Synthesis of selenium- and tellurium-containing nucleosides derived from uridine

The synthesis of selenium- and tellurium-containing nucleosides, derived from uridine is described herein. These compounds were prepared in a concise and short synthetic route in good yields, by nucleophilic substitution of a tosylate group by organoselenium nucleophiles. (C) 2009 Elsevier Ltd. All rights reserved.

Synthesis of seleno-carbohydrates derived from D-galactose

The synthesis of seleno-galactopyranosides in a short and efficient manner is described, starting from the parent carbohydrate D-galactose. The approach described allows the synthesis of small libraries of compounds with a number of structural variations at the group attached to selenium. Compounds with aryl, propargyl, allyl, acyl, and alkyl substituents are described. (C) 2010 Elsevier Ltd. All rights reserved.

Synthesis of 5 `-seleno-xylofuranosides

The synthesis of selenium derivatives of naturally occurring chiral molecules is becoming increasingly important in recent years. In this context, we describe herein an easy, straightforward synthetic route for the preparation of a series of chiral seleno-furanosides, starting from the readily available carbohydrate D-xylose. In addition, selected compounds were screened as inhibitors of the delta-aminolevulinate dehyclratase (delta-ALA-D) enzyme. Diselenide 4 was found to reduce significantly the enzymatic activity, while seleno-furanoside la increased delta-ALA-D activity. (C) 2010 Elsevier Ltd. All rights reserved.

On The Distinct Molecular Architectures Of Dipping- And Spray-lbl Films Containing Lipid Vesicles.

The introduction of spraying procedures to fabricate layer-by-layer (LbL) films has brought new possibilities for the control of molecular architectures and for making the LbL technique compliant with industrial processes. In this study we show that significantly distinct architectures are produced for dipping and spray-LbL films of the same components, which included DODAB/DPPG vesicles. The films differed notably in their thickness and stratified nature. The electrical response of the two types of films to aqueous solutions containing erythrosin was also different. With multidimensional projections we showed that the impedance for the DODAB/DPPG spray-LbL film is more sensitive to changes in concentration, being therefore more promising as sensing units. Furthermore, with surface-enhanced Raman scattering (SERS) we could ascribe the high sensitivity of the LbL films to adsorption of erythrosin.

A Putative Otu Domain-containing Protein 1 Deubiquitinating Enzyme Is Differentially Expressed In Thyroid Cancer And Identifies Less-aggressive Tumours.

This study aimed to identify novel biomarkers for thyroid carcinoma diagnosis and prognosis. We have constructed a human single-chain variable fragment (scFv) antibody library that was selected against tumour thyroid cells using the BRASIL method (biopanning and rapid analysis of selective interactive ligands) and phage display technology. One highly reactive clone, scFv-C1, with specific binding to papillary thyroid tumour proteins was confirmed by ELISA, which was further tested against a tissue microarray that comprised of 229 thyroid tissues, including: 110 carcinomas (38 papillary thyroid carcinomas (PTCs), 42 follicular carcinomas, 30 follicular variants of PTC), 18 normal thyroid tissues, 49 nodular goitres (NG) and 52 follicular adenomas. The scFv-C1 was able to distinguish carcinomas from benign lesions (P=0.0001) and reacted preferentially against T1 and T2 tumour stages (P=0.0108). We have further identified an OTU domain-containing protein 1, DUBA-7 deubiquitinating enzyme as the scFv-binding antigen using two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. The strategy of screening and identifying a cell-surface-binding antibody against thyroid tissues was highly effective and resulted in a useful biomarker that recognises malignancy among thyroid nodules and may help identify lower-risk cases that can benefit from less-aggressive management.

Synthesis And Antiproliferative Activity Of 8-hydroxyquinoline Derivatives Containing A 1,2,3-triazole Moiety.

Twelve novel 8-hydroxyquinoline derivatives were synthesized with good yields by performing copper-catalyzed Huisgen 1,3-dipolar cycloaddition (click reaction) between an 8-O-alkylated-quinoline containing a terminal alkyne and various aromatic or protected sugar azides. These compounds were evaluated in vitro for their antiproliferative activity on various cancer cell types. Protected sugar derivative 16 was the most active compound in the series, exhibiting potent antiproliferative activity and high selectivity toward ovarian cancer cells (OVCAR-03, GI50 < 0.25 μg mL(-1)); this derivative was more active than the reference drug doxorubicin (OVCAR-03, GI50 = 0.43 μg mL(-1)). In structure-activity relationship (SAR) studies, the physico-chemical parameters of the compounds were evaluated and docking calculations were performed for the α-glucosidase active site to predict the possible mechanism of action of this series of compounds.

A Modified Acidic Approach For Dna Extraction From Plant Species Containing High Levels Of Secondary Metabolites.

