Daniel Thomas Brozoski

University of São Paulo, San Paulo, São Paulo, Brazil

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Publications (11)16.57 Total impact

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    ABSTRACT: Saliva sampling used to quantify piroxicam and 5'-hydroxypiroxicam is a noninvasive and painless method when compared to sequential blood sampling. For that, a rapid, selective and sensitive liquid chromatography-tandem mass spectrometric method for simultaneous determination of piroxicam and 5'-hydroxypiroxicam in saliva and human plasma was developed and validated. Piroxicam and its major metabolite were separated using a LiChroCART 125-4 RP Select-B Sorbent C18 column using a mixture of methanol and 2% phosphoric acid (pH 2.7) (70:30, v/v) for the mobile phase with a flow injection of 1mL/min. The run time was 4min. Volunteers had saliva and blood sampled before, 1, 2, 3, 4, 5, 6, 8, 11, 24, 48 and 72h after taking a 20mg oral dose of piroxicam. The pharmacokinetic parameters of piroxicam in plasma samples were as follows: AUC0-72 (64819hng/mL), predicted clearance (0.2L/h), distribution volume (14.8L), elimination half-life (50.7h) and saliva/plasma concentration ratio (0.003). The estimation of all pharmacokinetic parameters for 5'-hydroxypiroxicam would require collections beyond 72h; however, it was possible to quantify the mean maximum concentration (133ng/mL), time to peak concentration (53.6h), mean AUC0-72 (6213hng/mL), predicted clearance (110.3L/h) and saliva/plasma concentration ratio (0.04). The developed methods proved effective and sensitive for determining the lower quantification limit of piroxicam in plasma (6.1ng/mL) and saliva (0.15ng/mL) and of 5'-hydroxypiroxicam in plasma (1.2ng/mL) and saliva (0.15ng/mL).
    No preview · Article · Dec 2015 · Journal of pharmaceutical and biomedical analysis
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    ABSTRACT: Objectives: In an effort to contribute to proper dental planning and define possible dental phenotypes of nonsyndromic cleft lip and/or palate (CL/P), this study aimed to investigate the occurrence of taurodontism, root dilaceration, and tooth transposition in persons with nonsyndromic CL/P, specifically analyzing the differences among gender, cleft types, and the most affected teeth. Design: This retrospective study analyzed 974 panoramic x-rays from nonsyndromic Brazilians older than 16 years and categorized into the following four groups: group 1, 250 persons with unilateral cleft lip and palate; group 2, 250 persons with unilateral cleft lip; group 3, 224 persons with cleft palate; and a control group of 250 persons without clefts. Radiographs were digitalized with a scanner and analyzed. Results: In the Brazilian population studied, the prevalence of taurodontism was 60.4% in group 1, 62.4% in group 2, 67.0% in group 3, and 42.8% in the control group. Root dilacerations had a prevalence of 31.2% in group 1, 29.6% in group 2, 26.3% in group 3, and 27.2% in the control group. The teeth most affected by taurodontism were 17 and 27; whereas root dilacerations were most common in teeth 38 and 48. No tooth transpositions were found in any radiograph analyzed. Conclusions: Taurodontism is significantly more prevalent in Brazilians with nonsyndromic CL/P than in persons without clefts; whereas the prevalence of root dilaceration no different from that in the control group. However, root dilacerations in anterior teeth were higher in groups 1 and 2 than in the control group.
