MTT versus other cell viability assays to evaluate the biocompatibility of root canal filling materials: a systematic review.

OBJECTIVES: This systematic review aimed to compare the cytotoxicity of root canal filling materials (RCFMs) assessed using tetrazolium salt-based tests (TSBT), including the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, with those obtained using other cell viability assays. METHODS: A search was performed on PubMed, Scopus, Web of Science and OpenGrey up to March 2019, followed by a manual search. According to the Participants, Exposure, Comparator and Outcomes (PECO) criteria, in vitro studies that evaluated the cytotoxic effect of RCFMss on animal and/or human cells through TSBT and at least one other viability assay were compared. The methodological quality of selected papers was assessed using ToxRTool® and SciRAP® . Data were analysed using Wilcoxon's signed-rank test for paired samples and linear weighting kappa. RESULTS: A total of 230 non-duplicated records were identified. After applying the eligibility criteria, 55 studies were selected for methodological evaluation, seven were selected by manual searching, 22 were excluded for methodological reasons, and 40 were included. A total of 410 comparisons were performed between TSBT and distinct cell viability tests (DCVT). MTT had moderate concordance with DCVT using human cells (n = 138 samples) (P = 0.507; k = 0.4225) and animal cells (n = 122 samples) (P = 0.124; k = 0.5775). XTT had good concordance using human (n = 110 samples) (P = 0.507; k = 0.6336) and animal cells (n = 12 samples) (P = 0.564; k = 0.6604). MTT, XTT, WST and MTS assays showed moderate concordance with DCVT (n = 410 samples) (P = 0.375; k = 0.5138) and complete agreement in 226 samples. DISCUSSION: The included studies had methodological heterogeneity that was minimized by the systematic review methodology. CONCLUSIONS: MTT and XTT do not cause over- or underestimation of cell viability during cytotoxicity screening of root canal filling materials, implying that these assays can be considered reliable for this purpose. Nonetheless, the development of protocols for the cytotoxic screening of these materials on 3D tissue-like cultures aiming to improve their predictability in the clinical scenario is suggested.

Moderate hypoxia is able to minimize the manganese-induced toxicity in tissues of silver catfish (Rhamdia quelen).

The aim of this study was to compare the effects of manganese (Mn) on silver catfish exposed to different levels of dissolved oxygen. Silver catfish (Rhamdia quelen) were exposed to increasing concentrations of Mn (4.2, 8.4 or 16.2mgL(-1)) under either normoxia (100 percent saturation) or moderate hypoxia (51.87 percent saturation) for 15 days. Under normoxia, Mn exposure increased lipid peroxidation (LP) in brain and kidney; it increased gluthatione (GSH) levels in brain and decreased catalase (CAT) activity in both tissues. Moderate hypoxia was able to prevent Mn-induced LP in brain and to reduce this oxidative parameter in kidney; GSH level was increased in brain, while CAT activity was reduced in both tissues. Activity of isolated mitochondria of liver and gills was reduced by Mn exposure under both levels of dissolved oxygen, but this effect was more prominent in normoxia. As expected, liver, kidney and gills showed an increase of Mn accumulation according to waterborne levels, and these parameters presented positive relationship. The highest waterborne Mn (8.4 and 16.2mgL(-1)) resulted in greater accumulation under normoxia, indicating that moderate hypoxia can stimulate mechanisms capable of reducing Mn accumulation in tissues (though not in blood). Moderate hypoxia can be considered a stress factor and Mn an aquatic anthropogenic contaminant. Therefore we hypothesized that these two conditions together are able to invoke defense mechanisms in juvenile silver catfish, acting in a compensatory form, which may be related to adaptation and/or hormesis.

Necrotizing sialometaplasia in an HIV positive cocaine user: a case report.

The aim of this paper was to present a case report of a male patient attending a Semiology and Stomatology Clinic with an erythematous ulcerated lesion on his palate. The patient reported that he was HIV positive as well as being addicted to cocaine. After a biopsy and a histopathological exam, he was diagnosed as having necrotizing sialometaplasia. The lesion diminished spontaneously in thirty days after the exam. Correct diagnosis as well as physical and complementary exams are paramount to avoid any incorrect therapy. As drug addiction and HIV infection have both been associated to necrotizing sialometaplasia, as in the present case, it is difficult to establish if the aetiological factor was drug usage or the HIV infection or even, the combination of these two factors. Although considering the influence of HIV infection on the oral health, we may assume that, at least, it favored the onset of this oral lesion.

