Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties. Objective: This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply). Material and Methods: Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37 degrees C for 48 h. The drug powder concentrations (nystatin 500,000U - G2; nystatin 1,000,000U - G3; miconazole 125 mg - G4; miconazole 250 mg - G5; ketoconazole 100 mg - G6; ketoconazole 200 mg - G7; chlorhexidine diacetate 5% - G8; and 10% chlorhexidine diacetate - G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers' instructions and stored in distilled water at 37 degrees C for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (alpha=0.05) and the failure modes were visually classified. Results: No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups. Conclusions: Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents.

Atividade antifúngica de óleos essenciais frente a amostras clínicas de Candida albicans isoladas de pacientes HIV positivos

Objetivou-se avaliar a atividade antifúngica dos óleos essenciais de Ocimum basilicum L. (manjericão), Cymbopogon martinii L. (palmarosa), Thymus vulgaris L. (tomilho) e Cinnamomum cassia Blume (canela da china) sobre cepas de Candida albicans isoladas de pacientes HIV positivos e cepa padrão (ATCC 76845). Quinze amostras clínicas de C. albicans (C1-C15) foram repicadas em ágar Sabouraud Dextrose, para confecção de suspensões em solução salina estéril (0,9%) contendo 1,5 x 10(6) UFC mL-1. As emulsões dos óleos essenciais foram preparadas em água destilada estéril e tween 80, com concentrações variando entre 1024 µg mL-1 e 4 µg mL-1. A ação antifúngica foi determinada por meio da Concentração Inibitória Mínima (CIM) utilizando-se a técnica da microdiluição. Foram utilizados como controles positivos a nistatina e o miconazol (50 µg mL-1). Os testes foram realizados em triplicata, sendo a CIM, a menor concentração capaz de inibir o crescimento das leveduras, observada por método visual de acordo com a turvação do meio de cultura. Para C. albicans (ATCC 76845), a CIM do óleo essencial de C. cassia foi 64 µg mL-1, enquanto para óleo de C. martinii foi 1024 µg mL-1. Para as cepas clínicas, verificou-se que a CIM de C. cassia para 80% das cepas foi 64 µg mL-1, sendo a variação dos valores da CIM entre 128 µg mL-1 e 64 µg mL-1. Observou-se que para 66,6% das amostras clínicas, a CIM de C. martinii foi 612 µg mL-1. Constatou-se que a nistatina não apresentou atividade frente às cepas clínicas (C1-C15), enquanto a atividade antifúngica do miconazol foi verificada em 100% das amostras. Não se constatou atividade antimicrobiana dos óleos essenciais de O. basilicum e T. vulgaris, nas concentrações avaliadas. Concluiu-se que os óleos essenciais de C. cassia e C. martinii, em diferentes concentrações, apresentam atividade antifúngica sobre cepas de C. albicans isoladas de pacientes HIV positivos e cepa padrão (ATCC 76845). Entretanto não foi observada inibição antimicrobiana para os óleos de O. basilicum e T. vulgaris.

In vitro antifungal susceptibility of Candida spp. oral isolates from HIV-positive patients and control individuals

Oropharyngeal candidiasis is the most common fungal infection among HIV-positive patients. This condition can be treated with either systemic or topical antifungal agents; treatments are usually indicated empirically on the basis of clinical data. The knowledge of in vitro antifungal susceptibility is important to determine correct therapeutic guides for the treatment of fungal infections. Therefore, the objective of this study was to determine the antifungal susceptibility profile of oral Candida isolates from HIV-positive patients and control individuals. Amphotericin B, fluconazole, flucytosine, nystatin and ketoconazole were tested according to the methodology of microdilution proposed by the Clinical and Laboratory Standards Institute (CLSI); results were recorded in values of minimal inhibitory concentration (MIC). A total of 71 Candida isolates from HIV-positive patients were examined with the following species represented: C. albicans (59), C. tropicalis (9), C. glabrata (1), C. guilliermondii (1) and C. krusei (1). A total of 15 Candida isolates were evaluated from control individuals comprised of 11 C. albicans and 4 C. tropicalis samples. Our results demonstrated that the tested antifungal agents showed good activity for most isolates from both groups; however, variability in MIC values among isolates was observed.

