Fucosyltransferase activities in human pancreatic tissue: comparative study between cancer tissues and established tumoral cell lines

This review focuses on polymerase chain reaction (PCR) sexing of bovine embryos in commercial situations with emphasis on new developments. Simplifications of the biopsy technique is one of the major simplifications over the last few years. The stabilization of the embryo by means of protein-free medium or scratches produced on the bottom of the Petri dish makes it possible to perform a biopsy with a single microinstrument. The traditional PCR sexing approach utilizes electrophoresis, which involves the risk of deoxyribonucleic acid (DNA) contamination of subsequent assays. Such contamination, resulting in females misdiagnosed as males, is avoided efficiently by using a non-electrophoretic method in which the sex is determined based on fluorescence of unopened tubes. However, female samples cannot be distinguished from blank samples in the non-electrophoretic assay, which thus relies on accurate transfer of biopsy into tubes. Nevertheless, an accuracy of about 95% can be reached with both approaches. High pregnancy rates (50-70%) can be reached with biopsied Grade 1 embryos, but there is evidence that pregnancy rates with Grade 2 embryos is 15-20% lower. Recent data indicate that pregnancy rates of 50% can be achieved with frozen-thawed biopsied Grade 1 embryos. In conclusion, recent developments in biopsy techniques, detection systems and freezing should increase interest in PCR sexing.     

In vivo detection of gold-imidazole self-assembly complexes: NIR-SERS signal reporters

Here we report in vitro and in vivo detection of self-assembled Au-imidazole by using near-infrared surface-enhanced Raman scattering (NIR-SERS). In vivo, the Au-imidazole structures were administered into tumor-bearing mice and detected noninvasively. The self-assembled Au-imidazole complexes were generated by the adsorption of imidazole molecules onto Au nanoparticles (NP) and were then characterized as aqueous suspensions by using NIR-SERS, angle-dependent light scattering with fractal dimension analysis, and visible extinction spectroscopy. The structure and optical activity was sensitive to imidazole concentration and Au NP size. Specifically, the Au-imidazole assemblies formed at lower imidazole concentrations had the lowest fractal dimension (D(f) = 1.2) and the largest Raman enhancement factors for the dominant NIR-SERS feature, a ring-breathing vibrational mode at 954 cm(-1). Changes in elastic scattering intensity, fractal dimension, and surface plasmon absorption were observed with increasing imidazole concentration. The Raman enhancement factor was also found to range between 10(6) and 10(9) with different primary Au nanoparticle sizes. For the higher enhancement factor systems, NIR-SERS detection of Au-imidazole was performed with data acquisitions time of only 5 s. The largest enhancement was observed for the 954-cm(-1) feature at an imidazole concentration of 1.9 microM when coupled to 54-nm-diameter Au NPs (the largest NP tested). Finally, we show the first demonstration of in vivo, noninvasive, and real-time SERS detection.     

Combinatorial vascular targeting in translational medicine

In the post-genomic era, the phage display technology surfaces as an alternative approach for large-scale study of tissue-specific protein interactions with direct clinical and therapeutic applications. The unbiased identification of molecular complexes expressed on the surface of cells and blood vessels of organs and tissues may eventually lead to a considerably improved understanding of cellular and vascular proteomics. The ultimate value of this technology consists in the conception of a new ligand-directed pharmacology, with broad implications for both treatment and molecular imaging of cancer patients. In this review, we describe the use and applications of phage display for efficient development of targeted drug discovery and design.     

Bis(dithiocarbamato) nitrido technetium-99m radiopharmaceuticals: a class of neutral myocardial imaging agents

The synthesis and biodistribution in various animal models (rat, dog, pig and monkey) of 99mTc radiopharmaceuticals containing the Tc = N multiple bond are reported. METHODS: The complexes are represented by the general formula 99mTcN(L)2, where L is the monoanionic form of a dithiocarbamate ligand of the type [R1(R2)-N-C(=S)S]-, and R1 and R2 are variable, lateral groups. The preparations were carried out, both as a liquid and freeze-dried formulation, through a simple procedure involving the initial reaction of [99mTcO4]- with S-methyl N-methyl dithiocarbazate [H2NN(CH3)C(=S)SCH3], in the presence of tertiary phosphines or Sn2+ ion as reductants, followed by the addition of the sodium salt of the ligand (NaL) to afford the final product. The chemical identity of the resulting complexes was determined by comparing their chromatographic properties with those of the corresponding 99Tc analogs characterized by spectroscopic and x-ray crystallographic methods. The complexes are neutral and possess a distorted, square pyramidal geometry. RESULTS: No decomposition of the complexes, in physiological solution, was observed over a period of 6 hr. Imaging and biodistribution studies demonstrated that these radiopharmaceuticals localize selectively in the myocardium of rats, dogs and primates, but that they failed to visualize the pig heart. The kinetics of heart uptake and clearance were studied in rats and dogs, and found to be strongly influenced by variation of the lateral R1 and R2 groups. CONCLUSION: The high quality of myocardial images obtained in dogs and monkeys demonstrates that the derivative 99mTcN[E-t(EtO)NCS2]2 [99mTcN(NOEt)] exhibits the most favorable distribution properties for further studies in humans.     

