingly preferred for surgical bypass because of inherent functional properties conferred by arterial endothelial cells, especially nitric oxide production in response to physiologic stimuli. Here we tested whether endothelial progenitor cells (EPCs) can replace arterial endothelial cells and promote patency in tissue-engineered small-diameter blood vessels (4 mm). We isolated EPCs from peripheral blood of sheep, expanded them ex vivo and then seeded them on decellularized porcine iliac vessels. EPC-seeded grafts remained patent for 130 days as a carotid interposition graft in sheep, whereas non-seeded grafts occluded within 15 days. The EPC-explanted grafts exhibited contractile activity and nitric-oxide-mediated vascular relaxation that were similar to native carotid arteries. These results indicate that EPCs can function similarly to arterial endothelial cells and thereby confer longer vascular-graft survival. Due to their unique properties, EPCs might have other general applications for tissue-engineered structures and in treating vascular diseases.

Animals↗

PubMed2001

Clonality and altered behavior of endothelial cells from hemangiomas.

Hemangioma, the most common tumor of infancy, is a benign vascular neoplasm of unknown etiology. We show, for the first time to our knowledge, that endothelial cells from proliferating hemangioma are clonal, and we demonstrate that these hemangioma-derived cells differ from normal endothelial cells in their rates of proliferation and migration in vitro. Furthermore, migration of hemangioma endothelial cells is stimulated by the angiogenesis inhibitor endostatin, unlike the inhibition seen with normal endothelial cells. We conclude that hemangiomas constitute clonal expansions of endothelial cells. This is consistent with the possibility that these tumors are caused by somatic mutations in one or more genes regulating endothelial cell proliferation.

Alleles↗

PubMed2001

Heparan sulfate and chondroitin sulfate proteoglycans inhibit E-selectin binding to endothelial cells.

E-selectin is a cell adhesion molecule involved in the initial rolling and adhesion of leukocytes to the endothelium during inflammation. In addition, in vitro studies have suggested that an interaction between E-selectin and binding sites such as sialyl Lewis X-containing oligosaccharides on endothelial cells may be important for angiogenesis. In order to investigate the binding of E-selectin to endothelial cells, we developed an ELISA assay using chimeric E-selectin-Ig molecules and endothelial cells fixed on poly-L-lysine coated plates. Our results indicate that E-selectin-Ig binds to both bovine capillary endothelial cells and human dermal microvascular endothelial cells in a calcium-dependent and saturable manner. The binding is inhibited markedly by heparin and by syndecan-1 ectodomain, and moderately by chondroitin sulfate, but not by sialyl Lewis X-containing oligosaccharides. These results suggest that heparan sulfate and chondroitin sulfate proteoglycans on endothelial cells are potential ligands for E-selectin.

Animals↗

PubMed2000

Treatment of Amanita phalloides poisoning: I. Retrospective evaluation of plasmapheresis in 21 patients.

Amanita phalloides poisoning is the most common cause of lethal mushroom poisoning (lethality >20% in adults). A specific antidote against the amanitin toxins is not available. This retrospective study reports results in 21 patients (12 males, 9 females; ages 9-59 years) treated for amanita phalloides poisoning between 1984 and 1993. Plasmapheresis was carried out using a commercial plasma protein solution (Biseko, Biotest, Dreieich, Germany) in 17 patients, fresh plasma in 2 patients, and human albumin/Ringer's solution in 2 patients. Ancillary drugs, including penicillin and silibinin, also were used for detoxification, correction of blood-clotting deficiencies, and hepatic protection. One patient died of acute hepatic failure. The results, assessed using mortality (4.8% overall) and frequency of complications, indicate that plasmapheresis is a safe and effective treatment for amanita phalloides poisoning but that further investigations are needed, especially involving measurements of efficacy and the efficiency of toxin removal.

Adolescent↗

PubMed2000

Plasmapheresis in the treatment of Amanita phalloides poisoning: II. A review and recommendations.

Amanita phalloides poisoning is the most common cause of lethal mushroom poisoning (lethality >20% in adults, >50% in children). However, there is no standard treatment strategy and no antidote against the ensuing hepatic failure. This review of 14 investigations published over the last 20 years shows that the introduction of detoxification techniques, in particular the use of plasmapheresis, in combination with supportive therapy to prevent the absorption of aminitine toxins into blood, produced a substantial reduction in mortality. The main complications in using these techniques include infections and coagulation disorders. Because of the latency period in the development of symptoms, treatment should begin on the first suspicion that an intoxication is present. The best therapeutic results can be expected when the detoxification techniques are applied in combination with conservative therapies within the first 36--48 h. Using this approach, mortality rates in some recent studies have been below 10%.

