938 research outputs found

    Characterization of Diclofenac Liposomes Formulated with Palm Oil Fractions

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    Purpose: To characterize diclofenac sodium (DS) liposomes prepared using palm oil fractions.Methods: Reverse-phase evaporation method was used to prepare liposomes containing 10, 20, 30 , 40 or 50% palm oil fractions. The effect of palm oil content on liposome formation, surface morphology, shape, size and zeta potential of the liposomes were studied using scanning electron microscopy (SEM) transmission electron microscopy (TEM) and particle analyzer. Drug loading, entrapment efficiency and in vitro drug release were measured in phosphate-buffered saline (PBS, pH 7.4) by UV spectrophotometry.Results: TEM and SEM images showed formation of liposomes for all formulations, However, increase in the proportion of palm oil in the formulations significantly reduced particle size and increased zeta potential. The effect on drug loading and drug release varied with palm oil fraction. The best release pattern with appropriate entrapment efficiency and stability was obtained with liposomes containing 33 % palm oil fraction. Introduction of 46 and 56 % of palm oil fractions yielded zeta potential of -42.8 and - 50.7 mV, respectively, compared with -31.2 mV for the formulation without palm oil.Conclusion: The results demonstrate the potentials of palm oil fractions in the preparation of suitable DS liposomes with good bioavailability.Keywords: Liposome, Drug delivery, Palm oil, Diclofenac

    Identifying the favored mutation in a positive selective sweep.

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    Most approaches that capture signatures of selective sweeps in population genomics data do not identify the specific mutation favored by selection. We present iSAFE (for "integrated selection of allele favored by evolution"), a method that enables researchers to accurately pinpoint the favored mutation in a large region (∼5 Mbp) by using a statistic derived solely from population genetics signals. iSAFE does not require knowledge of demography, the phenotype under selection, or functional annotations of mutations

    Evaluation of sperm chromatin integrity using aniline blue and toluidine blue staining in infertile and normozoospermic men

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    Background: Male infertility is defined as a man lost his ability to fertilize a fertile female naturally. Diagnosis of male infertility cannot be made just according to basic semen analysis. It is necessity to have specific tests for evaluation of chromatin integrity. In this study, an attempt was made to evaluate the sperm chromatin quality in fertile men and infertile subgroup. Methods: Among 1386 couples, 342 men were categorized into normospermia and 1044 were infertile and they were referred to Yazd Research and Clinical Center for infertility treatment. Standard semen analysis and sperm nuclear maturity tests including aniline blue (AB) and toluidine blue (TB) staining were done. Data were analyzed by SPSS software. The p=0.05 was considered statistically significant. Results: The mean value of TB staining was significantly higher in infertile group compared to normospermic group (p=0.005). Mean of sperm normal morphology was lower in idiopathic infertile men in comparison with normozoospermic men (p= 0.001). The highest negative correlation was obtained between sperm count and AB staining. Progressive motility was negatively correlated with AB and TB staining in both groups but there was no significant difference between AB staining and progressive motility in men normospermia group. Conclusion: Sperm chromatin staining using AB and TB showed a negative association between sperm chromatin condensation with sperm count, normal morphology and progressive motility. It seems that the AB and TB test may be useful for the assessment of male fertility potential. © 2019 Avicenna Research Institute. All rights reserved

    Genetic Signatures of Strong Recent Positive Selection at the Lactase Gene

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    In most human populations, the ability to digest lactose contained in milk usually disappears in childhood, but in European-derived populations, lactase activity frequently persists into adulthood (Scrimshaw and Murray 1988). It has been suggested (Cavalli-Sforza 1973; Hollox et al. 2001; Enattah et al. 2002; Poulter et al. 2003) that a selective advantage based on additional nutrition from dairy explains these genetically determined population differences (Simoons 1970; Kretchmer 1971; Scrimshaw and Murray 1988; Enattah et al. 2002), but formal population-genetics–based evidence of selection has not yet been provided. To assess the population-genetics evidence for selection, we typed 101 single-nucleotide polymorphisms covering 3.2 Mb around the lactase gene. In northern European–derived populations, two alleles that are tightly associated with lactase persistence (Enattah et al. 2002) uniquely mark a common (∼77%) haplotype that extends largely undisrupted for >1 Mb. We provide two new lines of genetic evidence that this long, common haplotype arose rapidly due to recent selection: (1) by use of the traditional FST measure and a novel test based on pexcess, we demonstrate large frequency differences among populations for the persistence-associated markers and for flanking markers throughout the haplotype, and (2) we show that the haplotype is unusually long, given its high frequency—a hallmark of recent selection. We estimate that strong selection occurred within the past 5,000–10,000 years, consistent with an advantage to lactase persistence in the setting of dairy farming; the signals of selection we observe are among the strongest yet seen for any gene in the genome
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