Iza Teixeira Alves Peixoto

University of Campinas, Conceição de Campinas, São Paulo, Brazil

Are you Iza Teixeira Alves Peixoto?

Claim your profile

Publications (12)5.14 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Shed teeth have been proposed as trace element biomarkers. This study determined variations in the spatial distribution of Ca, K, Zn, Pb, Mn, Cu, and Sr in four anatomical locations: superficial enamel (SE, 0-10 μm), subsuperficial enamel (SSE, 10-30 μm), primary dentine (PD), and secondary dentine (SD). Five primary incisors were analyzed by micro Synchrotron Radiation X-Ray Fluorescence (μ-SRXRF). Two teeth had low concentrations of lead in the SE (< 250 μg/g), while three contained very high lead concentrations in the SE (> 2,000 μg/g). Teeth were sliced, and five spot measurements (20 μm beam diameter) were accomplished in each location. The data are shown as absolute values and as the ratio between the different elements and Ca. The distribution of K was close to that of Ca. Zn was the third most abundant element, with the highest levels being found in the SE and SD and low levels detected in the PD. Increasing Sr levels were found progressing from the enamel to the dentine, with the highest levels being found in the SD, a distribution that was unique. Pb, Mn, and Cu exhibited a similar trend, with higher signals for these elements detected in the SE. This study provides preliminary data on the heterogeneous distribution of different elements in the tooth, highlighting the importance of the first 10 μm of the SE for determination of some elements, such as Zn, Pb, Mn, and Cu.
    Journal of Trace Elements in Medicine and Biology 01/2014; · 1.96 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Ethanolic crude extracts prepared from the arils and seeds, pericarp, peels and from the whole fruit of Punica granatum, known as pomegranate, had their antifungal activity tested against Candida spp. The ethanolic crude extracts were analyzed by Mass Spectrometry and yielded many compounds such as punicalagin and galladydilacton. The extracts from the pericarp and peel showed activity against Candida spp., with MICs of 125 μg/mL. The effect of pericarp and peel extracts upon the morphological and structure of C. albicans and C. krusei were examined by scanning and transmission electron microscopy, with the visualization of an irregular membrane and hyphae, formation of vacuoles and thickening of the cell wall. The data obtained revealed potential antimicrobial activity against yeasts cells of the Candida genus, and the bioactive compounds could be responsible for changes in cell morphology and structure. The data obtained open new perspectives for future research in continuation to this study, where information such as determination of the site of action of the compounds could contribute to an alternative therapy against these organisms.
    Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]. 01/2013; 44(3):839-48.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Objectives: a) to compare the concentrations of lead in dental enamel with those found in prenatal and postnatal dentin of primary teeth collected from different regions: Santo Amaro, Bahia State, Cubatão, São Paulo State and Ribeirão Preto, São Paulo State. Method: Methods: A surface enamel acid-etch microbiopsy was performed in vitro in the enamel surface.Lead was measured by Inductively coupled plasma mass spectrometry (ICP-MS) while phosphorus was measured colorimetrically to establish biopsy depth. Pieces of prenatal and postnatal dentin were dissolved in ultrapure nitric acid. Lead concentrations were expressed as μg/g. Result: Results: Median superficial enamel lead content of the teeth collected in Santo Amaro were statistically higher than the one from teeth collected in Ribeirão Preto and Cubatão (p<0.0001). The lead concentration in the enamel did not differ when results from Ribeirão Preto and Cubatão were compared. Median lead contents found in prenatal and postnatal dentin of Santo Amaro teeth were statistically higher than the ones found in teeth from Ribeirão Preto and Cubatao (p<0.001). Spearman’s correlation coefficient for lead concentration in dentine versus lead concentration in the enamel surface was significant for Ribeirão Preto (Prenatal dentin versus enamel r=0,3, p=0,003 e r=0,3, p=0,0013 and Posnatal dentin versus enamel r=0,27, p=0,06 e r=0,21 e p=0,15), and Santo Amaro (Prenatal dentin versus enamel r=0,38, p=0,0001 e r=0,18 e p=0,08 and Postnatal r=0,3, p=0,015 e r=0,2, p=0,1) . No correlation significant was found in Cubatão (Prenatal dentin r=0,118, p=0,195, r=0,05, p=0,59; Postnatal dentin r=0,05, p=0,59, r=0,09, p=0,28). Conclusion: Conclusions: this study shows that there is a weak but significant correlation between the lead levels found in the superficial enamel and the ones found in the pre- and postnatal dentin, but only in the samples from cities that showed higher lead concentrations (Ribeirao Preto and Santo Amaro). Supported by FAPESP (07/54346-4)