Amanita↗

PubMed2000

Human colon cancer cells express multiple glycoprotein ligands for E-selectin.

The interaction between the colon tumor cell surface and the endothelial cell layer is an important component of tumor intravasation, extravasation, and metastasis. Multiple studies suggest that tumor cells may bind to E-selectin expressed on endothelial cells during these processes. To identify possible E-selectin ligands on tumor cells that may participate in this mechanism, we used E-selectin-Ig chimera affinity chromatography to isolate glycoproteins from the human colon cancer cell line Colo-205. Binding of these cells to E-selectin was specific, required the presence of calcium, and could be blocked by antibodies against E-selectin. We identified LAMP-1 (lysosomal membrane glycoprotein-1), LAMP-2, and two high molecular weight glycoproteins (>400 kDa and 300 kDa) as the main E-selectin ligands on Colo-205 cells. Treatment of the cells with N-glycanase and O-sialoglycoprotease abolished their binding to E-selectin. The high MW glycoproteins contained sialyl Lewis X and/or sialyl Lewis A glycoconjugates, and appeared to be either alternatively spliced or alternatively glycosylated forms of MUC-1 (mucin-1).

Animals↗

PubMed1999

Noninflammatory expression of E-selectin is regulated by cell growth.

E-selectin, an endothelial-specific adhesion molecule best known for its role in leukocyte adhesion, is not detected in quiescent endothelial cells, but is induced by inflammatory stimuli. However, E-selectin is also expressed in proliferating endothelial cells under noninflammatory conditions in vivo and in vitro, suggesting that E-selectin is also regulated by growth signals. To investigate E-selectin expression in lipopolysaccharide-stimulated versus nonstimulated proliferating cells, we analyzed the distribution of E-selectin-positive human microvascular endothelial cells in G0/G1, S, and G2/M phases of the cell cycle under both conditions. Lipopolysaccharide treatment resulted in uniformly increased E-selectin expression in cells in G0/G1, S, and G2/M. In contrast, levels of E-selectin in nonstimulated proliferating cells showed a linear correlation with the percentage of cells in G2/M. E-selectin in proliferating endothelial cells was not reduced by addition of soluble tumor necrosis factor-alpha-receptor or soluble interleukin-1-receptor indicating that its expression was not due to endogenous production of either cytokine. In addition, E-selectin was increased in cells stimulated with basic fibroblast growth factor, a well-known mitogen for endothelial cells. E-selectin in proliferating endothelial cells is functional, as shown by E-selectin-dependent adhesion of the promyelocytic leukemia cell line HL-60 to subconfluent human microvascular endothelial cells. In summary, these studies indicate that E-selectin can be regulated by a non-inflammatory pathway that is related to the proliferative state of the endothelium.

Cell Adhesion↗

PubMed1999

Endotoxin inhibits heat shock protein 70 (HSP70) expression in peripheral blood mononuclear cells of patients with severe sepsis.

OBJECTIVE: To investigate the ex vivo endotoxin-inducible heat shock protein 70 (HSP70) expression in the peripheral blood mononuclear cells (PBMC) of patients with severe sepsis in order to assess the capacity of this potentially protective response during systemic inflammation. DESIGN: Prospective observational study in consecutive patients with severe sepsis and healthy blood donors. SETTING: Surgical intensive care unit in a university hospital. PATIENTS AND PARTICIPANTS: Eleven patients with the diagnosis of severe sepsis, one patient who had recovered from severe sepsis and 13 healthy blood donors. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: We studied the inducibility of HSP70 expression in the PBMC of patients with severe sepsis and healthy blood donors ex vivo. Human whole blood was incubated with variable lipopolysaccharide (LPS from Salmonella minnesota Re 595) concentrations (0; 0.1; 10; 100 ng/ml) for different periods of time (0.5; 2; 4; 10 h). The PBMC were separated by Ficoll density gradient and then disrupted by hypotonic lysis. HSP70 was measured by means of enzyme-linked immunosorbent assay (ELISA). We found a LPS dose- and time-dependent inhibition of ex vivo HSP70 expression in the PBMC of both patients with severe sepsis and healthy individuals. However, the levels of HSP70 expression in patients were significantly lower compared to those of healthy individuals at all LPS concentrations and incubation times. On average, HSP70 expression in the PBMC of healthy controls was 2.8 (range 1.2-3.9) times higher than in patients. HSP70 expression was inducible by thermal heat shock in the PBMC of both patients and healthy individuals. CONCLUSIONS: Endotoxin inhibits HSP70 expression in PBMC ex vivo. In vivo, the suppression of HSP70 expression induced by endotoxin and high levels of proinflammatory cytokines may contribute to the cellular dysfunction of immunocompetent cells concerning antigen presentation, phagocytosis and antibody production associated with decreased resistance to infectious insults during severe sepsis.

