Calendario de inicio sexual en México: Comparación entre encuestas nacionales y tendencias en el tiempo / Sexual debut in Mexico: a comparison of household national surveys

Objetivo. Estimar el calendario de inicio sexual en México y sus tendencias a partir de encuestas poblacionales. Material y métodos. Se analizaron cinco cohortes de nacimiento con cuatro encuestas nacionales (Encuesta Nacional de Salud 2000, Encuesta Nacional de la Dinámica Demográfica 2009, Encuesta Nacional de Juventud 2010 y Encuesta Nacional de Salud y Nutrición 2012) y se identificaron las proporciones de individuos que iniciaron actividad sexual antes de los 16 y antes de los 20 años. Resultados. Las distintas encuestas son, en general, consistentes, pero difieren entre ellas en algunas cohortes. En las cohortes más jóvenes, se identificó una proporción algo mayor de individuos que iniciaron antes de los 20 años; no se advierten cambios en el inicio sexual antes de los 16 años. Conclusiones. La falta de grandes cambios en la edad de inicio de vida sexual con tendencia al adelanto del calendario en México llama a fortalecer la educación sexual integral y la oferta de servicios de salud sexual y reproductiva accesibles a los adolescentes.

Objective. To estimate calendar of sexual debut in Mexico and its trends using national representative household surveys. Materials and methods. Analysis of five birth cohorts extracted from four national population based household surveys in Mexico (National Health Survey 2000, National Survey on Demographic Dynamics 2009, National Youth Survey 2010, and National Health & Nutrition Survey 2012), using as outcome the proportion of individuals that reported sexual debut before the age of 16 and before the age of 20. Results. Overall, the four analyzed surveys produce consistent results, although some differences were found. While a larger proportion among younger cohorts reported sexual debut before the age of 20, that was not the case for sexual debut before 16 years. Conclusions. While data seems to reflect a relative stable age of sexual debut in Mexico, there is a recent trend to prepone sexual initiation that highlights the need to strengthen comprehensive sexual education and the supply of sexual & reproductive health services that are accessible and friendly to adolescents thus responding to the growing demand from this age group.

Production, purification and biochemical characterization of cyclodextrin glucanotrans-ferase from bacillus cereus N1

Cyclodextrin glucanotransferase [CGTase], [EC .2.4.1.19] producing bacteria were isolated from different sources of soils and identified as Bacillus cereus N1 and the best source was the soil of the National Research Centre. The maximum production of the crude CGTase enzyme was observed after 48hr of incubation at 37°C producing CGTase activity of 3.5 U/ml. The effect of nutritional requirements on the CGTasc production were carried out. Soluble starch and yeast extracts were found to be the best carbon and nitrogen sources, respectively. The enzyme was successively purified by ammonium sulphate precipitation, DEAE-cellulose and sephadex G-100 column chromatography and the final specific activity of CGTasc enzyme was increased by 24 fold. The SDS-PAGE showed that the purified CGTase enzyme was homogenous and the molecular weight of the purified enzyme was about 75 kDa. The characterization of the enzyme exhibited optimum pH and temperature at 6.0 and 40°C, respectively. The enzyme was stable at pH 6.5 to 8.0 and retained its high activity up to 45°C

Inhibitory effect of cinnamoyl compounds against human malignant cell line.

In the present study, anti-proliferative effects of dietary polyphenolic compounds have been observed and demonstrated the strong anticancer efficacy of curcumin (CMN), an active constituent of dietary spice (turmeric) using human leukemia cancer cell line. CMN inhibited the proliferation of K562 leukemic cells by induction of apoptosis. The current study demonstrated synergy with combination of drug therapy, and suggested that combination of ferulic acid and cisplatin synergistically inhibited cellular proliferation. Cytotoxic synergy was observed independent of the sequence of addition of two drugs to cultured cells. The synergized growth inhibitory effect with cisplatin was probably associated with G2-M arrest in cell cycle progression. These findings suggested that among the cinnamoyl compounds, CMN was most potent and FER appeared to be a better modulating agent on human malignant cell line.

