Smart Delivery of Biomolecules Interfering with Peri-Implant Repair in Osteoporotic Rats.

Bisphosphonates are widely used for the treatment of postmenopausal osteoporosis; however, they cause several long-term side effects, necessitating the investigation of local ways to improve osseointegration in compromised bone tissue. The purpose of this study was to evaluate peri-implant bone repair using implants functionalized with zoledronic acid alone (OVX ZOL group, n = 11), zoledronic acid + teriparatide (OVX ZOL + TERI group, n = 11), and zoledronic acid + ruterpy (OVX ZOL + TERPY group, n = 11) compared to the control group (OVX CONV, n = 11). Analyses included computer-assisted microtomography, qualitative histologic analysis, and real-time PCR analysis. Histologically, all functionalized surfaces improved peri-implant repair, with the OVX ZOL + TERI group standing out. Similar results were found in computerized microtomography analysis. In real-time PCR analysis, however, the OVX ZOL and OVX ZOL + TERPY groups showed better results for bone formation, with the OVX ZOL + TERPY group standing out, while there were no statistical differences between the OVX CONV and OVX ZOL + TERI groups for the genes studied at 28 postoperative days. Nevertheless, all functionalized groups showed a reduced rate of bone resorption. In short, all surface functionalization groups outperformed the control group, with overall better results for the OVX ZOL + TERI group.

Analysis of peri-implant bone tissue between hydrophilic and rough implant surfaces in spontaneously hypertensive rats treated with losartan.

OBJECTIVES: to evaluate the morphological and functional characteristics of the peri-implant bone tissue that was formed during the healing process by the placement implants using two different surface treatments: hydrophilic Acqua™ (ACQ) and rough NeoPoros™ (NEO), in spontaneously hypertensive (SHR) and normotensive rats (Wistar) whether or not treated with losartan. METHODOLOGY: In total, 96 male rats (48 Wistar and 48 SHR) were divided into eight subgroups: absolute control rough (COA NEO), absolute control hydrophilic (COA ACQ), losartan control rough (COL NEO), losartan control hydrophilic (COL ACQ), SHR absolute rough (SHR NEO), SHR absolute hydrophilic (SHR ACQ), SHR losartan rough (SHRL NEO), and SHR losartan hydrophilic (SHRL ACQ). The rats medicated with losartan received daily doses of the medication. NeoPoros™ and Acqua™ implants were installed in the tibiae of the rats. After 14 and 42 days of the surgery, the fluorochromes calcein and alizarin were injected in the rats. The animals were euthanized 67 days after treatment. The collected samples were analyzed by immunohistochemistry, biomechanics, microcomputerized tomography, and laser confocal scanning microscopy analysis. RESULTS: The osteocalcin (OC) and vascular endothelium growth factor (VEGF) proteins had moderate expression in the SHRL ACQ subgroup. The same subgroup also had the highest implant removal torque. Regarding microarchitectural characteristics, a greater number of trabeculae was noted in the control animals that were treated with losartan. In the bone mineralization activity, it was observed that the Acqua™ surface triggered higher values of MAR (mineral apposition rate) in the COA, COL, and SHRL groups (p<0.05). CONCLUSION: the two implant surface types showed similar responses regarding the characteristics of the peri-implant bone tissue, even though the ACQ surface seems to improve the early stages of osseointegration.

Are salivary NO2- / NO2- and NO3- levels biomarkers for dental caries in children? Systematic review and meta-analysis.

The literature is conflicting regarding salivary nitrite (NO2-)/nitrite and nitrate (NO2- and NO3-) levels in children affected by dental caries. For this reason, a systematic review to provide a consensus on the subject was propose, whose objective is to verify whether these molecules could be used as biomarkers in children with caries. A comprehensive search was performed on online database and eleven articles were included in the meta-analysis. The methodological quality of studies was assessed by Newcastle-Ottawa Scale recommended for case-control studies and by AXIS tool for cross-sectional studies. Grading of Recommendations Assessment, Development and Evaluation was used for the assessment of the certainty of the evidence for each outcome. The results showed lower NO2- levels in the group of children affected by dental caries (SMD = -2.18 [-3.24, -1.13], p < 0.01). Age, saliva collection and methods of evaluation can impact the results. When evaluating the severity of the condition, an important variation was detected in relation to the different evaluation methods NO2-/NO2- and NO3-. In conclusion, based on the evidence presented, the results suggest that NO2- levels in saliva are a possible biomarker of dental caries. Results should be evaluated with caution due to the very low evidence from primary studies. Longitudinal studies are necessary to strengthen this hypothesis.

