Ácido Fítico e Ácido Metafosfórico como Agentes Alternativos para Condicionamento Dentinário: uma Revisão da Literatura

O objetivo do presente estudo foi realizar uma revisão de literatura sobre a ação do ácido fítico (IP6) e do ácido metafosfórico (MPA) como agentes condicionantes em dentina e avaliar seus respectivos resultados. Foi realizada uma busca nas bases de dados Pubmed, e Science Direct, entre 2013 e 2017, utilizando os descritores, separados e em combinação, “Phytic acid”, “Metaphosphoric acid” e “Dentin”. Foram obtidos 12 artigos no total, desses 3 estavam repetidos e foram excluídos. Dos demais, 8 eram estudos    in vitro e 1 era revisão de literatura. Através de uma leitura crítica dos títulos e dos resumos, foram selecionados 6, relevantes ao tema. Artigos de revisão de literatura e que não se adequavam ao objetivo do trabalho foram excluídos. Muitas estratégias são testadas com a finalidade de aumentar a longevidade das interfaces adesivas, recentemente foi proposto que IP6 e MPA poderiam ser usados como agente de condicionamento dentinário. O uso do MPA, os valores de resistência de união são melhores que os obtidos com o ácido ortofosfórico (OPA), padrão-ouro odontológico, além disso, é possível observar que o MPA desmineraliza menos a dentina que o OPA, além de formar o mineral bruxita que melhora a durabilidade da interface adesiva. Os achados em relação ao IP6 também apontam para valores de resistência de união similares ao PA, além da menor susceptibilidade de degradação colagenolítica, por possuir ação biomodificadora. São necessários mais estudos que comprovem a eficiência de tais materiais como agentes condicionantes, assim como, a aplicabilidade clínica.Palavras-chave: Phytic Acid. Metaphosphoric Acid. Dentin.

A CUso do Glutaraldeído como Agente de Ligações Cruzadas em Restaurações Resinosas em Dentina: uma Revisão de Literatura

O objetivo do presente estudo foi revisar a literatura para descrever a influência do glutaraldeido (GA) como agente de ligações cruzadas em restaurações em restaurações resinosas em dentina. Revisou-se a literatura no período de 2007 a 2017, nas bases de dados Pubmed, Bireme e Science Direct, no idioma Inglês, com os seguintes descritores: Glutaral, Dentin e Crosslinking Reagents. Chegando-se ao total de 12 artigos, realizou-se uma leitura crítica dos resumos e títulos. Desses, 5 são estudos in vitro, 4 estudos clínicos e 3 são revisões de literatura, foram excluídos artigos que fugiam do objetivo do estudo e revisões de literatura, sendo utilizados 9 artigos para o presente estudo. O GA é um agente biomodificador de origem sintética que forma ligações covalentes entre dois grupos aminas de hidroxilisina, presente na molécula de colágeno, com seus grupos aldeídos a fim de formar composto piridíneo estável. Conferindo uma boa biomecânica a matriz de colágeno desnudo e irá atuar inibindo colagenases, aumentando a durabilidade da interface adesiva. O GA possui um caráter citotóxico e, por isso, deve ser usado de maneira correta e cuidadosa, a fim de se conseguir o melhor resultado possível no sistema de adesão. O GA é capaz de promover um satisfatório aumento na resistência da união do material restaurador com a dentina. Em ação conjunta com outras substâncias – por exemplo, a HEMA – o GA cria uma barreira em áreas mais profundas dos túbulos dentinários, abaixo da zona de fibras colágenas expostas, ratificando, assim, a eficácia desse agente biomodificador.Palavras-chave: Glutaral. Dentin. Crosslinking Reagents.

