RESUMO

BACKGROUND: The aim of this study was to evaluate the effect of active oxygen-releasing gel as an adjuvant, with and without antimicrobial photodynamic therapy (aPDT), in the treatment of residual pockets in periodontal patients with type 2 diabetes mellitus (DM2). METHODS: Patients with residual pockets with probing depth (PD) ≥4 mm and bleeding on probing (BOP) were divided into the following groups: SI (n = 17)-subgingival instrumentation in a single session; BM (n = 17)-SI followed by local application of active oxygen-releasing gel inside the periodontal pocket for 3 min; BM + aPDT (n = 17)-SI followed by application of BM for 3 min and pocket irrigation with methylene blue, and 660-nm diode laser irradiation at 100 mW for 50 s. The periodontal clinical parameters, serum levels of glycated hemoglobin, and immunological analysis of crevicular fluid were evaluated. All data were submitted to statistical analysis (α = 5%). RESULTS: A significant reduction in BOP was verified at 90 and 180 days in the BM + aPDT group. The percentage of sites with PD ≥ 4 mm was significantly reduced at 90 days in BM + aPDT and BM, whereas after 180 days only BM showed a significant reduction. In the BM + aPDT group, there was a significant reduction in tumor necrosis factor α levels at 90 days. There were no differences between the treatments. CONCLUSION: The use of adjuvant active oxygen-releasing gel, with or without aPDT, resulted in the same clinical benefits as SI in the treatment of residual pockets in poorly controlled DM2 patients.

Assuntos

Diabetes Mellitus Tipo 2 , Géis , Líquido do Sulco Gengival , Hemoglobinas Glicadas , Lasers Semicondutores , Azul de Metileno , Índice Periodontal , Bolsa Periodontal , Fotoquimioterapia , Fármacos Fotossensibilizantes , Humanos , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Fotoquimioterapia/métodos , Bolsa Periodontal/tratamento farmacológico , Bolsa Periodontal/terapia , Masculino , Feminino , Pessoa de Meia-Idade , Líquido do Sulco Gengival/química , Azul de Metileno/uso terapêutico , Hemoglobinas Glicadas/análise , Lasers Semicondutores/uso terapêutico , Fármacos Fotossensibilizantes/uso terapêutico , Fator de Necrose Tumoral alfa , Idoso , Seguimentos , Terapia Combinada , Adulto , Raspagem Dentária/métodos , Resultado do Tratamento

RESUMO

Assessing the in vitro toxicity of compounds on cell cultures is an important step during the screening of candidate molecules for diverse applications. Among the strategies employed to determine cytotoxicity, MTT, neutral red, and resazurin are commonly used. Methylene blue (MB), a phenothiazinium salt, has several uses, such as dye, redox indicator, and even as treatment for human disease and health conditions, such as malaria and methemoglobinemia. However, MB has only been sparsely used as a cellular toxicity indicator. As a viability indicator, MB is mostly applied to fixed cultures at high concentrations, especially when compared to MTT or neutral red. Here we show that MB and its related compounds new methylene blue (NMB), toluidine blue O (TBO), and dimethylmethylene blue (DMMB) can be used as cytotoxicity indicators in live (non-fixed) cells treated for 72 h with DMSO and cisplatin. We compared dye uptake between phenothiazinium dyes and neutral red by analyzing supernatant and cell content via visible spectra scanning and microscopy. All dyes showed a similar ability to assess cell toxicity compared to either MTT or neutral red. Our method represents a cost-effective alternative to in vitro cytotoxicity assays using cisplatin or DMSO, indicating the potential of phenothiazinium dyes for the screening of candidate drugs and other applications.

Assuntos

Corantes , Fenotiazinas , Humanos , Fenotiazinas/farmacologia , Cisplatino/farmacologia , Vermelho Neutro , Dimetil Sulfóxido , Azul de Metileno

RESUMO

The unbridled dissemination of multidrug-resistant pathogens is a major threat to global health and urgently demands novel therapeutic alternatives. Antimicrobial photodynamic therapy (aPDT) has been developed as a promising approach to treat localized infections regardless of drug resistance profile or taxonomy. Even though this technique has been known for more than a century, discussions and speculations regarding the biochemical mechanisms of microbial inactivation have never reached a consensus on what is the primary cause of cell death. Since photochemically generated oxidants promote ubiquitous reactions with various biomolecules, researchers simply assumed that all cellular structures are equally damaged. In this study, biochemical, molecular, biological and advanced microscopy techniques were employed to investigate whether protein, membrane or DNA damage correlates better with dose-dependent microbial inactivation kinetics. We showed that although mild membrane permeabilization and late DNA damage occur, no correlation with inactivation kinetics was found. On the other hand, protein degradation was analyzed by three different methods and showed a dose-dependent trend that matches microbial inactivation kinetics. Our results provide a deeper mechanistic understanding of aPDT that can guide the scientific community toward the development of optimized photosensitizing drugs and also rationally propose synergistic combinations with antimicrobial chemotherapy.

