Apoptosis in B-cell lymphomas and reactive lymphoid tissues always involves activation of caspase 3 as determined by a new in situ detection method.

In vitro studies indicate that in lymphomas, execution of apoptosis involves activation of effector caspases. To investigate activation of effector caspases in vivo in biopsy specimens of lymphomas, a new assay was developed using antibodies against active caspase 3 and p89, a protein fragment generated by caspase-specific cleavage of poly-ADP ribose polymerase (PARP). Using this assay, it was found that in B-cell lymphomas, levels of active caspase 3/p89-positive cells correlate strongly with morphologically recognizable apoptotic cells.

Expression of the granzyme B inhibitor, protease inhibitor 9, by tumor cells in patients with non-Hodgkin and Hodgkin lymphoma: a novel protective mechanism for tumor cells to circumvent the immune system?

In tumor cells, the serine protease granzyme B is the primary mediator of apoptosis induced by cytotoxic T lymphocytes (CTLs)/natural killer (NK) cells. The human intracellular serpin proteinase inhibitor 9 (PI9) is the only known human protein able to inhibit the proteolytic activity of granzyme B. When present in the cytoplasm of T lymphocytes, PI9 is thought to protect CTLs against apoptosis induced by their own misdirected granzyme B.

MUC1 (EMA) is preferentially expressed by ALK positive anaplastic large cell lymphoma, in the normally glycosylated or only partly hypoglycosylated form.

Aims: To investigate whether MUC1 mucin, a high molecular weight transmembrane glycoprotein, also known as epithelial membrane antigen (EMA), differs in its expression and degree of glycosylation between anaplastic large cell lymphoma (ALCL) and classic Hodgkin's disease (HD), and whether MUC1 immunostaining can be used to differentiate between CD30 positive large cell lymphomas.

Methods/results: Using five different monoclonal antibodies (E29/anti-EMA, DF3, 139H2, VU-4H5, and SM3) that distinguish between various MUC1 glycoforms, high MUC1 expression (50-95% of tumour cells positive) was found in 13 of 17 anaplastic lymphoma kinase (ALK) positive systemic nodal ALCLs, and in one of 20 cases of classic HD. Scattered or focal staining (< 25% of tumour cells) was seen in two additional ALK positive systemic ALCLs, two additional classic HD cases, and in three of 20 cases of ALK negative systemic nodal ALCL.

Tetradecylthioacetic acid inhibits growth of rat glioma cells ex vivo and in vivo via PPAR-dependent and PPAR-independent pathways.

The peroxisome proliferator-activated receptors (PPARs) are transcription factors involved in fatty acid metabolism and energy homeostasis. The PPARs also play crucial roles in the control of cellular growth and differentiation. Especially, the recently emerged concept of ligand-dependent PPARgamma-mediated inhibition of cancer cell proliferation through induction of G(1)-phase arrest and differentiation is of clinical interest to cancer therapy.

Sustained retention of tetradecylthioacetic acid after local delivery reduces angioplasty-induced coronary stenosis in the minipig.

Objective: The sulfur containing tetradecylthioacetic acid (TTA) has a profound effect on lipid metabolism and may also exert antioxidant and anti-inflammatory actions and thereby counteract coronary stenosis after angioplasty balloon injury. This study examined the possible modulatory effects of TTA, delivered locally, on coronary stenosis in minipigs and the underlying mechanisms of action.

Methods: Coronary balloon angioplasty injury using an oversized balloon was performed to 40 coronary arteries (20 minipigs, Sus Scrofa, Gammelsroed) followed by delivery of placebo or TTA via a local drug delivery balloon catheter.

Tetradecylthioacetic acid reduces stenosis development after balloon angioplasty injury of rabbit iliac arteries.

Background: tetradecylthioacetic acid (TTA) is a synthetic long-chain fatty acid analogue that inhibits the oxidative modification of low-density lipoprotein particles in vitro. We examined the influence of TTA on the arterial wall response after balloon angioplasty injury in a rabbit iliac model.

Methods And Results: 14 rabbits were randomized to receiving either TTA fatty acids 800 mg daily perorally (weight 3.

Omega-3 fatty acids enhance tumor necrosis factor-alpha levels in heart transplant recipients.