Sensitivity of ant (Cephalotes) colonies and individuals to antibiotics implies feeding symbiosis with gut microorganisms

Ants in the tribe Cephalotini are exceptional in that they maintain microorganisms in their digestive tract. To understand what these microorganisms mean to the ants, we observed the feeding habits of Cephalotes pusillus and Cephalotes atratus, finding that in nature they feed on extrafloral nectars, homopteran secretions, and bird droppings. Feeding the antibiotic kanamycin to colonies of C. pusillus in the laboratory kills them. Ants desiccate or starve rather than feed on liquids to which the antibiotics gentamycin and netilmycin have been added, but feed and survive on liquids containing nystatin, penicillin, and ampicillin. We identified over 10 microorganisms from the intestine of C. pusillus with different antibiotic-resistance patterns. The bacteria are from the genera Corynebacterium, Brevibacterium, Sphingobacterium, Ochrobactrum, Myroides, Brevundimonas, Alcaligenes, Stenotrophomonas, Moraxella, and Pseudomonas. We hypothesize that the microorganisms provide nutrients to the ants by synthesizing amino acids from carbohydrates and nitrates. We do not know whether the ants collect the bacteria from the environment, but they transmit them to their young. They culture them in their digestive tract, eventually feeding on them.

Aromatic compounds produced by Periconia atropurpurea, an endophytic fungus associated with Xylopia aromatica

6,8-Dimethoxy-3-(2'-oxo-propyl)-coumarin (1) and 2,4-dihydroxy-6-[(1'E,3'E)-penta-1', 3'-dienyl]-benzaldehyde (2), in addition to the known compound periconicin B (3), were isolated from the ethyl acetate extract of Periconia atropurpurea, an endophytic fungus obtained from the leaves of Xylopia aromatica, a native plant of the Brazilian Cerrado. Their chemical structures were assigned based on analyses of MS, 1D and 2D-NMR spectroscopic experiments. Biological analyses were performed using two mammalian cell lines, human cervix carcinoma (HeLa) and Chinese hamster ovary (CHO). The results showed that compound I had no effect when compared to the control group, which was treated with the vehicle (DMSO). Compound 2 was able to induce a slight increase in cell proliferation of HeLa (37% of increase) and CHO (38% of increase) cell lines. Analysis of compound 3 showed that it has potent cytotoxic activity against both cell lines, with an IC50 of 8.0 mu M. Biological analyses using the phytopathogenic fungi Cladosporium sphaerospermum and C. cladosporioides revealed that also 2 showed potent antifungal activity compared to nystatin. (c) 2006 Elsevier Ltd. All rights reserved.

Antifungal constituents from roots of Virola surinamensis

Chromatographic fractionation of the dichloromethane extract from roots of Virola surinamensis yielded two new natural products, 3-epi-juruenolide C and 2'-hydroxy-7,4'-dimethoxyisoflavone, as well as various known steroids, lignans, isoflavones, flavonoids and diarylpropanes. of these, alpha,2'-dihydroxy-4,3'-dimethoxydihydrochal biochanin A and 2'-hydroxy-7,4'-dimethoxyisoflavone displayed antifungal activity against Cladosporium cladosporioides at a minimum amount of 5 mu g, whereas 7-hydroxyflavanone and 7-hydroxy-4'-methoxyisoflavone exhibited an antifungal activity 10-fold higher than the positive control Nystatin. (C) 1999 Elsevier B.V. Ltd. All rights reserved.

EFFECT OF A PERSISTENT INFLAMMATORY PROCESS ON EXPERIMENTAL HETEROTOPIC OSSIFICATION - THE INFLUENCE OF MACROPHAGES

1. We investigated the effect of a persistent carrageenin- or nystatin-induced inflammatory reaction on heterotopic ossification produced by the subcutaneous implant of a demineralized bone matrix in female Swiss mice (25 to 35 g).2. Subcutaneous carrageenin injection (0.3 ml of a 2% solution in saline) into mice induced an inflammatory reaction characterized by a mature granuloma predominantly of macrophages containing particles of the irritant in their cytoplasm and which remained unchanged until the end of the experiment (40th day).3. Subcutaneous nystatin inoculation (30,000 IU in 0.3 ml saline) induced an inflammatory reaction consisting initially of macrophages (4th day) but later turning into an epithelioid granuloma (7th day) consisting predominantly of epithelioid cells and which was present up to the 2 lst day when it was gradually replaced by adipocytes up to the 30th day.4. An intramuscular implant of demineralized bone matrix (DBM, approximately 10 mg) induced the formation of cartilage and bone tissue and of hemopoietic bone marrow (heterotopic ossification) in 100% of the control animals (N = 5). An intramuscular DBM implant in animals that received carrageenin (N = 19) or nystatin (N = 21) induced heterotopic ossification in 100 and 57% (P<0.01)) of the animals, respectively.5. The response to a dorsal subcutaneous DBM implant was essentially negative in control animals (N = 5), whereas implants performed near the site injected with carrageenin (N = 28) or nystatin (N = 31) produced a response in 71 (P <0.01) and 36 % (P<0.01) of the animals, respectively. A DBM implant into the contralateral (control) dorsal subcutaneous tissue of the same animals that received carrageenin (N = 25) or nystatin (N = 29) resulted in heterotopic ossification in 64 (P<0.01) and 7% of the animals, respectively.6. The results suggest that the macrophages present in the mature granuloma induced by carrageenin somehow favored the development of metaplastic plates after subcutaneous DBM implant and that this effect may be systemic since the same response was observed in contralateral subcutaneous tissue.