Assuntos

Anti-Infecciosos , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Fármacos Fotossensibilizantes/química , Fotoquimioterapia/métodos , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Viabilidade Microbiana , Antibacterianos/química

RESUMO

BACKGROUND: Antimicrobial photodymanic therapy mediated by methylene blue has been investigated as an adjunctive to periodontal treatment but the dimerization of photosensitizer molecules reduces the phototoxic effects. Sodium dodecyl sulfate is a surfactant that may control this aggregation. The aim of this study was evaluated the photodynamic effect of methylene blue in sodium dodecyl sulfate in periodontitis. METHODS: 36 participants with periodontitis were selected and allocated randomly in two group for intervention and other two for control - all of them were treated with scaling and root planing before aPDT. Three periodontal evaluations were done: at the selection time, at the day of intervention and thirty-day after this. Pre-irradiation time was 1 min and 2 min for irradiation. Laser (Therapy XT, DMC, São Carlos, Brazil) with wavelength of 660 nm and 100 mW of power was used. Two photosensitizer solutions with 100 µM methylene blue was used, one of them was in water and other in 0,25% of sodium dodecyl sulfate. Two sites of each participant were selected for the experimental procedures. Microbiological evaluations were performed to quantify microorganisms before and immediately after intervention. Quantitative microbiological evaluation was the primary outcome; morphological aspects of bacterial colony, and clinical probing depth was the secondary one. RESULTS: There was no significant difference between the groups in both bacterial reduction and the clinical parameter evaluated. CONCLUSION: The effect of methylene blue in surfactant did not cause enough phototoxic effects that could promote reduction of periodontal pocket depth.

Assuntos

Anti-Infecciosos , Periodontite Crônica , Periodontite , Fotoquimioterapia , Humanos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Tensoativos , Terapia Combinada , Dodecilsulfato de Sódio/uso terapêutico , Periodontite/tratamento farmacológico , Anti-Infecciosos/uso terapêutico , Adjuvantes Imunológicos/uso terapêutico , Raspagem Dentária , Aplainamento Radicular/métodos , Periodontite Crônica/tratamento farmacológico

RESUMO

The fast-emerging and multidrug-resistant Candida auris is the first fungal pathogen to be considered a threat to global public health. Thus, there is a high unmet medical need to develop new therapeutic strategies to control this species. Antimicrobial photodynamic therapy (APDT) is a promising alternative that simultaneously targets and damages numerous microbial biomolecules. Here, we investigated the in vitro and in vivo effects of APDT with four phenothiazinium photosensitizers: (i) methylene blue (MB), (ii) toluidine blue (TBO), and two MB derivatives, (iii) new methylene blue (NMBN) and (iv) the pentacyclic derivative S137, against C. auris. To measure the in vitro efficacy of each PS, minimal inhibitory concentrations (MICs) and survival fraction were determined. Also, the efficiency of APDT was evaluated in vivo with the Galleria mellonella insect model for infection and treatment. Although the C. auris strain used in our study was shown to be resistant to the most-commonly used clinical antifungals, it could not withstand the damages imposed by APDT with any of the four photosensitizers. However, for the in vivo model, only APDT performed with S137 allowed survival of infected G. mellonella larvae. Our results show that structural and chemical properties of the photosensitizers play a major role on the outcomes of in vivo APDT and underscore the need to synthesize and develop novel photosensitizing molecules against multidrug-resistant microorganisms.

