Cold photo-carving of halogen-bonded co-crystals of a dye and a volatile co-former using visible light.

The formation of co-crystals by the assembly of molecules with complementary molecular recognition functionalities is a popular strategy to design or improve a range of solid-state properties, including those relevant for pharmaceuticals, photo- or thermoresponsive materials and organic electronics. Here, we report halogen-bonded co-crystals of a fluorinated azobenzene derivative with a volatile component-either dioxane or pyrazine-that can be cut, carved or engraved with low-power visible light. This cold photo-carving process is enabled by the co-crystallization of a light-absorbing azo dye with a volatile component, which gives rise to materials that can be selectively disassembled with micrometre precision using low-power, non-burning laser irradiation or a commercial confocal microscope. The ability to shape co-crystals in three dimensions using laser powers of 0.5-20 mW-substantially lower than those used for metals, ceramics or polymers-is rationalized by photo-carving that targets the disruption of weak supramolecular interactions, rather than the covalent bonds or ionic structures targeted by conventional laser beam or focused ion beam machining processes.

The effects of soy milk and isoflavone supplements on cognitive performance in healthy, postmenopausal women.

RATIONALE: The decline in estrogen concentrations in women after menopause can contribute to health related changes including impairments in cognition, especially memory. Because of the health concerns related to hormone replacement therapy (HRT), alternative approaches to treat menopausal symptoms, such as nutritional supplements and/or diet containing isoflavones, are of interest. OBJECTIVES: This study investigated whether soy isoflavones (soy milk and supplement) could improve cognitive functioning in healthy, postmenopausal women. PARTICIPANTS, INTERVENTION AND DESIGN: A total of 79 postmenopausal women, 48-65 years of age, completed a double-blind, placebo-controlled trial in which they were randomly assigned to one of three experimental groups: cow's milk and a placebo supplement (control); soy milk and placebo supplement (soy milk, 72 mg isoflavones/day); or cow's milk and isoflavone supplement (isoflavone supplement, 70 mg isoflavones/day). MEASUREMENTS: Cognitive functioning was assessed using various cognitive tasks before the intervention (baseline) and after the intervention (test). RESULTS: In contrast to predictions, soy isoflavones did not improve selective attention (Stroop task), visual long-term memory (pattern recognition), short-term visuospatial memory (Benton Visual Retention Test), or visuo-spatial working memory (color match task). Also, the soy milk group showed a decline in verbal working memory (Digit Ordering Task) compared to the soy supplement and control groups. CONCLUSION: Soy isoflavones consumed as a food or supplement over a 16-week period did not improve or appreciably affect cognitive functioning in healthy, postmenopausal women.

Variation of liver-type fatty acid binding protein content in the human hepatoma cell line HepG2 by peroxisome proliferators and antisense RNA affects the rate of fatty acid uptake.

The liver-type fatty acid binding protein (L-FABP), a member of a family of mostly cytosolic 14-15 kDa proteins known to bind fatty acids in vitro and in vivo, is discussed to play a role in fatty acid uptake. Cells of the hepatoma HepG2 cell line endogenously express this protein to approximately 0.2% of cytosolic proteins and served as a model to study the effect of L-FABP on fatty acid uptake, by manipulating L-FABP expression in two approaches. First, L-FABP content was more than doubled upon treating the cells with the potent peroxisome proliferators bezafibrate and Wy14,643 and incubation of these cells with [1-14C]oleic acid led to an increase in fatty acid uptake rate from 0.55 to 0.74 and 0.98 nmol/min per mg protein, respectively. In the second approach L-FABP expression was reduced by stable transfection with antisense L-FABP mRNA yielding seven clones with L-FABP contents ranging from 0.03% to 0.14% of cytosolic proteins. This reduction to one sixth of normal L-FABP content reduced the rate of [1-14C]oleic acid uptake from 0.55 to 0. 19 nmol/min per mg protein, i.e., by 66%. The analysis of peroxisome proliferator-treated cells and L-FABP mRNA antisense clones revealed a direct correlation between L-FABP content and fatty acid uptake.

Subcellular distribution of cardiac fatty acid-binding protein in bovine heart muscle and quantitation with an enzyme-linked immunosorbent assay.