Adult↗

PubMed1999

Regulation of vascular endothelial growth factor-dependent retinal neovascularization by insulin-like growth factor-1 receptor.

Although insulin-like growth factor 1 (IGF-1) has been associated with retinopathy, proof of a direct relationship has been lacking. Here we show that an IGF-1 receptor antagonist suppresses retinal neovascularization in vivo, and infer that interactions between IGF-1 and the IGF-1 receptor are necessary for induction of maximal neovascularization by vascular endothelial growth factor (VEGF). IGF-1 receptor regulation of VEGF action is mediated at least in part through control of VEGF activation of p44/42 mitogen-activated protein kinase, establishing a hierarchical relationship between IGF-1 and VEGF receptors. These findings establish an essential role for IGF-1 in angiogenesis and demonstrate a new target for control of retinopathy. They also explain why diabetic retinopathy initially increases with the onset of insulin treatment. IGF-1 levels, low in untreated diabetes, rise with insulin therapy, permitting VEGF-induced retinopathy.

Animals↗

PubMed1998

Angiostatin upregulates E-selectin in proliferating endothelial cells.

Angiostatin, a 38 kilodalton fragment of plasminogen, is a potent inhibitor of angiogenesis. However, little is known about how angiostatin affects endothelial gene expression. To learn more about its effect on endothelial-specific genes implicated in angiogenesis, we examined E-selectin expression and function in bovine capillary endothelial cells treated with recombinant angiostatin. Angiostatin caused a four to five-fold increase in E-selection polypeptide levels in proliferating endothelial cells but little or no increase in confluent cells. P-selection polypeptide levels were unaffected by angiostatin in either proliferating or confluent cells. E-selectin mRNA and adhesion activity in proliferating endothelial cells were also increased by angiostatin. Angiostatin had little effect on the distribution of endothelial cells in G0/G1, S, and G2/M, indicating angiostatin does not alter cell cycle progression significantly. These data demonstrate that angiostatin selectively upregulates E-selectin in proliferating endothelial cells in vitro. This selectivity may provide insights into the mechanism by which angiostatin inhibits tumor growth in vivo without apparent effects on quiescent endothelium.

Angiostatins↗

PubMed1998

A simplified method for growth of human microvascular endothelial cells results in decreased senescence and continued responsiveness to cytokines and growth factors.

Human dermal microvascular endothelial cells are used to analyze the functions of microvascular endothelium in vitro. However, the low yield and short lifespan of these cells in culture has limited the types of analysis that could be performed. Human microvascular endothelial cells are typically grown in media containing supplements such as dibutyryl cyclic AMP, hydrocortisone, bovine brain extract, and antifungal agents, each of which increase the complexity of experimental design and interpretation of results. In the present study, endothelial cells were transferred after Ulex europeus-I selection into a simplified medium consisting of Endothelial Basal Medium 131, 10% fetal bovine serum, and 2 ng/ml basic fibroblast growth factor and analyzed over 3 mo. The human microvascular endothelial cells expressed the endothelial markers von Willebrand factor, CD31, P-selectin, and E-selectin. In addition, the cells showed increased proliferation in the presence of basic fibroblast growth factor (0.5 ng/ml) or vascular endothelial cell growth factor (10 ng/ml). Tumor necrosis factor-alpha-induced expression of E-selectin was similar in cells at Passages 3, 6, and 12, indicating that the cells maintained responsiveness to cytokines over several weeks. Furthermore, the endothelial cells attained a typical cobblestone morphology with increased cellular density and also formed capillarylike tubes on Matrigel. In summary, the human dermal microvascular endothelial cells display the expected endothelial characteristics when grown for several passages and, therefore, provide a valuable in vitro model for human microvascular endothelium.

Bucladesine↗