Enhanced cancer cell killing of a Pt(IV) prodrug promoted by outer-sphere coordination with polyethyleneimines.

The cisplatin prodrug c,c,t-[Pt(NH3)2Cl2(O2CCH2CH2CO2)2](2-) (1) forms outer-sphere coordination interactions with non-toxic low MW PEI, which results in enhanced cancer cell killing, also achieved using PEI-coated AuNPs.

Near infrared photolysis of a Ru polypyridyl complex by upconverting nanoparticles.

NaYF4:Yb(3+)/Er(3+)nanocrystals upconvert near infrared light (980 nm) into higher energy visible photons capable of effecting the photodissociation of the monodentate pyridyl ligand in cis-[Ru(bpy)2(py)2]Cl2: opening an opportunity for advancing the use of photoactivatable metal complexes in medicine and biology.

Interchain hydrogen-bonding interactions may facilitate translocation of K+ ions across the potassium channel selectivity filter, as suggested by synthetic modeling chemistry.

A 4-fold symmetric arrangement of TVGYG polypeptides forms the selectivity filter of the K+ channel from Streptomyces lividans (KcsA). We report the synthesis and properties of synthetic models for the filter, p-tert-butyl-calix[4]arene-(OCH(2)CO-XOBz)(4) (X = V, VG, VGY), 1-3. The first cation (Na+, K+) binds to the four -[OCH(2)CO]- units, a region devised to mimic the metal-binding site formed by the four T residues in KcsA. NMR studies reveal that cations and valine amide protons compete for the carbonyl oxygen atoms, converting NH(Val)...O=C hydrogen bonds to M+ ...O=C bonds (M+ = Na+ or K+). The strength of these interchain NH(Val)...O=C hydrogen bonds varies in the order 3 > 2 > 1. We propose that such interchain H-bonding may destabilize metal binding in the selectivity filter and thus help create the low energy barrier needed for rapid cation translocation.

Demencias Vasculares / Vascular dementia

Las demencias vasculares representam un problema médico serio. Constituyen la segunda causa de demencia en el mundo occidental y tienen un pronóstico peor que la enfermedad de Alzheimer. Su estudio ha permanecido por mucho tiempo relativamente inexplorado, quizá en parte por la diversidad de factores asociados a la génesis de la enfermedad. Este aparente olvido de una de las patologías de más prevalencia entre el grupo de personas mayores de 65 anos se ha traducido en el surgimiento de un sinnúmero de términos para una misma patología, lo cual ha dificultado en gran modo una adecuada definición del término. Las consecuencias de la falta de claridad en la fisiopatología y en el diagnóstico mismo de la enfermedad se refleja en las pocas medidas terapéuticas disponibles. En el momento, existe la feliz coincidencia de criterios diagnósticos más precisos y el desarrollo de técnicas imagenológicas que permiten una visualización más precisos de lo que sucede en el cerebro de estos pacientes. Este artículo tratara sobre el estado del arte de las demencias vasculares con un énfasis especial en los estudios que involucran las nuevas técnicas de evaluación imagenológica

Niveles lipídicos y calcificaciones coronarias detectadas por radioscopia con intensificador de imágenes TV en una población asintomática / Lipidic levels and fluoroscopyc detection of coronary artery calcification in asymptomatic subjects

Es sabido que la detección precoz de la arterosclerosis coronaria disminuye el riesgo de infarto. Con tal motivo se estudiaron 104 pacientes, de 52 años de edad promedio, mediante radioscopia TV. De acuerdo a los resultados de la calcificación coronaria CC y al número de territorios involucrados se clasificaron los pacientes en varios grupos, concluyendo que la radioscopia TV es un método de alta sensibilidad, bajo costo, rapidez y seguridad para la detección de CC

Liquid chromatographic determination of carminic acid in yogurt.

A reverse-phase liquid chromatographic method is described for the determination of carminic acid in yogurt. A C18 column is used with acetonitrile-1.19M formic acid (19 + 81) as mobile phase and diode array detection. Sample preparation includes deproteinization with papain and purification in a polyamide column. The relative standard deviation for repeated determinations of carminic acid in a commercial strawberry-flavored yogurt was 3.0%. Recoveries of carminic acid added to a natural-flavored yogurt ranged from 87.2 to 95.3% with a mean of 90.2%. The method permits measurement of amounts as low as 0.10 mg/kg.

[Drug use among students in Cali, Colombia]. / Uso de drogas entre estudiantes de Cali, Colombia.

The use of alcohol, tobacco, marihuana, cocaine, and bazuco was examined in a cross-sectional study of a random sample of 512 secondary-school students enrolled in public and private schools in Cali, Colombia. The overall prevalence of use for any of these substances was 59.38% in the public schools and 36.96% in the private schools (z = 4.6, P less than 0.05). The probability of finding an alcohol user was about 55.26%. The frequency of use for all the substances was 18.9% in the public schools and 7.46% in the private ones. Experience with marihuana, cocaine, and bazuco was more frequent in the public schools. The average age of users (19.91 years) was higher than that of non-users (16.25 years): t = 8.34, P less than 0.05. Students in the public schools with a family history of mental illness had almost a ninefold greater risk of being substance users (RR = 8.84, IC 95% = 1.22-3.37); among students in the private schools, having personal conflicts with authority figures (teachers and the police) was a significant risk factor (RR = 2.03, IC 95% = 1.22-3.37).