Analysis of peri-implant bone tissue between hydrophilic and rough implant surfaces in spontaneously hypertensive rats treated with losartan

Abstract Hypertensive individuals present alterations in their calcium metabolism that consequently decrease the concentration of this mineral in the bone tissue. Objectives to evaluate the morphological and functional characteristics of the peri-implant bone tissue that was formed during the healing process by the placement implants using two different surface treatments: hydrophilic Acqua™ (ACQ) and rough NeoPoros™ (NEO), in spontaneously hypertensive (SHR) and normotensive rats (Wistar) whether or not treated with losartan. Methodology In total, 96 male rats (48 Wistar and 48 SHR) were divided into eight subgroups: absolute control rough (COA NEO), absolute control hydrophilic (COA ACQ), losartan control rough (COL NEO), losartan control hydrophilic (COL ACQ), SHR absolute rough (SHR NEO), SHR absolute hydrophilic (SHR ACQ), SHR losartan rough (SHRL NEO), and SHR losartan hydrophilic (SHRL ACQ). The rats medicated with losartan received daily doses of the medication. NeoPoros™ and Acqua™ implants were installed in the tibiae of the rats. After 14 and 42 days of the surgery, the fluorochromes calcein and alizarin were injected in the rats. The animals were euthanized 67 days after treatment. The collected samples were analyzed by immunohistochemistry, biomechanics, microcomputerized tomography, and laser confocal scanning microscopy analysis. Results The osteocalcin (OC) and vascular endothelium growth factor (VEGF) proteins had moderate expression in the SHRL ACQ subgroup. The same subgroup also had the highest implant removal torque. Regarding microarchitectural characteristics, a greater number of trabeculae was noted in the control animals that were treated with losartan. In the bone mineralization activity, it was observed that the Acqua™ surface triggered higher values of MAR (mineral apposition rate) in the COA, COL, and SHRL groups (p<0.05). Conclusion the two implant surface types showed similar responses regarding the characteristics of the peri-implant bone tissue, even though the ACQ surface seems to improve the early stages of osseointegration.

Synergic Action of Systemic Risedronate and Local Rutherpy in Peri-implantar Repair of Ovariectomized Rats: Biomechanical and Molecular Analysis.

Postmenopausal osteoporosis and poor dietary habits can lead to overweightness and obesity. Bisphosphonates are the first-line treatment for osteoporosis. However, some studies show that they may increase the risk of osteonecrosis of the jaw. Considering the antimicrobial, angiogenic and vasodilatory potential of nitric oxide, this study aims to evaluate the local activity of this substance during the placement of surface-treated implants. Seventy-two Wistar rats were divided into three groups: SHAM (SHAM surgery), OVX + HD (ovariectomy + cafeteria diet), and OVX + HD + RIS (ovariectomy + cafeteria diet + sodium risedronate treatment), which were further subdivided according to the surface treatment of the future implant: CONV (conventional), TE10, or TE100 (TERPY at 10 or 100 µM concentration); n = 8 per subgroup. The animals underwent surgery for implant installation in the proximal tibia metaphysis and were euthanized after 28 days. Data obtained from removal torque and RT-PCR (OPG, RANKL, ALP, IBSP and VEGF expression) were subjected to statistical analysis at 5% significance level. For biomechanical analysis, TE10 produced better results in the OVX + HD group (7.4 N/cm, SD = 0.6819). Molecular analysis showed: (1) significant increase in OPG gene expression in OVX groups with TE10; (2) decreased RANKL expression in OVX + HD + RIS compared to OVX + HD; (3) significantly increased expressions of IBSP and VEGF for OVX + HD + RIS TE10. At its lowest concentration, TERPY has the potential to improve peri-implant conditions.

Estrogen Deficiency Impairs Osseointegration in Hypertensive Rats Even Treated with Alendronate Coated on the Implant Surface.