Several types of the 14-15 kDa fatty acid-binding proteins (FABPs) are known to occur in the cytosol of mammalian cells. With antibodies raised against the cardiac-type protein from bovine heart, immunoblots indicated a more widespread distribution of the cardiac FABP in subcellular fractions, such as mitochondria and nuclei. A detailed view was obtained when the post-embedding protein A-gold labeling method was applied to cross-sections of heart cells and isolated subcellular fractions. Cardiac FABP in myocytes was associated with myofibrils and localized within mitochondria and nuclei. After subfractionation of mitochondria, the binding protein was recovered with matrix proteins only. A non-competitive enzyme-linked immunosorbent assay (ELISA) of the direct type was developed specifically for bovine cardiac FABP. This assay was sensitive in the range of 0.05 to 1 ng, and concentrations of cardiac FABP per mg protein were found for cytosol, matrix and nuclei to be around 3.18, 0.18 and 0.03 micrograms, respectively. The newly found compartmentation of cardiac FABP in the heart cell must be considered when the true functions of the protein, yet to be defined, are studied.

Analysis of the ligand binding properties of recombinant bovine liver-type fatty acid binding protein.

The coding part of the cDNA for bovine liver-type fatty acid binding protein (L-FABP) has been amplified by RT-PCR, cloned and used for the construction of an Escherichia coli (E. coli) expression system. The recombinant protein made up to 25% of the soluble E. coli proteins and could be isolated by a simple two step protocol combining ion exchange chromatography and gel filtration. Dissociation constants for binding of oleic acid, arachidonic acid, oleoyl-CoA, lysophosphatidic acid and the peroxisomal proliferator bezafibrate to L-FABP have been determined by titration calorimetry. All ligands were bound in a 2:1 stoichiometry, the dissociation constants for the first ligand bound were all in the micro molar range. Oleic acid was bound with the highest affinity and a Kd of 0.26 microM. Furthermore, binding of cholesterol to L-FABP was investigated with the Lipidex assay, a liposome binding assay and a fluorescence displacement assay. In none of the assays binding of cholesterol to L-FABP was observed.

Bicalutamide ('Casodex') 150 mg in addition to standard care in patients with nonmetastatic prostate cancer: updated results from a randomised double-blind phase III study (median follow-up 5.1 y) in the early prostate cancer programme.

Trial 24 is one of three placebo-controlled trials within the ongoing bicalutamide ('Casodex') Early Prostate Cancer (EPC) programme evaluating bicalutamide 150 mg/day in addition to radical prostatectomy, radiotherapy or watchful waiting for T1b-4, any N, M0 prostate cancer. In Trial 24, at 5.1 y median follow-up, the addition of bicalutamide significantly (P < 0.0001) improved objective progression-free survival (PFS) and prostate-specific antigen PFS compared with standard care alone. There was no significant difference in overall survival (P = 0.746). In the context of the whole EPC programme, long-term bicalutamide is not appropriate for localised disease, yet provides advantages in delaying disease progression in patients with locally advanced prostate cancer.

Differentiation-dependent expression of heart type fatty acid-binding protein in C2C12 muscle cells.

The aim of the present work was to establish a cell culture model for the investigation of the influence of heart type fatty acid-binding protein (H-FABP) on differentiation and lipid metabolism. Up to now no data have been reported on H-FABP in cell lines of skeletal muscle, one of the major sources of this protein in vivo. For this purpose mouse C2C12 cells were chosen, because these cells can be stimulated to differentiate in vitro from myoblasts to spontaneously contracting, multiply nucleated myotubes expressing muscle-specific proteins like creatine kinase. Analysis of the cellular proteins by two-dimensional gel electrophoresis and ELISA demonstrated that the expression of H-FABP is differentiation dependent as well in these cells. Furthermore, immunofluorescent labeling with H-FABP-specific antibodies revealed that induction of this protein occurred mainly in myotubes. Myoblasts contained only 7.1 +/- 3.1 ng H-FABP/mg soluble protein, however, upon differentiation, this value increased about 60-fold to 420 +/- 90 ng/mg (n = 4) in a mixture of myoblasts and myotubes. H-FABP from C2C12 cells was subsequently cloned and shown to be identical to the known mouse H-FABP. The induction of H-FABP during differentiation was also detected at mRNA level by probing with H-FABP-cDNA. Insulin, a known stimulator of in vitro muscle cell differentiation, led to an increased differentiation as referenced by creatine kinase activity, which is paralleled by an increased H-FABP expression. The enhancement of H-FABP expression by insulin was found to be time- and dose-dependent. The increasing H-FABP content may relate to an increasing fatty acid oxidation that has been reported for differentiated L6 cells, a related muscle cell line from rat. Such a correlation would favor a role of H-FABP in lipid metabolism.

