Surface morphology and in vitro leachability of soft liners modified by the incorporation of antifungals for denture stomatitis treatment

Objective: To evaluate the surface morphology and in vitro leachability of temporary soft linings modified by the incorporation of antifungals in minimum inhibitory concentrations (MIC) for Candida albicans biofilm. Methodology: Specimens of soft lining materials Softone and Trusoft were made without (control) or with the addition of nystatin (Ny), miconazole (Mc), ketoconazole (Ke), chlorhexidine diacetate (Chx), or itraconazole (It) at their MIC for C. albicans biofilm. The surface analyses were performed using Confocal laser scanning microscopy after 24 h, 7 days, or 14 days of immersion in distilled water at 37ºC. In vitro leachability of Chx or Ny from the modified materials was also measured using Ultraviolet visible spectroscopy for up to 14 days of immersion in distilled water at 37ºC. Data (μg/mL) were submitted to ANOVA 1-factor/Bonferroni (α=0.05). Results: Softone had a more irregular surface than Trusoft. Morphological changes were noted in both materials with increasing immersion time, particularly, in those containing drugs. Groups containing Chx and It presented extremely porous and irregular surfaces. Both materials had biexponential release kinetics. Softone leached a higher concentration of the antifungals than Trusoft (p=0.004), and chlorhexidine was released at a higher concentration than nystatin (p<0.001). Conclusions: The surface of the soft lining materials changed more significantly with the addition of Chx or It. Softone released a higher concentration of drugs than Trusoft did, guiding the future treatment of denture stomatitis

Porosity, water sorption and solubility of denture base acrylic resins polymerized conventionally or in microwave

The proper selection of polymerization cycle is important to prevent overheating of the monomer that could cause degradation, porosity and, consequently, deleterious effects on the denture base properties. Objective: This study evaluated the porosity, water sorption and solubility of acrylic resins (Vipi Cril-VC and Vipi Wave-VW) after conventional or microwave polymerization cycles. Material and Methods: Specimens (n = 10) were made and cured: 1-WB = 65°C during 90 min + boiling during 90 min (VC cycle - control group); 2-M25 = 10 min at 270 W + 5 min at 0 W + 10 min at 360 W (VW cycle); 3-M3 = 3 min at 550 W; and 4-M5 = 5 min at 650 W. Afterward, they were polished and dried in a dessicator until a constant mass was reached. Specimens were then immersed in distilled water at 37°C and weighed regularly until a constant mass was achieved. For porosity, an additional weight was made with the specimen immediately immersed in distilled water. For water sorption and solubility, the specimens were dried again until equilibrium was reached. Data were submitted to 2 way-ANOVA and Tukey HSD (α=0.05). Results: Porosity mean values below 1.52% with no significant difference among groups for both materials were observed. Resins showed water sorption and solubility values without a significant difference. However, there was a significant difference among groups for these both properties (P<0.013). The highest sorption (2.43%) and solubility (0.13%) values were obtained for WB and M3, respectively. Conclusions: The conventional acrylic resin could be polymerized in a microwave since both the materials showed similar performance in the evaluated properties. Sho

Differences and similarities of postprandial lipemia in rodents and humans

The rat has been a mainstay of physiological and metabolic research, and more recently mice. This study aimed at characterizing the postprandial triglyceride profile of two members of the Muridae family: the Wistar rats (Rattus norvegicus albinus) and C57BL/6 mice (Mus musculus) plus comparing them to the profile obtained in humans. Thirty-one male and twelve female Wistar rats, ten C57BL/6 male and nine female mice received a liquid meal containing fat (17%), protein (4%) and carbohydrates (4%), providing 2 g fat/Kg. Thirty-one men and twenty-nine women received a standardized liquid meal containing fat (25%), dextromaltose (55%), protein (14%), and vitamins and minerals (6%), and providing 40 g of fat per square meter of body surface. Serial blood samples were collected at 2, 4, 6, 8 and 10 h after the ingestion in rats, at 1, 2, 3, 4, 5 and 6 h in mice and in humans at 2, 4, 6 and 8 h. Wilcoxon and Mann-Whitney tests were used. The triglyceride responses were evaluated after the oral fat loads. Fasting and postprandial triglyceridemia were determined sequentially in blood sample. AUC, AUIC, AR, RR and late peaks were determined. Rats are prone to respond in a pro-atherogenic manner. The responses in mice were closer to the ones in healthy men. This study presents striking differences in postprandial triglycerides patterns between rats and mice not correlated to baseline triglycerides, the animal baseline body weight or fat load in all animal groups.101CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNão temNão te