Purified genomic DNA can be difficult to obtain from some plant species because of the presence of impurities such as polysaccharides, which are often co-extracted with DNA. In this study, we developed a fast, simple, and low-cost protocol for extracting DNA from plants containing high levels of secondary metabolites. This protocol does not require the use of volatile toxic reagents such as mercaptoethanol, chloroform, or phenol and allows the extraction of high-quality DNA from wild and cultivated tropical species.

Effect Of Composite Containing An Iodonium Salt On The Bond Strength Of Brackets To Bovine Enamel.

This study investigated the effect of the incorporation of an iodonium salt in experimental composites, on the bond strength of metallic brackets bonded to bovine teeth. Two hundred and seventy bovine teeth were embedded in self-curing acrylic resin and divided into 18 groups (n=15), according to the experimental composite with an iodonium salt at molar concentrations 0 (control), 0.5, or 1%; the light-activation times (8, 20 and 40 s); and the storage times (10 min or 24 h). Metallic brackets were fixed on the tooth surface using experimental composites. Photoactivation was performed with a quartz-tungsten-halogen light-curing unit curing unit for 8, 20 and 40 s. The specimens were stored in distilled water at 37 °C for 10 min or 24 h and submitted to bond strength test at 0.5 mm/min. The data were subjected to three-way ANOVA and Tukey's test (α=0.05). The Adhesive Remnant Index (ARI) was used to classify the failure modes. The shear bond strengths (MPa) at 10 min for light-activation times of 8, 20 and 40 s were: G1 - 4.6, 6.9 and 7.1; G2 - 8.1, 9.2 and 9.9; G3 - 9.1, 10.4 and 10.7; and at 24 h were: G1 - 10.9, 11.1 and 11.7; G2 - 11.8, 12.7 and 14.2; G3 - 12.1, 14.4 and 15.8. There was a predominance of ARI score 3 for groups with 10 min storage time, and ARI score 2 for groups with 24 h storage time. In conclusion, the addition of iodonium salt (C05 and C1) to the experimental composite may increase the bond strength of brackets to bovine enamel using reduced light exposure times.

Metronidazole-containing gel for the treatment of periodontitis: an in vivo evaluation

The aim of this investigation was to monitor metronidazole concentrations in the gingival crevicular fluid (GCF) collected from periodontal pockets of dogs after treatment with an experimental 15% metronidazole gel. Five dogs had periodontitis induced by cotton ligatures placed subgingivally and maintained for a 30-day period. After the induction period, only pockets with 4 mm or deeper received the gel. Each pocket was filled up to the gingival margin by means of a syringe with a blunt-end needle. GCF was collected in paper strips and quantified in an electronic device before and after 15 minutes, 1 h, 6 h, 24 h and 48 h of gel administration. The GCF samples were assayed for metronidazole content by means of a high performance liquid chromatography method. Concentrations of metronidazole in the GCF of the 5 dogs (mean ± SD, in µg/mL) were 0 ± 0 before gel application and 47,185.75 ± 24,874.35 after 15 minutes, 26,457.34 ± 25,516.91 after 1 h, 24.18 ± 23.11 after 6 h, 3.78 ± 3.45 after 24 h and 3.34 ± 5.54 after 48 h. A single administration of the 15% metronidazole gel released the drug in the GCF of dogs in levels several-fold higher than the minimum inhibitory concentration for some periodontopathogens grown in subgingival biofilms for up to one hour, but metronidazole could be detected in the GCF at least 48 hours after the gel application.

Effect of fluoride-containing solutions on the surface of cast commercially pure titanium

This study evaluated the effects of fluoride-containing solutions on the surface of commercially pure titanium (CP Ti) obtained by casting. CP Ti specimens were fabricated and randomly assigned to 5 groups (n=10): group 1: stored in distilled water at 37 ± 1ºC; group 2: stored in distilled water at 37 ± 1ºC and daily immersed in 0.05% NaF for 3 min; group 3: stored in distilled water at 37 ± 1ºC and daily immersed in 0.2% NaF for 3 min; group 4: stored in distilled water at 37 ± 1ºC; and immersed in 0.05% NaF every 15 days for 3 min; and group 5: stored in distilled water at 37 ± 1ºC and immersed in 0.2% NaF every 15 days for 3 min. Surface roughness was measured with a profilometer immediately after metallographic polishing of the specimens (T0) and at 15-day intervals until completing 60 days of experiment (T15, T30, T45, T60). Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). There was no statistically significant difference (p>0.05) in surface roughness among the solutions. In conclusion, fluoride-containing solutions (pH 7.0) used as mouthwashes do not damage the surface of cast CP Ti and can be used by patients with titanium-based restorations.