Hypertension and estrogen deficiency can affect bone metabolism and therefore increase the risk of osseointegration. Antihypertensive drugs such as losartan not only control blood pressure but also enhance bone healing. In addition, alendronate sodium is widely used to treat postmenopausal osteoporosis. Hence, we evaluated the effect of systemic antihypertensive and local alendronate coted on implants on osseointegration under hypertensive and estrogen-deficiency conditions. A total of 64 spontaneously hypertensive rats (SHRs) treated with losartan were randomly divided according to the estrogen-deficiency induction by ovariectomy (OVX) or not (SHAM), and whether the implant surface was coated with sodium alendronate (ALE) or not, resulting in four groups: SHR SHAM, SHR SHAM ALE, SHR OVX, and SHR OVX ALE. The removal torque, microcomputed tomography, and epifluorescence microscopy were the adopted analyses. The hypertensive and estrogen-deficiency animals presented a lower removal torque even when treated with alendronate on implant surface. The microcomputed tomography revealed a higher bone volume and bone-to-implant contact in the SHRs than the SHR OVX rats. Epifluorescence showed a decreased mineral apposition ratio in the SHR OVX ALE group. The data presented indicate that estrogen deficiency impairs osseointegration in hypertensive rats; in addition, alendronate coated on the implant surface does not fully reverse this impaired condition caused by estrogen deficiency.

Assessment of the toxic effects of levetiracetam on biochemical, functional, and redox parameters of salivary glands in male Wistar rats.

Levetiracetam (LEV) is an anticonvulsant for epilepsy. The toxic effects of this medication in tissues have been associated with redox state imbalance, which can lead to salivary gland dysfunction. Therefore, the current work investigated the effects of LEV on the biochemical, functional, and redox parameters of the parotid and submandibular glands in rats. For this, male Wistar rats (Rattus norvegicus albinus) were randomly divided into 3 groups (n = 10/group): Control (0.9% saline solution), LEV100 (100 mg/kg), and LEV300 (300 mg/kg). After 21 consecutive days of intragastric gavage treatments, pilocarpine stimulated saliva secretion was collected for salivary biochemical analysis. The extracted salivary glands were utilized for histomorphometry and redox state analyses. Our results showed that LEV300 increased plasma hepatotoxicity markers and reduced salivary amylase activity and the acinar surface area of the parotid gland. Total oxidant capacity and oxidative damage to lipids and proteins were higher in the parotid gland, while total antioxidant capacity and uric acid levels were reduced in the submandibular gland of the LEV100 group compared to Control. On the other hand, total oxidant capacity, oxidative damage to lipids and proteins, total antioxidant capacity, and uric acid levels were lower in both salivary glands of the LEV300 group compared to Control. Superoxide dismutase and glutathione peroxidase activities were lower in the salivary glands of treated animals compared to Control. In conclusion our data suggest that treatment with LEV represents a potentially toxic agent, that contributes to drug-induced salivary gland dysfunction.

Analysis of salivary flow rate, biochemical composition, and redox status in orchiectomized spontaneously hypertensive rats.

OBJECTIVE: This study aimed to analyze the salivary flow rate, biochemical composition, and redox status in orchiectomized spontaneously hypertensive rats (SHR) compared to normotensive Wistar rats. DESIGN: Thirty-two young adult male SHR and Wistar (3-months-old) rats were randomly distributed into four groups; either castrated bilaterally (ORX) or underwent fictitious surgery (SHAM) as Wistar-SHAM, Wistar-ORX, SHR-SHAM, and SHR-ORX. Two months beyond castration, pilocarpine-induced salivary secretion was collected from 5-month-old rats to analyze salivary flow rate, pH, buffer capacity, total protein, amylase, calcium, phosphate, sodium, potassium, chloride, thiobarbituric acid reactive substances (TBARs), carbonyl protein, nitrite, and total antioxidant capacity. RESULTS: The salivary flow rate was higher in the Wistar-ORX compared to the Wistar-SHAM group, while remaining similar between the SHR-SHAM and SHR-ORX groups. ORX did not affect pH and salivary buffer capacity in both strains. However, salivary total protein and amylase were significantly reduced in the Wistar-ORX and SHR-ORX compared to the respective SHAM groups. In both ORX groups, salivary total antioxidant capacity and carbonylated protein were increased, while lipid oxidative damage (TBARs) and nitrite concentration were higher only in the Wistar-ORX than in the Wistar-SHAM group. In the Wistar-ORX and SHR-ORX, the salivary calcium, phosphate, and chloride were increased while no change was detected in the SHAM groups. Only salivary buffering capacity, calcium, and chloride in the SHR-ORX adjusted to values similar to Wistar-SHAM group. CONCLUSION: Hypertensive phenotype mitigated the orchiectomy-induced salivary dysfunction, since the disturbances were restricted to alterations in the salivary biochemical composition and redox state.

