Variación estacional de niveles de vitamina d en adultos de la región central de Chile / Seasonal variation of vitamin d levels in adults in the Chile´s central region

Objetivos: Comparar los niveles plasmáticos de Vitamina D (VD) en adultos en dos períodos estacionales y evaluar algunos factores que afectan a estos niveles. Pacientes y métodos: Estudio de corte transversal en el que se estudiaron adultos en dos períodos de tiempo, agosto a octubre de 2018 (grupo 1) y febrero a abril de 2019 (grupo 2). Se midieron niveles plasmáticos de VD a ambos grupos. Se obtuvieron datos demográficos y clínicos, incluyendo el uso de suplementos de VD, a través de un cuestionario autoaplicado validado. Se clasificó el nivel de VD en deficiente (< 20 ng/dl), insuficiente (21-30 ng/dl), y suficiente (> 30 ng/dl). Se consideró adulto mayor (AM) a sujetos de ≥ 65 años. Resultados: 207 pacientes (104 en el grupo 1 y 103 en grupo 2), 165 fueron mujeres. Un 31,9% (n=66) tenía niveles deficientes de VD y un 42,5% (n=88) utilizaba algún tipo de suplemento de VD. Los niveles de VD fueron mayores en el grupo 2 (media 31,2 ng/dl) respecto al grupo 1 (media 24,1 ng/dl; p<0,0001), pero esta diferencia solo fue significativa en quienes tomaban suplementos de VD. Por otro lado, el uso de suplemento de VD se asoció a niveles más altos de VD (media 33,1 ng/ml; p<0.001). Además, hubo mayores niveles en pacientes mayores de 65 años (p<0,01). No hubo diferencias estadísticamente significativas en niveles de VD según sexo ni estado nutricional. Conclusión: Se observaron mayores niveles de VD en usuarios de suplementos de esta vitamina, sin diferencias según período estacional.

Objectives:To compare plasmatic levels of vitamin D in adults in two seasonal periods and evaluate some factors affecting these levels. Patients and methods: Transversal cohort study in which adults were studied in two time periods, August to October 2018 (group 1) and February to April 2019 (group 2). Plasmatic levels of vitamin D were measured in both groups. Demographic and clinical details, including the use of vitamin D supplements, were obtained through a self-administered questionnaire. Results were classified as deficient (<20ng/dL), insufficient (21 ­ 30 ng/dL) and normal (>30 ng/dL). The elderly were defined to be the ≥65´s. Results: 207 patients (104 in group 1 and 103 in group 2), 165 were female. 31.9% (n=66) had deficient levels of vitamin D and 42,5% (n=88) used a vitamin D supplement. Vitamin D levels were higher in group 2 (median 31.2 ng/dL) compared with group 1 (median 24.1 ng/dL; p<0.0001), but this difference was significant only in those taking vitamin D supplements. On the other hand, use of vitamin D supplements was associated with higher vitamin D levels (median 33.1 ng/dL; p<0.001). Moreover, levels were higher in the over 65s (p<0.01). There were no statistically significant differences in vitamin D levels found between sexes or different nutritional states. Conclusion: Higher vitamin D levels were observed in persons taking vitamin D supplements. There were no seasonal differences.

Characterization of a putative grapevine Zn transporter, VvZIP3, suggests its involvement in early reproductive development in Vitis vinifera L.

BACKGROUND: Zinc (Zn) deficiency is one of the most widespread mineral nutritional problems that affect normal development in plants. Because Zn cannot passively diffuse across cell membranes, it must be transported into intracellular compartments for all biological processes where Zn is required. Several members of the Zinc-regulated transporters, Iron-regulated transporter-like Protein (ZIP) gene family have been characterized in plants, and have shown to be involved in metal uptake and transport. This study describes the first putative Zn transporter in grapevine. Unravelling its function may explain an important symptom of Zn deficiency in grapevines, which is the production of clusters with fewer and usually smaller berries than normal. RESULTS: We identified and characterized a putative Zn transporter from berries of Vitis vinifera L., named VvZIP3. Compared to other members of the ZIP family identified in the Vitis vinifera L. genome, VvZIP3 is mainly expressed in reproductive tissue - specifically in developing flowers - which correlates with the high Zn accumulation in these organs. Contrary to this, the low expression of VvZIP3 in parthenocarpic berries shows a relationship with the lower Zn accumulation in this tissue than in normal seeded berries where its expression is induced by Zn. The predicted protein sequence indicates strong similarity with several members of the ZIP family from Arabidopsis thaliana and other species. Moreover, VvZIP3 complemented the growth defect of a yeast Zn-uptake mutant, ZHY3, and is localized in the plasma membrane of plant cells, suggesting that VvZIP3 has the function of a Zn uptake transporter. CONCLUSIONS: Our results suggest that VvZIP3 encodes a putative plasma membrane Zn transporter protein member of the ZIP gene family that might play a role in Zn uptake and distribution during the early reproductive development in Vitis vinifera L., indicating that the availability of this micronutrient may be relevant for reproductive development.

