Tissue transglutaminase (TG2) acting as G protein protects hepatocytes against Fas-mediated cell death in mice.

Tissue transglutaminase (TG2) is a protein cross-linking enzyme known to be expressed by hepatocytes and to be induced during the in vivo hepatic apoptosis program. TG2 is also a G protein that mediates intracellular signaling by the alpha-1b-adrenergic receptor (AR) in liver cells. Fas/Fas ligand interaction plays a crucial role in various liver diseases, and administration of agonistic anti-Fas antibodies to mice causes both disseminated endothelial cell apoptosis and fulminant hepatic failure.

Circular dichroism and absorption spectroscopic data reveal binding of the natural cis-carotenoid bixin to human alpha1-acid glycoprotein.

Using circular dichroism (CD) and electronic absorption spectroscopy techniques, interaction of the natural dietary cis-carotenoid bixin with an important human plasma protein in vitro was demonstrated for the first time. The induced CD spectra of bixin obtained under physiological conditions (pH 7.4, 37 degrees C) revealed its binding to the serum acute-phase reactant alpha(1)-acid glycoprotein (AGP), a member of the lipocalin protein family.

Does increased 18FDG uptake reflect malignant transformation of a low-grade glioma? A diagnostic dilemma.

Benign gliomas of the brain show decreased uptake of 18F fluorodeoxyglucose (FDG) on positron emission tomography (PET). Malignant transformation is usually manifested by an increase of 18FDG uptake. A 45-year-old female has been followed up since 1987 by means of 18FDG-PET for a right hemispheric World Health Organization Grade II oligoastrocytoma.

Effects of selected flavonoids and carotenoids on drug accumulation and apoptosis induction in multidrug-resistant colon cancer cells expressing MDR1/LRP.

The effects of various flavonoids and carotenoids on Rhodamine 123 accumulation in multidrug-resistant Colo 320 human colon cancer cells expressing MDR1/LRP were studied. The Colo 205 cell line was used as a drug-sensitive control. Rotenon, Catechin, Neohesperidin, Naringin, Robinin, Phloridzin, Robinetin, Dihydrobinetin, Dihydrofisetin, Kampferol, Dihidroquercetin, Sakuranin and Sakuranetin were tested on Colo 320 cells: only Rotenon was found to be effective as regards multidrug resistance (MDR) reversal, while a majority of the flavonoids, such as Catechin, Neohesperidin, Naringin, Robinin, Phloridzin, Dihydrobinetin and Sakuranetin, had only marginal effects on Rhodamine 123 accumulation.

Thinning and flow of Tibetan crust constrained by seismic anisotropy.

Intermediate-period Rayleigh and Love waves propagating across Tibet indicate marked radial anisotropy within the middle-to-lower crust, consistent with a thinning of the middle crust by about 30%. The anisotropy is largest in the western part of the plateau, where moment tensors of earthquakes indicate active crustal thinning. The preferred orientation of mica crystals resulting from the crustal thinning can account for the observed anisotropy.

Long-term culture of embryonic rat cardiomyocytes on an organosilane surface in a serum-free medium.

Potential applications of engineered, functional, cardiac muscle extends from basic research through drug discovery to engineering heart tissue for transplantation. One of the central questions in cardiac tissue engineering is to understand and control the complex interactions between the cardiac muscle cells and their environment. Recent progress in chemistry, material science, and cell biology have made possible the control of the extracellular environment (soluble factors and also cell-substrate signaling) in in vitro systems.

Subcortical [18F]fluorodeoxyglucose uptake in lesional epilepsy in patients with intracranial tumour.

Background: We hypothesized that in patients with intracerebral tumours a subcortical metabolical shift may be present when the underlying pathology can, itself, be the epileptogenic focus. We also assumed that by studying the alterations in glucose metabolism beyond the tumour's borders we could identify a modulator area.

Methods: Sixty-seven patients with supratentorial brain tumour associated epilepsy were investigated interictally, in normoglycaemic conditions, by using [18F]fluorodeoxyglucose positron emission tomography (FDG PET).

Modulation of multidrug resistance and apoptosis of cancer cells by selected carotenoids.

