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N Brunner

Publications and source records attributed to N Brunner.

15 recordsLinked to original sources
PubMed2002

Levels of tissue inhibitor of metalloproteinases-1 in blood transfusion components.

Blood transfusion during surgery for solid tumors may reduce patient survival because of various bioactive substances present in blood preparations. The anti-proteolytic protein tissue inhibitor of metalloproteinases-1 (TIMP-1) present in large quantities in platelets has been shown to stimulate cell growth and to inhibit apoptosis and may therefore be considered to influence tumor progression. We measured TIMP-1 levels in blood transfusion preparations. especially in platelet-containing preparations, before and after leucofiltration and at different time-points during storage. The mean TIMP-1 levels in whole blood (WB) and platelet-rich plasma (PRP) were slightly reduced by leucofiltration; WB: 41.6 microg/L versus 34.9 microg/L. PRP: 139.8 microg/L versus 127.2 microg/L. However, with prestorage leucofiltration. TIMP-1 levels in buffy-coat-derived platelet (BCP) pools were significantly reduced from 134.2 microg/L to 102.2 microg/L (p=0.0013). In saline-adenine-glucose-mannitol (SAG-M) blood preparations in which the platelet content is reduced by more than 99%,. TIMP-1 could not be detected. Extracellular TIMP-1 accumulated significantly in non-filtered WB and in aferesis platelet concentrates (APC), but TIMP-1 was at no time detectable in SAG-M blood during storage. In conclusion. TIMP-1 is present in various platelet-containing blood preparations, but not in platelet-free preparations such as SAG-M, indicating that most of the TIMP-1 measured in blood preparations originates from platelets. Furthermore, TIMP-1 levels increased during storage in preparations containing platelets. which suggests a continuous disintegration of platelets. These data imply that information on preoperative blood transfusions should be taken into account when evaluating plasma TIMP-1 levels in patients.

Blood Component Transfusion↗
PubMed2001

The plasminogen activator inhibitor PAI-1 controls in vivo tumor vascularization by interaction with proteases, not vitronectin. Implications for antiangiogenic strategies.

The plasminogen (Plg)/plasminogen activator (PA) system plays a key role in cancer progression, presumably via mediating extracellular matrix degradation and tumor cell migration. Consequently, urokinase-type PA (uPA)/plasmin antagonists are currently being developed for suppression of tumor growth and angiogenesis. Paradoxically, however, high levels of PA inhibitor 1 (PAI-1) are predictive of a poor prognosis for survival of patients with cancer. We demonstrated previously that PAI-1 promoted tumor angiogenesis, but by an unresolved mechanism. We anticipated that PAI-1 facilitated endothelial cell migration via its known interaction with vitronectin (VN) and integrins. However, using adenoviral gene transfer of PAI-1 mutants, we observed that PAI-1 promoted tumor angiogenesis, not by interacting with VN, but rather by inhibiting proteolytic activity, suggesting that excessive plasmin proteolysis prevents assembly of tumor vessels. Single deficiency of uPA, tissue-type PA (tPA), uPA receptor, or VN, as well as combined deficiencies of uPA and tPA did not impair tumor angiogenesis, whereas lack of Plg reduced it. Overall, these data indicate that plasmin proteolysis, even though essential, must be tightly controlled during tumor angiogenesis, probably to allow vessel stabilization and maturation. These data provide insights into the clinical paradox whereby PAI-1 promotes tumor progression and warrant against the uncontrolled use of uPA/plasmin antagonists as tumor angiogenesis inhibitors.

Angiogenesis Inhibitors↗
PubMed1998

Absence of host plasminogen activator inhibitor 1 prevents cancer invasion and vascularization.

Acquisition of invasive/metastatic potential through protease expression is an essential event in tumor progression. High levels of components of the plasminogen activation system, including urokinase, but paradoxically also its inhibitor, plasminogen activator inhibitor 1 (PAI1), have been correlated with a poor prognosis for some cancers. We report here that deficient PAI1 expression in host mice prevented local invasion and tumor vascularization of transplanted malignant keratinocytes. When this PAI1 deficiency was circumvented by intravenous injection of a replication-defective adenoviral vector expressing human PAI1, invasion and associated angiogenesis were restored. This experimental evidence demonstrates that host-produced PAI is essential for cancer cell invasion and angiogenesis.

Adenoviridae↗
PubMed1998

Cloning, sequencing, and expression of the gene encoding cyclic 2, 3-diphosphoglycerate synthetase, the key enzyme of cyclic 2, 3-diphosphoglycerate metabolism in Methanothermus fervidus.