Avaliação da Influência do Ácido Tânico nos Procedimentos Restauradores

Na tentativa de diminuir as falhas nos procedimentos restauradores tem sido propostas várias alternativas, como o uso de agentes de ligação cruzada na dentina. O ácido tânico, que é um polifenol com fraca acidez, é uma substância natural que apresenta essa característica. O objetivo do presente estudo foi realizar uma revisão de literatura para avaliar a influência do Ácido Tânico, como um agente de ligação cruzada de colágeno, nas propriedades físico-mecânicas e na estabilidade dos procedimentos restauradores. Revisou-se a literatura no período de 1998 a 2017, nas bases de dados Pubmed e Science Direct, no idioma Inglês, com os seguintes descritores: Tannic Acid, Dentistry e Crosslinking Reagents. Foram encontrados 15 artigos, e desses, foram selecionados 07 artigos, realizou-se uma leitura crítica dos resumos e títulos. Desses, 06 foram estudos in vitro e 1 estudo químico. O Ácido Tânico reforça a matriz de colágeno constituinte da dentina, aumentando as ligações químicas entre as fibrilas, melhorando as propriedades físico- mecânicas e diminuindo a taxa de degradação enzimática. Existem estudos utilizando o ácido tânico como dessensibilizantes e agentes de remoção de smear layer, porém há pouca informação sobre seu efeito na interface adesiva. A relevância do trabalho consiste em discutir recentes estudos sobre as propriedades, possíveis utilizações do Ácido Tânico, uma vez que as suas aplicações na odontologia ainda são pouco conhecidas pela comunidade acadêmica e profissional.Palavras-chave: Tannic Acid. Dentin. Crosslinking Reagents.

A Influência da Carboiimida na Durabilidade de Restaurações Resinosas no Substrato Dentinário: uma Revisão de Literatura

A Carbodiimida (EDC) é um agente biomodificador que forma ligações covalentes estáveis entre aminoácidos presentes no colágeno da dentina. O objetivo do presente estudo é revisar a literatura para avaliar a influência do EDC na durabilidade de restaurações resinosas em substrato dentinário. Para isso, foi realizada uma busca bibliográfica na qual foram selecionados artigos publicados no período de 2007 a 2017 nas bases de dados PubMed, Bireme e Science Direct, no idioma Inglês, utilizando os descritores: Cross-Linking Reagents, Dentin-Bonding Agents e Carbodiimides. Chegando-se ao total de 19 artigos, realizou-se uma leitura crítica dos resumos e títulos. Desses, 10 são estudos in vitro e 9 são revisões de literatura, sendo excluídos casos clínicos e artigos que fugiam do objetivo do estudo. Selecionou-se 10 artigos mediante a relevância ao tema. O EDC mostrou-se eficaz na formação de ligações cruzadas entre fibras colágenas melhorando a biomecânica da dentina, além disso, atua inibindo enzimas como as Metaloproteinases (MMPs), levando a uma diminuição da degradação dessas fibras que não foram impregnadas por monômeros após o condicionamento ácido desse substrato, aumentando a longevidade da restauração. Entretanto, os estudos que avaliam a atuação desse agente biomodificador foram realizados em um espaço de tempo muito curto. O desenvolvimento de estudos mais longos é fundamental para que a comunidade científica obtenha resultados concretos sobre a atuação do EDC.Palavras-chave: Cross-Linking Reagents. Dentin-Bonding Agents. Carbodiimides.

Cloud forest trees with higher foliar water uptake capacity and anisohydric behavior are more vulnerable to drought and climate change

Many tropical montane cloud forest (TMCF) trees are capable of foliar water uptake (FWU) during leaf-wetting events. In this study, we tested the hypothesis that maintenance of leaf turgor during periods of fog exposure and soil drought is related to species' FWU capacity. We conducted several experiments using apoplastic tracers, deuterium labeling and leaf immersion in water to evaluate differences in FWU among three common TMCF tree species. We also measured the effect of regular fog exposure on the leaf water potential of plants subjected to soil drought and used these data to model species' response to long-term drought. All species were able to absorb water through their leaf cuticles and/or trichomes, although the capacity to do so differed between species. During the drought experiment, the species with higher FWU capacity maintained leaf turgor for a longer period when exposed to fog, whereas the species with lower FWU exerted tighter stomatal regulation to maintain leaf turgor. Model results suggest that without fog, species with high FWU are more likely to lose turgor during seasonal droughts. We show that leaf-wetting events are essential for trees with high FWU, which tend to be more anisohydric, maintaining leaf turgor during seasonal droughts.