Assuntos

Anti-Infecciosos , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Azul de Metileno/farmacologia , Candida auris , Antifúngicos/farmacologia , Cloreto de Tolônio , Fotoquimioterapia/métodos , Anti-Infecciosos/farmacologia

RESUMO

BACKGROUND: Our objective was to characterize the frequency, early impact, and risk factors for neurological manifestations in hospitalized children with acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or multisystem inflammatory syndrome in children (MIS-C). METHODS: Multicenter, cross-sectional study of neurological manifestations in children aged <18 years hospitalized with positive SARS-CoV-2 test or clinical diagnosis of a SARS-CoV-2-related condition between January 2020 and April 2021. Multivariable logistic regression to identify risk factors for neurological manifestations was performed. RESULTS: Of 1493 children, 1278 (86%) were diagnosed with acute SARS-CoV-2 and 215 (14%) with MIS-C. Overall, 44% of the cohort (40% acute SARS-CoV-2 and 66% MIS-C) had at least one neurological manifestation. The most common neurological findings in children with acute SARS-CoV-2 and MIS-C diagnosis were headache (16% and 47%) and acute encephalopathy (15% and 22%), both P < 0.05. Children with neurological manifestations were more likely to require intensive care unit (ICU) care (51% vs 22%), P < 0.001. In multivariable logistic regression, children with neurological manifestations were older (odds ratio [OR] 1.1 and 95% confidence interval [CI] 1.07 to 1.13) and more likely to have MIS-C versus acute SARS-CoV-2 (OR 2.16, 95% CI 1.45 to 3.24), pre-existing neurological and metabolic conditions (OR 3.48, 95% CI 2.37 to 5.15; and OR 1.65, 95% CI 1.04 to 2.66, respectively), and pharyngeal (OR 1.74, 95% CI 1.16 to 2.64) or abdominal pain (OR 1.43, 95% CI 1.03 to 2.00); all P < 0.05. CONCLUSIONS: In this multicenter study, 44% of children hospitalized with SARS-CoV-2-related conditions experienced neurological manifestations, which were associated with ICU admission and pre-existing neurological condition. Posthospital assessment for, and support of, functional impairment and neuroprotective strategies are vitally needed.

Assuntos

COVID-19/complicações , Doenças do Sistema Nervoso/epidemiologia , SARS-CoV-2 , Síndrome de Resposta Inflamatória Sistêmica/epidemiologia , Doença Aguda , Adolescente , Encefalopatias/epidemiologia , Encefalopatias/etiologia , COVID-19/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Cefaleia/epidemiologia , Cefaleia/etiologia , Humanos , Lactente , Unidades de Terapia Intensiva Pediátrica/estatística & dados numéricos , Modelos Logísticos , Masculino , Doenças do Sistema Nervoso/etiologia , Prevalência , Fatores de Risco , América do Sul/epidemiologia , Estados Unidos/epidemiologia

RESUMO

The widespread use of conventional chemical antifungal agents has led to worldwide concern regarding the selection of resistant isolates. In this scenario, antimicrobial photodynamic treatment (APDT) has emerged as a promising alternative to overcome this issue. The technique is based on the use of a photosensitizer (PS) and light in the presence of molecular oxygen. Under these conditions, the PS generates reactive oxygen species which damage the biomolecules of the target organism leading to cell death. The great potential of APDT against plant-pathogenic fungi has already been reported both in vitro and in planta, indicating this control measure has the potential to be widely used in crop plants. However, there is a lack of studies on environmental risk with ecotoxicological assessment of PSs used in APDT. Therefore, this study aimed to evaluate the environmental toxicity of four phenothiazinium PSs: i) methylene blue (MB), ii) new methylene blue N (NMBN), iii) toluidine blue O (TBO), and iv) dimethylmethylene blue (DMMB) and also of the commercial antifungal NATIVO®, a mixture of trifloxystrobin and tebuconazole. The experiments were performed with Daphnia similis neonates and zebrafish embryos. Our results showed that the PSs tested had different levels of toxicity, with MB being the less toxic and DMMB being the most. Nonetheless, the environmental toxicity of these PSs were lower when compared to that of NATIVO®. Furthermore, estimates of bioconcentration and of biotransformation half-life indicated that the PSs are environmentally safer than NATIVO®. Taken together, our results show that the toxicity associated with phenothiazinium PSs would not constitute an impediment to their use in APDT. Therefore, APDT is a promising approach to control plant-pathogenic fungi with reduced risk for selecting resistant isolates and lower environmental impacts when compared to commonly used antifungal agents.