    No preview · Article · Aug 2015 · The Cleft Palate-Craniofacial Journal
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    ABSTRACT: This double-blind crossover randomized clinical trial compared the efficacy of 2 concentrations of articaine, 2% (A2) and 4% (A4), with 1:200,000 epinephrine, for lower third molar removal. During 2 separate appointments with either A2 or A4, both similarly positioned lower third molars in 46 volunteers were extracted. The following were evaluated: onset and duration of anesthetic action on soft tissues, intraoperative bleeding, hemodynamic parameters, postoperative analgesia, and mouth opening and wound healing during the 7th postoperative day, along with the incidence, type, and severity of adverse reactions. Nearly identical volumes of both anesthetic solutions were used for each appointment: 3.4 ± 0.9 mL ≈ 68 mg of articaine (A2) and 3.3 ± 0.8 mL ≈ 132 mg of articaine (A4). Statistical analysis indicated no differences in onset or duration of anesthetic action on soft tissues or duration of postoperative analgesia evoked by A2 and A4 anesthetic solutions (P > 0.05). The surgeon's rating of intraoperative bleeding was considered minimal throughout all surgery with both anesthetic solutions. While transient changes in blood pressure, heart rate, and oxygen saturation were observed, these factors were clinically insignificant and were uninfluenced by articaine concentration (P > 0.05). No systemic or local adverse reactions were observed in the preoperative and postoperative periods due to A2 or A4, but 1 case of bilateral paresthesia was observed. There were no significant differences between preoperative and postoperative (7th day) values of mouth opening and wound healing whether volunteers received A2 or A4 (P > 0.05). In conclusion, both A2 and A4, administered in equal volumes, were effective and safe during lower third molar surgery, and no significant differences were found between their efficacy and safety (ClinicalTrials.gov NCT02457325). © International & American Associations for Dental Research.
    Full-text · Article · Jul 2015 · Journal of dental research
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    ABSTRACT: This study investigated how proteins of the insulin signaling cascade could modulate insulin resistance after dexamethasone (Dexa) treatment and aerobic training. Rats were distributed into 4 groups: sedentary control (SC), sedentary+Dexa (SD), trained control (TC), and trained+Dexa (TD), and underwent aerobic training for 70 days or remained sedentary. Dexa was administered during the last 10 days (1 mg · kg-1 per day i. p.). After 70 days, an intraperitoneal glucose tolerance test (ipGTT) was performed. Protein levels of IRS-1, AKT, and PKC-α in the tibialis anterior (TA) muscle were identified using Western blots. Dexa treatment increased blood glucose and the area under the curve (AUC) of ipGTT. Training attenuated the hyperglycemia and the AUC induced by Dexa. Dexa reduced IRS-1 (- 16%) and AKT (- 43%) protein level with no changes in PKC-α levels. Moreover, these effects on IRS-1 and AKT protein level were prevented in trained animals. These results show for the first time that aerobic exercise prevented reductions of IRS-1 and AKT level induced by Dexa in the TA muscle, suggesting that aerobic exercise is a good strategy to prevent Dexa-induced peripheral insulin resistance.
    Full-text · Article · Apr 2014 · Hormone and Metabolic Research
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    ABSTRACT: Objective Patients (n = 110) free of antibiotics, operated on by 3 surgeons ranging in clinical experiences, were evaluated for infection. Study Design In the preoperative period and during the second and seventh postoperative days, the following parameters were analyzed: pain, infection, swelling, trismus, body temperature, C-reactive protein levels (CRP), and salivary neutrophil counts (SNC). During surgery, the following parameters were analyzed: systolic, diastolic, and mean arterial pressure; oximetry; heart rate; anesthesia quality; local anesthetic amount; bleeding; surgery difficulty; and surgery duration. Results There were some differences in the surgery duration, local anesthetic amount, anesthesia quality, bleeding, pain experienced, trismus, CRP, and SNC, and no changes in hemodynamic parameters, rescue analgesic medication, wound healing, swelling, body temperature, confirmed case of dry socket, or any other type of local infection. Particularly, no systemic infections were found after lower third molar removal (LTMR). Conclusions This study suggests that antibiotic prescriptions are unnecessary after LTMR when preoperative infections are absent.