Hydrogels containing rutin intended for cutaneous administration: efficacy in wound healing in rats.

OBJECTIVE: Development of a hydrogel containing rutin at 0.025% (w/w) and evaluation of its in vivo efficacy in cutaneous wound healing in rats. METHODS: Hydrogels were prepared using Carbopol Ultrez® 10 NF and an aqueous dispersion of rutin in polysorbate 80. Hydrogels were characterized by means of pH measurement, rheological and spreadability analysis and rutin content determination by liquid chromatography. The in vivo healing effect was evaluated through the regression of skin lesions in rats and by analysis of oxidative stress. RESULTS AND DISCUSSION: Hydrogels showed adequate pH values (5.50-6.50) and pseudoplastic non-Newtonian behavior. After 5 days of treatment of wounds, hydrogels containing rutin presented a higher decrease in the wound area compared to the control hydrogels. Analysis of the oxidative stress showed a decrease in lipid peroxidation and protein carbonyl content as well as an increase in catalase activity after the treatment with the hydrogel containing rutin. Furthermore, this treatment increased total protein levels. CONCLUSION: This study shows for the first time the feasibility of using dermatological formulations containing rutin to improve skin wound healing.

Analysis of root canal treated primary incisor after trauma: two year outcomes.

BACKGROUND: The low number of clinical studies of traumatized teeth submitted to root canal treatment is completely out of proportion to the seriousness that dental trauma imposes on children in early years. AIM: This study evaluates the outcomes of root canal treatment (RCT) in traumatized primary incisors and identifies the predisposing factors associated with therapy success. METHODS: This is a retrospective study conducted with all dental records of 704 patients who had one or more teeth with traumatic injuries. Patients with irreversible pulp changes in primary teeth leading to RCT with a 24 month follow-up met the inclusion criteria. RESULTS: Twenty-five maxillary incisors of 17 children were evaluated. The children's age at the time of therapy ranged from 24 to 72 months (mean 47.3). Pulp necrosis was the most common disorder (84.0%) and pre-operative periapical lesions were observed in 52.0%. Coronal discoloration was found in 48.0%. The roots were filled with ZOE paste (68.0%) or Guedes-Pinto paste (32.0%). Overall RCT success rate was 68.0%. The absence of pre-operative periapical lesions (p = 0.02) and pathological root resorption (p = 0.02) presented positive association with therapy success. Success was not associated to filling paste (p = 0.49), filling extent (p = 0.44), of discoloration (p = 0.39) nor the patients' age (p = 0.59). CONCLUSIONS: RCT was considered successful in 68.0% of the cases at the 24 month follow-up. Failure of RCT in traumatized primary incisors was associated with pre-operatory periapical lesions and pathological root resorption. The filling paste, the filling extent and the patient's age were unrelated with therapy success.

Oxidative stress and anxiety-like symptoms related to withdrawal of passive cigarette smoke in mice: beneficial effects of pecan nut shells extract, a by-product of the nut industry.

The present study evaluated the role of pecan nut (Carya illinoensis) shells aqueous extract (AE) against oxidative damage induced by cigarette smoke exposure (CSE) and behavioral parameters of smoking withdrawal. Mice were passively exposed to cigarette smoke for 3 weeks (6, 10, and 14 cigarettes/day) and orally treated with AE (25 g/L). CSE induced lipid peroxidation in brain and red blood cells (RBC), increased catalase (CAT) activity in RBC, and decreased plasma ascorbic acid levels. AE prevented oxidative damage and increased antioxidant defenses of mice exposed to cigarette smoke. In addition, AE reduced the locomotor activity and anxiety symptoms induced by smoking withdrawal, and these behavioral parameters showed a positive correlation with RBC lipid peroxidation. Our results showed the beneficial effects of this by-product of the pecan industry, indicating its usefulness in smoking cessation.

ZOE paste pulpectomies outcome in primary teeth: a systematic review.

