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Norcantharidin (NCTD) is the demethylated analog of cantharidin, with allegedly reduced toxicity. However, there is still limited information regarding its posology and potential risk in its use in cancer treatment. Healthy BDF1 mice were intraperitoneally administered with norcantharidin (0, 3, 6, 12, and 25 mg/kg) every 24 h for 6 days. Survivor mice were euthanized, and the brain, lungs, kidneys, spleen, and liver were procured for enzymatic and histopathological analysis in the liver and kidney. DL50 were 8.86 mg/kg for females and 11.77 mg/kg for males. The treatments with 3.0 mg/kg and 6.0 mg/kg significantly modified the phosphorylase, alanine transaminase, and γ-glutamyl transferase activities; however, an organ-specific response was detected. A significant dose-dependent decrease was observed in the kidney for ROS, while the liver had the opposite effect. Histopathological analysis revealed a significant elevation in hepatocytes' nuclei average size and total area (3 mg/kg), as well as centrilobular vein and adjacent sinusoidal capillaries showed a significant difference. The portal triad presented a significant difference in veins and capillarity count in 6 mg/kg. Renal samples showed cortex convoluted tubules' average size significantly augmented in both doses' groups, and tubule count was found augmented in 6 mg/kg. These physiological effects of NCTD can be exploited as treatment strategies if able to operate in an established posology and proper testing.

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BACKGROUND AND OBJECTIVE: Local tissue oxygenation determines the relationship between the supply and the demand for oxygen by the tissue and it is an important indicator of the physiological or pathological condition of the tissue. Moreover, some therapeutic methods strongly depend on the oxygen content of the tissue. In photodynamic therapy, when molecular oxygen is present, the irradiation of the photosensitizer with light triggers the generation of reactive oxygen species that kill the target diseased cells within the treated tissue. To ensure the best possible therapy response, the tissue must be well oxygenated; hence, oxygen concentration measurement becomes a decisive factor. In this work, the design, construction and calibration of a module to locally measure the blood oxygen saturation in tissue is presented. METHODS: The system is built using a red (660-nm) and an infrared (940-nm) light emitting diodes as light sources, a photodiode as a detector, and a homemade handheld fiber optic-based reflectance pulse oximetry sensor. In addition, the developed sensor was modeled by means of multilayered Monte Carlo simulations, to study its behavior when used in different thickness and melanin content skin. RESULTS: From the simulation reflectance values, the oxygen saturation calibration curves considering different melanin concentrations and skin thicknesses were obtained for two different skin models, one comprising three skin layers and the second, assuming seven different layers for the skin. A comparison of the performances of the developed pulse oximeter sensor with a commercial one is also presented. CONCLUSIONS: A new pulseoximeter for the measurement of local oxygenation in tissue was developed. Its calibration strongly depends on the site of measurement due to the influence of tissue thickness, vascularization, and melanin content. A three-layer skin model is proved to be suitable for the calibration of the pulseoximeter in thin and medium thickness skin.

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Ptilonines A-F, pyranosylmagellanicus D-E and magellenediol are previously undescribed acetogenins isolated from the red alga Ptilonia magellanica. Their structures were determined from spectroscopic evidence. The absolute configuration of the known pyranosylmagellanicus A, was established by derivatization with (R)- and (S)-α-methoxy -α-phenylacetic acids (MPA). Ptilonines exhibit an unusual halogenation pattern, that may confer evolutionary advantages to Ptilonia magellanica, for which a biogenetic origin is proposed. The antimicrobial effect of some of these compounds was evaluated.