    No preview · Article · Nov 2012
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    ABSTRACT: Lower third molar removal provides a clinical model for studying analgesic drugs. The present study's aim was to compare the clinical efficacy of sublingual ketorolac and sublingual piroxicam in managing pain, trismus and swelling after lower third molar extraction in adult volunteers. In this double-blinded, randomized, crossover investigation, 47 volunteers received for 4 days ketorolac sublingually (10 mg 4 times daily) and piroxicam sublingually (20 mg once daily) during 2 separate appointments after lower third molar extraction of symmetrically positioned lower third molars. A surgeon evaluated objective parameters (surgery duration, mouth opening, rescue analgesic medication, and facial swelling) and volunteers documented subjective parameters (postoperative pain and global evaluation), comparing postoperative results for a total of 7 days after surgery. The means of the objective and subjective parameters were compared for statistical significance (P < .05). Volunteers reported low pain scores during the postoperative period when treated with either sublingual ketorolac or piroxicam. Also, volunteers ingested similar amounts of analgesic rescue medication (paracetamol) when they received either drug sublingually (P > .05). Additionally, values for mouth openings measured just before surgery and immediately after suture removal 7 days later were similar among volunteers (P > .05), and the type of nonsteroidal antiinflammatory drug (NSAID) used in this study showed no significant differences between swellings on the second or seventh days after surgery (P > .05). Pain, trismus, and swelling after lower third molar extraction, independent of surgical difficulty, were successfully controlled by sublingual ketorolac (10 mg 4 times daily) or sublingual piroxicam (20 mg once daily), and no significant differences were observed between the NSAIDs evaluated.
    Full-text · Article · Jul 2012
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    ABSTRACT: Periodontal disease (PD) comprises a group of lesions that affect protection (gingivitis) and support periodontal tissues (periodontitis). Recent research showed the existence of a local gingival renin-angiotensin system (RAS), and suggested that it might participate in PD. Objective: evaluate whether the RAS is involved in the initiation and progression of the experimentally induced PD in rats. Method: a model of ligature placement, for 7 and 14 days, around the lower first molar in rats, and the treatment of such animals with drugs that affect the RAS [losartan (50 mg/Kg/day), aliskiren (30 mg/Kg/day) or enalapril (10mg/Kg/day)] were employed. The following techniques were performed: alveolar bone loss analysis, qPCR and immunohistochemistry. Result: In the protein level, there was a significant increase in the majority of the RAS components in PD. Immunolocalization for renin increased when animals were treated with losartan, aliskiren or enalapril, for 7 and 14 days, in both sham (fictitious surgery for PD induction) and PD animals, whereas the control group (water) had no staining, demonstrating a drug-related effect. In animals with PD treated with losartan, aliskiren or enalapril there was an increase in staining for AT1 (7 and 14 days), AT2 (7 days) and angiotensin-converting enzyme (ACE; 7 and 14 days). There was also increased staining in PD animals for AT2 (14 days) and ACE (14 days) in the control group. As far as genic expression, there was an increase in mRNA expression for AT2 in control animals with PD (7 and 14 days), and in the animals treated with losartan or enalapril (7 days). Treatment for 14 days with losartan or aliskiren, but not enalapril, significantly decreased alveolar bone loss (p<0.05). Conclusion: RAS is involved in the initiation and progression of the experimentally-induced PD in rats.
    No preview · Conference Paper · Jun 2012
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    ABSTRACT: Background: Fibroblasts are now seen as active components of the immune response because these cells express Toll-like receptors (TLRs), recognize pathogen-associated molecular patterns, and mediate the production of cytokines and chemokines during inflammation. The innate host response to lipopolysaccharide (LPS) from Porphyromonas gingivalis is unusual inasmuch as different studies have reported that it can be an agonist for Toll-like receptor 2 (TLR2) and an antagonist or agonist for Toll-like receptor 4 (TLR4). This study investigates and compares whether signaling through TLR2 or TLR4 could affect the secretion of interleukin (IL)-6, IL-8, and stromal derived factor-1 (SDF-1/CXCL12) in both human gingival fibroblasts (HGF) and human periodontal ligament fibroblasts (HPDLF). Methods: After small interfering RNA-mediated silencing of TLR2 and TLR4, HGF and HPDLF from the same donors were stimulated with P. gingivalis LPS or with two synthetic ligands of TLR2, Pam2CSK4 and Pam3CSK4, for 6 hours. IL-6, IL-8, and CXCL12 mRNA expression and protein secretion were evaluated by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Results: TLR2 mRNA expression was upregulated in HGF but not in HPDLF by all the stimuli applied. Knockdown of TLR2 decreased IL-6 and IL-8 in response to P. gingivalis LPS, or Pam2CSK4 and Pam3CSK4, in a similar manner in both fibroblasts subpopulations. Conversely, CXCL12 remained unchanged by TLR2 or TLR4 silencing. Conclusion: These results suggest that signaling through TLR2 by gingival and periodontal ligament fibroblasts can control the secretion of IL-6 and IL-8, which contribute to periodontal pathogenesis, but do not interfere with CXCL12 levels, an important chemokine in the repair process.
