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Biomedical subjects

Marco Ferrari

Publications and source records attributed to Marco Ferrari.

At least 55 records · Page 3Linked to original sources
PubMed2005

The influence of the cutting speed on bond strength and integrity of microtensile specimens.

OBJECTIVES: To verify the influence of cutting speed during microtensile specimen preparation, on bond strength values and on the sample microscopic integrity of a single-bottle adhesive system to enamel and dentin. METHODS: Thirty sound human third molars were restored with light-cured Excite and Tetric Ceram according to manufacturers' instructions, being half in ground enamel [E], and half in flat dentin [D]. After 24 h storage in distilled water at 37 degrees C, the restored teeth were sectioned in x and y-axes under different cutting speed: 100, 200 or 400 RPM, obtaining stick shaped specimens with cross-sectional area of 1.0 mm(2). Five specimens from each experimental group were randomly selected before being loaded for SEM analysis, while the remaining samples were subjected to the microtensile bond strength test. Because the variance of dentin specimens was significantly higher than the variance of enamel samples, analysis of the influence of the cutting speed was performed separately, by substrate. RESULTS: The mean values in MPa were calculated including/excluding premature failures: E1: 24.67/27.31(a); E2: 24.03/25.81(a); E4: 19.06/21.52(b); D1: 35.80/36.33(A); D2: 35.84/36.65(A); D4: 37.78/38.50(A). In the SEM analysis, better integrity of the dentin specimens was observed when compared to the enamel samples, for which the integrity was greater in the lower cutting speed groups. SIGNIFICANCE: It can be concluded that the cutting speed is an important factor that should be considered, mainly when enamel is involved, since it may affect the bond strength results and the integrity of the specimens.

Acid Etching, Dental↗
PubMed2005

Single-bottle adhesives behave as permeable membranes after polymerisation. II. Differential permeability reduction with an oxalate desensitiser.

OBJECTIVES: This study examined the changes in hydraulic conductance and ultrastructure of dentine bonded with simplified etch-and-rinse adhesives to oxalate desensitiser pre-treated acid-etched dentine. METHODS: Human dentine disks were acid-etched, treated with an oxalate desensitiser (BisBlock, Bisco), and bonded with One-Step (OS), Single Bond (SB), OptiBond Solo Plus (OB) or Prime and Bond NT (PB). Similar disks from each group were acid-etched, and bonded without oxalate pre-treatment. Hydraulic conductance of the specimens was measured at 20 cm of water pressure and analysed with nonparametric statistical methods. Epoxy resin replicas of the smear layer-covered dentine and bonded dentine were examined with SEM for the extent of fluid transudation. Specimens bonded under perfusion were examined with TEM after tracer immersion. RESULTS: OB and PB exhibited a highly significant reversal of the reduced hydraulic conductance obtained with BisBlock on unbonded acid-etched dentine. Profuse water transudation across the bonded dentine was observed from the replicas. Adhesive interfaces were covered with spherical globules that interfered with dentine hybridization. Conversely, no significant difference in hydraulic conductance was observed in SB, between Bisblock pre-treated, unbonded and bonded acid-etched dentine. Significantly lower hydraulic conductance was shown on application of OS to Bisblock-treated acid-etched dentine. Water transudation was sparse, interfering surface globular structures were absent, and only angular subsurface crystals were seen in the dentinal tubules. CONCLUSIONS: Convective water fluxes through dentine may be reduced by applying Bisblock to acid-etched dentine before bonding with One-Step or Single Bond. However, reducing adhesive permeability with the use of oxalate desensitiser is not applicable to low acidity adhesives such as OptiBond Solo Plus and Prime and Bond NT.

Adhesives↗
PubMed2005

Solvent and water retention in dental adhesive blends after evaporation.