Keratinocytes and neutrophils are important sources of proinflammatory molecules in hidradenitis suppurativa

BACKGROUND

The pathogenesis of the chronic inflammatory skin disease hidradenitis suppurativa (HS, also known as acne inversa) involves epidermal alterations such as psoriasiform epidermal hyperplasia and keratin plugging. Keratinocytes are an important source of proinflammatory molecules in inflammatory skin diseases and can be stimulated by interleukin (IL)-17(+) cells.

OBJECTIVES

To explore the possible role of the epithelium in the pathogenesis of HS.

METHODS

We performed immunohistochemical stainings and Western blot experiments to investigate the localization and expression of inflammation-associated molecules, including the cytokine IL-17, components of the inflammasome including caspase-1, and the endogenous danger-associated molecular pattern molecules S100A8 and S100A9 (calprotectin). To examine a possible effect of upregulated proinflammatory cytokines on the inflammatory infiltrate, differences in the cellular composition of perifollicular and deep dermal infiltrates were analysed.

RESULTS

The number of IL-17(+) cells is increased in lesional and perilesional HS skin. The epidermis produces proinflammatory molecules and shows an upregulated expression of components of the NLRP3 inflammasome, activated caspase-1 and expression of S100A8/S100A9. Additionally, the course of the inflammatory process in HS involves influx of innate immune cells, particularly IL-17-expressing neutrophils.

CONCLUSIONS

IL-17-producing cells are present in lesional and perilesional HS skin and may contribute to the initiation of inflammatory processes. Furthermore, the epidermis is a source of proinflammatory cytokines, shows inflammasome activation and expresses S100A8/S100A9, thereby possibly contributing to the propagation of inflammation. A massive influx of IL-17-expressing neutrophils is observed in the deep infiltrate.

Effects of packaging, mineral oil coating, and storage time on biogenic amine levels and internal quality of eggs

This study was carried out with the aim of evaluating the effects of mineral oil application on eggshells and the use of plastic packages with lids on the physical-chemical and microbiological quality and biogenic amine contents of eggs stored under refrigeration for up to 125 d. A total of 1,920 eggs from 46-wk-old Hyline W36 laying hens were randomly distributed into 4 groups soon after classification: (i) 480 eggs were stored in pulp carton tray packages; (ii) 480 eggs were stored in plastic packages with lids; (iii) 480 eggs were stored in carton packages after the application of mineral oil; and (iv) 480 eggs were stored in plastic packages with lids after the application of mineral oil. The internal quality was measured by Haugh units, by the counts of mesophilic and psychrotrophic microorganisms, by the most probable number of total and thermal-tolerant coliforms, by the counts of molds and yeasts, by the analysis of Salmonella spp. and Staphylococcus spp., and by the levels of biogenic amines in the egg yolk and albumen. The application of mineral oil to the eggshell resulted in higher Haugh unit values throughout storage, and the use of plastic packages altered the internal quality. The application of mineral oil and the use of packaging had no effects on the microbiological and biogenic amine results. Microbiological analyses showed the absence of Salmonella spp., Staphylococcus aureus, thermal-tolerant coliforms, and fungi. However, the highest counts of mesophilic (1.1 × 10(7) cfu/g) and psychrotrophic (6.7 × 10(7) cfu/g) microorganisms were recorded. The highest values of biogenic amines detected and quantified were putrescine (2.38 mg/kg) and cadaverine (7.27 mg/kg) in the egg yolk and putrescine (1.95 mg/kg), cadaverine (2.83 mg/kg), and phenylethylamine (2.57 mg/kg) in the albumen. Despite these results, the biogenic amine levels recorded were considered low and would not be harmful to consumer health.