    Full-text · Article · Jun 2012 · Journal of Periodontology
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    ABSTRACT: This study investigated the role of periodontal disease in the development of stroke or cerebral infarction in patients by evaluating the clinical periodontal conditions and the subgingival levels of periodontopathogens. Twenty patients with ischemic (I-CVA) or hemorrhagic (H-CVA) cerebrovascular episodes (test group) and 60 systemically healthy patients (control group) were evaluated for: probing depth, clinical attachment level, bleeding on probing and plaque index. Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were both identified and quantified in subgingival plaque samples by conventional and real-time PCR, respectively. The test group showed a significant increase in each of the following parameters: pocket depth, clinical attachment loss, bleeding on probing, plaque index and number of missing teeth when compared to control values (p<0.05, unpaired t-test). Likewise, the test group had increased numbers of sites that were contaminated with P. gingivalis (60%x10%; p<0.001; chi-squared test) and displayed greater prevalence of periodontal disease, with an odds ratio of 48.06 (95% CI: 5.96-387.72; p<0.001). Notably, a positive correlation between probing depth and the levels of P. gingivalis in ischemic stroke was found (r=0.60; p=0.03; Spearman's rank correlation coefficient test). A. actinomycetemcomitans DNA was not detected in any of the groups by conventional or real-time PCR. Stroke patients had deeper pockets, more severe attachment loss, increased bleeding on probing, increased plaque indexes, and in their pockets harbored increased levels of P. gingivalis. These findings suggest that periodontal disease is a risk factor for the development of cerebral hemorrhage or infarction. Early treatment of periodontitis may counteract the development of cerebrovascular episodes.
    Full-text · Article · Feb 2012 · Journal of applied oral science: revista FOB
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    ABSTRACT: The aim of this study was to quantify and compare the production of transforming growth factor beta (TGF-β), interleukin (IL)-8 and IL-10 by human cultured periodontal ligament and gingival fibroblasts both obtained from the same donors challenged with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Fibroblasts were exposed to 0.1-10 µg/mL of LPS from P. gingivalis and after 24 h the supernatants were collected and analyzed by enzyme-linked immunosorbent assay (ELISA). TGF-β protein production was upregulated in a concentration-dependent manner, mainly in gingival fibroblasts, which was statistically significant when challenged by 10 µg/mL LPS. Additionally, at this concentration, gingival fibroblasts had almost a two-fold increase in the amount of TGF-β when compared to periodontal ligament fibroblasts. Both periodontal ligament and gingival fibroblasts showed an increase in IL-8 production when challenged with 1 µg/mL and 10 µg/mL LPS. IL-10 production remained unaffected when challenged by any of the LPS concentrations tested in either periodontal ligament or gingival fibroblasts. Our results demonstrate that periodontal ligament and gingival fibroblasts when challenged by LPS from P. gingivalis with 24 h may play a critical role in producing TGF-β and IL-8 but not IL-10.
    Full-text · Article · Apr 2011 · Brazilian oral research
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    ABSTRACT: In this study, 53 patients received piroxicam, administered orally or sublingually, after undergoing removal of symmetrically positioned lower third molars, during two separate appointments. This study used a randomized, blind, cross-over protocol. Objective and subjective parameters were recorded for comparison of postoperative results for 7 days after surgery. Patients treated with oral or sublingual piroxicam reported low postoperative pain scores. The patients who received piroxicam orally took a similar average amount of analgesic rescue medication compared with patients who received piroxicam sublingually (p>0.05). Patients exhibited similar values for mouth opening measured just before surgery and immediately following suture removal 7 days later (p>0.05), and showed no significant differences between routes of piroxicam administration for swelling control during the second or seventh postoperative days (p>0.05). In summary, pain, trismus and swelling after lower third molar extraction, independent of surgical difficulty, could be controlled by piroxicam 20mg administered orally or sublingually and no significant differences were observed between the route of delivery used in this study.
    Full-text · Article · Dec 2010 · International Journal of Oral and Maxillofacial Surgery