This study examined the extent of organic solvent and water retention in comonomer blends with different hydrophilicity (Hoy's solubility parameter for hydrogen bonding, delta(h)) after solvent evaporation, and the extent of tracer penetration in polymerised films prepared from these resins. For each comonomer blend, adhesive/solvent mixtures were prepared by addition of (1) 50 wt% acetone, (2) 50 wt% ethanol, (3) 30 wt% acetone and 20 wt% water and (4) 30 wt% ethanol and 20 wt% water. The mixtures were placed in glass wells and evaporated for 30-60s for acetone-based resins, and 60-120 s for ethanol-based resins. The weight of the comonomer mixtures was measured before and after solvent evaporation. Resin films were prepared for transmission electron microscopy (TEM) after immersion in ammonical silver nitrate. The percentages of solvent and water retained in the comonomer mixtures, and between the acetone and ethanol groups were measured gravimetrically and were statistically compared. In comonomer-organic solvent mixtures, the percentage of solvent retained in acetone and ethanol-based mixtures increased significantly with hydrophilicity of the comonomer blends (P < 0.05). In resin-organic solvent-water mixtures, significantly more solvent and water were retained in the ethanol-based mixtures (P < 0.0001), when compared to acetone-based mixtures after 60s of air-drying. TEM revealed residual water being trapped as droplets in resin films containing acetone and water. Water-filled channels were seen along the film periphery of all groups and throughout the entire resin films containing ethanol and water. The addition of water to comonomer-ethanol mixtures results in increased retention of both ethanol and water because both solvents can hydrogen bond to the monomers.

Absorption↗
PubMed2005

Fatigue resistance and structural characteristics of fiber posts: three-point bending test and SEM evaluation.

OBJECTIVES: The aim of the present study was to assess the fatigue resistance of different types of fiber posts, and to observe their ultrastructure through scanning electron microscopy (SEM) before and after undergoing the fatigue test. METHODS: Eight types of fiber posts were selected for this study. Easypost (Group 1), Para Post Fiber White (Group 2), FibreKor (Group 3), Ghimas White (Group 4), DT Light-Post radiopaque (Group 5), FRC Postec (Group 6), Luscent Anchors (Group 7), Snowpost (Group 8). Ten out of fifteen posts in each group were used for the fatigue test, and the other five were processed for SEM. A three-point bending machine, loading at an angle of 90 degrees and a frequency of 3 Hz was employed for fatigue testing. The test was carried out until two million cycles were completed or until fracturing of the post. SEM evaluation was performed using a three-step scale method to assess the fiber/resin ratio and fiber dimension. RESULTS: The fatigue test showed statistically significant differences among the different posts. Groups 5 and 6 performed better than all the other groups, withstanding practically all the stipulated number of load cycles. All the other posts fractured before the end of the test. SEM observations of the surface integrity of the fiber posts showed that Groups 4-6 obtained better scores for both longitudinal sections and cross-sections. SIGNIFICANCE: There was a large variation in the response of different kinds of fiber posts a fatigue resistance test. The absence of correlation between results of fatigue testing and parameters of structural integrity suggests that the latter mostly reflect random variations in the fiber post manufacturing process.

Composite Resins↗
PubMed2005

The adhesion between prefabricated FRC posts and composite resin cores: microtensile bond strength with and without post-silanization.

OBJECTIVES: Aim of the study was to measure the adhesion between two types of translucent prefabricated FRC posts (FRC Postec, Ivoclar-Vivadent, FRC; Light-Post, RTD, LP), and two types of flowable composites used as core materials (UnifilFlow, GC, UF; Tetric Flow, Ivoclar-Vivadent, TF), with or without the application of a silane (Monobond-S, Ivoclar-Vivadent, S) on the post surface. METHODS: The experimental groups were: 1.1 FRC+UF; 1.2 FRC+S+UF; 1.3 FRC+TF; 1.4 FRC+S+TF: 2.1 LP+UF; 2.2 LP+S+UF; 2.3 LP+TF; 1.4 LP+S+TF. The bond strength at the interface between post and core was measured with the microtensile non-trimming technique. Thirty to thirty-five beam-shaped specimens per group were obtained from cylinders of core material, which had been built up around the post by progressively adding small increments of composite resin. Each specimen was loaded in tension until failure at either one of the two post-core interfaces present in each stick. The differences in interfacial bond strength among the groups were tested for statistical significance with the two-way ANOVA. RESULTS: The measured bond strengths in MPa were: [table: see text]. The statistical analysis revealed that post-silanization had a significant effect on adhesion (p<0.05). With any combination of post and core materials tested, the application of a silane onto the post surface prior to building up the core significantly increased the post-core bond strength. SIGNIFICANCE: For improved adhesion at the interface between prefabricated FRC posts and composite resin cores, post-silanization is advisable.

Adhesiveness↗
PubMed2005

Interferon-gamma and interferon-beta affect endogenous catecholamines in human peripheral blood mononuclear cells: implications for multiple sclerosis.