Foliar uptake of fog water and transport belowground alleviates drought effects in the cloud forest tree species, Drimys brasiliensis (Winteraceae)

Foliar water uptake (FWU) is a common water acquisition mechanism for plants inhabiting temperate fog-affected ecosystems, but the prevalence and consequences of this process for the water and carbon balance of tropical cloud forest species are unknown. We performed a series of experiments under field and glasshouse conditions using a combination of methods (sap flow, fluorescent apoplastic tracers and stable isotopes) to trace fog water movement from foliage to belowground components of Drimys brasiliensis. In addition, we measured leaf water potential, leaf gas exchange, leaf water repellency and growth of plants under contrasting soil water availabilities and fog exposure in glasshouse experiments to evaluate FWU effects on the water and carbon balance of D. brasiliensis saplings. Fog water diffused directly through leaf cuticles and contributed up to 42% of total foliar water content. FWU caused reversals in sap flow in stems and roots of up to 26% of daily maximum transpiration. Fog water transported through the xylem reached belowground pools and enhanced leaf water potential, photosynthesis, stomatal conductance and growth relative to plants sheltered from fog. Foliar uptake of fog water is an important water acquisition mechanism that can mitigate the deleterious effects of soil water deficits for D. brasiliensis.

Enteric, hepatic and muscle tissue development of goat kids fed with lyophilized bovine colostrum

The objective of this study was to investigate the development of the enteric, hepatic and muscle tissues in goat kids fed with lyophilized bovine colostrum in the transition period of passive immunity to early active immunity. At 0, 7 and 14 h of life, 15 male newborns received 5% of their body weight of lyophilized bovine colostrum and 14 male newborns received goat colostrum, both with 55 mg/ml of IgG. Samples of the duodenum, jejunum, ileum, liver and muscle were collected at 18, 36 and 96 h of life to quantify total protein, DNA and RNA contents. In the jejunum and ileum, the highest levels of total protein and higher protein/RNA ratio were observed at 18 h (p < 0.05). There were no differences in DNA contents in any intestinal segment (p > 0.05). At 96 h, maximum levels of RNA were observed in the jejunum and ileum (p < 0.05) and higher RNA/DNA ratio in the three intestinal segments (p < 0.05), showing increased ability to synthesize intracellular RNA and proteins. The LBC group showed higher protein content and higher protein/DNA and protein/RNA ratios in the jejunum, a higher DNA content in the liver (p < 0.05) and a higher protein/RNA ratio in the muscle tissue (p < 0.05). In the muscle, higher protein and DNA levels were also found at 96 h (p < 0.05). Indicators of cellular activity suggest greater absorption of proteins from lyophilized bovine colostrum and increased cell maturity in the enteric and muscle tissues in the first hours of goat kids' life.

Characterization of light penetration in rat tissues

OBJECTIVE

The goal of this study is to determine the optical properties of different rat tissues with respect to spatial intensity variation and light distribution. We are interested mainly in the wavelength of 630 nm. Nevertheless, for liver tissue we have used 514 nm and 670 nm as well.

BACKGROUND DATA

In the past, many articles have been written about the interaction of lasers with rat tissues. However, the technique of imaging the light distribution allows us to obtain the spatial scattering as well as an effective attenuation coefficient for the light intensity.

METHODS

Slices of different rat tissues were placed between two microscope slide mounts (spaced by 3 mm). A laser beam was irradiated on the sandwiched tissue. A CCD camera placed on the side, orthogonal to the beam path, recorded the intensity distribution of the scattered light. Analysis of this spatial intensity profile allowed determining the variation of the intensity as the light penetrates the tissue.

RESULTS

We have found that abdominal wall fat presents the lowest exponential decay when compared with liver, muscle, and kidney. The obtained values provided good data about the light distribution in those tissues when irradiated with a nondiffuse laser beam. For all tissues, we observed a spherical light distribution and exponential decay. Cirrhotic liver shows much stronger decay than healthy liver. These results are useful for several applications of laser for biostimulation a phototherapy.