Comparative study between apocynin and protocatechuic acid regarding antioxidant capacity and vascular effects.

Reactive oxygen species (ROS) derived from NOX enzymes activity play an important role in the development of cardiovascular diseases. Compounds able to decrease oxidative stress damage are potential candidates as drugs and/or supplements for hypertension treatment. Here, we aimed to compare in vitro ROS scavenging potency, effective NOX inhibition and effects on vascular reactivity of apocynin to another phenolic compound, protocatechuic acid, in vascular cells from spontaneously hypertensive rat (SHR), where redox signaling is altered and contributes to the development and/or maintenance of hypertension. We evaluated the in vitro antioxidant capacity and free radical scavenging capacity of both phenolic compounds. Moreover, we investigated the effect of both compounds on lipid peroxidation, lucigenin chemiluminescence, nitric oxide (NO•) levels and ROS concentration in vascular cells of SHR or human umbilical vein endothelial cell (HUVEC). Apocynin and protocatechuic acid presented antioxidant capacity and ability as free radical scavengers, decreased thiobarbituric acid reactive substances (TBARS) in aortic cells from SHR, and increased NO• concentration in isolated HUVEC. Both compounds were able to reduce lucigenin chemiluminescence and increased the potency of acetylcholine in aorta of SHR. However, in SHR aortas, only apocynin diminished the contraction induced by phenylephrine. In conclusion, these results strongly reinforce the potential application of substances such as apocynin and protocatechuic acid that combine abilities as scavenging and/or prevention of ROS generation, establishment of NO bioactivity and modulation of vascular reactivity. Due to its phytochemical origin and low toxicity, its potential therapeutic use in vascular diseases should be considered.

Salivary biomarkers of oxidative stress in children with dental caries: Systematic review and meta-analysis.

OBJECTIVE: To assess the relationship between salivary biomarkers of oxidative stress and dental caries in children. METHODS: Studies conducted in children up to 12 years old comparing salivary biomarkers of oxidative stress such as malondialdehyde (MDA), superoxide dismutase (SOD), uric acid, and total antioxidant capacity (TAC), considering children with dental caries lesions and caries-free ones were selected. In addition, salivary parameters such as salivary flow, pH, buffering capacity, calcium and total protein levels were evaluated. A systematic literature review was carried out in 8 databases. The standardized mean difference (SMD) was measured using inverse variance as a statistical method and random effects as an analysis model, corresponding to a 95% confidence interval (CI). RESULTS: The TAC levels were higher in children affected by dental caries compared to caries-free ones (control group), regardless of age (SMD 2.66, CI 1.33, 3.98), or gender (SMD 0.98, CI 0.56, 1.39). When adjusted for normalized protein, MDA levels were lower in the dental caries group than in the control group (SMD -16.51, CI -29.02, -4.00), and SOD levels were higher in the dental caries group (SMD 5.09, CI 0.01.10.18). The total protein concentration in saliva of children with dental caries was higher than in the control group, regardless of age (SMD 0.98, CI 0.27, 1.69), or gender (SMD 0.77, CI 0.45, 1.10). The salivary parameters assessed had lower levels in children affected by dental caries (p < 0.05). CONCLUSIONS: The levels of oxidative stress biomarkers and salivary parameters are altered in saliva of children with dental caries.

Data of Nebivolol on oxidative stress parameters in hypertensive patients.

