RNA Interference in Mammalia Cells by RNA-3’-PNA Chimeras

The discovery of siRNAs as the mediators of RNA interference has led to an increasing interest in their therapeutic applications. Chemical modifications are introduced into siRNAs to optimize the potency, the stability and the pharmacokinetic properties in vivo. Here, we synthesize and test the effects of RNA-3’-PNA chimeras on siRNA functioning and stability. We demonstrate that the chemical modifications are compatible with the siRNA machinery, because all the PNA-modified siRNAs can efficiently mediate specific gene silencing in mammalian cells. Furthermore, we find that the modification on the sense strand of siRNA results in an increased persistence of the activity, whereas modification on both strands results in enhanced nuclease resistance in serum

On the asymptotic behaviour of solutions to the fractional porous medium equation with variable density

We are concerned with the long time behaviour of solutions to the fractional porous medium equation with a variable spatial density. We prove that if the density decays slowly at infinity, then the solution approaches the Barenblatt-type solution of a proper singular fractional problem. If, on the contrary, the density decays rapidly at infinity, we show that the minimal solution multiplied by a suitable power of the time variable converges to the minimal solution of a certain fractional sublinear elliptic equation.Comment: To appear in DCDS-

Evaluation of masticatory function in patients with cleft lip and/or palate

The aim of this study was to evaluate the masticatory pattern in children with cleft lip and/or palate (CL/P) through investigation of the prevalence of reverse sequencing chewing cycles. The study group included 18 patients with CL/P (mean age: 7.4 yr, SD: 1.4 yr), 15 of whom had dental crossbite. The controls included a group of 18 non-CL/P children with the same types of crossbite as the study group (mean age: 7.2 yr, SD: 1.5 yr) and a group of 18 non-CL/P subjects with normal occlusion (mean age: 9.8 yr, SD: 1.9 yr). Mandibular movements during chewing of soft and hard bolus were recorded with a kinesiograph. Kinematic signals were analysed using a custom-made software. A statistical analysis was performed to compare the degree of reverse-sequencing chewing cycles between patients and controls (Kruskal–Wallis test with Dwass-Steel-Critchlow-Fligner pairwise comparisons post hoc test). A significant difference between patients with CL/P and non-CL/P subjects with normal occlusion was highlighted on the left side of mastication, which was the side with the higher prevalence of crossbite with both types of bolus. No statistical differences were found between CL/P patients and healthy controls with crossbite. Cleft-affected patients with posterior crossbite exhibited an anomalous masticatory pattern with increased reverse chewing cycles on the crossbite side

Evaluation of masticatory function in patients with cleft lip and/or palate

The aim of this study was to evaluate the masticatory pattern in children with cleft lip and/or palate (CL/P) through investigation of the prevalence of reverse sequencing chewing cycles. The study group included 18 patients with CL/P (mean age: 7.4 yr, SD: 1.4 yr), 15 of whom had dental crossbite. The controls included a group of 18 non-CL/P children with the same types of crossbite as the study group (mean age: 7.2 yr, SD: 1.5 yr) and a group of 18 non-CL/P subjects with normal occlusion (mean age: 9.8 yr, SD: 1.9 yr). Mandibular movements during chewing of soft and hard bolus were recorded with a kinesiograph. Kinematic signals were analysed using a custom-made software. A statistical analysis was performed to compare the degree of reverse-sequencing chewing cycles between patients and controls (Kruskal–Wallis test with Dwass-Steel-Critchlow-Fligner pairwise comparisons post hoc test). A significant difference between patients with CL/P and non-CL/P subjects with normal occlusion was highlighted on the left side of mastication, which was the side with the higher prevalence of crossbite with both types of bolus. No statistical differences were found between CL/P patients and healthy controls with crossbite. Cleft-affected patients with posterior crossbite exhibited an anomalous masticatory pattern with increased reverse chewing cycles on the crossbite side

RNA Interference in Mammalia Cells by RNA-3’-PNA Chimeras

The discovery of siRNAs as the mediators of RNA interference has led to an increasing interest in their therapeutic applications. Chemical modifications are introduced into siRNAs to optimize the potency, the stability and the pharmacokinetic properties in vivo. Here, we synthesize and test the effects of RNA-3’-PNA chimeras on siRNA functioning and stability. We demonstrate that the chemical modifications are compatible with the siRNA machinery, because all the PNA-modified siRNAs can efficiently mediate specific gene silencing in mammalian cells. Furthermore, we find that the modification on the sense strand of siRNA results in an increased persistence of the activity, whereas modification on both strands results in enhanced nuclease resistance in serum

Allelochemicals from Rue (Ruta graveolens L.) and Olive (Olea europaea L.) oil mill waste waters as potential natural pesticides

Allelopathy involves the biochemical interactions among plants and other species, through the release into the environment of chemical compounds named allelochemicals. Medicinal plants and vegetable wastes are a primary and neglected source of secondary metabolites which can play a role as allelochemicals . This review deals with the assessment of allelochemicals from Ruta graveolens and Olive oil waste waters as potential natural pesticides in sustainable agricultural systems. Using chromatographic and spectroscopic methods, a bioassay-oriented study of rue and olive oil waste waters allowed us isolate and identify, some allelochemicals, such as coumarins, flavonoids, terpenoid derivates phenylpropanoids and polyphenols. Successively, a rue infusion, some chromatographic fractions and pure isolated compounds were assayed in vitro and in vivo for compounds for their biological activities on seed germination and radicle growth, algae, fungi and insects. Microscopic observations on cellular effects of allelochemicals in target organisms were also performed. Some allelochemicals (e.g. 5-methoxypsoralen) severely inhibited the growth and development of tested organisms. Results suggest that rue and olive oil waste waters are a cheap source of allelochemicals whose exploitation as a natural pesticides deserve attention. Eco-toxicological studies are in progress

Long polypeptide 3(10)-helices at atomic resolution

The crystal-state preferred conformation of the terminally blocked homooctapeptide from the C(α,α)-dimethylated α-aminoisobutyric acid (Aib) residue, pBrBz-(Aib)(8)-OBu(t), in which pBrBz is para-bromobenzoyl and OBu(t) is tert-butoxy, determined by x-ray diffraction analysis using direct methods, was found to be a 3(10)-helix stabilized by six consecutive intramolecular N—H....O=C hydrogen bonds of the C(10)-III (or III′) type. This is the first observation at atomic resolution of a regular 3(10)-helix longer than two complete turns. The solid-state structural analysis was extended to the terminally blocked, α-aminoisobutyric acid-rich octapeptide corresponding to the 2-9 sequence of the peptaibol antibiotics emerimicins III and IV, pBrBz-Aib(3)-L-Val-Gly-L-Leu-Aib(2)-OMe. Again, this peptide adopts a (right-handed) 3(10)-helical structure, although slightly distorted at the level of the L-leucine residue. The role of specific amino acid sequence and peptide main-chain length in stabilizing either the 3(10)- or the α-helical conformation and their possible implications on the nature of the channel formed by peptaibol antibiotics in the membrane are also briefly discussed