OBJECTIVE: To perform a systematic review in which the clinical research question for primary teeth with irreversible pulpal pathosis was "how pulpectomies with zinc oxide eugenol (ZOE) paste performed compared to other materials in their clinical and radiographic outcomes after twelve months or more follow-up period. STUDY DESIGN: A literature survey of the electronic database (1950-2010) used the Medical Subject Headings and free text terms. Forty three references were retrieved and inclusion criteria were applied; 15 articles remained for full-text evaluation. From these, two were selected for data extraction regarding quality characteristics and results. RESULTS: Selected studies showed moderate or high risk of bias. The overall success of pulpectomy was 80.0% (Calcicur), 60.0% (Sealapex) and varied from 85.0% to 100.0% (ZOE) and 89.0% to 100.0% (Vitapex). Solely Calcicur presented success rate significantly lower when compared to ZOE and Vitapex. These pastes lead to overfilled canals and particles of extruded ZOE were still evident even after the evaluation period. Resorption of Vitapex, Calcicur and Sealapex within the root canal was also reported. CONCLUSIONS: In primary teeth with irreversible pulpal changes ZOE pulpectomies yielded similar outcome than Vitapex and Sealapex, although there was no agreement with regard to filling materials' resorption.

Effect of cerebral palsy and dental caries on dental plaque index, salivary parameters and oxidative stress in children and adolescents.

PURPOSE: The aim of the present study was to investigate the effect of cerebral palsy and dental caries on dental plaque index, salivary parameters and oxidative stress in children and adolescents. METHODS: Seventy children and adolescents aged 2-20 years were divided into four groups: neurotypical controls-inactive caries (NCIC; n = 19); neurotypical controls-active caries (NCAC; n = 16); cerebral palsy-inactive caries (CPIC; n = 19); and cerebral palsy-active caries (CPAC; n = 16). The visible dental plaque index was determined after drying the tooth surfaces and without any mechanical or chemical disclosing methods. Salivary pH and buffer capacity were measured 1 hour after collection using a digital pH meter. Saliva was used to evaluate oxidative status based on the levels of reactive species, lipid peroxidation and non-enzymatic antioxidants (reduced glutathione and vitamin C). RESULTS: The CPIC and CPAC groups had lower salivary pH and a higher visible dental plaque index. CP was also associated with an increase in salivary levels of markers of oxidative stress and the modulation of salivary levels of non-enzymatic antioxidants. CONCLUSION: Cerebral palsy exerts an influence on the salivary profile, oral health and oxidative stress. The individuals with CP had more acidic saliva and a higher dental plaque index, which were positively correlated with caries activity. CP was associated with high salivary levels of reactive species and lipid peroxidation, demonstrating an imbalance in salivary redox that was particularly associated with caries activity. These factors facilitate the development of oral diseases in individuals with cerebral palsy.

Zinc oxide-eugenol paste retained in gingival mucosa after primary teeth pulpectomy.

AIM: Long-term follow-up evaluations of pulpectomy in primary teeth have revealed retention of ZOE filling particles in the periapical area even after root resorption. CASE REPORT: This paper reports a case of a child submitted to pulpectomy with ZOE paste in primary teeth. After 28 months, the filling particles remained, having migrated to the alveolar bone from the gingival vestibular mucosa during permanent dentition eruption. Aesthetics required periodontal surgical removal of the paste particles. Primary teeth submitted to pulpectomy should be evaluated carefully both clinically and radiographically to verify radicular and ZOE filling paste resorption. The consequences of retained particles during permanent dentition eruption are unknown.

Physical exercise modifies behavioral and molecular parameters related to opioid addiction regardless of training time.