Heart microvessels and aortic endothelial cells express the 15 kDa heart-type fatty acid-binding proteins.

Due to their hydrophobic nature, free fatty acids require carriers for transport across and within the cells. The endothelial layer is the first barrier to be traversed by the fatty acids, from the plasma to the underlying cells and tissues. We tried to find out whether cytosolic fatty acid-binding proteins (FABPs) are present in the endothelium of large vessels (aortic endothelial cells) and small vessels (myocardial capillaries) using the following experimental approaches: (i) loading the delipidated aortic endothelial cell (EC) homogenate and the heart cytosolic proteins and membrane proteins with [14C]palmitate or [14C]oleate, respectively, followed by autoradiographic detection of electrophoretically separated bands; (ii) detection by immunoprecipitation of heart-type FABP (H-FABP) using an affinity-purified antibody raised against bovine H-FABP (anti-H-FABP), and (iii) localization of FABP by indirect immunofluorescence and gold-immunocytochemistry applied to cultured EC and to thick and thin frozen sections of mouse heart. The results showed that: (i) within the EC homogenate proteins that express affinity for [14C]palmitate have an apparent Mr of 15000, and 40000-45000, that correspond as molecular mass to cytosolic and membrane FABPs, respectively. Similar affinity was found by incubation with [14C]oleate, that binds to a protein of Mr 15000 in the heart cytosol, and to a 40-45 kDa protein in the membrane fraction; (ii) anti-H-FABP immunoprecipitated specifically a cytosolic 15 kDa peptide (H-FABP); (iii) by indirect immunofluorescence, cytosolic H-FABP was localized on heart microvessels and myocytes and also in cultured aortic EC where intense spotted fluorescence characteristic for cytosolic antigens was present; (iv) by immunocytochemistry, H-FABP was detected in the EC cytoplasm, and in close proximity to the cytoplasmic aspect of plasmalemma and vesicle membranes. Together the data attest the presence of the 15 kDa, heart-type FABP in the endothelium of aorta and heart microvessels.

Cloning and chromosomal localisation of the murine epidermal-type fatty acid binding protein gene (Fabpe).

We succeeded in cloning the gene encoding the murine epidermal-type fatty acid binding protein (E-FABP). To avoid the screening of pseudogenes, the presence of which was shown by PCR, we designed an intron-specific probe and screened a bacterial artificial chromosome library from mouse embryonic stem cells. One of the clones obtained was analysed by restriction with various enzymes and an 11-kb EcoRI fragment with the complete gene was subcloned. The gene revealed the canonical exon/intron FABP structure consisting of four exons (112, 173, 102 and 544bp, respectively) and three introns (2217, 327 and 546bp, respectively). The exon sequences were identical with the cDNA encoding mouse E-FABP (Krieg, P., Feil, S., Fürstenberger, G., Bowden, T.G., 1993. Tumor-specific overexpression of a novel keratinocyte lipid-binding protein. Identification and characterisation of a cloned sequence activated during multistage carcinogenesis in mouse skin. J. Biol. Chem. 268, 17362-17369). Of the 5' region, 2470bp were sequenced and searched for transcription factor binding sites. Putative responsive elements within the promoter region were identified that may be responsible for the wide expression observed for E-FABP in mouse tissues. The 11-kb EcoRI fragment was used to localise Fabpe on chromosome 3 in the region 3A1-3 by fluorescence in-situ hybridisation.

Heart-type fatty acid binding protein - involvement in growth inhibition and differentiation.