Assuntos

Triazóis

RESUMO

There are several studies that evaluate the use of lasers in periodontal treatment in non-surgical or surgical therapy. However, while several studies showed clinically beneficial effects of some lasers in periodontal treatment, there are few clinical reports of additional advantages of lasers as adjunctive treatments in periodontology. The aim of this paper is to demonstrate and critically analyze the level of scientific evidence of effects of low-level lasers and high-power lasers in periodontology. A narrative review of the studies was carried out in each topic and type of laser or periodontal treatment. In nonsurgical periodontal therapy the results showed that there is an additional clinical benefit when using a diode laser (DL) associated with scaling and root planing (SRP) in patients with moderate to severe periodontitis. The Er:YAG laser seems to be the most suitable for nonsurgical periodontal therapy and promotes the same clinical effects as conventional therapy. In periodontal surgery vaporization of the gingival or mucosal tissue can be carried out with DL, CO2, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers. Photobiomodulation (PBM), mediated by low-level lasers associated with non-surgical periodontal therapy, promotes additional benefits in the short term and accelerates the bone and gingival tissue repair process and also reduces postoperative symptoms of periodontal surgery. The effect of antimicrobial Photodynamic Therapy is relevant in the initial reevaluation periods. Studies have shown controversial results of the use of lasers in periodontics, and this fact may be due to the lack of standard parameters of irradiation in each clinical application.

Assuntos

Periodontite Crônica , Terapia a Laser , Lasers de Estado Sólido , Periodontite , Raspagem Dentária , Humanos , Lasers Semicondutores/uso terapêutico , Lasers de Estado Sólido/uso terapêutico , Aplainamento Radicular

RESUMO

BACKGROUND: Halitosis is a term that defines any foul odor emanating from the oral cavity. The origin may be local or systemic. The aim of the proposed protocol is to determine whether treatment with antimicrobial photodynamic therapy (aPDT) and treatment with probiotics are effective at eliminating halitosis. MATERIALS AND METHODS: Eighty-eight patients, from 18 to 25 years old with a diagnosis of halitosis (H2S≥112 ppb, determined by gas chromatography) will be randomly allocated to four groups (n = 22) that will receive different treatments: Group 1 -treatment with teeth brushing, dental floss and tongue scraper; Group 2 -brushing, dental floss and aPDT; Group 3 -brushing, dental floss and probiotics; Group 4 -brushing, flossing, aPDT and probiotics. The results of the halimetry will be compared before, immediately after, seven days and thirty days after treatment. The microbiological analysis of the coated tongue will be performed at these same times. The normality of the data will be determined using the Shapiro-Wilk test. Data with normal distribution will be analyzed using analysis of variance (ANOVA). Non-parametric data will be analyzed using the Kruskal-Wallis test. The Wilcoxon test will be used to analyze the results of each treatment at the different evaluation periods. CLINICAL TRAIL REGISTRATION: NCT03996044.

Assuntos

Fotoquimioterapia/métodos , Probióticos/uso terapêutico , Adulto , Análise de Variância , Halitose/terapia , Humanos , Fármacos Fotossensibilizantes/uso terapêutico

RESUMO

Abstract There are several studies that evaluate the use of lasers in periodontal treatment in non-surgical or surgical therapy. However, while several studies showed clinically beneficial effects of some lasers in periodontal treatment, there are few clinical reports of additional advantages of lasers as adjunctive treatments in periodontology. The aim of this paper is to demonstrate and critically analyze the level of scientific evidence of effects of low-level lasers and high-power lasers in periodontology. A narrative review of the studies was carried out in each topic and type of laser or periodontal treatment. In nonsurgical periodontal therapy the results showed that there is an additional clinical benefit when using a diode laser (DL) associated with scaling and root planing (SRP) in patients with moderate to severe periodontitis. The Er:YAG laser seems to be the most suitable for nonsurgical periodontal therapy and promotes the same clinical effects as conventional therapy. In periodontal surgery vaporization of the gingival or mucosal tissue can be carried out with DL, CO2, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers. Photobiomodulation (PBM), mediated by low-level lasers associated with non-surgical periodontal therapy, promotes additional benefits in the short term and accelerates the bone and gingival tissue repair process and also reduces postoperative symptoms of periodontal surgery. The effect of antimicrobial Photodynamic Therapy is relevant in the initial reevaluation periods. Studies have shown controversial results of the use of lasers in periodontics, and this fact may be due to the lack of standard parameters of irradiation in each clinical application.

