Influence of SDZ-PSC833 on daunorubicin intracellular accumulation in bone marrow specimens from patients with acute myeloid leukaemia

From August 1987 through February 1995 we performed 42 surgical procedures in 29 patients with occluded or stenotic radiocephalic arteriovenous fistulae. Operations were designed to preserve native veins for cannulation (Group I) or to preserve access in the same forearm, bypassing the failed fistula (Group II). For 27 procedures in 22 Group I patients, cumulative primary patency was 70%, 57%, and 47% at 6, 12, and 18 months, respectively. A subgroup of patients was identified, however, in whom excellent results could be reliably predicted. Among 19 hemodynamically stable patients with mature fistulae amendable to more proximal arteriovenous anastomoses, cumulative primary patency was 100%, 81%, and 67% at 6, 12, and 18 months, respectively. Secondary patency for 17 such patients was 100%, 89% and 89% for these same intervals. In Group II only two of ten patients required use of other access sites (9 1/2, 18 1/2 months). We believe that all occluded or stenotic radiocephalic arteriovenous fistulae should be considered for surgical salvage. Excellent results can be predicted for (1) hemodynamically stable patients with (2) mature fistulae that (3) fail near the arterial anastomosis and are (4) amendable to new more proximal arteriovenous anastomoses.     

Study of congenital cardiopathies with left-right shunt using gamma-angiocardiography

Red blood cells labelled with radioactive Technetium were injected intravenously, and the passage of the tracer through the cardio-pulmonary system recorded using a scintillation camera coupled with a numerical dosimeter. The results are presented as serial analoque pictures taken at the rate of two per second, as numerical tracings which are later processed, and as flow charts from predetermined areas of interest: the chambers of the heart, the lung parenchyma, and the aorta. This study is concerned with 58 patients with a left-to-right shunt, and about 40 normal examinations were used as a baseline for comparison. In cases of left-to-right shunt, the finding on the tracings is of abnormally prolonged activity in the lungs after a normal passage through the right side. The intensity-duration curves highlight this finding, and show an early recirculation peak in the right side of the heart and a slowing of pulmonary emptying, which can be evaluated numerically from the ratio C2/C1. A correlation has been found between this value and the ratio of pulmonary to systemic flow as calculated by oximetry. The correlation is even closer if a comparison is made between the curves of pulmonary radioactivity and the dye dilution curves. In certain cases, the shunt can be localised to the atrial or ventricular level. There are many indications for this safe investigation: --the diagnosis and monitoring of the flow through a left-to-right shunt in a child; --confirmation of the closure of septal defects after surgery; --clarification of an infudibulo-pulmonary syndrome.     

Real-Time Electrochemical PCR with a DNA Intercalating Redox Probe

The proof-of-principle of a nonoptical real-time PCR method based on the electrochemical monitoring of a DNA intercalating redox probe that becomes considerably less easily electrochemically detectable once intercalated to the amplified double-stranded DNA is demonstrated. This has been made possible thanks to the finding of a redox intercalator that (i) strongly and specifically binds to the amplified double-stranded DNA, (ii) does not significantly inhibit PCR, (iii) is chemically stable under PCR cycling, and (iv) is sensitively detected by square wave voltammetry during PCR cycling. Among the different DNA intercalating redox probes that we have investigated, namely, methylene blue, Os[(bpy)(2)phen](2+), Os[(bpy)(2)DPPZ](2+), Os[(4,4'-dimethyl-bpy)(2)DPPZ](2+) and Os[(4,4'-diamino-bpy)(2)DPPZ](2+) (with bpy = 2,2'-bipyridine, phen = phenanthroline, and DPPZ = dipyrido[3,2-a:2',3'-c]phenazine), the one and only compound with which it has been possible to demonstrate the proof-of-concept is the Os[(bpy)(2)DPPZ](2+). In terms of analytical performances, the methodology described here compares well with optical-based real-time PCRs, offering finally the same advantages than the popular and routinely used SYBR Green-based real-time fluorescent PCR, but with the additional incomes of being potentially much cheaper and easier to integrate in a hand-held miniaturized device.     

