Search results for "VITRO"
showing 10 items of 2786 documents
An in vitro evaluation of two dentine adhesive systems to seal the pulp chamber using a glucose penetration model
2010
Objectives: To evaluate the sealing capability of Cavit TM G with or without Clearfil TM S3 Bond and Prime & Bond NT placed in the pulp chamber. Study Design: Forty single rooted premolars, extracted for orthodontic and periodontal reasons, with intact coronal surface and mature apices, were standardized to a length of 15 mm. The teeth were instrumented, filled with a gutta-percha master cone and divided into three groups to obturate the pulp chambers: Cavit TM G; Clearfil TM S3 Bond plus Cavit TM G and Prime & Bond® NT plus Cavit TM G. A glucose leakage model was used for evaluating the coronal microleakage. The Mann-Whitney test was used to evaluate the differences in the means of the glu…
Luting of ceramic crowns with a self-adhesive cement: Effect of contamination on marginal adaptation and fracture strength
2012
Objectives: This study evaluated the percentages of continuous margins (%CM) and fracture strength (FS) of crowns made out from blocs of leucite-reinforced ceramic (IPS Empress CAD) and luted with a representative self-adhesive cement (RelyX Unicem) under four contaminating agents: saliva, water, blood, a haemostatic solution containing aluminium chloride (pH= 0.8) and a control group with no contamination. Study Design: %CM at both tooth-cement (TC) and cement-crown (CC) interfaces were determined before and after a fatigue test consisting of 600’000 chewing loads and 1’500 temperature cycles changing from 5º C to 50º C. Load to fracture was recorded on fatigued specimens. Kruskal-Wallis t…
Cytotoxic Activity of Organotin(IV) Derivatives with Triazolopyrimidine Containing Exocyclic Oxygen Atoms
2020
In this study cytotoxicity of organotin(IV) compounds with 1,2,4-triazolo[1,5-a]pyrimidines, Me3Sn(5tpO) (1), n-Bu3Sn(5tpO) (2), Me3Sn(mtpO) (3), n-Bu3Sn(mtpO) (4), n-Bu3Sn(HtpO2) (5), Ph3Sn(HtpO2) (6) where 5HtpO = 4,5-dihydro-5-oxo-[1,2,4]triazolo-[1,5-a]pyrimidine, HmtpO = 4,7-dihydro-5-methyl-7-oxo-[1,2,4]triazolo-[1,5-a]pyrimidine, and H2tpO2 = 4,5,6,7-tetrahydro-5,7- dioxo-[1,2,4]triazolo-[1,5-a]-pyrimidine, was assessed on three different human tumor cell lines: HCT-116 (colorectal carcinoma), HepG2 (hepatocarcinoma) and MCF-7 (breast cancer). While 1 and 3 were inactive, compounds 2, 4, 5 and 6 inhibited the growth of the three tumor cell lines with IC50 values in the submicromolar …
Organotin(IV) derivatives with 5,7-disubstituted-1,2,4-triazolo[1,5-a]pyrimidine and their cytotoxic activities: The importance of being conformers
2014
Abstract The organotin(IV) compounds Me2SnCl2(dbtp)(1), Me2SnCl2(dbtp)2 (2), Et2SnCl2(dbtp) (3), Et2SnCl2(dbtp)2 (4), Et2SnCl2(dptp) (5), nBu2SnCl2(dbtp)2 (6), nBu2SnCl2(dptp) (7), Ph2SnCl2(dbtp) (8), Ph2SnCl2(EtOH)2(dptp)2 (9), where dbtp = 5,7-di-tert-butyl-1,2,4-triazolo[1,5-a]pyrimidine and dptp = 5,7-diphenyl-1,2,4-triazolo [1,5-a]pyrimidine, have been tested by MTT for their cytotoxic activity on three tumor cell lines, HepG2 (human hepatocellular carcinoma), HeLa (human cervix adenocarcinoma) and MCF-7 (human breast cancer). Except for 1 and 2, which were ineffective, all compounds significantly showed a dose-dependent anti-proliferative effect against the three cell lines. By calcul…
In vitro analysis of the pH stability of dental bleaching gels during in-office procedures
2021
Background Previous studies have shown that acidic bleaching gels could lead to worse collateral effects during an in-office bleaching procedure, while neutral or basic products leads towards a better experience. Considering this fact, the main purpose of this study was to evaluate the pH behavior of 6 in-office bleaching gels, compared to the information provided by their manufacturers. Material and methods Thirty enamel discs of bovine teeth were prepared, the initial colors of which were measured by a spectrophotometer and then divided into 6 groups. A pH meter was used to measure the pH every 30 seconds until the end of each procedure, when a new color evaluation was then made. The Tuke…
High-performance liquid chromatographic determination of sumatriptan after in vitro transdermal diffusion studies.