Addiction is a devastating worldwide disorder that requires effective and innovative therapies. Physical exercise could be useful in addiction treatment because it shares a common neural circuit with addictive drugs. Based on this, molecular adaptations consequent to time of exercise in opioid exposed animals were evaluated. Rats were designed as sedentary (SED) or exercised (EXE). This last group was separated to perform three different periods of swimming: short-term (S-EXE), medium-term (M-EXE) and long-term (L-EXE) for 14, 28 and 42 days, respectively. On the last exercising week, one-half of the animals from SED and all animals from S-, M- and l-EXE were concomitantly exposed to morphine-conditioned place preference (CPP) paradigm and y-maze task for behavioral assessments followed by molecular assays in both Nucleus accumbens (NAc) and hippocampus. Between SED groups, morphine conditioning showed drug-CPP and increased dopamine transporter (DAT), dopamine receptor type-1 (D1R), type-2 (D2R) and glucocorticoid receptor (GR) in both brain areas in relation to saline group. Besides the small morphine-CPP in relation to SED group, all periods decreased DAT, D1R, and GR immunoreactivity in NAc, DAT and D1R in hippocampus, while D2R in both brain areas and GR in hippocampus were primarily decreased by L-EXE. Our findings show that even a short-term exercise modifies behaviors related to drug withdrawal, changing DA targets and GR, which are closely linked to addiction. Therefore, our outcomes involving physical exercise are interesting to perform a possible clinical trial, thus expanding the knowledge about drug addiction.

Involvement of the endogenous opioid system in the beneficial influence of physical exercise on amphetamine-induced addiction parameters.

Psychostimulant drugs addiction is a chronic public health problem and individuals remain susceptible to relapses increasing public expenses even after withdrawal and treatment. Our research group has focused on finding new therapies to be employed in drug addiction treatment, suggesting the physical exercise as a promising tool. This way, it is necessary to know the mechanisms involved in the beneficial influences of physical exercise observing the pathway that could be explored in drug addiction treatment. Male Wistar rats were conditioned with amphetamine (AMPH) following the conditioned place preference (CPP) protocol and subsequently submitted to swimming for 5 weeks (1 h per day, 5 days per week). Half of the animals were injected with Naloxone (0.3 mg/mL/kg body weight, i.p.) 5 min prior each physical exercise day. After AMPH-CPP re-exposure, our outcomes showed that physical exercise, in addition to minimizing the relapse behavior in the CPP, it increased D1R, D2R and DAT in the Ventral Tegmental Area (VTA), but not in the Nucleus accumbens (NAc). Interestingly, while naloxone inhibited the partial beneficial influence of the exercise on drug-relapse behavior, exercise-induced changes in the dopaminergic system were not observed in the group administered with naloxone as well. Based on these evidences, besides reinforcing the beneficial influence of the physical exercise on AMPH-induced drug addiction, we propose the involvement of endogenous opioid system activation, not as a single one, but as a possible mechanism of action resulting from the physical activity practice, thus characterizing an important therapeutic approach, which may contribute to drug withdrawal consequently preventing relapse.

Hypoxia acclimation and subsequent reoxygenation partially prevent Mn-induced damage in silver catfish.

This study investigated if hypoxia acclimation modifies the hematological and oxidative profiles in tissues of Mn-exposed silver catfish (Rhamdia quelen), and if such modifications persist upon subsequent reoxygenation. Silver catfish acclimated to hypoxia (~3mgL-1) for 10days and subsequently exposed to Mn (~8.1mgL-1) for additional 10days exhibited lower Mn accumulation in plasma, liver and kidney, even after reoxygenation, as compared to normoxia-acclimated fish. Hypoxia acclimation increased per se red blood cells count and hematocrit, suggesting adaptations under hypoxia, while the reoxygenation process was also related to increased hematocrit and hemoglobin per se. Fish exposed to Mn under normoxia for 20days showed decreased red blood cells count and hematocrit, while reoxygenation subsequent to hypoxia increased red blood cells count. Hypoxia acclimation also prevented Mn-induced oxidative damage, observed by increased reactive species generation and higher protein carbonyl levels in both liver and kidney under normoxia. Mn-exposed fish under hypoxia and after reoxygenation showed decreased plasma transaminases in relation to the normoxia group. Moreover, acclimation to hypoxia increased reduced glutathione levels, catalase activity and Na+/K+-ATPase activity in liver and kidney during Mn exposure, remaining increased even after reoxygenation. These findings show that previous acclimation to hypoxia generates physiological adjustments, which drive coordinated responses that ameliorate the antioxidant status even after reoxygenation. Such responses represent a physiological regulation of this teleost fish against oxygen restriction and/or Mn toxicity in order to preserve the stability of a particular tissue or system.