Oxidative stress is a key feature in hypertension, since reactive oxygen species are involved in all stages of cardiovascular diseases. Saliva is a body fluid that can be used to investigate alterations in the oxidative system with several specific advantages over blood. Nebivolol is a third-generation selective ß1-adrenergic receptor antagonist that promotes vasodilation and has been shown to reduce oxidative stress in pre-clinical and clinical studies. The use of Nebivolol in different periods of treatment demonstrated that it is an efficient anti-hypertensive drug. We evaluated the oxidative stress biomarkers and the enzymatic and non-enzymatic antioxidant systems in saliva of hypertensive patients before and after the use of anti-hypertensive therapeutic doses of Nebivolol, since saliva can be used as an auxiliary tool to analyze parameters of oxidative stress.

Effects of orchiectomy and testosterone replacement therapy on redox balance and salivary gland function in Wistar rats.

The objective of this study was to investigate the effects of orchiectomy (ORX) and testosterone replacement therapy (TRT) on redox balance and function of salivary glands. Forty-five young adult male Wistar rats (3 months old) were either castrated bilaterally or underwent fictitious surgery (SHAM) and were subsequently distributed into 3 groups: SHAM, ORX, and TRT (castrated rats that received an intramuscular injection of testosterone cypionate 10 mg/kg/weekly). All treatments started 4 weeks after castration (4 months old) and lasted 4 weeks (5 months old). At the end of treatment, pilocarpine-induced salivary secretion was collected to analyze salivary flow rate and biochemistry composition, and the parotid (PG) and submandibular (SMG) glands were sampled for redox balance markers and histomorphometric analyses. ORX increased salivary flow rate, calcium, phosphate, and chloride, and decreased total protein and amylase, while not changing the salivary buffer capacity, pH, sodium, and potassium compared to SHAM. TRT restored all salivary parameters to SHAM values. ORX increased oxidative lipid and protein damage, total antioxidant capacity, and uric acid in both salivary glands compared to SHAM. Superoxide dismutase, catalase, and glutathione peroxidase activities were greater only in the SMG of the ORX group in relation to SHAM. ORX decreased duct and acini area, while increasing connective tissue in the PG. On the other hand, ORX reduced duct area and increased acini area in the SMG compared to SHAM. TRT restored the redox balance and histomorphometric parameters to close to SHAM values in both salivary glands. Orchiectomy-induced salivary gland dysfunction was characterized by an increase in the salivary flow rate and changes in the secretion of total protein, amylase, and electrolytes, which are key factors, considered important for maintaining oral health status. To sum up, orchiectomy impaired the redox balance of the salivary glands. Our results also showed that TRT reversed the oxidative damage, morphological alterations, and salivary gland dysfunction induced by orchiectomy. Therefore, these results suggest an important action of testosterone on the redox balance and secretory ability of salivary glands.

Caveolin-1/Endothelial Nitric Oxide Synthase Interaction Is Reduced in Arteries From Pregnant Spontaneously Hypertensive Rats.

We have investigated the role caveolae/caveolin-1 (Cav-1) plays in endothelial nitric oxide synthase (eNOS) activation and how it impacts pregnancy-induced decreased vascular reactivity in normotensive (Wistar rats) and spontaneously hypertensive rats (SHR). Wistar rats and SHR were divided into non-pregnant (NP) and pregnant (P). Nitrite levels were assessed by the Griess method in the aorta and mesenteric vascular bed. In functional studies, arteries were incubated with methyl-ß-cyclodextrin (dextrin, 10mmol/L), which disrupts caveolae by depleting cholesterol, and concentration-response curves to phenylephrine (PE) and acetylcholine (ACh) were constructed. Electronic microscopy was used to determine endothelial caveolae density in the aorta and resistance mesenteric artery in the presence of vehicle or dextrin (10mmol/L). Western blot was performed to evaluate Cav-1, p-Cav-1, calmodulin (CaM), and heat shock protein 90 (Hsp90) expression. Cav-1/eNOS interaction in the aorta and mesenteric vascular bed was assessed by co-immunoprecipitation. Nitric oxide (NO) generation was greater in arteries from P groups compared to NP groups. Dextrin did not change vascular responses in the aorta from P groups or the number of caveolae in P groups compared to NP groups. Compared to NP Wistar rats, NP SHR showed smaller number of caveolae and reduced Cav-1 expression. Pregnancy did not alter Cav-1, CaM, or Hsp90 expression in the aorta or mesenteric vascular bed from Wistar rats or SHR. These results suggest that pregnancy does not alter expression of the main eNOS regulatory proteins, but it decreases Cav-1/eNOS interaction. Reduced Cav-1/eNOS interaction in the aorta and mesenteric vascular bed seems to be an important mechanism to increase eNOS activity and nitric oxide production in pregnant normotensive and hypertensive rats.