Maximum inhibitory dilution of mouthwashes containing chlorhexidine and polyhexamethylene biguanide against salivary staphylococcus aureus

OBJECTIVE: The aim of the present study was to determine the in vitro maximum inhibitory dilution (MID) of two chlorhexidinebased oral mouthwashes (CHX): Noplak®, Periogard®, and one polyhexamethylene biguanide-based mouthwash (PHMB): Sanifill Premium® against 28 field Staphylococcus aureus strains using the agar dilution method. MATERIALS AND METHODS: For each product, decimal dilutions ranging from 1/10 to 1/655,360 were prepared in distilled water and added to Mueller Hinton Agar culture medium. After homogenization, the culture medium was poured onto Petri dishes. Strains were inoculated using a Steers multipoint inoculator and dishes were incubated at 37ºC for 24hours. For reading, MID was considered as the maximum dilution of the mouthwash still capable of inhibiting microbial growth. RESULTS: Sanifill Premium® inhibited the growth of all strains at 1/40 dilution and of 1 strain at 1/80 dilution. Noplak® inhibited the growth of 23 strains at 1/640 dilution and of all 28 strains at 1/320 dilution. Periogard® showed inhibited growth of 7 strains at 1/640 dilution and of all 28 strains at 1/320 dilution. Data were submitted to Kruskal-Wallis statistical test, showing significant differences between the mouthwashes evaluated (p<0.05). No significant difference was found between Noplak® and Periogard® (p>0.05). Sanifill Premium® was the least effective (p<0.05). CONCLUSION: It was concluded that CHX-based mouthwashes present better antimicrobial activity against S. Aureus than the PHMB-based mouthwash.

Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus

The maximum inhibitory dilution (MID) of triclosan-based mouthwashes against 28 Staphylococcus aureus strains was evaluated. Dilutions ranging from 1/10 to 1/655,360 were prepared. Strains were inoculated using a Steers multipoint inoculator. The MID was considered as the maximum dilution capable of inhibiting microorganism growth. The mouthwashes presented different MIDs.

Use of chewing gum containing 15% of xylitol and reduction in mutans streptococci salivary levels

Frequent use of Xylitol may decrease the S. mutans levels. However, very little is known about whether this effect on the levels of cariogenic bacteria is maintained after the interruption of short-term usage of xylitol. This study aimed at evaluating changes in mutans streptococci (MS) salivary levels after using a chewing gum containing xylitol. Twelve volunteers harboring > 10(5) CFU MS/ml saliva levels were asked to chew Happydent-xylit® for 5 minutes, 5 X/day, for 30 days. Saliva samples were collected at baseline, at 30 days after xylitol usage began, and at 30 days beyond its interruption. MS salivary levels were estimated. The average salivary levels of MS in the ten subjects who completed the study were 13.17 (NL-CFU) at baseline (A). After the 30 days experimental period (B), this average decreased to 9.45 (NL-CFU). Nine of ten subjects studied showed a reduction in MS salivary levels in relation to baseline, whereas salivary levels were maintained in the remaining subject. At thirty days beyond the interruption of xylitol usage (C), the average levels of MS were still reduced to 10.31 (NL-CFU). Multiple sample comparison using the Bonferroni test revealed that the decrease in MS levels observed from baseline (A) to the time immediately after 30 days of xylitol usage (B) was statistically significant (p < 0.05), and those levels were still decreased between baseline and 30 days beyond the interruption of xylitol usage (C). So, the use of xylitol induced a reduction in MS salivary levels after a short period of usage which persisted beyond its interruption.

Near-infrared third-order nonlinearity of PbO-GeO(2) films containing Cu and Cu(2)O nanoparticles

We report measurements of the nonlinear (NL) refractive index n(2) of lead-germanium films (LGFs) containing Cu and Cu(2)O nanoparticles (NPs). The thermally managed eclipse Z-scan technique with 150 fs pulses from a laser operating at 800 nm was used. The NL refractive index measured, n(2)=6.3x10(-12) cm(2)/W has electronic origin and the NL absorption coefficient alpha(2) is smaller than 660 cm/GW. The figure of merit n(2)/lambda alpha(2) is enhanced by more than two orders of magnitude in comparison with the result for the LGFs without the copper based NPs. (C) 2008 American Institute of Physics.

Frequency upconversion luminescence from Yb(+3)-Tm(+3) codoped PbO-GeO(2) glasses containing silver nanoparticles

Infrared-to-visible and infrared-to-infrared frequency upconversion processes in Yb(3+)-Tm(3+) doped PbO-GeO(2) glasses containing silver nanoparticles (NPs) were investigated. The experiments were performed by exciting the samples with a diode laser operating at 980 nm (in resonance with the Yb(3+) transition (2)F(7/2)->(2)F(5/2)) and observing the photoluminescence (PL) in the visible and infrared regions due to energy transfer from Yb(3+) to Tm(3+) ions followed by excited state absorption in the Tm3+ ions. The intensified local field in the vicinity of the metallic NPs contributes for enhancement in the PL intensity at 480 nm (Tm(3+) :(1)G(4)->(3)H(6)) and at 800 nm (Tm(3+) : (3)H(4) -> (3)H(6)). (C) 2009 American Institute of Physics. [doi:10.1063/1.3211300]