Interferon (IFN)-gamma plays a pivotal role in the pathogenesis of multiple sclerosis (MS), while IFN-beta may be able to modify the clinical course of the disease, eventually also by counterbalancing IFN-gamma-mediated effects. Catecholamines (CA) exert important effects on the immune response, both as transmitters between the nervous and the immune system, as well as autocrine/paracrine mediators in immune cells, and several lines of evidence support their involvement in MS. In particular, dysregulated production of CA seems to occur in peripheral blood mononuclear cells (PBMCs) of MS patients. We assessed the effects of IFN-beta and IFN-gamma on endogenous CA in PBMCs. In cultured PBMCs stimulated with phytohaemagglutinin (PHA), IFN-beta increased CA production and induced CA release in the culture medium, while IFN-gamma decreased both CA production and the expression of mRNA for the CA-synthesizing enzyme tyrosine hydroxylase. Coincubation with both IFNs prevented the inhibitory effect of IFN-gamma, as well as the stimulatory effect of IFN-beta. IFNs are the first physiological compounds shown to affect endogenous CA in PBMCs: in view of the role of CA-dependent mechanisms in the immune response, these findings may help to better understand the mechanisms of action of IFN-beta as an immunomodulatory drug in MS.

Blotting, Northern↗
PubMed2005

Foot pulse oximeter perfusion index correlates with calf muscle perfusion measured by near-infrared spectroscopy in healthy neonates.

OBJECTIVE: In critically ill neonates, peripheral perfusion and oxygenation assessment may provide indirect information on the circulatory failure of vital organs during circulatory shock. The development of pulse oximetry has recently made it possible to calculate the perfusion index (PI), obtained from the ratio between the pulsatile and nonpulsatile signals of absorbed light. The main goals of this study were: (1) to study foot PI; and (2) to evaluate the relationship between foot PI, obtained continuously by pulse oximetry, and a number of variables, i.e. blood flow (BF), oxygen delivery (DO(2)), oxygen consumption (VO(2)), and fractional oxygen extraction (FOE), measured indirectly by near-infrared spectroscopy (NIRS) on the calf in 43 healthy term neonates (weight 3474.6 +/- 466.9 g; gestational age 39.1 +/- 1.4 weeks). STUDY DESIGN: Calf BF, DO(2) and VO(2) were assessed by NIRS on short-lived venous and arterial occlusion maneuvers. PI was measured on the contralateral foot. RESULTS: Foot PI was 1.26 +/- 0.39. There was a positive correlation between foot PI and both calf BF (r = 0.32, p = 0.03) and DO(2) (r = 0.32, p = 0.03), but no correlation was found between foot PI and calf FOE and between foot PI and VO(2). CONCLUSIONS: In the neonatal intensive care unit, continuously measuring foot PI by pulse oximetry seems clinically more feasible for peripheral perfusion monitoring than spot measurements of the calf BF and/or VO(2) by indirect NIRS.

Foot↗
PubMed2005

The contribution of friction to the dislocation resistance of bonded fiber posts.

This study tested the null hypothesis that the use of dentin adhesives produces no improvement on the fixation of fiber posts with resin cements in endodontically treated teeth. Post spaces were prepared in 36 single-rooted root-filled teeth. Silanized glass fiber posts were cemented to the post spaces using a self-etch (ED primer/Panavia 21) and a total etch resin cement (Excite DSC/Variolink II), with or without the accompanying dentin adhesives. Fixation strengths and interfacial ultrastructure were evaluated using a "thin slice" push-out test and transmission electron microscopy. For both resin cements, the fixation strengths obtained from specimens luted with resin cement only did not differ significantly from those in which the intraradicular dentin was first bonded with a dentin adhesive. In the presence of incomplete smear layer removal and interfacial gaps, the dislocation resistance of bonded fiber posts was contributed largely by sliding friction.

Acid Etching, Dental↗
PubMed2005

Interfacial strength of Resilon and gutta-percha to intraradicular dentin.