Effect of testosterone replacement therapy and mate tea (Ilex paraguariensis) on biochemical, functional and redox parameters of saliva in orchiectomized rats.

OBJECTIVE: Evaluate the effects of testosterone replacement therapy (TRT) and mate tea (MT) [Ilex paraguariensis] on biochemical, functional, and redox parameters of saliva in orchiectomized rats (ORX) DESIGN: Sixty young adult male Wistar rats (3 months old) were either castrated bilaterally or underwent fictitious surgery (SHAM) and were distributed into 5 groups: SHAM, ORX, TU (castrated rats that received a single intramuscular injection of testosterone undecanoate 100 mg/kg), MT (castrated rats that received MT 20 mg/kg, via intragastric gavage, daily), and TU + MT. All treatments started 4 weeks after castration (4 months old) and lasted 4 weeks (5 months old). At the end of treatment, pilocarpine-induced salivary secretion was collected to analyze salivary flow rate (SFR) and biochemistry composition through determination of total protein (TP), amylase (AMY), electrolyte, and biomarkers of oxidative stress. RESULTS: ORX increased SFR, salivary buffering capacity, calcium, phosphate, chloride, total antioxidant capacity, thiobarbituric acid reactive substances (TBARs), and carbonyl protein, reduced TP and AMY activity, and did not change pH, sodium, and potassium compared to SHAM. TU and TU+MT restored all salivary parameters to values of SHAM, while only TBARs and AMY returned to SHAM levels in the MT group. CONCLUSIONS: TRT with long-acting TU restored the biochemical, functional, and redox parameters of saliva in orchiectomized rats. Although MT did not have a TRT-like effect on salivary gland function, the more effective reduction in lipid oxidative damage in the MT and TU + MT groups could be considered as adjuvant to alleviate the salivary oxidative stress induced by orchiectomy.

Pregnancy decreases O-GlcNAc-modified proteins in systemic arteries of normotensive and spontaneously hypertensive rats.

AIM: We determined the role played by O-linked N-acetylglucosamine (O-GlcNAc) of proteins in systemic arteries during late pregnancy in normotensive and hypertensive rats. MAIN METHODS: O-GlcNAc levels and O-GlcNAc modification of endothelial nitric oxide synthase (eNOS) were determined in aorta (conductance vessel) and mesenteric arteries (resistance vessels) of non-pregnant (NP) and pregnant (P) Wistar rats and spontaneously hypertensive rats (SHR). Vascular O-GlcNAc-modified proteins, O-GlcNAcase (OGA) and O-GlcNAc transferase (OGT) expression, and OGA activity were analyzed. Concentration-response to phenylephrine (PE) curves were constructed for arteries with and without endothelium. Arteries were treated with vehicle or PugNAc (OGA inhibitor, 100 µmol/L) in the presence of L-NAME (NOS inhibitor, 100 µmol/L). KEY FINDINGS: The content of vascular O-GlcNAc-modified proteins was lower, OGT and OGA expression did not change, and OGA activity was higher in arteries of P-Wistar rats and P-SHR compared to arteries of NP-groups. Reactivity to PE increased in arteries of P-Wistar rats treated with PugNAc compared to vehicle. O-GlcNAcylation of eNOS decreased in P-SHR compared to NP-SHR. PugNAc partially inhibited the effects of endothelium removal and L-NAME on reactivity to PE in arteries of P-Wistar rats. However, PugNAc did not alter reactivity to PE in arteries of P-SHR. Our data showed that pregnancy decreased the content of vascular O-GlcNAc-modified proteins. SIGNIFICANCE: Increased OGA activity and decreased O-GlcNAc modification of eNOS boosts eNOS activity in arteries of P-Wistar rats. In P-SHR, altered OGA activity may lower the content of O-GlcNAc-modified proteins, but decreased OGT activity seems a potential mechanism to reduce glycosylation.