Tea flavanols inhibit cell growth and DNA topoisomerase II activity and induce endoreduplication in cultured Chinese hamster cells.

Tea polyphenols are promising chemopreventive anticancer agents, the properties of which have been studied both in vitro and in vivo, providing evidence that - within this group of compounds - the tea flavanols are able to inhibit carcinogenesis, an effect that in some cases could be correlated with increased cell apoptosis and decreased cell proliferation. Of four main tea flavanols, namely (-)-epigallocatechin-3-gallate (EGCG), (-)-epigallocatechin (EGC), (+)-catechin (CA) and (-)-epicatechin (EC), it was found that EGCG was the most potent to inhibit dose dependently the topoisomerase II (TOPO II) catalytic activity isolated from hamster ovary AA8 cells. In the range of concentrations that caused TOPO II inhibition, a high level of endoreduplication, a rare phenomenon that consists in two successive rounds of DNA replication without intervening mitosis, was observed, while neither micronuclei nor DNA strand breaks (Comet assay) were detected at the same doses. We propose that the anticarcinogenic effect of tea flavanols can be partly explained by their potency and effectiveness to induce endoreduplication. Concerning such an induction, maximum effect seems to require a pyrogallol structure at the B-ring. Additional substitution with a galloylic residue at the C3 hydroxyl group leads to further augmentation of the effect. Thus, we suggest that the chemopreventive properties of tea flavanols can be at least partly due to their ability to interfere with the cell cycle and block cell proliferation at early stages of mitosis.

Anti-tumour activity of Digitalis purpurea L. subsp. heywoodii.

Recent research has shown the anticancer effects of digitalis compounds suggesting their possible use in medical oncology. Four extracts obtained from the leaves of Digitalis purpurea subsp. heywoodii have been assessed for cytotoxic activity against three human cancer cell lines, using the SRB assay. All of them showed high cytotoxicity, producing IC50 values in the 0.78 - 15 microg/mL range with the methanolic extract being the most active, in non toxic concentrations. Steroid glycosides (gitoxigenin derivatives) were detected in this methanolic extract. Gitoxigenin and gitoxin were evaluated in the SRB assay using the three human cancer cell lines, showing IC50 values in the 0.13 - 2.8 microM range, with the renal adenocarcinoma cancer cell line (TK-10) being the most sensitive one. Morphological apoptosis evaluation of the methanolic extract and both compounds on the TK-10 cell line showed that their cytotoxicity was mediated by an apoptotic effect. Finally, possible mechanisms involved in apoptosis induction by digitalis compounds are discussed.

Cytotoxic effect of Plantago spp. on cancer cell lines.

Methanolic extracts from seven Plantago species used in traditional medicine for the treatment of cancer, were evaluated for cytotoxic activity against three human cancer cell lines recommended by the National Cancer Institute (NCI, USA). The results showed that Plantago species exhibited cytotoxic activity, showing a certain degree of selectivity against the tested cells in culture. Since the flavonoids are able to strongly inhibit the proliferation of human cancer cell lines, we have identified luteolin-7-O-beta-glucoside as major flavonoid present in most of the Plantago species. Also, we have evaluated this compound and its aglycon, luteolin, for their cytotoxic and DNA topoisomerase I poisons activities. These results could justify the traditional use of the Plantago species and topoisomerase-mediated DNA damage might be a possible mechanism by which flavonoids of Plantago exert their cytotoxicity potential.

Efecto antihipertensivo de la nifedipina comparado con metoprolol y alfa metil dopa / Antihypertensive effect of the nifedipine compared with metoprolol and alpha methyl dopa

Estudiamos 100 pacientes con Hipertension Arterial Sistemica (H.A.S) asociada y/o complicada en el Hospital HGZ 1-A I.M.S.S. se clasificaron en 4 gruposGrupo A: Pacientes con H.A.S esencial; Grupo B: H.A,S. asociada a Cardiopatia isquemica. Grupo C; H.A.S.e insuficiencia Renal Cronica. Grupo D: H.A.S. asociado a EPOC. El estudio fue propspectivo, abierto de grupos aleatorios. Se lograronefectos beneficos en todos los pacientes tratados con Nifedipina con diferencia significativa comparando con Alfa Metil Dopa (P 0.001) y efectos similares con el Metoprolol con una clara indicacion de H.A.S. leve o moderada y ademas disminuye la isquemia del Miocardo Nifedipina y Metoprolol fueron superiores a la Alfa Metil Dopa