Strengthening of Resilon-filled roots via an adhesive interface should be reflected by improvement in the interfacial strength and dislocation resistance between the root fillings and intraradicular dentin. This study compared the interfacial strengths of Resilon/Epiphany and gutta-percha/AH Plus using a thin-slice push-out test design. Failure modes of root slices after push-out testing were examined with environmental scanning electron microscopy. The gutta-percha group exhibited significantly higher interfacial strength than the Resilon group, when premature failures that occurred in Resilon root slices were included in the statistical analysis. The gutta-percha root slices failed exclusively along the gutta-percha/sealer interface. The Resilon root slices failed predominantly along the sealer/dentin interface with recognizable, fractured resin tags. Detachment of the Resilon from the Epiphany sealer was also surprisingly observed in some specimens. The similarly low interfacial strengths achieved with both types of root filling challenges the concept of strengthening root-filled teeth with the new endodontic material.

Bismuth↗
PubMed2005

Effectiveness of resin-coated gutta-percha cones and a dual-cured, hydrophilic methacrylate resin-based sealer in obturating root canals.

The introduction of a polybutadiene-diisocyanate-methacylate resin-coating of gutta-percha enables the polyisoprene to be chemically coupled to methacrylate-based resin root canal sealers. This study examined the effectiveness of using passively fitting cones of this type of gutta-percha with a dual-cured version of EndoREZ sealer in obturating cleaned and shaped root canals. The hydrophilic nature of the sealer enabled the creation of an extensive network of 800 to 1200 mum long sealer resin tags after removal of the endodontic smear layer. Although no adhesive was employed, thin hybrid layers in root dentin were observed when EDTA was used as the final rinse. Nevertheless, interfacial gaps and silver leakage could be observed along the sealer-dentin interfaces that might be attributed predominantly to polymerization shrinkage of the sealer. Gaps and silver leakage were also identified between the gutta-percha resin-coating and the sealer.

Bicuspid↗
PubMed2005

Scanning electron microscopic evaluation of fiber post-resin core units built up with different resin composites.

PURPOSE: To microscopically evaluate the structural characteristics of post-and-core units made of a fiber post and of different types of resin-based composites used as core materials. METHODS: 55 endodontically treated human maxillary incisors were prepared for receiving a fiber post (AEsthetic Post Plus). One-Step and C&B resin cement were used for luting the post. Samples were randomly divided into 11 groups. Eleven different composite materials were selected to build-up the abutment. The materials on trial were: Group 1: Z100; Group 2: Light-Core; Group 3: Lumiglass; Group 4: Gradia Direct; Group 5: Build-It!; Group 6: Tetric Ceram; Group 7: Biscore self-curing; Group 8: Unifil Flow; Group 9: Definite Flow; Group 10: Tetric Flow; Group 11: AEliteFlo. All the post-and-core specimens were cut perpendicularly to their long axis and processed for SEM observations. The presence of voids/bubbles within the resin abutment and of defects at the interface between the post surface and the core material was scored. These aspects were quantified with reference to a predefined index. The differences among the scores were tested for statistical significance (P< 0.05). RESULTS: Cores built up with flowable composites showed the highest integrity and the best adaptation onto the post.

Analysis of Variance↗
PubMed2005

In vitro evaluation of wall-to-wall adaptation of a self-adhesive resin cement used for luting gold and ceramic inlays.

PURPOSE: This in vitro study evaluated the wall-to-wall adaptation of a new self-adhesive resin-based cement (RelyX Unicem) in comparison with that of other cements when luting gold and porcelain inlays in standardized Class II cavities in extracted teeth. MATERIALS AND METHODS: In each experimental group (n = 10), a different combination of inlay and luting material was tested. Group 1: Porcelain Empress II (Ell) and RelyX Unicem (U); group 2: Ell and resin-based cement Variolink II in combination with primer and bonding Excite DSC; group 3: gold inlays (G) and U; group 4: G and Harvard zinc-oxy-phosphate cement; group 4: G and glass-ionomer cement Fuji Cem. After storage and thermocycling, microleakage testing was carried out and dye penetration was examined at the occlusal and cervical margins of each inlay. The differences in microleakage score were tested for statistical significance first comparing all groups, then pooling the groups for inlay material (Kruskal-Wallis nonparametric ANOVA and Mann-Whitney U test, p < 0.05). SEM observations of the tooth/cement/restoration interfaces were also made in each group. RESULTS: Harvard cement had the highest microleakage. The sealing ability exhibited by RelyX Unicem was satisfactory with both gold and porcelain inlays, and comparable to that of Fuji Cem and Variolink II. CONCLUSION: RelyX Unicem achieved an adequate seal on both enamel and dentin when used to lute in vitro gold and porcelain inlays.

Dental Cavity Preparation↗
PubMed2005

SEM evaluation of the cement layer thickness after luting two different posts.

