Effect Of Sodium Hypochlorite And Peracetic Acid On The Surface Roughness Of Acrylic Resin Polymerized By Heated Water For Short And Long Cycles.

To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3). The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified. Specimens were fabricated, divided into four groups (n = 10) depending on the polymerization time and disinfectant. After polishing, the specimens were stored in distilled deionized water. Specimens were immersed in 1% NaClO or 1% C2H4O3 for 30 min, and then were immersed in distilled deionized water for 20 min. The release of C2H4O3 and NaClO was measured via visual colorimetric analysis. Roughness was measured before and after disinfection. Roughness data were subjected to two-way ANOVA and Tukey's test. There was no interaction between polymerization time and disinfectant in influencing the average surface roughness (Ra, P = 0.957). Considering these factors independently, there were significant differences between short and conventional long cycles (P = 0.012), but no significant difference between the disinfectants hypochlorite and C2H4O3 (P = 0.366). Visual colorimetric analysis did not detect release of substances. It was concluded that there was the difference in surface roughness between short and conventional long cycles, and disinfection at acrylic resins polymerized by heated water using a short cycle modified the properties of roughness.

Antiproliferative Activity Of Synthetic Fatty Acid Amides From Renewable Resources.

In the work, the in vitro antiproliferative activity of a series of synthetic fatty acid amides were investigated in seven cancer cell lines. The study revealed that most of the compounds showed antiproliferative activity against tested tumor cell lines, mainly on human glioma cells (U251) and human ovarian cancer cells with a multiple drug-resistant phenotype (NCI-ADR/RES). In addition, the fatty methyl benzylamide derived from ricinoleic acid (with the fatty acid obtained from castor oil, a renewable resource) showed a high selectivity with potent growth inhibition and cell death for the glioma cell line-the most aggressive CNS cancer.

Solid Lipid Nanoparticles As Nucleic Acid Delivery System: Properties And Molecular Mechanisms.

Solid lipid nanoparticles (SLNs) have been proposed in the 1990s as appropriate drug delivery systems, and ever since they have been applied in a wide variety of cosmetic and pharmaceutical applications. In addition, SLNs are considered suitable alternatives as carriers in gene delivery. Although important advances have been made in this particular field, fundamental knowledge of the underlying mechanisms of SLN-mediated gene delivery is conspicuously lacking, an imperative requirement in efforts aimed at further improving their efficiency. Here, we address recent advances in the use of SLNs as platform for delivery of nucleic acids as therapeutic agents. In addition, we will discuss available technology for conveniently producing SLNs. In particular, we will focus on underlying molecular mechanisms by which SLNs and nucleic acids assemble into complexes and how the nucleic acid cargo may be released intracellularly. In discussing underlying mechanisms, we will, when appropriate, refer to analogous studies carried out with systems based on cationic lipids and polymers, that have proven useful in the assessment of structure-function relationships. Finally, we will give suggestions for improving SLN-based gene delivery systems, by pointing to alternative methods for SLNplex assembly, focusing on the realization of a sustained nucleic acid release.

Ethanol Modulates The Synthesis And Catabolism Of Retinoic Acid In The Rat Prostate.

All-trans retinoic acid (atRA) maintains physiological stability of the prostate, and we reported that ethanol intake increases atRA in the rat prostate; however the mechanisms underlying these changes are unknown. We evaluated the impact of a low- and high-dose ethanol intake (UChA and UChB strains) on atRA metabolism in the dorsal and lateral prostate. Aldehyde dehydrogenase (ALDH) subtype 1A3 was increased in the dorsal prostate of UChA animals while ALDH1A1 and ALDH1A2 decreased in the lateral prostate. In UChB animals, ALDH1A1, ALDH1A2, and ALDH1A3 increased in the dorsal prostate, and ALDH1A3 decreased in the lateral prostate. atRA levels increased with the low activity of CYP2E1 and decreased with high CYP26 activity in the UChB dorsal prostate. Conversely, atRA was found to decrease when the activity of total CYP was increased in the UChA lateral prostate. Ethanol modulates the synthesis and catabolism of atRA in the prostate in a concentration-dependent manner.

Association Between Cationic Liposomes And Low Molecular Weight Hyaluronic Acid.