Isolamento e caracterização de candida albicans e outras leveduras de águas de recreação não marinha e de materiais clínicos

Candida albicans and other yeasts from recreational water or clinical materials were isolated. Sixty-six water samples, originating from eight swimming pools and five lakes with beaches were examined for the presence of these yeasts, by a membrane filter method and 'pour plate' technique. Sixty-two clinical materials from suspected cases of candidiasis were studied in the same period. Rhodotorula sp and C. albicans were more frequently isolated from lakes and swimming pools, respectively; C. albicans and C. parapsilosis from clinical materials. From 44 samples of C. albicans, 90,9% were serotype A, and 9,1%, serotype B; C. albicans from recreational waters belong only serotype A. No difference was observed in the M.I.C. of C. albicans strains from waters and clinical materials. All strains were susceptible to the antifungal drugs tested.

Triterpenes and saponins from Rudgea viburnioides

A novel triterpene; viburgenin (1), has been isolated from an extract of the ripe fruit rinds of Rudgea viburnioides, together with the known saponins, arjunglucoside I and trachelosperosides B-1 and E-l, and the triterpenes trachelosperogenin B (2) and arjungenin. Compound 2 was previously obtained as a product from enzymatic hydrolysis, and it is reported for the first time as a natural product. The structure of compound 1 was determined as 2α,3β,19α,23,24-pentahydroxyurs-12-ene by extensive use of 1D and 2D NMR spectroscopic methods. Compound 1 exhibited moderate antifungal activity against Cladosporium cladosporioides.

Acesso a medicamentos essenciais em farmácias e drogarias do Município de Araraquara

A survey to determine the availability of 20 essential medicines for the diseases with highest prevalence in primary health care was conducted in the city of Araraquara. The presence and the price of these medicines in private sector pharmacies and drugstores of the city were recorded. Two forms, recommended by the WHO, were used in the survey, one for availability and the other for prices. The drugs most commonly available in pharmacies and drugstores were: propranolol (90.5%), captopril (96%) and ranitidine (96%), while the least available were ferrous sulfate (27%), beclomethasone (33.8%) and ibuprofen (41.9%). The drugs that showed the greatest variation among the prices charged were: propranolol (97.1%), hydrochlorothiazide (96.4%) and glibenclamide (95.0%), while the least variable were salbutamol (30.8%) and trimethoprim-sulfamethoxazole (30.2%). Generic drugs, which were half (10) of those assessed, had the lowest prices. The indicators of access, referring to the ability of patients to acquire drugs for the treatment of major diseases at the primary health care level, showed that no establishment stocked all 20 essential drugs and that wide variations existed in their prices, undermining their availability to drug users, whose only sources are pharmacies and drugstores. These data demonstrate the importance of the popular pharmacy to improve the access to medicines, by lowering the cost and increasing the availability of the items selected for the National List of Essential Drugs (RENAME).

Avaliação clínica e microbiológica do tratamento da estomatite protética com tintura de Schinus terebinthifolius Raddi (Aroeira)

Objective: To evaluate the clinical efficacy of Schinus terebinthifolius Raddi (aroeira) tincture in the treatment of denture stomatitis. Method: Eighteen removable denture wearers with clinical diagnosis of type II denture stomatts and presence of candidosis associated to the denture use, as confirmed by clinical and mycological examinations, were selected for the study. The patients were allocated to two groups: TG (test group) - treatment with Schinus terebinthifolius Raddi (aroeira) tincture; CG (control group), treatment with nystatin. All patients were instructed to clean the dentures with toothbrush and dentifrice, and then apply the product on the palatal mucosa and on denture surface 3 times a day, during 15 consecutive days, removing the denture at bedtime and keeping it in a receptacle with water. At the 15th day of use, the clinical and mycological examinations were redone to evaluate treatment efficacy. Data were analyzed statistically by Wilcoxon and Mann-Whitney tests at 5% significance level. Results: The inflammatory process and Candida spp. infect on were eliminated in 66.7% and 77.8% of the cases, respectively, in TG. In CG, elimination of the inflammatory process and fungal infect on occurred in 77.8% and 88.9% of the cases, respectively. These results were statistically significant (p=0.01). There was no statistically significant difference between the treatments (p>0.05). In all cases, fungal infect on was detected only on the denture, and C. albicans was the most prevalent microorganism, being present in 94.4% of the cases. Conclusion: The treatment with Schinus terebinthifolius Raddi (aroeira) tincture was effective in the treatment of denture stomatitis, promoting remission of the inflammatory process and Candida spp infection.