The multidrug resistance (MDR) proteins that belong to the ATP-binding casette superfamily are present in a majority of human tumors and are an important final cause of therapeutic failure. Therefore, compounds which inhibit the function of the MDR-efflux proteins may improve the cytotoxic action of anticancer chemotherapy. The effects of carotenoids were studied on the activity of the MDR-1 gene-encoded efflux pump system.

[Cervical neuroblastoma in an infant].

The case of a one-month-old patient admitted to the Department of Pediatrics (Medical and Health Science Center, Debrecen University) because of respiratory distress caused by a cervical mass compressing the upper respiratory pathways is presented. The mass could only be partially removed, the histological diagnosis proved to be neuroblastoma (SBCT: "small blue cell tumor"). Despite the fact that the DNA index of tumor cells (ploidy measurements) and the age of the patient suggested a favourable prognosis, the tumor continued to grow and metastases appeared.

Epimerisation of lutein to 3'-epilutein in processed foods.

Lutein can convert to 3'-epilutein and anhydrolutein I in acidic medium as well as during different cooking methods. To our knowledge, this is the first demonstration of the epimerisation and dehydration of lutein in native samples. During different cooking processes the lutein content of the processed vegetables and fruits dramatically decreases, thus the bioavailability of processed plant food may also decrease.

Electrophysiological and morphological characterization of rat embryonic motoneurons in a defined system.

In an attempt to integrate biological components with silicon-based devices and systems, artificial silane surfaces have been successfully used to grow motoneurons in a defined environment. In this study we characterized the morphology and electrophysiology of purified rat embryonic (E14) motoneurons grown on a self-assembled monolayer (SAM) of N-1[3-(trimethoxysilyl)propyl]diethylenetriamine (DETA) versus that on ornithine/laminin surfaces in serum-free media. On DETA motoneurons were flat and grew more processes, whereas on ornithine/laminin they tended to aggregate.

Short-term frequency-dependent plasticity at recurrent mossy fiber synapses of the epileptic brain.

The recurrent mossy fiber pathway of the dentate gyrus expands dramatically in human temporal lobe epilepsy and in animal models of this disorder, creating monosynaptic connections among granule cells. This novel granule cell network can support reverberating excitation but is difficult to activate with low-frequency stimulation. This study used hippocampal slices from pilocarpine-treated rats to explore the dependence of synaptic transmission in this pathway on stimulus frequency.

Transglutaminase 2-/- mice reveal a phagocytosis-associated crosstalk between macrophages and apoptotic cells.

Tissue transglutaminase (TGase2) is a protein-crosslinking enzyme known to be associated with the in vivo apoptosis program. Here we report that apoptosis could be induced in TGase2-/- mice; however, the clearance of apoptotic cells was defective during the involution of thymus elicited by dexamethasone, anti-CD3 antibody, or gamma-irradiation, and in the liver after induced hyperplasia. The lack of TGase2 prevented the production of active transforming growth factor-beta1 in macrophages exposed to apoptotic cells, which is required for the up-regulation of TGase2 in the thymus in vivo, for accelerating deletion of CD4+CD8+ cells and for efficient phagocytosis of apoptotic bodies.

FT-IR study of some seco- and apocarotenoids.

FT-IR spectroscopy was applied to investigate 15 different carotenoids. The following compounds were examined: beta-carotenone (1); semi-beta-carotenon-epoxide (2); beta-apo-8'-carotenal (3); ethyl-beta-apo-8'-carotenoate (4); beta-citraurin (5); 5,6-Epoxy-beta-caroten-8'-al (6); beta-citraurin-epoxide (7); apo-10'-violaxanthal (8); persicaxanthin (9); capsylaldehyde (10); capsanthylal (11); retinol (12); retinal (13); retinoic acid (14); and bixin (15). Some characteristic functional groups (Cz.

[FDG-PET-scan in subarachnoid hemorrhage].

Ruptured aneurysms cause subarachnoidal hemorrhage (SAH) that may or may not result in neurological sequelae. Acute SAH has been shown to reduce cerebral blood flow and metabolism. An important question is whether or not the SAH induced vasospasm without clinical symptoms leads to cerebral ischemia? Using postoperative [18F]-fluorodeoxyglucose positron emission tomography in patients with vasospasm diagnosed by transcranial Doppler without clinical changes, hypermetabolism was detected as an indicator of diffuse compensated ischemia in 6 cases.