Fatty acid binding proteins (FABPs) comprise a well-established family of cytoplasmic hydrophobic ligand binding proteins and are thought to be involved in lipid metabolism by binding and intracellular transport of long-chain fatty acids. However, from other studies role for FABPs in cell signalling, growth inhibition and differentiation has also been implied. In particular, the heart-type (H-FABP) is abundantly expressed in differentiated mammary gland and its relationship with a very homologous (95%) mammary derived growth inhibitor (MDGI) was disputed. Here we give a survey on the experimental evidence for the existence of such protein with growth inhibitory function. After cloning of the bovine adipocyte-type (A-)FABP cDNA from mammary gland we conclude that the reported MDGI sequence actually represents a mixture of bovine H- and A-FABP and that the MDGI function is exerted by H-FABP. We also monitored the H-FABP level during differentiation of C2C12 muscle cells from myoblasts to multiply nucleated myotubes. H-FABP expression is clearly detected after that of the transcription factor myogenin which is upregulated immediately upon onset of differentiation and after that of the typical muscle enzyme creatine kinase. This argues against an active role of H-FABP in muscle development unlike the situation in the mammary gland.

Fatty acids in cell signalling: modulation by lipid binding proteins.

Long-chain fatty acids and several of their metabolites have now been shown to be involved as primary or secondary messengers in specific cell signalling pathways. In view of their extremely low aqueous solubility, the extracellular as well as intracellular transport of these compounds is assumed to be facilitated by specific lipid binding proteins, such as cytoplasmic fatty acid-binding protein (FABP). In this paper a survey is given on the biological significance and possible modulatory action of intracellular lipid binding proteins for fatty acid-mediated signal transduction pathways.

Mediatorless biosensor for H(2)O(2) based on recombinant forms of horseradish peroxidase directly adsorbed on polycrystalline gold.

Four forms of horseradish peroxidase (HRP) have been used to prepare peroxidase-modified gold electrodes for mediatorless detection of peroxide: native HRP, wild type recombinant HRP, and two recombinant forms containing six-His tag at the C-terminus and at the N-terminus, respectively. The adsorption of the enzyme molecules on gold was studied by direct mass measurements with electrochemical quartz crystal microbalance. All the forms of HRP formed a monolayer coverage of the enzyme on the gold surface. However, only gold electrodes with adsorbed recombinant HRP forms exhibited high and stable current response to H(2)O(2) due to its bioelectrocatalytic reduction based on direct electron transfer between gold and HRP. The sensitivity of the gold electrodes modified with recombinant HRPs was in the range of 1.4-1.5 A M(-1) cm(-2) at -50 mV versus Agmid R:AgCl. The response to H(2)O(2) in the concentration range 0.1-40 microM was not dependent on the presence of a mediator (i.e. catechol) giving strong evidence that the electrode currents are diffusion limited. Lower detection limit for H(2)O(2) detection was 10 nM at the electrodes modified with recombinant HRPs.

Nodular pulmonary vasculitis in a twelve-year-old boy.

A 12-year-old boy presented with left shoulder pain during physical exercise and complained of uncommon sweating and fatigue. Diagnostic evaluation revealed a solitary pulmonary nodule in the left upper lobe. All laboratory values were within normal limits, except for an elevated level of antineutrophil cytoplasmic antibodies directed against myeloperoxidase (p-ANCA). Surgery was performed, and pathological examination showed a localized granulomatous vasculitis. Antineutrophil cytoplasmic antibodies directed against affinity purified proteinase 3 (p-ANCA) concentrations returned to baseline within 6 months, and the patient has done well during a follow-up period of 2 years. While nodular vasculitis is known to occur in Wegener's granulomatosis, to the best of our knowledge, this case represents the first c-ANCA negative primary pulmonary vasculitis in childhood.

IUPAC collaborative trial study of a method to detect genetically modified soy beans and maize in dried powder.

