Efficacy of disinfection procedures performed prior to regenerative endodontic therapy: An integrative review.

The aim of this integrative review was to identify whether the disinfection procedures performed prior to regenerative endodontic treatment were effective on biofilm removal from the root canals. The research was based on PubMed, Latin American and Caribbean Health Sciences Literature (Lilacs) and Scientific Electronic Library Online (SciELO) databases. Four articles were selected; one of the studies was in vivo and the others ex vivo. Different disinfection procedures were studied, characterised mainly by the use of intracanal medication, highlighting the double antibiotic paste, triple antibiotic paste and calcium hydroxide paste. Disinfection ability was evaluated against Enterococcus faecalis and multispecies biofilms by using the fluorescence technique and colony forming unit counting, for 7 to 21 days. Double antibiotic paste and triple antibiotic paste demonstrated excellent antibiofilm activity, unlike CH paste that showed limited disinfection, even when associated with different antimicrobial agents. Triple antibiotic paste was the most effective medication against biofilm.

Neamine and 2-deoxystreptamine neomycin derivatives exhibit antinociceptive activity in rat models of phasic, incision and neuropathic pain.

OBJECTIVES: To assess the antinociceptive activity of the neomycin derivatives neamine and 2-deoxystreptamine following intraspinal administration in rats. METHODS: We used the tail-flick test and measured the threshold to mechanical stimulation in models of incisional and neuropathic pain. KEY FINDINGS: The derivatives produced antinociception in the tail-flick test and reduced mechanical allodynia in models of incisional and neuropathic pain. The approximate ED50 in milligrams (confidence limits in parenthesis) in these tests were 1.35 mg (0.61; 2.95), 0.20 mg (0.14; 0.27) and 0.28 mg (0.12; 0.63) for neamine, and 1.05 mg (0.68; 1.60), 0.78 mg (0.776; 0.783) and 0.79 mg (0.46; 1.34) for 2-deoxystreptamine, respectively. Neamine was more potent than 2-deoxystreptamine in the incisional and neuropathic pain models, but they had similar potency in the tail-flick test. Tetra-azidoneamine, a neamine derivative in which free amino groups are replaced with azido groups, did not change the incisional mechanical allodynia. The reduction of incisional allodynia by neamine and 2-deoxystreptamine was transitorily antagonized by intrathecal administration of calcium chloride. CONCLUSIONS: The intraspinal administration of neamine and 2-deoxystreptamine is antinociceptive in rats. The presence of amino groups in the structure of these derivatives is fundamental to their antinociceptive effect, which may be due to a calcium antagonist activity.

Synthesis of neamine-based pseudodisaccharides as potential vestibulotoxic agents to treat vertigo in Ménière's disease.

Ménière's disease (MD) is a progressive disease of the inner ear characterized by recurring attacks of disabling vertigo, hearing loss and tinnitus. Patients who do not respond to vestibular sedatives or steroids may require an intratympanic application of aminoglycoside antibiotics, which destroys the vestibular function of the affected ear in order to avoid the debilitating vertigo attacks. Although effective, this procedure causes hearing loss in almost one third of the patients due to the aminoglycosides cochlear toxicity. Here we describe the synthesis of two pseudodisaccharides structurally related to neamime aiming to mimic the aminoglycosides pharmacophore core by replacing their toxic amine by azide and hydroxyl groups. Products 1 and 2 selectively promoted 'in vivo' damage to vestibular tissues without causing hearing loss or cochlear toxicity. Therefore, these pseudodisaccharides stand as promising lead compounds for the development of a safer and more effective therapeutic procedure to manage the symptoms of MD severe dizziness.

Effect of neomycin B on rotavirus plus- and minus-strand RNA synthesis.

Rotavirus multiplication was inhibited by neomycin B by affecting the synthesis of the viral genome. Genome replication involves a two-step mechanism, one is plus-strand synthesis or transcription, and the other is minus-strand synthesis or replication. The results indicate that both activities are inhibited by aminoglycoside. The effect on the minus-strand was determined by an in vitro assay using a template-dependant open core preparation. The effect on transcription was explored using transcriptionally active virus particles. In the case of transcription, the inhibitory effect of neomycin B was studied in both initiation and the elongation of the mRNA. Initiation was defined by the synthesis of short transcripts of less than 25 nucleotides in length and elongation as an extension of those molecules into full-length transcripts. The inhibitory effect of neomycin was also mimicked by other aminoglycosides such as lividomycin, paromomycin, and tobramycin. The results may be explained based on the ability of the drug to interact with the stem and loop regions, which, in the case of rotavirus, have been identified at the end of the templates required for both transcription and minus-strand synthesis.

Avaliaçäo da sensibilidade "in vitro" à associaçäo de sulfato de framicetina, sulfato de polimixina B e gramicidina / Evaluation of the sensibility \"in vitro\" to the association of framycetin sulfate, polymyxin B sulfate and gramicidin

A fim de avaliar a sensibilidade "in vitro" à associaçäo de sulfato de framicetina, sulfato de polimixina B e gramicidina, estudamos amostras de 96 pacientes portadores de patologias oculares externas e de 4 lentes de contato gelatinosas. De 112 antibiogramas realizados, 80 (71,4%) foram por Staphylococcus aureus, cuja sensibilidade incluindo todas as bactérias de 85,7% (96). Esta associaçäo é composta por 3 antibióticos bactericidas näo usados sistematicamente de rotina