Porosity of temporary denture soft liners containing antifungal agents

Incorporation of antifungals in temporary denture soft liners has been recommended for denture stomatitis treatment; however, it may affect their properties. Objective: To evaluate the porosity of a tissue conditioner (Softone) and a temporary resilient liner (Trusoft) modified by minimum inhibitory concentrations (MICs) of antifungal agents for Candida albicans biofilm. Material and Methods: The porosity was measured by water absorption, based on exclusion of the plasticizer effect. Initially, it was determined by sorption isotherms that the adequate storage solution for specimens (65×10×3.3 mm) of both materials was 50% anhydrous calcium chloride (S50). Then, the porosity factor (PF) was calculated for the study groups (n=10) formed by specimens without (control) or with drug incorporation at MICs (nystatin: Ny-0.032 g, chlorhexidine diacetate: Chx-0.064 g, or ketoconazole: Ke-0.128 g each per gram of soft liner powder) after storage in distilled water or S50 for 24 h, seven and 14 d. Data were statistically analyzed by 4-way repeated measures ANOVA and Tukey's test (α=.05). Results: Ke resulted in no significant changes in PF for both liners in water over 14 days (p>;0.05). Compared with the controls, Softone and Trusoft PFs were increased at 14-day water immersion only after addition of Ny and Chx, and Chx, respectively (p;0.05). In all experimental conditions, Softone and Trusoft PFs were significantly lower when immersed in S50 compared with distilled water (

INIBIÇÃO DA COLONIZAÇÃO DE STAPHYLOCOCCUS E CANDIDA APÓS A ADIÇÃO DE AGENTES ANTIMICROBIANOS EM CONDICIONADOR TECIDUAL

Esse estudo teve por objetivo avaliar a efetividade a longo prazo da incorporação de agentes antimicrobianos em um condicionador tecidual (Softone-Bosworth Co, IL, EUA) na inibição de colonização bacteriana (Staphylococcus aureus-Sa) e fúngica (Candida albicans-Ca). As doses dos agentes incorporados ao pó do material (6 g) foram: sem adição de droga-controle (G1); nistatina-500.000 U (G2) e 1.000.000 U (G3); miconazol-125 mg (G4) e 250 mg (G5); cetoconazol-100mg (G6) e 200mg (G7); diacetato de clorexidina a 5% (G8) e diacetato de clorexidina a 10% (G9). As amostras (n=144) (10 x 1 mm) foram colocadas em placas de ágar Mannitol Salt para Sa e de ágar Sabourand para Ca previamente semeadas, as quais foram incubadas a 37ºC por 14 dias para a mensuração diária dos halos de inibição. Os dados foram submetidos à ANOVA e teste de Tukey (α=0,05). Para Ca, as maiores médias de halos de inibição foram obtidas para G7 (22,2 mm) e G6 (20,2 mm) e as menores para G2 (12,2 mm) (P<0,05). Houve inibição fúngica por 14 dias nos grupos G4, G5, G6 e G7 (13,8-20,6; 15,8-22,8; 16,4-23 e 19,2-25,4 mm, respectivamente). G3 (10,4-17 mm) apresentou inibição de Ca por 13 dias; G9 (10,8-17,2 mm) e G2 (10,4-16 mm) por 12 dias e G8 (11-16,8 mm) por 11 dias. Para Sa, as maiores médias de halos de inibição foram obtidas para G8 (19,2 mm) e G9 (13,6 mm) e as menores para G2 (10,2 mm) (P<0,05). No G8, houve inibição de Sa por 14 dias (1,8-9,0 mm) e no G9 por 12 dias (10,8-17,2 mm). O Sa foi inibido por 2 dias nos grupos G3, G4, G5, G6 e G7 (12,2-13,8; 12-13,8; 12,6-13,6; 12,8-13,6; 13,6-14,2 mm, respectivamente) e por 1 dia no G2 (12,6 mm). Não houve inibição de Ca e Sa no G1. Quando incorporados ao condicionador tecidual, a clorexidina e o cetoconazol foram, a longo prazo, os agentes antimicrobianos mais efetivos na inibição de Sa e Ca, respectivamente

A novel acrylic resin palatal device contaminated with Candida albicans biofilm for denture stomatitis induction in Wistar rats

Denture stomatitis is the most frequent oral lesion in removable prosthesis wearers, with high recurrence rates and a complex treatment.&nbsp;Objective:&nbsp;This study describes a protocol to obtain and to contaminate a palatal device with Candida albicans biofilm that could be used for an animal model of denture stomatitis.&nbsp;Methodology: Acrylic resin devices (N=41) were obtained from impressions of the palates of Wistar rats with individual trays and polyether. The efficacy of microwave irradiation (MW), ultraviolet light (UV), or ultrasonic bath (US) was assessed by colony viability and spectrophotometric analyses (n=5) in order to select the most appropriate method for sterilizing the devices. Then, different devices (n=5) were contaminated with C. albicans and evaluated by CFU/mL determination, scanning electron microscopy, and laser confocal microscopy. Device stabilization was assessed with either autopolymerizing acrylic resins or a self-adhesive resin cement (n=2). The spectrophotometric data were analyzed by one-way ANOVA followed by the Tukey’s HSD post-hoc test (α=0.05).&nbsp;Results: MW was the only method capable of sterilizing the devices, and the contamination protocol developed a mature and viable C. albicans biofilm (~1.2 x 106 CFU/mL). The self-adhesive resin cement was the best stabilization material.&nbsp;Conclusions: This acrylic resin palatal device was designed to be similar to the clinical situation of contaminated prostheses, with easy manufacturing and handling, effective stabilization, and satisfactory contamination. Thus, the acrylic device can be a valuable tool in the development of denture stomatitis in rats