    IADR General Session 2012; 06/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this randomized clinical trial, we investigated, using the microbial culture technique and scanning electron microscopy, the contamination of acrylic baseplates of removable orthodontic appliances by mutans streptococci (MS) and evaluated the efficacy of different home disinfection protocols with a 0.12% chlorhexidine gluconate spray (Periogard, Colgate-Palmolive, São Bernardo do Campo, Brazil). Fifteen dental students were randomly enrolled in a 3-stage changeover system with a 1-week interval between each stage. The acrylic baseplates were worn full time except at meals to simulate the routine use of removable appliances under clinical conditions. Three 1-week home disinfection protocols were tested in all stages by a different group of students: protocol I, toothbrushing + baseplate brushing + sterile tap water spraying once a day; protocol II, toothbrushing + baseplate brushing + Periogard spraying on the seventh day after appliance placement; and protocol III, toothbrushing + baseplate brushing + Periogard spraying on the fourth and seventh days after appliance placement. After the first week, the volunteers received new baseplates, toothbrushes, and dentifrices, and the regimens were repeated 2 more times. At the end of each week, the baseplates had a randomized disinfection protocol and were sent for microbiologic analysis. A scanning electron microscope was used to examine 3 acrylic baseplates representing each home protocol. The Friedman test (α = 0.05) compared the home protocols for the formation of MS colonies or biofilms on the acrylic surfaces. MS colonies or biofilms were found on all acrylic baseplates after protocol I. Protocols II and III reduced significantly (P <0.05) the number of MS colonies and biofilms on the acrylic surfaces. No significant difference (P >0.05) was observed between protocols II and III. The scanning electron microscope analysis confirmed the results of the microbiologic cultures. Disinfection of baseplates of removable orthodontic appliances by using 0.12% chlorhexidine spray once or twice a week reduced the contamination by MS on the acrylic surface in vivo.
    American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 07/2011; 140(1):51-7. · 1.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: Due to the increased drug resistance and lack of effective antifungals for the treatment of Candida infections, screening plant extracts for antimicrobial activity is a potential means of identifying new antifungal agents. The aim of this work was to assess the in vitro activity of aqueous extracts of Thymus vulgaris, Croton lechleri, and Amphypterygium adstringens on planktonic cultures and biofilm formation or inhibition of Candida spp. on the surfaces of wells of microtiter plates. Methods: The extracts were tested in vitro for their antifungal activity against two yeasts (Candida albicans CBS-562 and Candida dubliniensis CBS-7987) as planktonic cells, using microdilution and agar diffusion method. For C. albicans biofilm formation and inhibition on the surface of wells of microtiter plates, the model was coupled with a colorimetric XTT-reduction assay. Results: Activity on planktonic cells: A. adstringens exhibited significant antifungal activity at 16 g/mL for C. albicans and C. dubliniensis followed by Thymus vulgaris at 62.5 g/mL for C. dubliniensis and 125 g/mL for C. albicans. Croton lechleri had activity at 250 g/mL for both strains. Activity on biofilm formation or inhibition: our results showed that A. adstringens exhibited strong antifungal activities against C. albicans biofilm formation inhibiting 88.25% at a concentration of 62.5 g/mL, while T. vulgaris and C. lechleri had low activity against the formation of C. albicans biofilms. Conclusions: In this work, plant extracts had inhibitory effects on the growth of Candida spp planktonic cultures and reduce the formation of biofilms but none of the plant extracts had inhibitory effects on preformed C. albicans biofilms.