Interaction of terfenadine with cyclodextrin

The potentiality of molecular interaction of terfenadine with alpha- cyclodextrin [alpha-CyD] and beta-cyclodextrin [beta-CyD] was investigated by spectrophotometric methods. Differential UV spectrophotometry revealed an increase in the optical density of terfenadine in presence of cyclodextrins. Application of the continuous variation method to spectrophotometric measurements revealed equimolar stoichiometry of interaction. The apparent solubility of the drug in presence of alpha- and beta-CyD was investigated and the stability constants [Kc] were estimated from the straight portion of the phase-solubility diagram and found to be higher for the drug beta-CyD system pointing out that the larger the cyclodextrin cavity, the more profitable it would be to include that, bulky terfenadine molecule. Complexes of the drug alpha- and beta- CyDS were prepared and the process of complexation was also monitored by IR spectrophotometry. The dissolution profiles of the drug, physical mixtures of the drug and cyclodextrins as well as the prepared complexes showed enhanced drug dissolution properties of the prepared complexes compared to physical mixtures or the drug per se. The dissolution rate of the drug-beta-CyD complex was found to be higher than that of alpha-CyD complex which runs parallel with their stability constants confirming the great role played by cyclodextrin complexation in enhancing the dissolution rate of the drug

Interaction of dicumarol with beta-cyclodextrin

The potentiality of interaction of dicumarol with beta-cyclodextrin was monitored by spectrophotometry, vapor pressure osmometry and DSC thermograms. The results revealed a very strong evidence for molecular interaction between dicumarol and beta-cyclodextrin

Interaction of hydrochlorothiazide with beta-cyclodextrin

Interaction of hydrochlorothiazide with beta-cyclodextrin was investigated by spectrophotometry, vapor pressure osmometry and differential scanning calorimetry. The results revealed a very strong evidence for molecular interaction between hydrochlorothiazide and cyclodextrin. The continuous variation method was utilized to elucidate the stoichiometry of molecular interaction via spectrophotometric as well as vapor pressure measurements. Both types of data are in full agreement and revealed the formation of 1:1 complex. The stability constant of the complex was determined at different temperatures by the vapor pressure osmometric method. The complex was found to undergo partial dissociation with increasing temperature above 25C and more or less complete dissociation at 60C. The apparent solubility of the drug in presence of beta-cyclodextrin was found to increase to a marked extent. The amount of drug solubilized in the form of complex was determined and the results revealed that the solubilizing effect of beta-cyclodextrin is entirely due to complex-formation. The dissolution profiles of the drug, physical mixture of the drug and beta-cyclodextrin as well as the prepared complex showed an enhancement of drug dissolution from the prepared complex or the physical mixture compared to the drug per se. The effect of beta-cyclodextrin on the bioavailability of hydrochlorothiazide was determined by quantifying the diuretic effect of the drug in healthy human volunteers. The data revealed that, coadministration of the drug with beta-cyclodextrin either in the form of physical mixture or complex leads to an increase in the diuretic response intensity and there is a good correlation between the in vivo performance of the drug and its dissolution rate determined according to the USP rotating basket method

Inclusion complexion of ketoprofen with B-cyclodextrin and hydroxypropyl B-cyclodextrin in water and in solid state

Inclusion complexation of ketoprofen with beta -cyclodextrin[beta -CD] and hydroxypropyl beta cyclodextrin [HP beta -CD] in aqueous solutions and in the solid phase were examined by phase solubility diagrams, infrared spectroscopy, and diffraction patterns. Ketoprofen-cyclodextrin inclusion complexes were obtained applying different techniques including spray drying, freeze drying, evaporation under vacuum and co-grinding in presence and absence of water. The dissolution profile of ketoprofen was highly improved in the complexed from compared to non- treated ketoprofen or its physical mixtures with either- beta CD or HP beta-CD in the same ratio

Complexation of khellin with different cyclodextrins

Inclusion complexation of khellin and beta cyclodextrin [beta CD], gamma cyclodextrin [gamma CD] and hydroxypropyl beta cyclodextrin [HP beta CD] in water and in solid state were studied by the solubility method, UV spectrophotometry, differential scanning calorimetry [DSC], X-ray diffractometry, IR-spectroscopy and dissolution study. Solubility of khellin in water increased with the addition of cyclodextrins. The complex system formed had 1: 1 stoichiometric ratio with beta, gamma and HP beta CD. The apparent 1: 1 stability constant of khellin complexes with beta, gamma and HPBCD were 27.71 M-1, 66.67 M-1, 32.46 M-1 respectively. Phase solubility studies revealed 14, 24 and 35 fold increase in the solubility of khellin in the presence of cyclodextrins. More evidence of complex formation was obtained from the analysis of UV, IR, DSC and X-ray diffraction studies. The dissolution rate of khellin was significantly enhanced by complexation with cyclodextrins