Antifungal efficiency of chemically and thermally-activated acrylic resins after surface treatment using poly (diallyldimethylammonium chloride)

Abstract INTRODUCTION: Acrylic resins are used in the preparation of facial prostheses and may be colonized by fungi. Here, we verified the antifungal efficacy of this material after surface treatment using poly (diallyldimethylammonium chloride). METHODS: Acrylic resin specimens with and without surface treatment were subjected to tests for fungistatic and fungicidal activities. Standard strains of Candida albicans and Aspergillus niger were used. RESULTS: After surface treatment, the fungistatic and fungicidal efficacies of the resins against C. albicans and fungistatic action against A. niger were verified. CONCLUSIONS: The surface treatment was a determinant of the antifungal activity of the material.

Use of green fluorescent protein labeled non-tuberculous mycobacteria to evaluate the activity quaternary ammonium compound disinfectants and antibiotics

Abstract Although infections with NonTuberculous Mycobacteria have become less common in AIDS patients, they are important opportunistic infections after surgical procedures, likely because they are ubiquitous and not efficiently killed by many commonly used disinfectants. In Venezuela there have recently been many non-tuberculous mycobacteria soft tissue infections after minor surgical procedures, some apparently related to the use of a commercial disinfectant based on a Quaternary Ammonium Compound. We studied the activity of this and other quaternary ammonium compounds on different non-tuberculous mycobacteria by transforming the mycobacteria with a dnaA-gfp fusion and then monitoring fluorescence to gauge the capacity of different quaternary ammonium compounds to inhibit bacterial growth. The minimum inhibitory concentration varied for the different quaternary ammonium compounds, but M. chelonae and M. abscessus were consistently more resistant than M. smegmatis, and M. terrae more resistant than M. bovis BCG.

Intragastric gavage with denatonium benzoate acutely induces neuronal activation in the solitary tract nucleus via the vagal afferent pathway

Natural toxic substances have a bitter taste and their ingestion sends signals to the brain leading to aversive oral sensations. In the present study, we investigated chronological changes in c-Fos immunoreactivity in the nucleus tractus solitarius (NTS) to study the bitter taste reaction time of neurons in the NTS. Equal volumes (0.5 mL) of denatonium benzoate (DB), a bitter tastant, or its vehicle (distilled water) were administered to rats intragastrically. The rats were sacrificed at 0, 0.5, 1, 2, 4, 8, or 16 h after treatment. In the vehicle-treated group, the number of c-Fos-positive nuclei started to increase 0.5 h after treatment and peaked 2 h after gavage. In contrast, the number of c-Fos-positive nuclei in the DB-treated group significantly increased 1 h after gavage. Thereafter, the number of c-Fos immunoreactive nuclei decreased over time. The number of c-Fos immunoreactive nuclei in the NTS was also increased in a dose-dependent manner 1 h after gavage. Subdiaphragmatic vagotomy significantly decreased DB-induced neuronal activation in the NTS. These results suggest that intragastric DB increases neuronal c-Fos expression in the NTS 1 h after gavage and this effect is mediated by vagal afferent fibers.

[Comparison of efficacy of hand washing with betadin and sterillium on bacterial colony count in intensive care unit personnel]

Nosocomial infections are common with known complications and high mortality and morbidity rate. There are several efficient and quick-acting antiseptic alcohol solutions such as Sterillium that require no scrubbing. The aim of this study was to compare the efficacy of betadin and Sterillium hand rubs for hand disinfection in a before-after trial according to prEN12054 prEN 1500. We compared Betadin and Sterillium hand rubbing for hand disinfection in a before-after study. The study was done with 72 healthy ICU staff, whose hand microbial flora were measured before and after 30 seconds hands washing with Betadin and Sterillium. Sampling was achieved according to the stratified randomization. Samples cultured on BA and EMB media and the frequency of microorganisms and the efficacy of two agents were determined. Then we compared results of Betadin and Sterillium by using Chi square and Fisher's Exact and McNemar tests. The most frequent pathogens were staph epidermidis [32], aerobacter aerogenosa [4], staph saprofiticus [3], pseudomonas [1], klebsiella [1], acintobacter [1], and E.coli [1]. The percentage of organism reduction following the usage of antibacterial agents was 94% for betadin and 87% for Sterillium [P = 0.8]. This reduction was significant statistically. We did not find significant difference about sex, ward, shift and job before and after washing with regard to Betadin, but in Sterillum we found significant difference[P = 0.04] only after rubbing. The rate of negative culture about Betadin was more than Sterillium but was not statistically significant. Since skin is a routine source of infections transmission, and with respect to the satisfactory results, we advise the usage of this agent for ICU staff for hand disinfection

The presence of qacA/B gene in Brazilian methicillin-resistant Staphylococcus aureus

A total of 74 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from three government hospitals in 2002 and 2003 were examined concerning the distribution of qacA/B gene, which is the determinant of resistance to quaternary ammonium compounds largely employed in hospital disinfection. By polymerase chain reaction the qacA/B gene was found in 80 percent of the isolates, which is a significant result considering it is the first time that qacA/B gene is being reported for Brazilian MRSA strains and it is presented at a high rate.