[The PET scan in neuro-oncology--indications, differential diagnosis and clinical application].

Results of 157 PET (positron emission tomography) studies in 102 patients with known or presumed intracranial (ic.) tumors are reviewed. In 106 studies [18F]-2-fluoro-2-deoxy-D-glucose (FDG) and in 51 cases [11C]-methionine (MET) was used as the PET tracer.

Non-covalent associations of cyclomaltooligosaccharides (cyclodextrins) with carotenoids in water. A study on the alpha- and beta-cyclodextrin/psi,psi-carotene (lycopene) systems by light scattering, ionspray ionization and tandem mass spectrometry.

Water-soluble complexes of the dietary carotenoid psi,psi-carotene (lycopene 1) with cyclomaltohexaose (alpha-cyclodextrin, alphaCD) and cyclomaltoheptaose (beta-cyclodextrin, betaCD) have been prepared and characterized via multiangle light scattering (MALS), ionspray/electrospray ionization (IS/ESI) mass spectrometry (MS) and tandem MS. MALS experiments point out that large aggregates of particles, on the nanometer-size scale, are present in water, with meaningful differences in the shape of the alphaCD/1 aggregates with respect to betaCD/1 analogues. The true 1:1 alphaCD/1 inclusion complex has been observed by IS/ESIMS and confirmed by tandem MS.

The binding of Xanthophylls to the bulk light-harvesting complex of photosystem II of higher plants. A specific requirement for carotenoids with a 3-hydroxy-beta-end group.

The pigment composition of the light-harvesting complexes (LHCs) of higher plants is highly conserved. The bulk complex (LHCIIb) binds three xanthophyll molecules in combination with chlorophyll (Chl) a and b. The structural requirements for binding xanthophylls to LHCIIb have been examined using an in vitro reconstitution procedure.

[Biomechanical experiments for measuring traction lengthening of the lumbar spine during weight bath therapy].

Introduction: Weight-bath as an effective traction therapy has successfully been applied in Hungary for nearly a half century, however, it has still been constrained exclusively to empirical bases until the numerical biomechanical analysis of Bene and Kurutz appeared in 1993. Due to their calculations, for cervical suspension in traction bath, the value and distribution of tensile force along the spine became known, however, the most important information, namely, the deformation of spine segments to be stretched by the therapy is so far unknown.

Aims: In this paper the results of a wide-ranging in vivo biomechanical experimental analysis are presented, aimed partly to obtain the traction deformation effects of weight-bath therapy, partly to obtain the biomechanical traction model of human lumbar segments.

(9Z)-capsanthin-5,6-epoxide, a new carotenoid from the fruits of Asparagus falcatus.

From the fruits of Asparagus falcatus a novel minor (Z)-carotenoid has been isolated and, on the basis of spectral data interpretation, characterized as (9Z)-capsanthin-5,6-epoxide [(9Z,3S,5R,6S,3'S,5'R)-5,6-epoxy-3,3'-dihydroxy-5,6-dihydro-beta,kappa-caroten-6'-one, (1)]. In addition, seven other (Z)-carotenoids [namely, (9Z)-, (9'Z)-, (13Z)-, and (13'Z)-capsanthins, (9Z)- and (13Z)-capsorubins, and (9Z)-violaxanthin], which have been previously described from other plants, were isolated and identified.

The blood-brain barrier in primary CNS lymphomas: ultrastructural evidence of endothelial cell death.

The vasculature of 24 primary CNS B-cell lymphomas that were not related to acquired immunodeficiency syndrome was systematically studied by electron microscopy. Seven low-grade astrocytic tumors were included for comparison. Classical electron microscopy features of apoptosis were found in lymphoma cells of 21 of 22 subjects.

Synaptically-released zinc inhibits N-methyl-D-aspartate receptor activation at recurrent mossy fiber synapses.

Hippocampal slices from pilocarpine-treated rats were used to explore the effect of zinc released at mossy fiber synapses on dentate granule cells. Chelation of zinc enhanced the N-methyl-D-aspartate (NMDA) receptor-mediated component of the excitatory postsynaptic current (EPSC), but did not affect the AMPA/kainate receptor-mediated component. Its effect was detectable only at negative membrane potentials and was pathway specific.