Thermo-mechanical behaviour of Polyamide 6 chain extended with 1,1′-Carbonyl-Bis-Caprolactam and 1,3-Phenylene-Bis-2-Oxazoline

A commercial Polyamide 6 (PA6) was melt compounded by using a twin screw extruder with a combination of 1,1′-Carbonyl-Bis-Caprolactam (CBC) and 1,3-Phenylene-Bis-2-Oxazoline (PBO), in order to evaluate their effect on the chain extension behaviour of the resulting materials. An increase of the viscosity values with the chain-extender amount was evidenced by rheological tests on the compounded pellets and relative viscosity measurements on solubilized samples, while the opposite trend was determined increasing the residence time at elevated temperatures. The increase of the molecular weight due to the presence of CBC and PBO was confirmed by the reduction of carboxylic and aminic functionalities evidenced in end group analysis. DSC tests showed a reduction of the melting temperature and of the crystallinity degree proportionally to the chain extender amount. Elastic modulus of the chain-extended materials was similar to that of the corresponding PA6 grades at different molecular weight, while crystallinity drop due to chain extension determined an increase of the strain at break values.     

Phenolic compounds of Pinus laricio needles: A bioindicator of the effects of prescribed burning in function of season

Fire is a dominant ecological factor in Mediterranean-type ecosystems. Forest management includes many preventive tools, in particular for fire prevention, such as mechanical treatments and prescribed burning. Prescribed burning is a commonly used method for treating fuel loads, but fuel reduction targets for reducing wildfire hazards must be balanced against fuel retention targets in order to maintain habitat and other forest functions. This approach was used on Pinus nigra ssp laricio var. Corsicana, a pine endemic to Corsica of great ecological and economic importance. Many studies of plant phenolic compounds have been carried out concerning responses to various stresses. The aim of this study was to understand i) the effects of prescribed burning 1 to 16 months later and ii) the effects of the seasonality of burning, spring or fall, on the production of phenolic compounds in Pinus laricio. After prescribed burning conducted in spring, Pinus laricio increases the synthesis of total phenolic compounds for a period of 7 months. The increase is greater after spring-burning than fall-burning. With regard to simple phenols, only dihydroferulic acid responds about 1 year after both types of prescribed burning. The causes of these increases are discussed in this paper. Total phenolic compounds could be used as a bioindicator for the short-term response of Pinus laricio needles to prescribed burning. Simple phenols may be useful for revealing the medium-term effects of prescribed burning. The results of this study include recommending forest managers to use prescribed burning in the fall rather than spring to reduce fuel loads and have less impact on the trees.     

Use of SPOT 5 for mapping seagrasses: An application to Posidonia oceanica

The SPOT 5 satellite was launched in May 2002; it provides multispectral imagery with a spatial resolution of 10 m and fused imagery with a spatial resolution of 2.5 m. These types of satellite imagery were used for mapping beds of Posidonia oceanica in the Mediterranean Sea, where it is a dominant species forming monospecific beds in a structurally simple environment (four classes: sand, photophilous algae on rock, patchy seagrass beds and continuous seagrass beds). Supervised classifications by depth range were made of both types of image. A direct comparison of overall accuracy between SPOT 2.5 m and SPOT 10 m revealed that this tool provided accurate mapping in both cases (between 73 and 96% accuracy). Although SPOT 2.5 m provides lower overall accuracy than SPOT 10 m, it is a very useful tool for the mapping of P. oceanica, as it allows the patchiness of the formations to be better taken into account. The opportunity to use a reliability scale, which takes into account the effects of extrinsic factors on the processing of the images, confirmed the usefulness of the option of using a reduced pixel size in order to obtain an improved match between the results from mapping and field observations.