RESUMO

Antimicrobial photodynamic treatment (APDT) has emerged as an effective therapy against pathogenic fungi with both acquired and intrinsic resistance to commonly used antifungal agents. Success of APDT depends on the availability of effective photosensitizers capable of acting on different fungal structures and species. Among the phenothiazinium dyes tested as photoantifungals, new methylene blue N (NMBN) and the novel pentacyclic compound S137 are the most efficient. In the present study we compared the effects of APDT with NMBN and S137 on the survival of Candida albicans and employed a set of fluorescent probes (propidium iodide, FUN-1, JC-1, DHR-123 and DHE) together with confocal microscopy and flow cytometry to evaluate the effects of these two chemically diverse photosensitizers on cell membrane permeability, metabolism and redox status, and mitochondrial activity. Taken together, our results indicate that, due to chemical features resulting in different lipophilicity, NMBN and S137 localize to distinct subcellular structures and hence inactivate C. albicans cells via different mechanisms. S137 localizes mostly to the cell membrane and, upon light exposure, photo-oxidizes membrane lipids. NMBN readily localizes to mitochondria and exerts its photodynamic effects there, which was observed to be a less effective way to achieve cell death at lower light fluences.

Assuntos

Anti-Infecciosos/química , Candida albicans/metabolismo , Azul de Metileno/química , Fármacos Fotossensibilizantes/química , Frações Subcelulares/metabolismo , Anti-Infecciosos/metabolismo , Corantes Fluorescentes/química , Azul de Metileno/metabolismo , Fármacos Fotossensibilizantes/metabolismo

RESUMO

BACKGROUND: Periodontal disease (PD) is a chronic inflammatory disease caused by the presence of microbial biofilm. The aim of this study was to evaluate antimicrobial effect of antimicrobial photodynamic therapy (A-PDT) mediated by methylene blue (MB) in monomer form on A. actinomycetemcomitans and P. gingivalis. METHODS: A. actinomycetemcomitans ATCC 29523 and P. gingivalis ATCC 33577 were cultured on anaerobic jars at 37 °C for 48 h, and we tested APDT in the presence of 0.25% sodium dodecyl sulfate (SDS) in phosphate-buffered saline (PBS) or in PBS alone. APDT was carried out with 100 µM MB under laser radiation (PhotolaseIII, DMC, Brazil) at ʎ =660 nm and parameters as following (P =100 mW; I =250 mW/cm2, and doses of 15, 45 and 75 J/cm2). RESULTS: Following A-PDT, PBS groups of A. actinomycetemcomitans presented 4 Logs of microbial death after 5 min irradiation. However, there was no bacterial reduction in SDS groups. On the other hand, P. gingivalis was sensitive to APDT in the presence of 0.25% SDS with 2 logs reduction from dark toxicity. CONCLUSION: The presence of 0.25% SDS can lead to different responses depending on the different microbial species.

Assuntos

Anti-Infecciosos , Fotoquimioterapia , Anti-Infecciosos/farmacologia , Brasil , Azul de Metileno/farmacologia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Tensoativos/farmacologia

RESUMO

Neospora caninum is an Apicomplexan parasite related to important losses in livestock, causing abortions and decreased fertility in affected cows. Several chemotherapeutic strategies have been developed for disease control; however, no commercial treatment is available. Among the candidate drugs against neosporosis, phenothiazinium dyes, offer a low cost-efficient approach to parasite control. We report the anti-parasitic effects of the phenothiaziums Methylene Blue (MB), New Methylene Blue (NMB), 1,9-Dimethyl Methylene Blue (DMMB) and Toluidine Blue O (TBO) on N. caninum, using in vitro and in vivo models. The dyes inhibited parasite proliferation at nanomolar concentrations (0.019-1.83 µM) and a synergistic effect was achieved when Methylene Blue was combined with New Methylene Blue (Combination Index = 0.84). Moreover, the phenothiazinium dyes improved parasite clearance when combined with Pyrimethamine (Pyr). Combination of Methylene Blue + 1,9-Dimethyl Methylene Blue demonstrated superior efficacy compared to Pyrimethamine based counterparts in an in vivo model of infection. We also observed that Methylene Blue, New Methylene Blue and 1,9-Dimethyl Methylene Blue increased by 5000% the reactive oxygen species (ROS) levels in N. caninum tachyzoites. Phenothiazinium dyes represent an accessible group of candidates with the potential to compound future formulations for neosporosis control.