Atenolol increases dental mineralization in male offspring of treated hypertensive rats and normotensive rats.

This study evaluates how atenolol affects dental mineralization in offspring of female spontaneously hypertensive rats (fSHR) and normotensive Wistar rats (fW). fSHR and fW were treated with atenolol (100 mg/Kg/day, orally) during pregnancy and lactation. Non-treated fSHR and fW were the control groups. Enamel and dentin hardness were analyzed (Knoop, 15 g load, 10s) in mandibular incisor teeth (IT) and molar teeth (MT) obtained from the male offspring of atenolol-treated and non-treated fWistar and fSHR. Data were analyzed by ANOVA, followed by Tukey post hoc test (p < 0.05). Atenolol reduced the arterial blood pressure (SBP) in fSHR, but it did not change the SBP in fW. The offspring of non-treated fSHR had lower enamel (IT and MT) and dentin (IT) hardness than the offspring of non-treated fW (p < 0.05). Atenolol increased enamel and dentin hardness in the IT obtained from the offspring of fSHR and fW (p<0.05), but the offspring of fSHR presented higher values (p < 0.05). Atenolol did not alter enamel width in the IT obtained from any of the groups, but it increased enamel and dentin hardness in the IT obtained from the offspring of fSHR and fW. Atenolol affected the IT obtained from the offspring of fSHR. Atenolol increased only enamel hardness in the MT obtained from the offspring of fW. In conclusion, maternal hypertension reduces tooth hard tissues, and treatment with atenolol increases tooth hardness in male offspring of hypertensive and normotensive female rats.

Oxidative stress in the medullary respiratory neurons contributes to respiratory dysfunction in the 6-OHDA model of Parkinson's disease.

KEY POINTS: Parkinson's disease (PD) is associated with respiratory dysfunction. In the 6-OHDA rat model of PD this is seen as a reduction in respiratory frequency and minute ventilation during normoxia and hypercapnia stimulus. Respiratory dysfunction is caused by neuronal death of medullary respiratory nuclei in the 6-OHDA model of PD. Oxidative stress can be considered a strong candidate for neurodegeneration via miR-34c downregulation and pro-apoptotic signalling in respiratory neurons, preceding the functional impairment observed in the 6-OHDA model of PD. ABSTRACT: Parkinson's disease (PD) is a neurodegenerative disease caused by dopaminergic neuron death in the substantia nigra (SN). New evidence has revealed that this neurodegeneration is the result of complex interactions between genetic abnormalities, environmental toxins, mitochondrial dysfunction and disruption of the blood-brain barrier (BBB) in the SN. In addition to classic symptoms, PD patients also exhibit respiratory failure. Here, we investigated whether oxidative stress was associated with neurodegeneration in a respiratory group (RG) of 6-OHDA-treated rats, which act as a model of PD. We analysed how oxidative stress affected apoptotic signalling in the RG 30 days after 6-OHDA treatment, shortly before commencement of breathing impairment (40 days). After 30 days, a dihydroethidium assay showed increased oxidative stress in the RG, anti-apoptotic signalling, as shown by an increase in p-Akt and BcL-2 and a decrease in Bax in the caudal aspect of the nucleus of the solitary tract (cNTS), and a decrease in p-p38 and Bax levels in the retrotrapezoid nucleus (RTN); pro-apoptotic signalling was indicated by a decrease in p-Akt and BcL-2 and an increase in Bax in the rostral ventral respiratory group (rVRG) and pre-Botzinger complex (preBotC). miR-34c, a known oxidative stress protector, was downregulated in 6-OHDA animals in the RC. After 40 days of 6-OHDA, the NTS, rVRG, preBotC and RTN exhibited reduced NeuN immunoreactivity, no BBB disruption and an increase in thiobarbituric acid reactivity. We conclude that in the 6-OHDA model of PD, oxidative stress contributes to neurodegeneration in medullary respiratory neurons.

Carious Lesion Severity Induces Higher Antioxidant System Activity and Consequently Reduces Oxidative Damage in Children's Saliva.