Background: Proinflammatory cytokines may contribute to clinical complications in heart transplant (HTx) recipients. Previous studies have shown immunomodulating effects of omega-3 fatty acids, but the results are somewhat conflicting. In this study, we examined plasma levels of tumor necrosis factor alpha (TNF-alpha), interleukin (IL) 10, and their relations to antioxidant vitamins in 45 HTx recipients before and after treatment with omega-3 fatty acids or placebo.

Transient up-regulation of liver mitochondrial thymidine kinase activity in proliferating mitochondria.

Administration of the fatty acid analogue tetradecylthioacetic acid (TTA) to rodents up-regulates peroxisomal and mitochondrial lipid-metabolizing enzymes and induces a proliferation of these organelles in hepatocytes. We show here that male NMRI mice fed a diet containing 0.3% (w/w) TTA revealed a transient two-fold increase in the incorporation of [3H]thymidine into the liver mtDNA followed by a 1.

Long-term retention of a novel antioxidant sulphur-substituted fatty acid analogue after local delivery in porcine coronary arteries.

Objective: Antioxidants have been suggested to reduce restenosis after balloon angioplasty. A novel sulphur-containing fatty acid, tetradecylthioacetic acid (TTA), with antioxidant properties, is efficiently incorporated into cellular phospholipids. We have determined the uptake and retention of TTA after local coronary artery delivery in 20 pigs.

Modulation of keratinocyte gene expression and differentiation by PPAR-selective ligands and tetradecylthioacetic acid.

Peroxisome proliferator-activated receptors (PPARs) are pleiotropic regulators of growth and differentiation of many cell types. We have performed a comprehensive analysis of the expression of PPARs, transcriptional cofactors, and marker genes during differentiation of normal human keratinocytes using a combination of reverse transcriptase polymerase chain reaction, Northern and Western blotting, and immunohistochemistry. PPARdelta was the predominant PPAR subtype in human keratinocytes and highly expressed in basal cells and suprabasal cells.

Optimization of methods and treatment conditions for studying effects of fatty acids on cell growth.

Antiproliferative properties of molecular regulators of lipid metabolism have been increasingly studied during recent years. Discussion is ongoing concerning optimal treatment conditions and assays used for monitoring proliferation and cytotoxicity. The objective of the present work was to optimize methods and treatment conditions used for studying antiproliferative effects of fatty acids and analogs, represented by palmitic acid (PA) and the beta-oxidation-restricted fatty acid analog tetradecylthioacetic acid (TTA), in rat (BT4Cn) and human (D54Mg and GaMg) glioma cell lines.

Acyl-CoA esters antagonize the effects of ligands on peroxisome proliferator-activated receptor alpha conformation, DNA binding, and interaction with Co-factors.

The peroxisome proliferator-activated receptor alpha (PPARalpha) is a ligand-activated transcription factor and a key regulator of lipid homeostasis. Numerous fatty acids and eicosanoids serve as ligands and activators for PPARalpha. Here we demonstrate that S-hexadecyl-CoA, a nonhydrolyzable palmitoyl-CoA analog, antagonizes the effects of agonists on PPARalpha conformation and function in vitro.

Growth reduction in glioma cells after treatment with tetradecylthioacetic acid: changes in fatty acid metabolism and oxidative status.

During aerobic metabolism, a small amount of partially reduced oxygen is produced, yielding reactive oxygen species (ROS). Peroxisomes and mitochondria are major contributors to cellular ROS production, which is normally balanced by consumption by antioxidants. The fatty acid analogue tetradecylthioacetic acid (TTA) promotes mitochondrial and peroxisomal proliferation, and may induce oxidative stress and change the growth potential of cancer cells.

Effects of long-chain monounsaturated and n-3 fatty acids on fatty acid oxidation and lipid composition in rats.

Long-chain n-3 fatty acids and fat fish are reported, among multiple physiological properties, to enhance peroxisomal beta-oxidation and effect triacylglycerol status. Long-chain n-3 and monounsaturated fatty acids are the main portion of fatty acids in fat fish. The individual effect of long-chain monounsaturated fatty acids on beta-oxidation and fatty acid composition was tested and compared to the effect of n-3 polyunsaturated and saturated fatty acids in a 3-week feeding experiment of rats.

Percentage of activated cytotoxic T-lymphocytes in anaplastic large cell lymphoma and Hodgkin's disease: an independent biological prognostic marker.