Assuntos

Coccidiose , Azul de Metileno/análogos & derivados , Neospora/crescimento & desenvolvimento , Animais , Chlorocebus aethiops , Coccidiose/tratamento farmacológico , Coccidiose/metabolismo , Masculino , Azul de Metileno/farmacologia , Camundongos , Células Vero

RESUMO

The in vitro susceptibilities of Candida albicans and Candida tropicalis to Antimicrobial Photodynamic Treatment with aluminum phthalocyanine chloride in nanoemulsion (ClAlPc/NE) were investigated. PS concentration- and fluence-dependent cell survival after APDT were compared before and after unbound extracellular PS had been washed out. The PS uptake and its subcellular localization were also determined. Exposure to light in the absence of the PS and treatment with the PS in the absence of light did not kill the fungi. APDT with ClAlPc/NE resulted in a reduction of five orders of magnitude in viability for C. albicans and between four and five orders of magnitude for C. tropicalis. Washing the cells to remove unbound PS before light exposure did not impair fungal inactivation, suggesting that cell photosensitization was mainly carried out by cell bound ClAlPc. The degree of ClAlPc uptake was dependent on its concentration. Internalization of ClAlPc by C. albicans and C. tropicalis was confirmed by confocal fluorescence microscopy that showed the PS does not penetrate the nucleus and instead accumulates in specific regions of the cytoplasm. Our results show that incorporating the water-insoluble ClAlPc into a nanoemulsion leads to an efficient formulation capable of photoinactivating both Candida species.

Assuntos

Candida albicans , Candida tropicalis , Viabilidade Microbiana , Candida albicans/efeitos dos fármacos , Candida albicans/efeitos da radiação , Candida tropicalis/efeitos dos fármacos , Candida tropicalis/efeitos da radiação , Indóis/farmacologia , Compostos Organometálicos/farmacologia , Fármacos Fotossensibilizantes/farmacologia

RESUMO

Chagas disease is a tropical illness caused by the protozoan Trypanosoma cruzi. The disease affects populations of the Americas and has been spread to other continents due to the migration process. The disease is partially controlled by two drugs, Benznidazole and Nifurtimox. These molecules are active in the acute phase of the infection but are usually ineffective during the symptomatic chronic phase. Several research groups have developed novel candidates to control Chagas disease; however, no novel commercial formulation is available. In this article, we described the anti-T. cruzi effects of phenothiazinium dyes in amastigote and trypomastigote forms of the parasite. Methylene Blue, New Methylene Blue, Toluidine Blue O, and 1,9-Dimethyl Methylene Blue inhibited the parasite proliferation at nanomolar concentrations and also demonstrated low toxicity in host cells. Moreover, combinations of phenothiazinium dyes indicated a synergic pattern against amastigotes compared to the Benznidazole counterparts. Phenothiazinium dyes levels of reactive oxygen species (ROS) and decreased the mitochondrial potential in trypomastigotes, indicating the mechanism of action of the dyes in T. cruzi. Our article offers a basis for future strategies for the control of Chagas disease using low-cost formulations, an important point for endemic underdeveloped regions.

Assuntos

Proliferação de Células/efeitos dos fármacos , Doença de Chagas/tratamento farmacológico , Fenotiazinas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Linhagem Celular , Doença de Chagas/parasitologia , Corantes/farmacologia , Humanos , Azul de Metileno/análogos & derivados , Azul de Metileno/farmacologia , Nifurtimox/farmacologia , Nitroimidazóis/farmacologia , Cloreto de Tolônio/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/patogenicidade