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Fundamento: la hipertensión arterial se puede prevenir al modificar los factores de riesgo relacionados con el comportamiento de las personas. En la ciudad de Esmeraldas, Ecuador, no se han realizado estudios que permitan conocer qué factores inciden en esta condición médica. Objetivo: determinar los posibles factores de riesgo cardiovasculares presentes en la población hipertensa de tres barrios del cantón Esmeraldas. Métodos: se realizó un estudio descriptivo, cuantitativo y de corte transversal, desde febrero hasta agosto de 2016. La muestra estuvo constituida por 36 pacientes hipertensos de los 85 casos documentados existentes en los tres barrios, y a los que se les aplicó una encuesta con 15 preguntas cerradas. Las variables utilizadas fueron: edad biológica, factores de riesgo cardiovasculares y desconocimiento de los riesgos por parte de la muestra estudiada. Resultados: el grupo etario de mayor incidencia fue el de 41 a 60 años, el sexo femenino fue el más afectado por la hipertensión, los factores de riesgo cardiovasculares más frecuentes encontrados fueron el sedentarismo, el estrés, seguido por las dietas ricas en sodio Otro de los hallazgos encontrados fue el desconocimiento sobre la enfermedad. Conclusiones: son múltiples los factores de riesgo cardiovasculares que acompañan a la población de hipertensos observados; algunos de esos factores, como el sedentarismo o la obesidad, son determinantes directos de la respuesta al desconocimiento sobre la enfermedad y éstos, asociados a otras condicionantes, podrían incidir de forma importante en su pronóstico cardiovascular.

Background: high blood pressure can be prevented by modifying risk factors related to the behavior of people. In the city of Esmeraldas, Ecuador, studies have not been carried out to know what factors are affecting this medical condition. Objective: to determine the possible cardiovascular risk factors present in the hypertensive population of three neighborhoods of the Esmeraldas canton. Methods: a descriptive, quantitative and cross-sectional study was carried out between February and August 2016. The sample consisted of 36 hypertensive patients from the 85 documented cases in the three neighborhoods, to whom a survey with 15 closed questions was applied. The variables used were biological age, cardiovascular risk factors and lack of knowledge of the risks by the sample studied. Results: the highest incidence was found in the age group between 41 to 60 years of age, with 61,1 % and the female gender was the most affected by hypertension, with 68,3 %; The most frequent cardiovascular risk factors were sedentary lifestyle, with 63,8 % and stress with 50 %, followed by diets high in sodium with 44,4 %. Another finding was the lack of knowledge about the disease. Conclusions: there are multiple cardiovascular risk factors that accompany the hypertensive population studied; some of these factors, such as sedentary lifestyle or obesity, are direct determinants of the response to the disease, and these, associated with other conditions, could have a significant impact on their cardiovascular prognosis.

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This study comprises an innovative approach based on the combination of chromatography (analytical pyrolysis and pyrolysis compound-specific isotope analysis (Py-CSIA)), light stable isotopes, microscopy and mineralogy analyses to characterize the internal layering of coralloid speleothems from the Ana Heva lava tube in Easter Island (Chile). This multidisciplinary proxy showed that the speleothems consist of banded siliceous materials of low crystallinity with different mineralogical compositions and a significant contribution of organic carbon. Opal-A constitutes the outermost grey layer of the coralloids, whereas calcite and amorphous Mg hydrate silicate are the major components of the inner whitish and honey-brown layers, respectively. The differences found in the mineralogical, elemental, molecular and isotopic composition of these distinct coloured layers are related to environmental changes during speleothem development. Stable isotopes and analytical pyrolysis suggested alterations in the water regime, pointing to wetter conditions during the formation of the Ca-rich layer and a possible increase in the amount of water dripping into the cave. The trend observed for δ(15)N values suggested an increase in the average temperature over time, which is consistent with the so-called climate warming during the Holocene. The pyrolysis compound-specific isotope analysis of each speleothem layer showed a similar trend with the bulk δ(13)C values pointing to the appropriateness of direct Py-CSIA in paleoenvironmental studies. The δ(13)C values for n-alkanes reinforced the occurrence of a drastic environmental change, indicating that the outermost Opal layer was developed under drier and more arid environmental conditions.

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