Oxidative stress biomarkers can be found at detectable concentrations in saliva. These salivary biomarkers reflect specific oxidation pathways associated with caries and periodontitis. Our study evaluated the influence of dental caries severity (assessed using the ICCMS™ criteria) on the levels of oxidative stress biomarkers in saliva from children. Unstimulated saliva samples were collected from patients (from one to three years old) in a day care center in Birigui, SP, Brazil, two hours after fasting. Children were divided into four groups (n = 30/group), according to caries severity: caries free (group A), early carious lesions (group B), moderate carious lesions (group C), and advanced carious lesions (group D). The following salivary biomarkers were determined: total proteins (TP), measured by the Lowry method; oxidative damage, measured by the TBARS method; total antioxidant capacity (TAC); superoxide dismutase (SOD) enzymatic antioxidant activity; and uric acid (UA) non-enzymatic antioxidant activity. Data were analyzed by ANOVA, followed by the Student-Newman-Keuls test, Pearson and Spearman correlation coefficients, and multivariable linear regression (p < 0.05). TP, TAC, SOD enzymatic antioxidant activity, and UA non-enzymatic antioxidant activity increased with caries severity, consequently reducing salivary oxidative damage. It was concluded that higher caries severity increases salivary antioxidant system activity, with consequent reduction in salivary oxidative damage.

Atenolol increases dental mineralization in male offspring of treated hypertensive rats and normotensive rats

Abstract This study evaluates how atenolol affects dental mineralization in offspring of female spontaneously hypertensive rats (fSHR) and normotensive Wistar rats (fW). fSHR and fW were treated with atenolol (100 mg/Kg/day, orally) during pregnancy and lactation. Non-treated fSHR and fW were the control groups. Enamel and dentin hardness were analyzed (Knoop, 15 g load, 10s) in mandibular incisor teeth (IT) and molar teeth (MT) obtained from the male offspring of atenolol-treated and non-treated fWistar and fSHR. Data were analyzed by ANOVA, followed by Tukey post hoc test (p < 0.05). Atenolol reduced the arterial blood pressure (SBP) in fSHR, but it did not change the SBP in fW. The offspring of non-treated fSHR had lower enamel (IT and MT) and dentin (IT) hardness than the offspring of non-treated fW (p < 0.05). Atenolol increased enamel and dentin hardness in the IT obtained from the offspring of fSHR and fW (p<0.05), but the offspring of fSHR presented higher values (p < 0.05). Atenolol did not alter enamel width in the IT obtained from any of the groups, but it increased enamel and dentin hardness in the IT obtained from the offspring of fSHR and fW. Atenolol affected the IT obtained from the offspring of fSHR. Atenolol increased only enamel hardness in the MT obtained from the offspring of fW. In conclusion, maternal hypertension reduces tooth hard tissues, and treatment with atenolol increases tooth hardness in male offspring of hypertensive and normotensive female rats.

Losartan improves alveolar bone dynamics in normotensive rats but not in hypertensive rats.

OBJECTIVES: Hypertension is one of the main causes of premature death in the world; also, it is associated with several bone alterations. Preclinical studies have demonstrated delayed alveolar bone healing in hypertensive rats. However, losartan has been favorable for consolidation of bone grafts and reduction in active periodontitis. Therefore, losartan is suggested to be effective in bone formation stages, as well as in the synthesis of matrix proteins and mineralization. To evaluate the alveolar bone dynamics in hypertensive rats treated with losartan by laser confocal microscopy and histological analysis. METHODOLOGY: Thirty-two rats, 16 spontaneously hypertensive rats (SHR) and 16 Wistar albinus rats, treated or not with losartan (30 mg/kg/day) were used. Calcein fluorochrome at 21 days and alizarin red fluorochrome at 49 days were injected in rats (both 20 mg/kg). The animals were submitted to euthanasia 67 days after treatment, and then the right maxilla was removed for laser confocal microscopy analysis and the left maxilla for histological analysis. RESULTS: This study showed a greater calcium marking in normotensive animals treated with losartan in relation to the other groups. Laser confocal microscopy parameters showed higher values of bone volume formed, mineralized surface, active surface of mineralization and bone formation rate in normotensive animals treated with losartan. However, a smaller mineralized surface was observed in all hypertensive animals. CONCLUSION: Losartan can improve bone mineralization parameters under normal physiological conditions, but the same anabolic effect does not occur under hypertension.