2004
A simple, accurate, precise and rapid HPLC method with UV detection has been validated in order to determine the in vitro transdermal absorption of sumatriptan succinate. The HPLC method is a modification of that described by Nozal et al. [M.J. Nozal, J.L. Bernal, L. Toribio, M.T. Martin, F.J. Diez, J. Pharm. Biomed. Anal. 30 (2002) 285-291]. Separation was carried out on a 250 mm Kromasil C18 column at room temperature. The detector response, at 282.7 nm, was found to be linear in a concentration range between 0.145 and 145 microM. The limit of detection (LOD) was 0.019 microM and the limit of quantification (LOQ) was 0.145 microM.
Mechanical and electrophysiological effects of cromakalim on the human urinary bladder.
1994
The effects of cromakalim on spontaneous and induced mechanical activity of human detrusor muscle were investigated in vitro. Cromakalim produces a concentration-related decrease of spontaneous as well as carbachol- and K(+)-evoked contractions. This is the first study to utilize the patch clamp technique to elucidate the mechanism of action of cromakalim on human detrusor cells. Cromakalim hyperpolarizes the detrusor cells by increasing the net outward current which is most likely carried by potassium ions. In the human urinary bladder, this effect is mediated by a glibenclamide-sensitive potassium channel, as glibenclamide is able to diminish the relaxant effect of cromakalim and to preve…
Synaptic release of zinc from brain slices: factors governing release, imaging, and accurate calculation of concentration.
2006
Cerebrocortical neurons that store and release zinc synaptically are widely recognized as critical in maintenance of cortical excitability and in certain forms of brain injury and disease. Through the last 20 years, this synaptic release has been observed directly or indirectly and reported in more than a score of publications from over a dozen laboratories in eight countries. However, the concentration of zinc released synaptically has not been established with final certainty. In the present work we have considered six aspects of the methods for studying release that can affect the magnitude of zinc release, the imaging of the release, and the calculated concentration of released zinc. We…
Mast cells promote homeostasis by limiting endothelin-1-induced toxicity
2004
Endothelin-1 (ET-1) is a 21-amino-acid peptide, derived from vascular endothelial cells, with potent vasoconstrictor activity. ET-1 has been implicated in diverse physiological or pathological processes, including the vascular changes associated with sepsis. However, the factors that regulate ET-1-associated toxicity during bacterial infections, or in other settings, are not fully understood. Both the pathology associated with certain allergic and autoimmune disorders, and optimal host defence against bacterial and parasitic infections are mediated by mast cells. In vitro, mast cells can produce ET-1 (ref. 11), undergo ET-1-dependent and endothelin-A receptor (ET(A))-dependent activation, a…
Direct synthesis of C3-mono-functionalized oxindoles from N-unprotected 2-oxindole and their antileishmanial activity.
2014
A novel approach for the synthesis of unprecedented C3-mono-functionalized indolin-2-ones is reported, starting from 2-oxindole and chalcones. The reactions proceed regioselectively under mild conditions, without di- and tri-alkylated side products. The new compounds have been evaluated in vitro for their antiproliferative effects against the protozoan Leishmania infantum. Interestingly, they appear able to kill L. infantum promastigotes and amastigotes, without significant cytotoxic effects.