    IADR General Session 2011; 03/2011
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Candida-associated denture stomatitis is the most common form of oral candidal infection, with Candida albicans being the principal etiological agent. Candida adheres directly or via an intermediary layer of plaque-forming bacteria to denture acrylic. Despite antifungal therapy to treat denture stomatitis, infection is reestablished soon after the treatment ceases. In addition, many predisposing factors have been identified as important in the development of oral candidiasis, including malnourishment, common endocrine disorders, such as diabetis mellitus, antibacterial drug therapy, corticosteroids, radiotherapy and other immunocompromised conditions, such as acquired immunodeficiency syndrome (AIDS). These often results in increased tolerance to the most commonly used antifungals. So this review suggests new therapies to oral candidiasis.
    Brazilian Journal of Microbiology 10/2010; 41(4):824-31. · 0.76 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: The aim is evaluate the antifungal activity of Thymus vulgaris, Croton lechleri and Julliana adstringens Schl. added to Chitosan and Pullulan biopolymers against Candida albicans biofilm formation. Methods: Different parts of these plants were collected and extracted with solvents to obtain aqueous and organic extracts. These extracts were added to biopolymers in concentrations about 10% to T. vulgaris, 11% J. adstringens Schl. and 20% C. lechleri. The polymers were used at 1% Chitosan and 10% Pullulan. This study makes use of a 96-well microtiter plate model of C. albicans biofilm formation to test the susceptibility of biofilms to the polymers with plant extracts. This model is coupled with a colorimetric XTT-reduction assay in which metabolically active sessile cells reduce a tetrazolium salt to water-soluble orange formazan compounds, and the intensity this product can be determined using a microtiter-plate reader. Results: Pullulan added with J. adstringens Schl. inhibited biofilm formation about 100%, while T. vulgaris showed low activity (2.5% biofilm inhibition), and C. lechleri inhibited biofilm formation about 52.5%. The Chitosan biopolymers showed activity with T. vulgaris and C. lechleri, with 51.5% and 44% biofilm inhibition, respectively. However, there was low activity using J. adstringens in Chitosan. Our finding showed that J. adstringens exhibited strong antifungal activities in C. albicans biofilm inhibition in Pullulan, while T. vulgaris and C. lechleri exhibited inhibitory effects in Chitosan . The biopolymers did not have any inhibitory effects on preformed C. albicans biofilms. Conclusion: Chitosan and Pullulan added with certain plant extracts have potential to be used as antifungal on Candida albicans biofilms.
    IADR General Session 2010; 07/2010
  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction:Studies have shown that teeth are valuable biomarkers of trace elements. However, some biological differences in dental tissues result in differences in the distribution of elements in various anatomical locations, and those differences have been overlooked in many studies. Objective: this study aimed at determining variations in the spatial distribution of Ca, K, Zn, Pb, Mn, Cu, and Sr in four anatomical locations: superficial enamel (SE, 0-10 um) and subsuperficial enamel (SSE, 10-30 um), primary dentine (PD), and secondary dentine (SD) of primary incisors by micro Synchrotron Radiation X-Ray Fluorescence (-SRXRF), a semiquantitative technique with spacial resolution. Methods: Two of the 5 teeth selected for this study had low superficial enamel concentrations of lead (< 250 ug/g), while 3 were included for their very high superficial enamel lead concentrations (> 2,000 ug/g). On each tooth section five spot measurements (20 m beam diameter) were made in the four anatomical locations (SE, SSE, PD, and SD). The data are shown as absolut values and as the ratio of the different elements by Ca. Results: K showed a distribution that closely followed that of Ca. Zn was the third most abundant element found, with the highest levels of Zn found in SE and SD, and low levels found in PD in all 5 teeth. Increasing levels of Sr were found from the enamel to dentine, with the highest levels found in SD, a unique distribution found among the elements tested. Pb, Mn, and Cu showed a similar trend. Higher amounts of Pb were found in the SE. Conclusion: In conclusion, this study confirms the heterogeneous distribution of different elements in teeth, clearly highlighting the importance of the first 10 um of SE for the determination of some elements, such as Zn, Pb, Mn, and Cu.