EFEITO DA ADIÇÃO DE AGENTES ANTIMICROBIANO/ANTIFÚNGICO SOBRE DUREZA E RUGOSIDADE SUPERFICIAL DE CONDICIONADOR TECIDUAL

O objetivo desse estudo foi determinar o efeito da incorporação de antifúngicos (nistatina- N, miconazol- M ou cetoconazol- K) ou de agente antimicrobiano (diacetato de clorexidina-C) sobre propriedades físicas de um condicionador de tecido (Softone-S). Foi avaliado o padrão de incorporação destas drogas no material S por MEV/EDS. Os grupos avaliados foram: G1 = controle (sem adição de droga); G2 = N-500.000 U; G3 = N-1.000.000 U; G4 = M-125 mg; G5 = M-250 mg; G6 = K-100 mg; G7 = K-200 mg; G8 = C-5% e G9 = C-10% em relação à quantidade total (6 g) de S. As quantidades das drogas (em pó) foram misturadas ao pó de S, sendo o líquido de S posteriormente adicionado à mistura. Amostras (n = 5) foram plastificadas à temperatura ambiente por 10 min. As leituras de dureza (Shore A) e rugosidade (Ra) foram realizadas após imersão das amostras em água destilada a 37°C por 24 h, 7 e 14 dias. Os resultados foram analisados pela análise de variância (2-ANOVA)/ Tukey (α = 0,05). Após todos os períodos avaliados (24 h, 7 e 14 dias), a dureza dos grupos experimentais foi superior (P 0,05) à do G1 (5,83 µm). Após 14 dias, a rugosidade do G5, G8 e G9 foi superior (P < 0,05) (7,93; 9,63 e 10,29 µm, respectivamente) à do G1 (6,92 µm). O material modificado demonstrou morfologia favorável, por meio de MEV/EDS, para liberação intra-bucal das drogas avaliadas. Foram observadas alterações nas propriedades físicas do material modificado, entretantodeve-se avaliar se são clinicamente significantes

Evidence of two deeply divergent co-existing mitochondrial genomes in the Tuatara reveals an extremely complex genomic organization

Animal mitochondrial genomic polymorphism occurs as low-level mitochondrial heteroplasmy and deeply divergent co-existing molecules. The latter is rare, known only in bivalvian mollusks. Here we show two deeply divergent co-existing mt-genomes in a vertebrate through genomic sequencing of the Tuatara (Sphenodon punctatus), the sole-representative of an ancient reptilian Order. The two molecules, revealed using a combination of short-read and long-read sequencing technologies, differ by 10.4% nucleotide divergence. A single long-read covers an entire mt-molecule for both strands. Phylogenetic analyses suggest a 7–8 million-year divergence between genomes. Contrary to earlier reports, all 37 genes typical of animal mitochondria, with drastic gene rearrangements, are confirmed for both mt-genomes. Also unique to vertebrates, concerted evolution drives three near-identical putative Control Region non-coding blocks. Evidence of positive selection at sites linked to metabolically important transmembrane regions of encoded proteins suggests these two mt-genomes may confer an adaptive advantage for an unusually cold-tolerant reptile

Interrogating the Impact of Intestinal Parasite-Microbiome on Pathogenesis of COVID-19 in Sub-Saharan Africa

Intestinal parasitic infections affect more than 2 billion people throughout the world with disproportionately high prevalence rates in Low- and Middle-Income Countries (LMICs) (Herricks et al., 2017). Multicellular and highly complex parasites such as Ascaris, hook worm, Trichuris, Enterobius and Schistosoma, as well as unicellular organisms including Entamoeba, Giardia, Toxoplasma, Cyclospora, and Cryptosporidium are among major pathogens that contribute to the global intestinal parasitic disease burden. Parasites can cause persistent infection due to their ability to resist immune-mediated expulsion by modulating the host's immune response (McSorley and Maizels, 2012; Wammes et al., 2014; Chabé et al., 2017; Burrows et al., 2019; Ryan et al., 2020). There is a complex interaction between parasites and human microbiota which can triangulate with host's immune homeostasis and host responses to bystander antigens, vaccines or other unrelated diseases, both infectious and non-communicable diseases (McSorley and Maizels, 2012; Wammes et al., 2014). Recently, the world has grappled with an unprecedented pandemic due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that causes coronavirus disease 2019 (COVID-19) (WHO, 2020). The pathogenesis of severe disease in COVID-19 has been linked to the phenomenon of immune hyperactivation (Sinha et al., 2020; Tay et al., 2020). Here, we propose that the interplay between intestinal parasites and microbiome may have a potential direct or indirect effects on the pathogenesis of SARS-CoV-2 infection, in particular in the context of LMICs

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