José Alexandre da Rocha Curvelo

Supplementing the Antimicrobial Effects of Chemomechanical Debridement with Either Passive Ultrasonic Irrigation or a Final Rinse with Chlorhexidine: A Clinical Study

INTRODUCTION The ability of 2 different approaches to supplement the antimicrobial effects of chemomechanical debridement in infected root canals was compared in vivo. METHODS Samples from necrotic root canals of teeth with apical periodontitis were taken at the baseline (S1), after preparation with rotary nickel-titanium BioRaCe instruments and 2.5% NaOCl irrigation (S2), and then after either passive ultrasonic irrigation (PUI) for activation of NaOCl (n = 13) or a final rinse with 2% chlorhexidine (CHX) (n = 14) (S3). The incidence of positive culture for bacteria and fungi as well as positive broad-range polymerase chain reaction (PCR) results for bacteria, fungi, and archaea was determined. RESULTS All S1 samples were positive for bacteria in all methods. Fungi were not detected, and archaea occurred in only one S1 sample. Treatment procedures were significantly effective in reducing the incidence of positive culture and PCR results. Although both supplementary approaches reduced the incidence of positive bacteriologic results when compared with postinstrumentation samples, reduction was not statistically significant (P > .05). There was no significant difference for intergroup comparisons either (P > .05). CONCLUSIONS Although supplementary disinfection with either PUI or a final rinse with CHX can reduce the number of cases with positive culture and PCR results for bacteria, many cases still remain with detectable bacteria in the main root canal. Research on alternative or supplementary antimicrobial methods or substances should be encouraged.

Curcumin acts synergistically with fluconazole to sensitize a clinical isolate of Candida albicans showing a MDR phenotype

The primary objective of this work was to evaluate the capability of curcumin, a natural compound found in the Curcuma longa plant, to sensitize a clinical isolate of Candida albicans, which was found to have a high resistance to fluconazole. In addition, we assessed whether the resistance of this isolate was the result of the existence of efflux pumps, which could confer a multiple drug resistance phenotype. To evaluate azole resistance, we used the Clinical Laboratory Standard Institute (CLSI) MIC assays procedures with minor modifications. For evaluation of synergistic interaction of curcumin and fluconazole, checkerboard experiments were employed. Nile red and Rhodamine 6G accumulation assays were used to evaluate efflux pump activity. Curcumin was found to have a great capability to inhibit fluconazole resistance of the isolate of C. albicans. It was capable of restoring its sensitivity to this azole when used at 11 μM. Analysis with different azoles and the two indicated dyes showed that an efflux pump could be acting and contributing to the resistance of this isolate to fluconazole. The results suggest that a major facilitator superfamily (MFS) transporter might be involved in this process.

Resins-based denture soft lining materials modified by chlorhexidine salt incorporation: An in vitro analysis of antifungal activity, drug release and hardness

OBJECTIVES To evaluate the in vitro growth inhibition of Candida albicans, the rate of chlorhexidine release and shore A hardness from resins-based denture soft lining materials modified by chlorhexidine diacetate (CDA) or chlorhexidine hydrochloride (CHC) incorporation. METHODS Resin discs were prepared from soft denture liners based on poly (methyl methacrylate) (PMMA) or poly (ethyl methacrylate) (PEMA) containing 0.5, 1.0 and 2.0 wt.% of CDA or CHC. For antifungal activity resin discs were placed on agar plates inoculated with C. albicans, after 48 h at 37°C the diameters of inhibition zones were measured. For the chlorhexidine release, discs were immersed into distilled water at 37°C, and spectral measurements were made after 48 h. Shore A hardness was evaluated at the baseline, 2 and 7 days, using 6mm thick rectangular specimens also immersed into distilled water at 37°C. Data were statistically processed by SigmaStat software using ANOVA and all pairwise multiple comparison procedures was done using the Holm-Sidak method, with α=0.05 (p<0.001). RESULTS CDA added to PMMA soft liner and PEMA soft liner had a dose-related inhibitory effect on C. albicans and on chlorhexidine release rate (p<0.001). The PMMA and PEMA hardness increased statistically by time but not for the different CDA concentrations. CHC had no inhibitory effect on C. albicans. SIGNIFICANCE Chlorhexidine diacetate released from resins-based soft lining materials can be convenient to reduce the biofilm development on the material surface and treat denture stomatitis, without depending on patient compliance.

Antileishmanial activity of nerolidol-rich essential oil from Piper claussenianum

Leishmaniasis is one of the most neglected tropical diseases, representing a group of parasitic diseases worldwide spread, occurring in 88 tropical and subtropical countries. Approximately 350 million people live in areas of active transmission of leishmaniasis, with about 1-2 million estimated new cases occurring every year. More than 90% of the cutaneous cases appear in developing countries. Efforts to improve the therapeutic arsenal against leishmaniasis have led to the search for new and cheap range of drugs. In this study, the nerolidol-rich essential oil from Piper claussenianum (Miq.) C. DC., Piperaceae, was assayed on arginase activity of Leishmania amazonensis. The effect of this essential oil on arginase activity levels showed an enzyme inhibition of 62.2%. This result stimulates the scientific interest about the potential value of this plant species on neglected diseases as potential new natural product source of pharmacological interest for the treatment of leishmaniasis.

A novel nerolidol-rich essential oil from Piper claussenianum modulates Candida albicans biofilm.