This paper presents results of a collaborative trial study (IUPAC project No. 650/93/97) involving 29 laboratories in 13 countries applying a method for detecting genetically modified organisms (GMOs) in food. The method is based on using the polymerase chain reaction to determine the 35S promotor and the NOS terminator for detection of GMOs. reference materials were produced that were derived from genetically modified soy beans and maize. Correct identification of samples containing 2% GMOs is achievable for both soy beans and maize. For samples containing 0.5% genetically modified soy beans, analysis of the 35S promotor resulted also in a 100% correct classification. However, 3 false-negative results (out of 105 samples analyzed) were reported for analysis of the NOS terminator, which is due to the lower sensitivity of this method. Because of the bigger genomic DNA of maize, the probability of encountering false-negative results for samples containing 0.5% GMOs is greater for maize than for soy beans. For blank samples (0% GMO), only 2 false-positive results for soy beans and one for maize were reported. These results appeared as very weak signals and were most probably due to contamination of laboratory equipment.

Involvement of arginine in the binding of heme and fatty acids to fatty acid-binding protein from bovine liver.

Fatty acid-binding protein from bovine liver but not from bovine heart binds hematin in a saturable manner with high affinity. This property is not confined to a particular isoform as both, pI 6.0- and pI 7.0 L-FABP, bind hematin similarly. In competition experiments hematin and oleic acid could replace each other demonstrating that they share at least parts of the same binding site. Common structural features, i.e. the presence of carboxylic groups and of hydrophobic carbon chains led to the hypothesis that both ligands interact similarly with L-FABP. This was supported by the decrease of binding affinity for either ligand upon modification with phenylglyoxal. Modification in the presence of fatty acid revealed the protection of one of the two arginines of L-FABP. By peptide mapping and Edman degradation Arg122 was identified as the counterpart of the fatty acids carboxylic group.

Priapism - a surgical emergency.

Priapism is a surgical emergency, and a glandular cavernous shunt is good emergency treatment. The technique is simple, easy and quick, can be performed under local anaesthesia if necessary, and has a good chance of success; should it fail or the priapism recur, a more formidable shunt may be performed.

Fatty acids and hypolipidemic drugs regulate peroxisome proliferator-activated receptors alpha - and gamma-mediated gene expression via liver fatty acid binding protein: a signaling path to the nucleus.

Peroxisome proliferator-activated receptor alpha (PPARalpha) is a key regulator of lipid homeostasis in hepatocytes and target for fatty acids and hypolipidemic drugs. How these signaling molecules reach the nuclear receptor is not known; however, similarities in ligand specificity suggest the liver fatty acid binding protein (L-FABP) as a possible candidate. In localization studies using laser-scanning microscopy, we show that L-FABP and PPARalpha colocalize in the nucleus of mouse primary hepatocytes. Furthermore, we demonstrate by pull-down assay and immunocoprecipitation that L-FABP interacts directly with PPARalpha. In a cell biological approach with the aid of a mammalian two-hybrid system, we provide evidence that L-FABP interacts with PPARalpha and PPARgamma but not with PPARbeta and retinoid X receptor-alpha by protein-protein contacts. In addition, we demonstrate that the observed interaction of both proteins is independent of ligand binding. Final and quantitative proof for L-FABP mediation was obtained in transactivation assays upon incubation of transiently and stably transfected HepG2 cells with saturated, monounsaturated, and polyunsaturated fatty acids as well as with hypolipidemic drugs. With all ligands applied, we observed strict correlation of PPARalpha and PPARgamma transactivation with intracellular concentrations of L-FABP. This correlation constitutes a nucleus-directed signaling by fatty acids and hypolipidemic drugs where L-FABP acts as a cytosolic gateway for these PPARalpha and PPARgamma agonists. Thus, L-FABP and the respective PPARs could serve as targets for nutrients and drugs to affect expression of PPAR-sensitive genes.

Heterologous expression and characterisation of mouse brain fatty acid binding protein.

A novel brain-type member of the fatty acid binding protein family (B-FABP) was heterologously expressed in Escherichia coli, either as inclusion bodies at 37 degrees C or in soluble form at 22 degrees C. Both B-FABP renatured from inclusion bodies and the solubly expressed protein could be purified to homogeneity by anion exchange chromatography and gel filtration in a functional conformation as they bound oleic acid with high affinity. None of the five cysteines of B-FABP was involved in disulphide bond formation. Isoelectric focusing revealed heterogeneity of the renatured protein but not of the solubly expressed protein. By Western blotting using affinity purified rabbit antibodies raised against the recombinant B-FABP it was demonstrated that in adult mice, B-FABP is predominantly expressed in the olfactory bulb.