Recently, we demonstrated that the presence of high percentages of activated cytotoxic T-lymphocytes (CTLs) in biopsy specimens of both Hodgkin's disease (HD) and ALK negative anaplastic large cell lymphoma (ALCL) is associated with a poor prognosis. To test whether this biological prognostic factor is more important in predicting clinical outcome than histological diagnosis or clinical factors, we compared the prognostic value of these parameters in an expanded group of classical HD and ALK negative ALCL. Tumor biopsies of classical HD (n = 83) and ALK negative systemic nodal ALCL (n = 43) were investigated for the presence of activated CTLs by immunohistochemistry, using a monoclonal antibody directed against granzyme B.

Interaction between chemokines and oxidative stress: possible pathogenic role in acute coronary syndromes.

Objectives: We sought to study the relationships between chemokines and oxidative stress in acute coronary syndrome.

Background: In view of existing knowledge on the participation of leukocytes and oxidative stress in the pathogenesis of acute coronary syndrome, we hypothesized that chemokines may play a role in recruiting and activating leukocytes in this disorder.

Methods: The levels of chemokines and oxidative stress were studied in 38 patients with stable and 38 with unstable angina and in 20 controls.

Proliferation of mitochondria and gene expression of carnitine palmitoyltransferase and fatty acyl-CoA oxidase in rat skeletal muscle, heart and liver by hypolipidemic fatty acids.

Morphological and biochemical effects were induced at the subcellular level in the skeletal muscle, heart and liver of male rats as a result of feeding with EPA, DHA, and 3-thia fatty acids. The 3-thia fatty acid, tetradecylthioacetic acid (TTA) and EPA induced mitochondrial growth in type I muscle fibers in both the diaphragm and soleus muscle, and the size distribution of mitochondrial areas followed a similar pattern. Only the 3-thia fatty acid induced mitochondrial growth in type II muscle fibers.

Virological and immunological effects of antioxidant treatment in patients with HIV infection.

Background: Intracellular oxidative stress in CD4+ lymphocytes due to disturbed glutathione homeostasis may lead to impaired lymphocyte functions and enhanced HIV replication in patients with HIV infection, especially in those with advanced immunodeficiency. The aim of the present study was to assess whether short-term, high-dose antioxidant treatment might have effects on immunological and virological parameters in patients with HIV infection.

Materials And Methods: In this pilot study, we examined virological and immunological effects of antioxidant combination treatment for 6 days with high doses of N-acetylcysteine (NAC) and vitamin C in 8 patients with HIV infection.

[Immunology in medical practice. XXX. Organ transplantation: indications and results].

During the past 30 years, solid organ transplantation has developed into a routine medical procedure. Currently, one-year transplant survival rates for kidney, heart, liver and pancreas are between 80 and 90%; for most organs, the long-term results are fair with 5-year survival rates of 60%. Inclusion criteria for potential recipients have become less stringent.

Epstein-Barr virus is present in neoplastic cytotoxic T cells in extranodal, and predominantly in B cells in nodal T non-Hodgkin lymphomas.

Epstein-Barr virus (EBV)-positive T non-Hodgkin lymphomas (T-NHLs) have been described, but it is at present unknown how EBV infects T lymphocytes. It has been postulated that cytotoxic T cells (CTLs) or natural killer (NK) cells can be infected by EBV during the killing of an EBV-infected target cell. The objective of this study was therefore to determine whether the neoplastic cells in EBV-positive T-NHLs (n=221) of various locations have a cytotoxic phenotype.

ALK expression in extranodal anaplastic large cell lymphoma favours systemic disease with (primary) nodal involvement and a good prognosis and occurs before dissemination.

Aims: In anaplastic large cell lymphoma (ALCL), the site of origin has been described as an important prognostic factor. Recently, a fusion protein containing anaplastic lymphoma kinase (ALK) was described in systemic nodal ALCL, and shown to be associated with a good prognosis. The aims of this study were to investigate whether the presence of ALK protein differs between ALCL of different sites of origin; to determine whether ALK expression occurs before dissemination to other sites; and, finally, to investigate whether the site of origin remains a prognostic parameter in ALK negative ALCL.

Tetradecylthioacetic acid and tetradecylselenoacetic acid inhibit lipid peroxidation and interact with superoxide radical.

Reactive oxygen species are thought to induce cellular damage and to play a pathological role in several human diseases. Tetradecylthioacetic acid (TTA) was previously reported to prevent the oxidative modification of low-density lipoprotein (LDL) particles and to act as an antioxidant. In this study we present a new fatty acid analogue, namely tetradecylselenoacetic acid (TSA), in which the sulfur atom of TTA is replaced by a selenium atom.