Interactions between cationic liposomes and drugs or biomolecules

Multiple uses for synthetic cationic liposomes composed of dioctadecyldimethylammonium bromide (DODAB) bilayer vesicles are presented. Drugs or biomolecules can be solubilized or incorporated in the cationic bilayers. The cationic liposomes themselves can act as antimicrobial agents causing death of bacteria and fungi at concentrations that barely affect mammalian cells in culture. Silica particles or coverage with DODAB bilayers or polystyrene microspheres can be functionalized by phospholipid monolayers. Negatively charged antigenic proteins can be carried by the cationic liposomes which generate a remarkable immunoadjuvant action. Nucleotides or DNA can be physically adsorbed to the cationic liposomes to be transferred to mammalian cells for gene therapy. An overview of the interactions between DODAB vesicles and some biomolecules or drugs clearly points out their versatility for useful applications in a near future

Uso del agente espamolitico otilonio bromuro (spamonen) en endoscopia digestiva: estudio prospectivo en 63 pacientes / Use of spasmolytic agent otilonium bromide in digestive endoscopy: a prospective study in 63 patients

El otilonio bromuro es un antagonista del calcio con un efecto miolítico directo, el cual está indicado en estados espásticos y disguinesias funcionales del aparato gastroentérico (sindrome del intestino irritable) y como premedicación para procedimientos endoscópicos gastrointestinales. El presente estudio evaluó el otilonio bromuro 40 mg PO la noche anterior y 40 mg PO la mañana de 49 fibroscopías bajas en 63 pacientes, para determinar la presencia o ausencia de peristalsis y relajación del píloro. No se observaron efectos colaterales debido a la medicación. En 46 (93.8 por ciento) endoscopías altas se observó marcada relajación del tracto gastrointestinal y del píloro. En 13 (92.8 por ciento) endoscopías bajas también se observó marcada relajación del tracto colónico. Todos los pacientes toleraron bien las endoscopías. El otilonio bromuro fue útil como premedicación para facilitar las exploraciones endoscópicas altas y bajas, debido a su efecto espasmolítico.

Differences in the levels of aminoacylation and contents of modified nucleotides between total tRNAs from N2- and NH4(+)-grown Azospirillum lipoferum cells.

Total tRNAs isolated from N2- and NH4(+)-grown Azospirillum lipoferum cells were compared with respect to amino acid acceptance, isoacceptor tRNA species levels and extent of nucleotide modifications. Amino-acylation of these two tRNA preparations with ten different amino acids indicated differences in the relative acceptor activities. Comparison of aminoacyl-tRNA patterns by RPC-5 column chromatography revealed no qualitative differences in the elution profiles. However, quantitative differences in the relative amounts of some isoacceptors were observed. These results indicate that alterations of relative amounts of functional tRNA species occur to match cellular requirements of the bacterial cells using N2 or NH4+ as nitrogen source. In addition, the content of modified nucleotides in total tRNAs of N2- and NH4(+)-grown cells was determined. In the NH4(+)-grown cells, content of most of the modified nucleotides decreased significantly. Based upon these results, the relationship of chargeability of tRNAs to base modifications is discussed.

Quaternary ammonium salt derivatives of allylphenols with peripheral analgesic effect

Ammonium salt derivatives of natural allylphenols were synthesized with the purpose of obtaining potential peripheral analgesics. These drugs, by virtue of their physicochemical properties, would not be able to cross the blood brain barrier. Their inability to enter into the central nervous system (CNS) should prevent several adverse effects observed with classical opiate analgesics (Ferreira et al., 1984). Eugenol (1) O-methyleugenol (5) and safrole (9) were submitted to nitration, reduction and permethylation, leading to the ammonium salts 4, 8 and 12. Another strategy applied to eugenol (1), consisting in its conversion to a glycidic ether (13), opening the epoxide ring with secondary amines and methylation, led to the ammonium salts 16 and 17. All these ammonium salts showed significant peripheral analgesic action, in modified version of the Randall-Sellito test (Ferreira et al. 1978), at non-lethal doses. The ammonium salt 8 showed an activity comparable to that of methylnalorphinium, the prototype of an ideal peripheral analgesic (Ferreira et al., 1984).