PURPOSE: To verify with SEM the cement layer thickness and uniformity of resin-relined translucent fiber posts (anatomic posts) and standard translucent fiber posts. MATERIALS AND METHODS: On 20 extracted maxillary anterior teeth, the roots were endodontically treated and prepared for the insertion of a fiber post. Translucent fiber posts (DT) were luted with a dual-curing resin cement (Duo-Link) in 10 specimens (group 1) after the canal walls had been treated with the One-Step bonding system. In the other 10 specimens (group 2), experimental anatomic posts (Anatomic Post'n Core) were tested. To these posts, a layer of light-curing resin is added to allow for a pre-cementation relining of the post, aimed at improving its fit into the endodontic space. For luting, the same adhesive-resin cement combination of group 1 was used. All the roots were sectioned and prepared for SEM observations. At the 1-mm, 4.5-mm, and 8-mm level of each root, cement thickness was measured, and the presence of gaps or voids within the luting material or at its interfaces was evaluated. A statistical analysis was performed to test the significance of differences in the cement layer thickness around the two types of post and at different levels of the same type of post. RESULTS: In the presence of anatomic posts, the cement layer was significantly thinner and more uniform at the coronal and middle level of the root. In both groups, voids and bubbles were detected within the luting material, within the abutment material, and between fiber post and cement. Gaps were also visible between post and relining material. CONCLUSIONS: The resin cement thickness was significantly lower in the anatomic post group than in the control group (standardized posts), except at the apical third of the canal, where there was no statistically significant difference. A good adaptation of anatomic posts was evident in all of the specimens.

Analysis of Variance↗
PubMed2005

Microtensile bond strength of current dentin adhesives measured immediately and 24 hours after application.

PURPOSE: To evaluate the immediate microtensile bond strengths achieved with representative adhesive systems from each of the four current bonding approaches. MATERIALS AND METHODS: Resin composite was bonded incrementally to flat, midcoronal dentin from 33 human molars, using the adhesives (Adper Scotchbond MP; Adper Scotchbond 1; Optibond Solo Plus; Clearfil SE Bond; AdheSE; Tyrian SPE + One Step Plus; Optibond Solo Plus self-etching; One-Up Bond F; iBond; Adper Prompt L-Pop; Xeno III) according to the respective manufacturer's instructions. The bonded specimens were immediately sectioned into sticks and underwent microtensile bond testing either immediately or after 24 h. Data were analyzed with two-way ANOVA and LSD tests. RESULTS: No significant differences were found between immediate and 24-h bond strengths (p > 0.05). However, significant differences were observed among adhesives (p = 0.001). The all-in-one adhesive iBond showed statistically lower values when compared to all the other adhesives. Adper Prompt L-Pop, Xeno III, Tyrian SPE + One Step Plus and One-Up Bond F, all self-etching adhesives, were significantly weaker than AdheSE, Optibond Solo Plus, Adper Scotchbond 1, Optibond Solo Plus self-etching, Clearfil SE Bond, and Adper Scotchbond MP, which did not differ statistically from each other. CONCLUSION: Microtensile bond strengths of representative adhesive systems from the four categories of bonding agents were not equivalent, with the lowest values recorded for the one-step self-etching adhesives. There were no differences in the bond strengths when measured immediately and after 24 h.

Acrylic Resins↗
PubMed2004

Microtensile bond strength to ground enamel by glass-ionomers, resin-modified glass-ionomers, and resin composites used as pit and fissure sealants.