[Evaluation of inflammatory activity in chronic osteomyelitis. Contribution of scintigraphy with polyclonal antibodies]

BACKGROUND

Active chronic osteomyelitis or complicating osteomyelitis are difficult to be diagnosed by radiological imaging modalities, such as plain radiograph and CT. They frequently cause increased bone remodeling, leading to nonspecific uptake of Tc-99m-bone scan agents and gallium-67. New radiopharmaceuticals with greater infection avidity are being developed, including the nonspecific polyclonal immunoglobulin (IgG) labeled with technetium-99m. Tc-99m-IgG may be available as a ready to use kit, with no reported side effects, low patient absorbed radiation dose and low cost.

MATERIAL AND METHODS

23 bone segments with suspected active chronic osteomyelitis or violated bone osteomyelitis were studied by Tc-99m-IgG scintigraphy. All patients underwent standard three-phase bone scintigraphy using methylene diphosphonate (Tc-99m-MDP), gallium-67 scintigraphy and plain radiographs, compared with clinical evaluation and laboratory tests values.

RESULTS

Infection was found in 8 sites. Sensitivity and specificity for Tc-99m-MDP, gallium-67 and Tc-99m-IgG scintigraphy were, respectively, 88 and 36%, 75 and 73%, 88 and 82%.

CONCLUSION

Tc-99m-IgG may be usefull in the scintigraphic evaluation of osteomyelitis.

Case report: Long-term outcome of class II division 1 malocclusion treated with rapid palatal expansion and cervical traction

A case of a Class II Division 1 malocclusion with reduced transpalatal width and unfavorable axial inclinations of the posterior teeth is reported. Rapid palatal expansion (RPE) was used for maxillary enhancement and molar distalization therapy to correct the anteroposterior dental discrepancy. This case report illustrates the results of the method of treatment used with a long-term (16-year-posttreatment) follow-up.

Roxithromycin treatment for diarrhoea caused by Cryptosporidium spp. in patients with AIDS

In view of the action of newer macrolide antibiotics on intracellular protozoa, we have investigated the efficacy of roxithromycin in the treatment of cryptosporidiosis in 26 patients with AIDS. Cryptosporidiosis was confirmed either by faecal examination for parasites (modified Kinyoun method) or by detection of the parasite in biopsy material obtained by colonoscopy. Patients received oral roxithromycin (300 mg bd) for 4 weeks. Twenty-two patients completed the study. At the end of the study, 15 patients (68%) were considered to be cured and six patients (27%) improved, and treatment failed in one patient (5%). We conclude that roxithromycin is a useful treatment for diarrhoea caused by Cryptosporidium spp. associated with AIDS.

Ultrasonic fragmentation of cataract in uveitis

Thirty-nine eyes with uveitis from various causes, and complicated by cataract and vitreous opacification, underwent pars plana lensectomy and vitrectomy by ultrasonic fragmentation. Anatomical results were excellent, with clearing of all lens and vitreous opacities in all eyes. Visual results showed that there was no exacerbation and no recurrence of uveitis. Visual results depended mainly on the presence of previous damage of the uveitis to the retina and optic nerve. Visual results did not depend on the presence of uveitis activity at the time of the surgery. Complications that occurred were cystoid macular edema, which was present in 17.94% of the eyes and diagnosed in some eyes at the surgery, retinal detachment in one eye (2.56%), sterile hypopyon in one eye (2.56%), and ultrasonic lesion of the retina in one eye (2.56%). Visions of 20/20 to 20/40 were obtained in 23% of the eyes, 20.5% had vision between 20/50 and 20/80, and 56.4% had vision of 20/100 or less. The good results justify the surgical intervention in cases of cataracts associated with uveitis. Pars plana lensectomy and vitrectomy appears to be the procedure of choice in removal of cataracts secondary to uveitis.