Role of the adjunctive antimicrobial photodynamic therapy to periodontal treatment at plasmatic oxidative stress and vascular behavior.

BACKGROUND: To evaluate for the first time in vivo the effects of methylene blue (MB) photosensitizer dissolved in ethanol in antimicrobial photodynamic therapy (aPDT) as adjuvant periodontal treatment, at plasmatic oxidative stress and vascular behavior in rat model. METHODS: Wistar rats were divided into negative control (NC, no periodontitis) and positive control (PC, with periodontitis, without any treatment). The other groups had periodontitis and were treated with scaling and root planing (SRP); SRP+aPDT+MB dissolved in water (aPDT I); SRP+aPDT+MB dissolved in ethanol (aPDT II). The periodontitis was induced by ligature at the mandibular right first molar. At 7/15/30days, rats were euthanized, the plasma was used to determine oxidative stress parameters and gingival tissue for histomorphometric analysis. RESULTS: PC showed higher thiobarbituric acid reactive substances levels in 7/15/30days. aPDT II was able to block the lipid peroxidation, especially between 15th and 30th days. Glutathione reduced levels were consumed in PC, aPDT I and II groups throughout the experiment. aPDT II increased the vitamin C levels which were restored in this group in the 30th day. aPDT II group showed the highest number of blood vessels. CONCLUSION: In summary, the aPDT with MB dissolved in ethanol provides better therapeutic responses in periodontitis treatment.

Could hypoxia acclimation cause morphological changes and protect against Mn-induced oxidative injuries in silver catfish (Rhamdia quelen) even after reoxygenation?

Exposure to hypoxia has shown beneficial adjustments in different species, including silver catfish (Rhamdia quelen), especially in situations of aquatic contamination with pollutants such as manganese (Mn). Considering that hypoxia is seasonal in the natural aquatic environment, we decided to assess whether these adaptive mechanisms could be maintained when reoxygenation is established. Silver catfish acclimated to moderate hypoxia (∼3 mg L-1, 41% O2 saturation) for 10 days and subsequently exposed to Mn (∼8.1 mg L-1) for additional 10 days displayed lower (47%) Mn accumulation in the gills, and it was maintained (62.6%) after reoxygenation, in comparison to normoxia. Oxidative status in the gills allowed us to observe increased reactive species (RS) generation and protein carbonyl (PC) level together with decreased mitochondrial viability induced by Mn under normoxia. Inversely, while hypoxia per se was beneficial on RS generation and PC level, this acclimation was able to minimize Mn toxicity, as observed by the minor increase of RS generation and the minor reduction of mitochondrial viability, together with decreased PC level. Interestingly, after reoxygenation, part of the protective influences observed during hypoxia against Mn toxicity were maintained, as observed through a lower level of PC and higher mitochondrial viability in relation to the group exposed to Mn under normoxia. Only groups exposed to Mn under hypoxia showed increased activity of both catalase (CAT) and Na+/K+-ATPase in the gills, but, while CAT activity remained increased after reoxygenation, Na+/K+-ATPase activity was decreased by Mn, regardless of the oxygen level. Based on these outcomes, it is possible to propose that environment events of moderate hypoxia are able to generate rearrangements in the gills of silver catfish exposed to Mn, whose influence persists after water reoxygenation. These responses may be related to the adaptive development, reducing Mn toxicity to silver catfish. Moderate hypoxia generates rearrangements in the gills of Silver catfish, exerting beneficial and persistent protection against Mn toxicity.

Influence of physical activity on addiction parameters of rats exposed to amphetamine which were previously supplemented with hydrogenated vegetable fat.