OBJECTIVES: To measure the microtensile bond strength to ground enamel of different types of materials used as pit and fissure sealants in combination with different substrate conditioners. METHODS: From 40 sound extracted molars, eight groups of five teeth were randomly formed. The experimental groups were: (1) (C) 37% phosphoric acid/ClinPro Sealant (3M ESPE); (2) (G) 37% phosphoric acid/Guardian Seal (Kerr); (3) (E/TF) 37% phosphoric acid/Excite/Tetric Flow (Ivoclar-Vivadent) (4) (OS/UF) 37% phosphoric acid/One Step (Bisco)/UniFil Flow (GC); (5) (OS/AE) 37% phosphoric acid/One Step/AEliteflo (Bisco); (6) (UB/UF) UniFil Bond/UniFil Flow (GC); (7) (CC/FVII) GC Cavity Conditioner/Fuji VII (GC); (8) (CC/FII) GC Cavity Conditioner/Fuji II LC Improved (GC). On the buccal of each tooth, a 5mm high build-up was created by incrementally adding layers of the sealing material on the conditioned enamel. By serially cutting the built-up tooth, multiple beam-shaped specimens about 1mm x 1mm in cross section were obtained, and loaded in tensile (0.5 mm/min) until failure occurred. RESULTS: The bond strengths measured in MPa were: (C) 20.41+/-11.79; (G) 16.02+/-7.99; (E/TF) 24.06+/-9.67; OS/UF 15.63+/-9.00; (OS/AE) 9.31+/-6.05; (UB/UF) 4.96+/-3.46; (CC/FVII) 1.70+/-2.19; (CC/FII) 2.19+/-1.44. CONCLUSIONS: The conventional and the resin-modified glass ionomers measured bond strengths significantly lower than those of any resin-based materials. Failure frequently occurred cohesively within the cement. Flowable composites in combination with phosphoric acid and a total-etch adhesive performed similarly to resin-based materials specifically conceived for sealings, such as ClinPro Sealant and Guardian Seal. The bond achieved by resin composite when treating enamel with the self-etching primer used in this study (UniFil Bond) was significantly lower than that developed when the substrate was etched with 37% phosphoric acid.

Acrylic Resins↗
PubMed2004

Intracellular calcium changes induced by the endozepine triakontatetraneuropeptide in human polymorphonuclear leukocytes: role of protein kinase C and effect of calcium channel blockers.

BACKGROUND: The endozepine triakontatetraneuropeptide (TTN) induces intracellular calcium ([Ca++]i) changes followed by activation in human polymorphonuclear leukocytes (PMNs). The present study was undertaken to investigate the role of protein kinase (PK) C in the modulation of the response to TTN by human PMNs, and to examine the pharmacology of TTN-induced Ca++ entry through the plasma membrane of these cells. RESULTS: The PKC activator 12-O-tetradecanoylphorbol-13-acetate (PMA) concentration-dependently inhibited TTN-induced [Ca++]i rise, and this effect was reverted by the PKC inhibitors rottlerin (partially) and Ro 32-0432 (completely). PMA also inhibited TTN-induced IL-8 mRNA expression. In the absence of PMA, however, rottlerin (but not Ro 32-0432) per se partially inhibited TTN-induced [Ca++]i rise. The response of [Ca++]i to TTN was also sensitive to mibefradil and flunarizine (T-type Ca++-channel blockers), but not to nifedipine, verapamil (L-type) or omega-conotoxin GVIA (N-type). In agreement with this observation, PCR analysis showed the expression in human PMNs of the mRNA for all the alpha1 subunits of T-type Ca++ channels (namely, alpha1G, alpha1H, and alpha1I). CONCLUSIONS: In human PMNs TTN activates PKC-modulated pathways leading to Ca++ entry possibly through T-type Ca++ channels.

Journal Article↗
PubMed2004

Dopaminergic modulation of oxidative stress and apoptosis in human peripheral blood lymphocytes: evidence for a D1-like receptor-dependent protective effect.

Dopamine (DA) is a neurotransmitter in the central and peripheral nervous system, which can be either cytotoxic or cytoprotective under selected conditions. Such effects involve oxidative mechanisms and are likely to play a role in neurodegenerative disorders. Because increasing evidence points to peripheral blood lymphocytes (PBL) as a feasible model for studying DA-related mechanisms of cell death and survival, we have explored in these cells the effects of DA on oxidative metabolism and apoptosis. Our results show that, whereas DA 100-500 microM resulted in increased intracellular reactive oxygen species (ROS) levels and apoptotic cell death through oxidative stress, DA 0.1-5 microM decreased ROS levels and apoptosis. DA (both 1 and 500 microM) partially counteracted the decrease in Cu/Zn superoxide dismutase levels observed in untreated PBL. However, whereas the effect of the low dose lasted for the whole incubation period (24 h), the effect of DA 500 microM was transient. DA-dependent reduction of ROS levels and apoptosis was prevented by D1-like (but not D2-like) receptor antagonism. The present findings add knowledge about the sensitivity of PBL to DA and strengthen the rationale for exploiting these cells as an easily accessible peripheral model for the ex vivo investigation of oxidative stress-related dopaminergic mechanisms underlying human neurodegenerative diseases.

Apoptosis↗