Candidiasis is a major opportunistic fungal infection in humans, and its incidence has increased steadily over the last two decades. Candida albicans, the main species of the genus, has a large arsenal of virulence attributes that contribute to successful infections, such as dimorphism and biofilm formation. The adverse effects of eukaryotic antimicrobial therapies associated with an increase in resistance to the compounds presently available have boosted efforts to improve the therapeutic arsenal against candidiasis with a newer and cheaper range of drugs. In this study, a novel nerolidol-rich essential oil (EO) derived from Piper claussenianum (Miq.) C. DC., Piperaceae, was tested on the growth, transition (yeast to hyphae), formation and stability of biofilms produced by C. albicans. Both inflorescence and leaf EOs were evaluated and revealed MIC values ranging from 0.04 to 0.1 % and 0.2 to 1.26 %, respectively. Furthermore, leaf EO managed to downregulate the yeast-to-hyphae transition by 81 %, as well as reducing biofilm formation by about 30 and 50 % after incubation for 24 and 48 h, respectively. The EO was also able to reduce the viability of pre-formed biofilm by 63.9 %. Finally, the association between the leaf EO and fluconazole was evaluated and revealed an interesting synergistic effect. Taken together, these results demonstrate that this novel compound could be a promising agent and could reinforce the arsenal of therapeutic alternatives for the treatment of candidiasis. Furthermore, it may represent a novel and natural source of nerolidol, which could be of interest pharmaceutically.

Effect of the secretory leucocyte proteinase inhibitor (SLPI) on Candida albicans biological processes: A therapeutic alternative?

OBJECTIVES The aim of this study was to evaluate the effect of SLPI on the growth and biological processes of Candida albicans. METHODS Two C. albicans strains were used in this study, a clinical isolate resistant to fluconazole (PRI) and a reference strain ATCC 24433. The minimal inhibitory concentration (MIC) was determined according to the CLSI methodology. The influence of SLPI on secreted serine proteinase activities (SSP) was measured by the cleavage of specific substrate, and surface hydrophobicity was determined by the aqueous-hydrocarbon biphasic separation method. Flow cytometry was performed to investigate receptors for SLPI and variations in the cell wall mannoprotein expression. Interaction between yeast and epithelium was assessed using the MA-104 cells lineage. Ultrastructure was analyzed by transmission electron microscopy (TEM). RESULTS MIC values were calculated as 18 and 18.9μM for the PRI and ATCC 24433, respectively. SSP activity was reduced by 48.8% by 18μM of SLPI and cell surface hydrophobicity increased by 11.1%. Flow cytometry suggest the existence of SLPI binding sites on the surface of the yeast. Results showed a reduction in the expression of mannoproteins in 20.8% by the cells treated with 80μM of SLPI, and 18μM reduced the adhesion of yeasts to mammalian cells in 60.1%. TEM revealed ultrastructural changes in cells treated with 80μM of SLPI, such as the presence of membrane-like structures within the cytoplasm. CONCLUSIONS SLPI exerts a significant influence on C. albicans viability and biological processes. Considering its constitutive and physiologic features, SLPI may become a promising tool for the development of new methodologies for the treatment and control of candidiasis.

Validation study of a scale of life quality evaluation in a group of pediatric patients infected by HIV

With the advent of potent antiretroviral therapy and the increase in life expectancy of pediatric patients infected with HIV, the quest for the promotion of enhanced quality of life should currently be the main focus in care of children with HIV/Aids. The scope of this study was to validate the Scale of Childrens Quality of Life in a group of children infected with HIV receiving clinical care in Aids Service Units in Rio de Janeiro, Brazil. This scale consists of 26 questions and was tested on 100 children, with ages varying between 4 and 12, and their respective parents or guardians. Statistical analysis was conducted using canonical correlation and confidence interval analysis and the X² test. The results showed that the cut-off point obtained was 49; the internal consistency with Cronbachs alpha was 0.73 for the children and 0.67 for parents or guardians. The response profile revealed marked satisfaction with aspects such as vacations and birthdays, though less satisfaction with items including hospitalization and playing alone. The conclusion was that the scale revealed satisfactory psychometric measurements, proving to be a reliable, consistent, valid and recommended instrument for measuring the quality of life of children infected with HIV.

Genital and oral human papillomavirus infection in a patient from the group of women who have sex with women

A 21-year-old self-declared lesbian patient of Africandescent was referred to a sexually transmitted disease (STD)center at the Federal Fluminense University (UFF) from aprivate clinic with a case of genital warts of 1 year’sduration. The patient, who denied tobacco use but admittedsocial alcohol use, had been in a stable homosexualrelationship for the previous 16 months, and routinelyperforms unprotected oral sex on her partner. She had beenpreviously treated with trichloroacetic acid (TCA) 90%throughout the year with no signs of improvement. Shepresented with multiple, large, and hardened genital warts(Fig. 1) and a single, small lesion on her lower lip (Fig. 2).The lower lip lesion was first noticed by the patientapproximately 30 days before her consultation. She hadbeen treated with TCA 90% applied to the genital area for 4weeks, without any noticeable clinical improvement; abiopsy was then carried out on both the genital area andthe lips. Twenty-one days after the procedure, the genitallesions disappeared completely. Laboratory examinationswere ordered (anti-HIV and Venereal Disease ResearchLaboratory), both of which tested negative; an examinationof the larynx was also normal. The patient’s partner wasalso tested. Her hymen was found to be intact and noalterations were found in the colposcopy examination.Both women denied past history of STDs and hetero-sexual intercourse; although they did declare previousrelationships with digital–vaginal and digital–anal prac-tices, as well as vulvar and oral-to-oral contact. Biopsyresults for lesions of the lips and vulva revealed condylo-mata acuminata (Figs 3 and 4). Polymerase chain reaction(PCR) tests for human papillomavirus (HPV) were per-formed on both lesions but the viral subtype was notdefined. Specific orientations were offered to these womenwho are now symptom-free, and follow-up was undertakenby the STD center.