Autocrine and paracrine purinergic signaling in the most lethal types of cancer.

Cancer comprises a collection of diseases that occur in almost any tissue and it is characterized by an abnormal and uncontrolled cell growth that results in tumor formation and propagation to other tissues, causing tissue and organ malfunction and death. Despite the undeniable improvement in cancer diagnostics and therapy, there is an urgent need for new therapeutic and preventive strategies with improved efficacy and fewer side effects. In this context, purinergic signaling emerges as an interesting candidate as a cancer biomarker or therapeutic target. There is abundant evidence that tumor cells have significant changes in the expression of purinergic receptors, which comprise the G-protein coupled P2Y and AdoR families of receptors and the ligand-gated ion channel P2X receptors. Tumor cells also exhibit changes in the expression of nucleotidases and other enzymes involved in nucleotide metabolism, and the concentrations of extracellular nucleotides are significantly higher than those observed in normal cells. In this review, we will focus on the potential role of purinergic signaling in the ten most lethal cancers (lung, breast, colorectal, liver, stomach, prostate, cervical, esophagus, pancreas, and ovary), which together are responsible for more than 5 million annual deaths.

Measurement of thermodiffusion coefficient of hydrocarbon binary mixtures under pressure with the thermogravitational technique.

It was designed and constructed a new thermogravitational column able to operate at high pressures (up to 50 MPa). This new thermogravitational column is of the cylindrical type with closed ends. It is made of stainless steel. The length of the column is 0.5 m and the gap between its two walls is variable. First, the column was validated at atmospheric pressure by means of measurements of the thermodiffusion coefficient of well-known binary mixtures. Then, this new thermogravitational column was used to measure the thermodiffusion coefficient of the binary mixtures 1,2,3,4-tetrahydronaphtalene/isobutylbenzene, 1,2,3,4-tetrahydronaphtalene/n-dodecane, and isobutylbenzene/n-dodecane at high pressures and within the pressure range between 0.1 and 20 MPa at a mean temperature of 25 °C. We have found a linear dependence between the thermodiffusion coefficient and the pressure.

Determination of molecular diffusion coefficient in n-alkane binary mixtures: empirical correlations.

In this work we have measured the molecular diffusion coefficient of the n-alkane binary series nC(i)-nC(6), nC(i)-nC(10), and nC(i)-nC(12) at 298 K and 1 atm and a mass fraction of 0.5 by using the so-called sliding symmetric tubes technique. The results show that the diffusion coefficient at this concentration is proportional to the inverse viscosity of the mixture. In addition, we have also measured the diffusion coefficient of the systems nC(12)-nC(6), nC(12)-nC(7), and nC(12)-nC(8) as a function of concentration. From the data obtained, it is shown that the diffusion coefficient of the n-alkane binary mixtures at any concentration can be calculated from the molecular weight of the components and the dynamic viscosity of the corresponding mixture at 50% mass fraction.

Measurement of thermodiffusion coefficient in n-alkane binary mixtures: composition dependence.

In this work, we have measured the thermodiffusion coefficient of different n-alkane binary mixtures at several concentrations using the thermogravitational technique. In particular, we have studied the n-dodecane/n-heptane system as a function of composition and other systems covering a large range of mass differences and concentration at 25 degrees C and 1 atm. The results show that for any concentration the thermodiffusion coefficient of n-alkane mixtures is proportional to the mass difference between the components and to the ratio of the thermal expansion coefficient and viscosity of the mixture. The obtained equation allows us to determine the infinite dilution values of the thermodiffusion coefficient. We compare these values with recent experimental results in dilute polymer solutions and analyze the Brenner theory of thermodiffusion. Finally, it is shown that the thermodiffusion coefficient depends linearly with the mass fraction, and it can be calculated from the viscosity and thermal expansion of the pure components.

Soret coefficients in some water-methanol, water-ethanol, and water-isopropanol systems.

In this article, we re-examine the published experimental values of the Soret coefficients of a few water-alcohol systems at a mean temperature of 37.5 degrees C, because we feel that these published values (including microgravity values) are doubtful. The main technique applied is the use of thermogravitational columns to determine the thermodiffusion coefficient. The obtained values did not agree with the published values; worse, sometimes the sign was different.

[The effect of antihypertensive therapy on left ventricular mass and diastolic filling in light and moderate hypertension]. / Efecto de la terapia antihipertensiva sobre la masa ventricular izquierda y el llenado diastólico en la hipertensión ligera a moderada.