RESUMO

BACKGROUND: Antimicrobial photodynamic therapy (aPDT) has been investigated as an adjunctive to periodontal treatment but the dosimetry parameters adopted have discrepancies and represent a challenge to measure efficacy. There is a need to understand the clinical parameters required to obtain antimicrobial effects by using aPDT in periodontal pockets. The aim of this study was to investigate parameters relating to the antimicrobial effects of photodynamic therapy in periodontal pockets. MATERIAL AND METHODS: This randomized controlled clinical trial included 30 patients with chronic periodontitis. Three incisors from each patient were selected and randomized for the experimental procedures. Microbiological evaluations were performed to quantify microorganisms before and after treatments and spectroscopy was used to identify methylene blue in the pocket. A laser source with emission of radiation at wavelength of ʎ = 660 nm and output radiant power of 100 mW was used for 1, 3 and 5 min. One hundred µM methylene blue was used in aqueous solution and on surfactant vehicle. RESULTS: The results demonstrated the absence of any antimicrobial effect with aqueous methylene blue-mediated PDT. On the other hand, methylene blue in the surfactant vehicle produced microbial reduction in the group irradiated for 5 min (p < 0.05). Spectroscopy showed that surfactant vehicle decreased the dimer peak signal at 610 nm. CONCLUSION: Within the parameters used in this study, PDT mediated by methylene blue in a surfactant vehicle reached significant microbial reduction levels with 5 min of irradiation. The clinical use of PDT may be limited by factors that reduce the antimicrobial effect. Forms of irradiation and stability of the photosensitizers play an important role in clinical aPDT.

Assuntos

Azul de Metileno/uso terapêutico , Bolsa Periodontal/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Tensoativos/química , Terapia Combinada , Composição de Medicamentos , Feminino , Humanos , Masculino , Azul de Metileno/administração & dosagem , Índice Periodontal , Fármacos Fotossensibilizantes/administração & dosagem , Fatores de Tempo

RESUMO

OBJECTIVES: To produce a treatment algorithm for the ICU management of infants, children, and adolescents with severe traumatic brain injury. DATA SOURCES: Studies included in the 2019 Guidelines for the Management of Pediatric Severe Traumatic Brain Injury (Glasgow Coma Scale score ≤ 8), consensus when evidence was insufficient to formulate a fully evidence-based approach, and selected protocols from included studies. DATA SYNTHESIS: Baseline care germane to all pediatric patients with severe traumatic brain injury along with two tiers of therapy were formulated. An approach to emergent management of the crisis scenario of cerebral herniation was also included. The first tier of therapy focuses on three therapeutic targets, namely preventing and/or treating intracranial hypertension, optimizing cerebral perfusion pressure, and optimizing partial pressure of brain tissue oxygen (when monitored). The second tier of therapy focuses on decompressive craniectomy surgery, barbiturate infusion, late application of hypothermia, induced hyperventilation, and hyperosmolar therapies. CONCLUSIONS: This article provides an algorithm of clinical practice for the bedside practitioner based on the available evidence, treatment protocols described in the articles included in the 2019 guidelines, and consensus that reflects a logical approach to mitigate intracranial hypertension, optimize cerebral perfusion, and improve outcomes in the setting of pediatric severe traumatic brain injury.

Assuntos

Lesões Encefálicas Traumáticas/terapia , Protocolos Clínicos/normas , Guias de Prática Clínica como Assunto , Adolescente , Algoritmos , Barbitúricos/administração & dosagem , Encéfalo/fisiopatologia , Lesões Encefálicas Traumáticas/complicações , Circulação Cerebrovascular/fisiologia , Criança , Pré-Escolar , Consenso , Craniectomia Descompressiva/métodos , Escala de Coma de Glasgow , Humanos , Hipotermia Induzida/métodos , Lactente , Hipertensão Intracraniana/etiologia , Hipertensão Intracraniana/terapia , Respiração Artificial/métodos

RESUMO

Fusarium keratoplasticum and Fusarium moniliforme are filamentous fungi common in the environment and cause mycosis in both animals and plants. Human infections include mycetoma, keratitis and onychomycosis, while deeper mycosis occurs in immunocompromised patients. Most of the Fusarium spp. are frequently resistant to treatment with currently used antifungals. The frequent occurrence of antifungal resistance has motivated the study of antimicrobial photodynamic therapy as an alternative treatment for fungal infections. Many studies have investigated the in vitro use of antimicrobial photodynamic therapy to kill fungi, but rarely in animal models of infection. Thus, here we employed the invertebrate wax moth Galleria mellonella to study the in vivo effects of antimicrobial photodynamic therapy with three different phenothiazinium photosensitizers, methylene blue, new methylene blue N and the pentacyclic S137 against infection with microconidia of Fusarium keratoplasticum and Fusarium moniliforme. The effect of antimicrobial photodynamic therapy using these photosensitizers and light-emitting diodes with an emission peak at 635 nm and an integrated irradiance from 570 to 670 nm of 9.8 mW cm-2 was investigated regarding the toxicity, fungal burden, larval survival and cellular immune response. The results from this model indicate that antimicrobial photodynamic therapy with methylene blue, new methylene blue N and S137 is efficient for the treatment of infection with F. keratoplasticum and F. moniliforme. The efficiency can be attributed to the fungal cell damage caused by antimicrobial photodynamic therapy which facilitates the action of the host immune response.