Amphetamine (AMPH) and its derivatives are addictive drugs used to promote and enhance alertness, motivation, willingness, courage and wellbeing. However, their chronic use is related to memory loss, emotional instability, insomnia, psychosis and paranoia. In the last decades, modern society has included processed foods, rich in trans fatty acids (TFA), in their diet, what has been related to several health problems including increased AMPH preference and self-administration. In this scenario, physical activity appears to be useful to attenuate rewarding symptoms related to addictive drugs mainly by affecting brain neuroplasticity and neurotransmission. The current study has been developed to assess the influence of physical activity on addiction parameters of rats exposed to AMPH which were previously supplemented with hydrogenated vegetable fat (HVF), rich in TFA. After six weeks of HVF or soybean oil (SO, control group) supplementation, adult rats were conditioned with d,l-AMPH or vehicle for 14 days. Then, half of each experimental group was submitted to physical activity in treadmill running sessions (60min/day, 5 days/week) for 5 weeks. Animals were re-conditioned with AMPH or vehicle for 3 more days, to observe drug relapse. Locomotor activity and anxiety-like symptoms were observed 24h after the last AMPH reconditioning, and fatty acids composition was quantified in the ventral tegmental area, striatum and prefrontal cortex. All animals showed AMPH preference, but only SO sedentary showed drug relapse. No differences were observed in locomotor activity among groups, while HVF-supplemented group showed decreased exploration per se, and physical activity prevented this. Moreover, AMPH-HVF group showed increased anxiety-like symptoms, which were prevented by physical activity. These results indicate that HVF supplementation modifies AMPH addiction, whereas regular physical activity could be protective against both AMPH and TFA damages.

Creatine and the Liver: Metabolism and Possible Interactions.

The process of creatine synthesis occurs in two steps, catalyzed by L-arginine:glycine amidinotransferase (AGAT) and guanidinoacetate N-methyltransferase (GAMT), which take place mainly in kidney and liver, respectively. This molecule plays an important energy/pH buffer function in tissues, and to guarantee the maintenance of its total body pool, the lost creatine must be replaced from diet or de novo synthesis. Creatine administration is known to decrease the consumption of Sadenosyl methionine and also reduce the homocysteine production in liver, diminishing fat accumulation and resulting in beneficial effects in fatty liver and non-alcoholic liver disease. Different studies have shown that creatine supplementation could supply brain energy, presenting neuroprotective effects against the encephalopathy induced by hyperammonemia in acute liver failure. Creatine is also taken by many athletes for its ergogenic properties. However, little is known about the adverse effects of creatine supplementation, which are barely described in the literature, with reports of mainly hypothetical effects arising from a small number of scientific publications. Antioxidant effects have been found in several studies, although one of the theories regarding the potential for toxicity from creatine supplementation is that it can increase oxidative stress and potentially form carcinogenic compounds.

m-Trifluoromethyl-diphenyldiselenide as a pharmacological tool to treat preference symptoms related to AMPH-induced dependence in rats.

Amphetamine (AMPH) abuse is a world concern and a serious public health problem. Repeated administration of high doses of AMPH induces neuropsychiatric consequences, including addiction, reward and psychosis, whose pharmacological treatment has shown limited effectiveness. The m-trifluoromethyl-diphenyldiselenide [(m-CF3-PhSe)2] has been documented as a promising pharmacological agent in different animal models related to oxidative damage. In this study, we examined the influence of (m-CF3-PhSe)2 on withdrawal following re-exposure to AMPH. Wistar rats received d,l-AMPH or saline in the conditioned place preference (CPP) paradigm for 8days. Then, half of each initial (AMPH or saline) experimental group was treated with (m-CF3-PhSe)2 or vehicle, resulting in four final groups: i) Saline/vehicle; ii) (m-CF3-PhSe)2/saline; iii) AMPH/vehicle; and iv) AMPH/(m-CF3-PhSe)2. After fourteen days of (m-CF3-PhSe)2 treatment, animals were re-exposed to AMPH or vehicle in the CPP paradigm for three more days in order to assess drug re-conditioning and memory/locomotor activity, performed 24h after AMPH re-exposure in the CPP and the Y maze, respectively. Subsequently, ex-vivo assays were carried out in samples of the prefrontal cortex (PFC) of the animals. The (m-CF3-PhSe)2 treatment was able to prevent AMPH-induced re-conditioning symptoms in rats. Behavioral observations in the Y maze task showed no significant changes. AMPH exposure was able to increase 5-HT uptake as well as oxidative damage in the PFC, whereas (m-CF3-PhSe)2 treatment exerted a preventative effect against these alterations. The current findings suggest that (m-CF3-PhSe)2 might be considered a promising therapeutic tool for AMPH-induced addiction.

Microhardness of dentine underlying ART restorations in primary molars: an in vivo pilot study.