Cyclic 2,3-diphosphoglycerate synthetase (cDPGS) catalyzes the synthesis of cyclic 2,3-diphosphoglycerate (cDPG) by formation of an intramolecular phosphoanhydride bond in 2,3-diphosphoglycerate. cDPG is known to be accumulated to high intracellular concentrations (>300 mM) as a putative thermoadapter in some hyperthermophilic methanogens. For the first time, we have purified active cDPGS from a methanogen, the hyperthermophilic archaeon Methanothermus fervidus, sequenced the coding gene, and expressed it in Escherichia coli. cDPGS purification resulted in enzyme preparations containing two isoforms differing in their electrophoretic mobility under denaturing conditions. Since both polypeptides showed the same N-terminal amino acid sequence and Southern analyses indicate the presence of only one gene coding for cDPGS in M. fervidus, the two polypeptides originate from the same gene but differ by a not yet identified modification. The native cDPGS represents a dimer with an apparent molecular mass of 112 kDa and catalyzes the reversible formation of the intramolecular phosphoanhydride bond at the expense of ATP. The enzyme shows a clear preference for the synthetic reaction: the substrate affinity and the Vmax of the synthetic reaction are a factor of 8 to 10 higher than the corresponding values for the reverse reaction. Comparison with the kinetic properties of the electrophoretically homogeneous, apparently unmodified recombinant enzyme from E. coli revealed a twofold-higher Vmax of the enzyme from M. fervidus in the synthesizing direction.

2,3-Diphosphoglycerate↗
PubMed1996

The T61 human breast cancer xenograft: an experimental model of estrogen therapy of breast cancer.

Endocrine therapy is one of the principal treatment modalities of breast cancer, both in an adjuvant setting and in advanced disease. The T61 breast cancer xenograft described here provides an experimental model of the effects of estrogen treatment at a molecular level. T61 is an estrogen receptor positive tumor which was originally derived from a T1N0M0 invasive ductal cancer and has been carried as a serially transplanted xenograft in nude mice. T61 is a hormone sensitive tumor whose growth is suppressed by both estrogen and tamoxifen, in contrast to other estrogen receptor positive tumors such as MCF-7 which are stimulated by estrogen. Molecular studies have demonstrated that T61 expresses easily detectable levels of mRNA for a number of peptide growth factors, including transforming growth factor alpha (TGF-alpha) and insulin-like growth factors I and II (IGF-I and IGF-II), but not transforming growth factor beta-I (TGF-beta1). Of these, IGF-II is the only peptide whose expression is altered by endocrine therapy. Treatment of T61-bearing nude mice with physiologic doses of estrogen is accompanied by loss of IGF-II mRNA expression within 24 hours, and rapid regression of tumor. T61 tumor growth is also inhibited in animals treated with a monoclonal antibody which blocks binding of ligand to the IGF-I receptor, which mediates the mitogenic signal of bound IGF-II through autophosphorylation of its intracellular tyrosine kinase domain. These results demonstrate the utility of the T61 model in the study of the molecular mechanism of estrogen therapy in breast cancer, and suggest that in this system, modulation of a specific growth factor (IGF-II) by endocrine therapy can have profound effects on tumor growth.

Animals↗
PubMed1994

Hormonal carcinogenesis in breast cancer: cellular and molecular studies of malignant progression.

We have established and characterized a series of variant cell lines in which to identify the critical factors associated with E2-induced malignant progression, and the acquisition to tamoxifen resistance in human breast cancer. Sublines of the hormone-dependent MCF-7 cell line (MCF7/MIII and MCF7/LCC1) form stable, invasive, estrogen independent tumors in the mammary fat pads of ovariectomized athymic nude mice. These cells retain expression of both estrogen (ER) and progesterone receptors (PGR), but retain sensitivity to each of the major structural classes of antiestrogens. The tamoxifen-resistant MCF7/LCC2 cells retain sensitivity to the inhibitory effects of the steroidal antiestrogen ICI 182780. By comparing the parental hormone-dependent and variant hormone-independent cells, we have demonstrated an altered expression of some estrogen regulated genes (PGR, pS2, cathepsin D) in the hormone-independent variants. Other genes remain normally estrogen regulated (ER, laminin receptor, EGF-receptor). These data strongly implicate the altered regulation of a specific subset or network of estrogen regulated genes in the malignant progression of human breast cancer. Some of the primary response genes in this network may exhibit dose-response and induction kinetics similar to pS2, which is constitutively upregulated in the MCF7/MIII, MCF7/LCC1 and MCF7/LCC2 cells.

Adenocarcinoma↗
PubMed1991

A double-blind, multicenter, parallel-group trial with 0.05% halobetasol propionate ointment versus 0.1% diflucortolone valerate ointment in patients with severe, chronic atopic dermatitis or lichen simplex chronicus.