This work presents a study of the association between low molecular weight hyaluronic acid (16 kDa HA) and cationic liposomes composed of egg phosphatidylcholine (EPC), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP). The cationic liposome/HA complexes were evaluated to determine their mesoscopic structure, average size, zeta potential, and morphology as a function of the amount of HA in the system. Small angle X-ray scattering results revealed that neighboring cationic liposomes either stick together after a partial coating of low concentration HA or disperse completely in excess of HA, but they never assemble as multilamellar vesicles. Cryo-transmission electron microscopy images confirm the existence of unilamellar vesicles and large aggregates of unilamellar vesicles for HA fractions up to 80% (w/w). High concentrations of HA (> 20% w/w) proved to be efficient for coating extruded liposomes, leading to particle complexes with sizes in the nanoscale range and a negative zeta potential.

Hypobromous Acid, A Powerful Endogenous Electrophile: Experimental And Theoretical Studies.

Hypobromous acid (HOBr) is an inorganic acid produced by the oxidation of the bromide anion (Br(-)). The blood plasma level of Br(-) is more than 1,000-fold lower than that of chloride anion (Cl(-)). Consequently, the endogenous production of HOBr is also lower compared to hypochlorous acid (HOCl). Nevertheless, there is much evidence of the deleterious effects of HOBr. From these data, we hypothesized that the reactivity of HOBr could be better associated with its electrophilic strength. Our hypothesis was confirmed, since HOBr was significantly more reactive than HOCl when the oxidability of the studied compounds was not relevant. For instance: anisole (HOBr, k2=2.3×10(2)M(-1)s(-1), HOCl non-reactive); dansylglycine (HOBr, k2=7.3×10(6)M(-1)s(-1), HOCl, 5.2×10(2)M(-1)s(-1)); salicylic acid (HOBr, k2=4.0×10(4)M(-1)s(-1), non-reactive); 3-hydroxybenzoic acid (HOBr, k2=5.9×10(4)M(-1)s(-1), HOCl, k2=1.1×10(1)M(-1)s(-1)); uridine (HOBr, k2=1.3×10(3)M(-1)s(-1), HOCl non-reactive). The compounds 4-bromoanisole and 5-bromouridine were identified as the products of the reactions between HOBr and anisole or uridine, respectively, i.e. typical products of electrophilic substitutions. Together, these results show that, rather than an oxidant, HOBr is a powerful electrophilic reactant. This chemical property was theoretically confirmed by measuring the positive Mulliken and ChelpG charges upon bromine and chlorine. In conclusion, the high electrophilicity of HOBr could be behind its well-established deleterious effects. We propose that HOBr is the most powerful endogenous electrophile.

Six new cases confirm the clinical molecular profile of complete combined 17α-hydroxylase/ 17,20-lyase deficiency in Brazil

In 2004, Costa-Santos and cols. reported 24 patients from 19 Brazilian families with 17α-hydroxylase deficiency and showed that p.W406R and p.R362C corresponded to 50% and 32% of CYP17A1 mutant alleles, respectively. The present report describes clinical and molecular data of six patients from three inbred Brazilian families with 17α-hydroxlyse deficiency. All patients had hypogonadism, amenorrhea and hypertension at diagnosis. Two sisters were found to be 46,XY with both gonads palpable in the inguinal region. All patients presented hypergonadotrophic hypogonadism, with high levels of ACTH (> 104 ng/mL), suppressed plasmatic renin activity, low levels of potassium (< 2.8 mEq/L) and elevated progesterone levels (> 4.4 ng/mL). Three of them, including two sisters, were homozygous for p.W406R mutation and the other three (two sisters and one cousin) were homozygous for p.R362C. The finding of p.W406R and p.R362C in the CYP17A1 gene here reported in additional families, confirms them as the most frequent mutations causing complete combined 17α-hydroxylase/17,20-lyase deficiency in Brazilian patients.

Central retinal vein thrombosis as an initial manifestation of heterozygous protein C deficiency: case report

The purpose of this paper is to report a case of central retinal vein thrombosis associated with isolated heterozygous protein C deficiency. Acute occlusion of the central retinal vein presents as one of the most dramatic pictures in ophthalmology. It is often a result of both local and systemic causes. A rare systemic cause is heterozygous protein C deficiency, and it usually occurs in combination with other thrombophilic conditions. This case highlights that isolated heterozygous protein C deficiency may be the cause of central retinal vein thrombosis and underscores the importance of its screening in young patients with this ophthalmologic disease.