OBJECTIVE: To evaluate the microhardness of dentine underlying glass ionomer restorations made with Atraumatic Restorative Treatment. DESIGN: An experimental single-centre study. SETTING: University Department, Brazil, 2001. MATERIALS AND METHODS: Sixteen children were selected showing primary molars containing carious cavities (n = 29), which were restored using Fugi IX. Subsequently, some teeth were extracted respecting Nolla stage 7 or 8 of the permanent successor, and categorised according to the post-restoration time in the mouth: G1 (baseline, immediate extraction), G2 (30 days), G3 (90 days) and G4 (180 days). Four teeth were excluded because they were not in time of normal exfoliation. The 25 extracted teeth were resin embedded, sectioned mesiodistally and prepared metallographically. Knoop microhardness analysis (Micromet 2003; 10g for 1.5 sec.) produced identations in three areas of dentine: Zone 1 (just below the restoration), Zone 3 (as close as possible to the pulp) and Zone 2 (intermediate region between 1 and 3). Non-parametric statistical tests were done--at a significance level of 5%. RESULTS: Four teeth were excluded. No significant difference was noted among the zones, inside the groups. Zones 1 and 2 showed a considerable increase of microhardness according to the time, except for Group 3 (p > 0.05). CONCLUSION: Although microhardness had increased, it was not sufficiently equal to the microhardness of the healthy dentine, regardless of the depth evaluated.

Trans-fat supplementation over two generations of rats exacerbates behavioral and biochemical damages in a model of mania: Co-treatment with lithium.

AIMS: We investigated whether trans-fat supplemented over two generations of rats could alter neuronal membranes and influence mania-like behaviors, as well as the effects of lithium (Li). MAIN METHODS: Two generations of female rats were supplemented with soybean oil (SO-C, rich in n-6 fatty acids - FA) or hydrogenated vegetable fat (HVF, rich in trans-fatty acids - TFA). Male rats born from the 1st and 2nd generations were maintained in the same supplementation until adulthood, when they were exposed to an amphetamine (AMPH)-induced model of mania and co-treated with Li or not. KEY FINDINGS: AMPH increased locomotion of both generations and this influence was higher in the HVF than in the SO-C group. Conversely, AMPH increased long-term memory in SO-C group of the 2nd generation. HVF supplementation allowed hippocampal TFA incorporation in rats of both generations (0.1 and 0.2%, respectively). Oxidative parameters indicated higher levels of protein carbonyl (PC) in the HVF group with no changes in catalase (CAT) activity in the 1st generation. In the 2nd generation, AMPH increased PC levels of both experimental groups, whereas CAT activity was lower per se in the HVF group only. The co-treatment with Li leveled out all behavioral parameters, PC levels and CAT activity indicating a significant neuroprotective role. SIGNIFICANCE: These findings suggest that chronic HVF consumption allows a rising incorporation of TFA in the brain, which may be reflected on the neuropsychiatric conditions related to mania, whereas the effects of Li are not modified in the course of this harmful dietary habit.

Chronic consumption of trans fat can facilitate the development of hyperactive behavior in rats.

In recent decades, the increased consumption of processed foods, which are rich in hydrogenated vegetable fat (HVF), has led to a decreased consumption of fish and oilseed, rich in omega-3 fatty acids. This eating habit provides an increased intake of trans fatty acids (TFA), which may be related to neuropsychiatric conditions, including inattention and hyperactivity. In this study, we evaluated the potential connection between prolonged trans fat consumption and development of hyperactivity-like symptoms in rats using different behavioral paradigms. Trans fat intake for 10 months (Experiment 1), as well as during pregnancy and lactation across two sequential generations of rats, (Experiment 4) induced active coping in the forced swimming task (FST). In addition, HVF supplementation was associated with increased locomotion before and after amphetamine (AMPH) administration (Experiment 2). Similarly, HVF supplementation during pregnancy and lactation were associated with increased locomotion in both young and adult rats (Experiment 3). Furthermore, trans fat intake across two sequential generations increased locomotor and exploratory activities following stressors (Experiment 4). From these results, we suggest that chronic consumption of trans fat is able to enhance impulsiveness and reactivity to novelty, facilitating hyperactive behaviors.