Tailoring of physical and chemical properties of macro- and microhydrogels based on telechelic PVA

Poly(vinyl alcohol), PVA, is amenable to several structural modifications because of the presence of the hydroxyl moiety in the backbone. The chemical versatility of this polymer can be used for the obtainment of new wall-to-wall pH-responsive PVA chemical hydrogels and for the preparation of air-filled microspheres, for example, microbubbles. Here, we report on the characterization of the physical and chemical properties of these novel networks that can be potentially used in different biomedical applications as controlled drug delivery and as ultrasonic contrast agent.     

Xanthan and glucomannan mixtures: synergistic interactions and gelation

The synergistic interaction between xanthan and glucomannan in solution and in the gel phase has been studied by circular dichroism spectroscopy and differential scanning calorimetry. The study in solution of the polysaccharidic mixture indicates a preferred stoichiometry of the interaction corresponding to a weight fraction of xanthan around 0.55. This finding is in reasonable agreement with the differential scanning calorimetry measurements carried out on the gel phase. Models from conformational analysis based on these results were formulated in terms of 1:1 and 2:1 Konjac glucomannan/xanthan molecular assemblies. The experimental and calculation results clearly indicate the involvement of the side chains of xanthan and suggest that the ordered portions of the macromolecular complex in solution act in the gel phase as junction zones.     

Comparison of the efficacy of 1% flutrimazole cream twice a day with 1% flutrimazole cream once a day for the treatment of superficial dermatophytoses

Different clinical studies have demonstrated flutrimazole's efficacy in the treatment of superficial dermatomycoses when administered either twice daily or once daily for four weeks. The aim of the present study was to compare both dosing schedules for the treatment of superficial dermatomycoses. In this randomized, controlled, double blind study, we included 84 patients suffering superficial dermatophytosis (confirmed by microscopic examination (KOH) and culture) susceptible for topical monotherapy. Forty-one patients received flutrimazole 1% twice daily (TD) and forty-three once daily (OD) for four weeks. The efficacy of treatment was evaluated by clinical and mycological criteria at the end of treatment (D28) and after four weeks without treatment (D58). Clinical and mycological cure rates on D28 were 50% with TD and 65% with OD treatment. Only considering clinical evaluation, clinical cure rates on D28 were 63% (TD) and 70% (OD). Also, clinical and mycological cure rates on D56 were 65% with TD and 72% with OD treatment. Only considering clinical evaluation, clinical cure rates on D56 were of 68% (TD) and 72% (OD). The overall tolerability was similar in both treatment groups. The efficacy assessment at the end of treatment (D28) and four weeks after treatment discontinuation (D56) showed that the OD treatment is not inferior to the TD treatment, with similar clinical and mycological cure rates and clinical cure rates in both cases. The OD administration of flutrimazole cream 1% is the most appropriate dosing schedule as it provides the same efficacy, it improves patient's compliance and the cost per day of treatment.     

Comparative Phenomenology of Ataques de Nervios,Panic Attacks,and Panic Disorder

This article examines a clinicalsample of 66 Dominican and Puerto Ricansubjects who reported ataques de nerviosand also psychiatric disorder, and disentanglesthe phenomenological experiences of ataquede nervios, panic attacks, and panic disorder. In-depth cultural interviews assessed thesymptomatic phenomenology of ataqueepisodes from the local perspective as well asin terms of key panic features, such asrecurrence, rapid peaking of symptoms, and lackof provocation. Independent diagnosticassessments of panic attacks and disorder werealso used to establish the phenomenologicaloverlap between ataque and panic. Ourfindings indicate that 36 percent ofataques de nervios fulfill criteria for panicattacks and between 17 percent and 33 percentfor panic disorder, depending on the overlapmethod used. The main features distinguishingataques that fulfill panic criteria fromataques that do not include whether theepisodes were provoked by an upsetting event inthe person's life and the rapidity of crescendoof the actual attack. A key finding is thatataques often share individualphenomenological features with panic episodes,but that these features usually do not ``runtogether' during the ataque experience.This confirms previous findings thatataque is a more inclusive construct thanpanic disorder. The importance of thesefindings for the clinical diagnosis andtreatment of persons with ataques isdiscussed.     

Effects of MCH/NEI in the striatum and interactions between them and with alpha-MSH on IP3 levels

In this study, we investigated: (a) the effect of melanocyte concentrating hormone (MCH) and neuropeptide glutamine (E)-isoleusine-(I) (NEI) on IP(3) production on an "in vitro" model using slices containing caudate putamen (CP) and accumbens nuclei (ACC); and (b) the interaction between these peptides and with alpha-melanocyte-stimulating-hormone (alpha-MSH) on the production of this second messenger. Only MCH at the highest dose studied (3.6 microM) increased the production of IP(3), whereas at the low concentration (0.6 microM) it did not affect IP(3) levels. NEI and alpha-MSH at both concentrations tested (0.6 and 3.6 microM), did not affect IP(3) production either. However, when NEI or alpha-MSH (at 3.6 microM) were added together with 3.6 microM MCH, the increase in the IP(3) content induced by this last peptide was blocked.     

An efficient haplotyping method with DNA pools

Determination of haplotype frequencies (the joint distribution of genetic markers) in large population samples is a powerful tool for association studies. This is due to their greater extent of polymorphism since any two bi-allelic single nucleotide polymorphisms (SNPs) generate a potential four-allele genetic marker. Therefore, a haplotype may capture a given functional polymorphism with higher statistical power than its SNP components. The statistical estimation of haplotype frequencies, usually employed in linkage disequilibrium studies, requires individual genotyping for each SNP in the haplotype, thus making it an expensive process. In this study, we describe a new method for direct measurement of haplotype frequencies in DNA pools by allele-specific, long-range haplotype amplification. The proposed method allows the efficient determination of haplotypes composed of two SNPs in close vicinity (up to 20 kb).     

Development and validation of a gas chromatography-mass spectrometry assay for hair analysis of amphetamine, methamphetamine and methylenedioxy derivatives

A procedure based on gas chromatography-mass spectrometry (GC-MS) is described for the determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA, ecstasy), 3,4-methylenedioxyethylamphetamine (MDE or MDEA) and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB) in hair. Hair samples were digested with 1 M sodium sulfide at 37 degrees C (by shaking for 3 h and was kept at room temperature overnight), and extracted with two sequential extraction procedures: liquid-liquid extraction with tert-butyl methyl ether and solid-phase extraction with Bond-Elut Certify columns. Extracted analytes were derivatised with N-methyl-bis(trifluoroacetamide), separated by a 5% phenylmethylsilicone column and determined by a mass spectrometer detector in selected ion monitoring mode. A good reproducibility (intra-assay R.S.D.=1.5-15.7%), accuracy (intra-assay error = 2.0-11.7%) and sensitivity (LOD=0.03-0.08 ng/mg hair) were attained. The method was successfully applied to the analysis of the proximal (1 cm) hair segment to assess recent self-reported use in "ecstasy" consumers. Otherwise, further studies are needed to validate methodology developed in case of amphetamine consumption.