Assuntos

Fusarium/efeitos dos fármacos , Fenotiazinas/farmacologia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Animais , Antifúngicos/farmacologia , Dipeptídeos/farmacologia , Farmacorresistência Fúngica , Larva/efeitos dos fármacos , Lasers Semicondutores/uso terapêutico , Azul de Metileno/análogos & derivados , Azul de Metileno/farmacologia , Mariposas , Pirimidinas/farmacologia

RESUMO

Neoscytalidium spp. are ascomycetous fungi consisting of pigmented and hyaline varieties both able to cause skin and nail infection. Their color-based identification is inaccurate and may compromise the outcome of the studies with these fungi. The aim of this study was to genotype 32 isolates morphologically identified as Neoscytalidiumdimidiatum or N. dimidiatum var. hyalinum by multilocus sequence typing (MLST), differentiate the two varieties by their sequence types, evaluate their susceptibility to seven commercial antifungal drugs [amphotericin B (AMB), voriconazole (VOR), terbinafine (TER), 5-flucytosine (5FC), ketoconazole (KET), fluconazole (FLU), and caspofungin (CAS)], and also to the antimicrobial photodynamic treatment (APDT) with the phenothiazinium photosensitizers (PS) methylene blue (MB), new methylene blue (NMBN), toluidine blue O (TBO) and the pentacyclic derivative S137. The efficacy of each PS was determined, initially, based on its minimal inhibitory concentration (MIC). Additionally, the APDT effects with each PS on the survival of ungerminated and germinated arthroconidia of both varieties were evaluated. Seven loci of Neoscytalidium spp. were sequenced on MLST revealing eight polymorphic sites and six sequence types (ST). All N. dimidiatum var. hyalinum isolates were clustered in a single ST. AMB, VOR and TER were the most effective antifungal agents against both varieties. The hyaline variety isolates were much less tolerant to the azoles than the isolates of the pigmented variety. APDT with S137 showed the lowest MIC for all the isolates of both varieties. APDT with all the PS killed both ungerminated and germinated arthroconidia of both varieties reducing the survival up to 5 logs. Isolates of the hyaline variety were also less tolerant to APDT. APDT with the four PS also increased the plasma membrane permeability of arthroconidia of both varieties but only NMBN and S137 caused peroxidation of the membrane lipids.

Assuntos

Antifúngicos/farmacologia , Ascomicetos/classificação , Ascomicetos/efeitos dos fármacos , Farmacorresistência Fúngica , Fenotiazinas/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Técnicas de Tipagem Micológica , Micoses/microbiologia , Esporos Fúngicos/efeitos dos fármacos

RESUMO

Global amphibian biodiversity has declined dramatically in the past 4 decades, and many amphibian species have declined to near extinction as a result of emergence of the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd). However, persistent or recovering populations of several amphibian species have recently been rediscovered, and such populations may illustrate how amphibian species that are highly susceptible to chytridiomycosis may survive in the presence of Bd. We conducted field surveys for Bd infection in 7 species of Costa Rican amphibians (all species that have declined to near extinction but for which isolated populations persist) to characterize infection profiles in highly Bd-susceptible amphibians post-decline. We found highly variable patterns in infection, with some species showing low prevalence (~10%) and low infection intensity and others showing high infection prevalence (>80%) and either low or high infection intensity. Across sites, infection rates were negatively associated with mean annual precipitation, and infection intensity across sites was negatively associated with mean average temperatures. Our results illustrate that even the most Bd-susceptible amphibians can persist in Bd-enzootic ecosystems, and that multiple ecological or evolutionary mechanisms likely exist for host-pathogen co-existence between Bd and the most Bd-susceptible amphibian species. Continued monitoring of these populations is necessary to evaluate population trends (continuing decline, stability, or population growth). These results should inform efforts to mitigate impacts of Bd on amphibians in the field.

Assuntos

Quitridiomicetos/isolamento & purificação , Micoses/veterinária , Animais , Costa Rica , Ecossistema , Monitoramento Ambiental , Dinâmica Populacional , Chuva , Temperatura