Candida species: Current epidemiology, pathogenicity, biofilm formation, natural antifungal products and new therapeutic options

The incidence of fungal infections has increased significantly, so contributing to morbidity and mortality. This is caused by an increase in antimicrobial resistance and the restricted number of antifungal drugs, which retain many side effects. Candida species are major human fungal pathogens that cause both mucosal and deep tissue infections. Recent evidence suggests that the majority of infections produced by this pathogen are associated with biofilm growth. Biofilms are biological communities with a high degree of organization, in which micro-organisms form structured, coordinated and functional communities. These biological communities are embedded in a self-created extracellular matrix. Biofilm production is also associated with a high level of antimicrobial resistance of the associated organisms. The ability of Candida species to form drugresistant biofilms is an important factor in their contribution to human disease. The study of plants as an alternative to other forms of drug discovery has attracted great attention because, according to the World Health Organization, these would be the best sources for obtaining a wide variety of drugs and could benefit a large population. Furthermore, silver nanoparticles, antibodies and photodynamic inactivation have also been used with good results. This article presents a brief review of the literature regarding the epidemiology of Candida species, as well as their pathogenicity and ability to form biofilms, the antifungal activity of natural products and other therapeutic options. © 2013 SGM.

Anti-Candida properties of urauchimycins from actinobacteria associated with Trachymyrmex ants

After decades of intensive searching for antimicrobial compounds derived from actinobacteria, the frequency of isolation of new molecules has decreased. To cope with this concern, studies have focused on the exploitation of actinobacteria from unexplored environments and actinobacteria symbionts of plants and animals. In this study, twenty-four actinobacteria strains isolated from workers of Trachymyrmex ants were evaluated for antifungal activity towards a variety of Candida species. Results revealed that seven strains inhibited the tested Candida species. Streptomyces sp. TD025 presented potent and broad spectrum of inhibition of Candida and was selected for the isolation of bioactive molecules. From liquid shake culture of this bacterium, we isolated the rare antimycin urauchimycins A and B. For the first time, these molecules were evaluated for antifungal activity against medically important Candida species. Both antimycins showed antifungal activity, especially urauchimycin B. This compound inhibited the growth of all Candida species tested, with minimum inhibitory concentration values equivalent to the antifungal nystatin. Our results concur with the predictions that the attine ant-microbe symbiosis may be a source of bioactive metabolites for biotechnology and medical applications. © 2013 Thais D. Mendes et al.

Ricinus communis treatment of denture stomatitis in institutionalised elderly

This study compared the effectiveness of Ricinus communis (RC) with Nystatin (NYS) and Miconazole (MIC) in the treatment of institutionalised elderly with denture stomatitis (DS). They (n = 30) were randomly distributed into three groups: MIC, NYS or RC. Clinical and mycological evaluations were performed prior to the use of the antifungal (baseline) and repeated after 15 and 30 days of treatment. The sample was clinically examined for oral mucosal conditions. Standard photographs were taken of the palate, and the oral candidiasis was classified (Newton's criteria). Mycological investigation was performed by swabbing the palatal mucosa, and Candida spp. were quantified by counting the number of colony-forming units (cfu mL-1). The clinical and mycological data were analysed, respectively by Wilcoxon and Student's t-test (α = 0·05). Significant improvement in the clinical appearance of DS in the MIC and RC groups was observed between the 1st and 3rd collections (MIC - P = 0·018; RC - P = 0·011) as well as between the 2nd and 3rd collections (MIC - P = 0·018; RC - P = 0·011). Neither groups showed a statistically significant reduction in cfu mL-1 at any time. Although none of the treatments decreased the cfu mL-1, it was concluded that Ricinus communis can improve the clinical condition of denture stomatitis in institutionalised elderly patients, showing similar results to Miconazole. © 2013 Blackwell Publishing Ltd.