    IADR General Session 2010; 07/2010
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although the main reservoir of Candida spp. is believed to be the buccal mucosa, these microorganisms can coaggregate with bacteria in subgingival biofilm and adhere to epithelial cells. Such interactions are associated with the capacity of Candida spp. to invade gingival conjunctive tissue, and may be important in the microbial colonization that contributes to progression of oral alterations caused by diabetes mellitus, some medications, and immunosuppressive diseases such as AIDS. In addition, immune deficiency can result in proliferation of Candida spp. and germination of forms that are more virulent and have a higher capacity to adhere to and penetrate cells in host tissues. The virulence factors of Candida spp. increase host susceptibility to proliferation of these microorganisms and are likely to be important in the study of periodontal disease. Herein, we briefly review the literature pertaining to the role of Candida spp. in periodontal disease, and consider the main virulence factors, the host immune response to these microorganisms, and the effect of concomitant immunosuppressive conditions.
    Journal of Oral Science 06/2010; 52(2):177-85.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: During the past few years, interest in the potential clinical and pharmacological basis of the efficacy and safety of herbal medicines has increased greatly, due to widespread domestic self-medication with these agents. Some authors have analyzed the use of Mentha ssp. in the pharmacological industry. The essential oil from Mentha spp. is used to treat discomfort of the gastrointestinal tract, irritable bowel syndrome, myalgia and neuralgia, as well as oral mucosal inflammation, and also as an expectorant, an antimicrobial and an ingredient in many analgesic creams. The essential oil also contains chemical compounds that are associated with side effects such as nausea, vomiting, allergic reactions, flushing and headaches. Therefore, the purpose of the present review was to examine the literature on the efficacy and safety of the possible clinical and pharmacological uses of the essential oil from Mentha spp. in human beings. Keywords: Mentha spp. Antimicrobial activity. Essential oil.
    Revista de Ciências Farmacêuticas Básica e Aplicada. 01/2010;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Primary teeth were analyzed by micro-SRXRF. The aim of this study was to determine the elemental distribution of lead and calcium in different regions of primary incisor of children living in a notoriously contaminated area (Santo Amaro da Purificação, Bahia State, Brazil). The measurements were performed in standard geometry of 45 degrees incidence, exciting with a white beam and using a conventional system collimation (orthogonal slits) in the XRF beamline at the Synchrotron Light National Laboratory (Campinas, Brazil).
    Applied radiation and isotopes: including data, instrumentation and methods for use in agriculture, industry and medicine 09/2009; 68(1):71-5. · 1.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This article documents the case history of a 9-year-old Brazilian child diagnosed with Kabuki make-up syndrome (KMS). The clinical features are described, with emphasis on the craniofacial and orodental manifestations. The patient had the distinctive KMS craniofacial features consisting of long palpebral fissure, hypertelorism, high-arched eyebrows with sparse hair in the lateral one-third, eyes with eversion of the lateral one-third of the lower eyelids, long and curved eyelashes, palpebral ptosis, large anteverted prominent ears in a lower position, broad, depressed nasal root with a flat nasal tip, and mild neuropsychomotor developmental deficits. The intraoral examination revealed an anterior open bite, overretention of primary teeth, and a high-arched palate. Two findings in this child have not been previously reported in patients with KMS: the presence of supernumerary teeth and taurodontic teeth in the maxillary arch. The clinical and radiographic detection of these unique dental features may be helpful in identifying children who may have milder forms of KMS.
    Special Care in Dentistry 01/2008; 28(2):53-7.