BACKGROUND: To valorate the effect of four antihypertensive drugs on the regression of cardiac mass and diastolic function, by echocardiography-Doppler, in not treated hypertensive subjects. METHODS: 60 mild-moderate hypertensive subjects were studied randomized in four groups of 15 patients each one: enalapril (10-40 mg/d), atenolol (25-100 mg/d), verapamil-retard (120-240 mg/d), alphametildopa (250 mg/8h to 3 g/d). The active drug therapy phase was 6 months, performing echo-Doppler, evaluating posterior-wall and septal-wall thicknesses, ventricular mass index, ratio of early to atrial peak diastolic filling velocity (E/A), the first-third filling fraction and atrial filling fraction. RESULTS: The cardiac mass index decreased with the four drugs: with enalapril from 178 +/- 28 to 155 +/- 29 g/m2 (p < 0.05), with atenolol from 170 +/- 23 to 154 +/- 19 g/m2 (p < 0.05), with verapamil from 180 +/- 27 to 159 +/- 22 g/m2 (p < 0.05) and with alphametildopa from 176 +/- 30 to 142 +/- 22 g/m2 (p < 0.01). The E/A ratio and first-third filling fraction only improved in the atenolol subgroup, from 0.79 +/- 0.13 to 0.97 +/- 0.16 (p < 0.01) and from 36 +/- 5 to 44 +/- 9% (p < 0.01), decreasing atrial filling fraction from 37 +/- 6 to 30 +/- 8% (p < 0.01), without modifying with enalapril (0.74 +/- 0.14 to 0.76 +/- 0.20, 35 +/- 5% to 36 +/- 7%, 38 +/- 5 to 39 +/- 7%, p = NS), verapamil (0.69 +/- 0.12 to 0.74 +/- 0.17, 35 +/- 6% to 36 +/- 8% to 40 +/- 12%, p = NS) neither alphametildopa (0.72 +/- 0.14 to 0.71 +/- 0.21, 34 +/- 5% to 35 +/- 7%, 40 +/- 6% to 41 +/- 9%, p = NS). The heart rate decreased more with atenolol than with the other drugs (61 +/- 15 vs 71 +/- 12, p < 0.01). CONCLUSIONS: In hypertensive patients the decreasing of cardiac mass is not accompanied of improvement of the diastolic function except in patients treated with atenolol, probably due to bradycardia.

[The 2-dimensional and Doppler color echocardiographic study of a congenital aneurysm of the sinus of Valsalva with a fistula of the right atrium in an adult]. / Estudio con ecografía bidimensional y Doppler en color de un aneurisma congénito del seno de Valsalva con fístula a la aurícula derecha en un adulto.

This report describe a 69-year old woman with a congenital aneurysm of the non-coronary sinus of Valsalva ruptured in the right atrium, causing severe hemodynamic derangement of the right ventricle. The site of the communication between the aneurysm and the receiving chamber was accurately diagnosed by two-dimensional color flow Doppler imaging which provided more valuable preoperative information than conventional aortography.

[Doppler analysis of mitral flow in mild to moderate hypertension]. / Análisis de la curva de flujo Doppler mitral en la hipertensión arterial leve a moderada.

We evaluate by Echo-Doppler the left ventricular relaxation disturbance produced by mild to moderate hypertension. It's a comparative study between 15 healthy and 40 patients with hypertension (diastolic blood pressure between 90-114 mmHg and/or systolic greater than 160 mmHg). Echocardiography was performed in all cases and diameters, thickness, volumes, ejection fraction, mass, transmitral flow by Doppler and cardiac output were evaluated . In hypertensive patients the septal and posterior wall thicknesses were significantly higher (1.39 +/- 0.2 cm vs 1.1 +/- 0.1, p less than 0.001 cm. and 1.26 +/- 0.12 cm vs 0.98 +/- 0.1 cm, p less than 0.001), and also the absolute mass and corrected according to corporal surface (339 +/- 58 g vs 203 +/- 44, p less than 0.001, and 185 +/- 34 g/m2 vs 115 +/- 16, p less than 0.001). In transmitral flow Doppler the higher isovolumetric period and lower diastolic filling in the first 1/3 (71 +/- 19 msec vs 53 +/- 20, p less than 0.05, and 35 +/- 5% vs 52 +/- 4%, p less than 0.001) are indicators of relaxation disturbance. A lower deceleration of early inflow and a higher deceleration time (265 +/- 98 cm/sec2/vs 454 +/- 139, p less than 0.001, and 226 +/- 38 msec vs 156 +/- 15, p less than 0.001) show compliance damage. The atrial filling was significantly higher in hypertensive patients (37 +/- 7% vs 20 +/- 8%, p less than 0.001). The E/A ratio, separate both groups but corrected by the age the signification was rather lower.(ABSTRACT TRUNCATED AT 250 WORDS)