Novel optically active methacrylic polymers containing side-chain porphyrin moieties for chiral recognition

Novel optically active methacrylic homopolymers bearing in the side chain one or more chiral groups of one single configuration (l-lactic acid residue) linked to tetraphenylporphyrin have been successfully synthesized and fully characterized.These intrinsically chiral polymers exhibit remarkable thermal stability, with glass transition temperature in the range 250-315 °C and decomposition temperatures in the range 360-390 °C. Spectroscopic, thermal and chiroptical characterizations indicate the occurrence of dipolar interactions among the side chain moieties and the presence of chiral helix conformation at least for chain segments of the macromolecules.The macromolecular Zinc-porphyrin material resulted capable to bind optically active α,ω-diamine guests through nitrogen/zinc coordination to form complexes exhibiting exciton-coupled bisignate Circular Dichroism (CD) spectra with signs related to the absolute configuration of the guest compound. This behavior is due to the formation of diastereomeric complexes which lead to a preferred porphyrin helicity, at least for chain segments. The method turns out to be very sensitive, requiring only few micrograms of guest compound.     

Hydrogen storage properties of various carbon supported NaBH4 prepared via metathesis

Sodium borohydride nanoparticles prepared via the metathesis reaction between LiBH₄ and NaCl were successfully deposited on various carbon supporting materials such as graphite, graphene oxide and carbon nanotubes. The X-ray diffraction analyses were conducted to identify the phase of NaBH₄ deposited on various carbon supporting materials. The transmittance electron micrograph analyses were also conducted to investigate the particle size and dispersion of NaBH₄ within carbon supporting materials. The particle size and size distribution of NaBH₄ on graphite were observed to be larger and broader than of other two supporting materials, graphene oxide and CNT due to the lower surface energy as compared to GO and CNT. The bonding state of NaBH₄ was confirmed by the Fourier-transformed infrared spectroscopy analysis. The TG and PCT results show that the hydrogen desorption of the NaBH₄ deposited on carbon supports takes place at temperature (130 °C～) significantly lower than that of pure NaBH₄ (above 500 °C) and the amount of desorption was in the order of graphene oxide (12.3 mass %) > CNT (9.8 mass %) > graphite (5.7 mass %). The reversibility of hydrogen adsorption after five cycles of adsorption-desorption showed that NaBH₄/GO and NaBH₄/CNT were much better than that of pure NaBH₄ due to excellent structural stability.     

Expert system based on computer vision to estimate the content of impurities in olive oil samples

The determination of the content of impurities is a very frequent analysis performed on virgin olive oil samples, but the official method is quite work-intensive, and it would be convenient to have an alternative approximate method to evaluate the performance of the impurity removal process. In this work we develop a system based on computer vision and pattern recognition to classify the content of impurities of the olive oil samples in three sets, indicative of the goodness of the separation process of olive oil after its extraction from the paste. Starting from the histograms of the channels of the Red–Green–Blue (RGB), CIELAB and Hue-Saturation-Value (HSV) color spaces, we construct an initial input parameter vector and perform a feature extraction previous to the classification. Several linear and non-linear feature extraction techniques were evaluated, and the classifiers used were Support Vector Machines (SVMs) and Artificial Neural Networks (ANNs). The best classification rate achieved was 87.66%, obtained using Kernel Principal Components Analysis (KPCA) and a grade-3-polynomial kernel SVM. The best result using ANNs was 82.38%, yielded by the use of Principal Component Analysis (PCA) with the Perceptron.     

Blanching of Strawberries by Ohmic Heating: Effects on the Kinetics of Mass Transfer during Osmotic Dehydration

The effect of blanching by ohmic heating (OH) on the kinetics of osmotic dehydration of strawberries was studied. Ohmic heating parameters obtained at two temperatures (65 and 85 °C). The osmotic dehydration (OD) parameters are the temperature (26 and 37 °C) and the sucrose in osmotic solution (30–70 °B). An approximate solution of Fick’s law for unsteady state mass transfer in spherical configuration has been used to calculate the effective diffusion coefficients of water and sucrose. Results show that ohmic heating increases drastically the mass transfer and the effective diffusion rates. After 4 h of OD (without OH) in a sucrose solution (at 37 °C and 70 °B), the dry matter of the untreated strawberry halves was 20.3%; while it reached 68% when OD was combined with blanching by OH at 85 °C for 3-min. Ohmic blanching permits the effective damage of cells by combination of electrical and thermal effects. That result has an important enhancement of water and sugar transfers during osmotic dehydration of strawberries.