In a double-blind, parallel-group, multicenter, comparative trial in 120 evaluable patients with chronic, localized atopic dermatitis or lichen simplex chronicus, the success rate (described as "healed" and "marked improvement") was 91.5% in patients treated with halobetasol propionate ointment and 83.6% in those in the diflucortolone valerate treatment group. Of patients treated with halobetasol propionate ointment, 40.7% reported healing within 17 days, whereas of those in the diflucortolone valerate treatment group, 32.8% reported healing within that time. Early onset of therapeutic effect, that is, within 3 days of the start of treatment, was reported in a higher percentage of patients treated with halobetasol propionate ointment than in those treated with diflucortolone valerate ointment (70% versus 59%). Adverse effects at the site of application were less frequently reported in patients belonging to the halobetasol propionate treatment group than in those treated with diflucortolone valerate ointment (3% versus 8%).

Adolescent↗
PubMed1989

Regulation of breast cancer cells by hormones and growth factors: effects on proliferation and basement membrane invasiveness.

The current understanding of the regulation of breast cancer cell proliferation and invasiveness by hormones and growth factors is reviewed. It has been shown that polypeptide growth factors are involved in hormone-independent breast cancer, and are sometimes oestrogen-regulated in hormone-responsive models. Basement-membrane invasiveness, relating to the metastatic potential of these cells, is also stimulated by oestrogen in hormone-dependent models, elevated in hormone-independent models, and is growth factor sensitive. Further understanding of the differential effects of growth factors on breast cancer cell proliferation and invasiveness should facilitate better therapeutic exploitation of regulation at this level.

Animals↗
PubMed1989

Regulation of human breast cancer by secreted growth factors.

Laboratory evidence is presented that estrogens are able to induce the production of numerous growth factors which can act in an autocrine or paracrine fashion in estrogen dependent breast cancer. Estrogen independent tumors can produce these same growth factors constitutively and so escape the need for estrogen stimulation. Growth inhibitory factors such as TGF-beta can also be controlled by estrogens and antiestrogens. It is unclear at present, however, how much of the cytostatic effect of antiestrogens in vivo is explained by the production of growth inhibitors. The overall control of breast cancer growth is mediated by the combined effects of these growth stimulatory and inhibitory factors in both breast stroma and epithelium. Interruption of the action of growth factors and the use of growth inhibitors may provide opportunities for new approaches to the treatment of breast cancer.

Breast Neoplasms↗
PubMed1982

Urinary incontinence following prostatectomy in patients with myasthenia gravis.

An unusual incidence of urinary incontinence was observed in patients with myasthenia gravis who required transurethral resection of the prostate for relief of obstruction secondary to benign prostatic hypertrophy. This urinary incontinence was not observed in patients who had open prostatectomies (suprapubic and retropubic). The urinary incontinence did not appear to be related to the control of the underlying muscular disorder. It is suggested that the external sphincter in patients with myasthenia gravis may be more vulnerable to thermal changes that occur when a blended current is used during transurethral resection. If prostatectomy is required in a patient with myasthenia gravis, open surgery should be the procedure of choice. If a TURP is used, then a high frequency current is advised with prudent resection in the area of the prostatic apex.

Aged↗
PubMed1976

[Generalized infantile neuroaxonal dystrophies with pigmentation and lipophanerosis of the pallidum in concordant twins (author's transl)].

Monozygotic male twins died at the age of 6 1/2 and 7 1/2 years respectively after a progressive course of mental deterioration, hypotonia, spasticity, optic atrophy and seizures that had commenced at the age of 2 years. Both patients showed generalized neuroaxonal dystrophy (NAD), marked by numerous spheroids, iron-positive pigment and lipophanerosis of the pallidum. NAD can be classified as a generalized form without pigmentation of the pallidum (infantile type of Seitelberger), a juvenile type of Rozdilsky, a generalized form with pigmentation (cases described here), and localized forms (infantile, late infantile, juvenile = classic Hallervorden-Spatz disease, adult types).

Axons↗
PubMedDate not supplied

Cysteine proteinases and their inhibitors in extracellular fluids: markers for diagnosis and prognosis in cancer.

Cathepsins B, H and L have been shown to participate in processes of tumor growth, vascularization, invasion and metastasis. Their levels in tumor tissue extracts can provide useful clinical information to predict disease-free and overall survival in breast, lung, colorectal, brain and head and neck cancer patients. Recently we have found that both cysteine cathepsins and their endogenous protein inhibitors stefins and cystatin C can also predict prognosis when measured extracellularly. In melanoma and colorectal cancer patients high serum levels of cathepsins B and H correlated with shorter survival. Similarly, increased extracellular levels of stefins A and B and cystatin C correlated significantly with high risk of adverse outcome in cancer patients. However, the cathepsin B/cystatin C complex was found to be less abundant in sera of patients with malignant tumors than in those with benign diseases or in healthy controls, suggesting an imbalance between the enzyme and its inhibitor in cancer patients.

Biomarkers, Tumor↗