Exploring the potential of omics technologies in medicinal plant research: a review in Colombia / Explorando el potencial de las tecnologías ómicas en la investigación de plantas medicinales: una revisión en Colombia

This review presents advances in the implementation of high - throughput se quencing and its application to the knowledge of medicinal plants. We conducted a bibliographic search of papers published in PubMed, Science Direct, Google Scholar, Scopus, and Web of Science databases and analyzed the obtained data using VOSviewer (versi on 1.6.19). Given that medicinal plants are a source of specialized metabolites with immense therapeutic values and important pharmacological properties, plant researchers around the world have turned their attention toward them and have begun to examine t hem widely. Recent advances in sequencing technologies have reduced cost and time demands and accelerated medicinal plant research. Such research leverages full genome sequencing, as well as RNA (ribonucleic acid) sequencing and the analysis of the transcr iptome, to identify molecular markers of species and functional genes that control key biological traits, as well as to understand the biosynthetic pathways of bioactive metabolites and regulatory mechanisms of environmental responses. As such, the omics ( e.g., transcriptomics, metabolomics, proteomics, and genomics, among others) have been widely applied within the study of medicinal plants, although their usage in Colombia is still few and, in some areas, scarce. (185)

El extracto de cloroformo (CE) y las fracciones obtenidas de las raíces de Aldama arenaria se evaluaron para determinar su actividad antiproliferativa in vitro contra 10 líneas ce lulares tumorales humanas [leucemia (K - 562), mama (MCF - 7), ovario que expresa un fenotipo resistente a múltiples fármacos (NCI/ADR - RES), melanoma (UACC - 62), pulmón (NCI - H460), próstata (PC - 3), colon (HT29), ovario (OVCAR - 3), glioma (U251) y riñón (786 - 0)]. CE presentó actividad antiproliferativa débil a moderada (log GI 50 medio 1.07), mientras que las fracciones 3 y 4, enriquecidas con diterpenos de tipo pimarane [ent - pimara - 8 (14), ácido 15 - dien - 19 - oico y ent - 8(14),15 - pimaradien - 3 ß - ol], presentaron activid ad moderada a potente para la mayoría de las líneas celulares, con un log GI 50 medio de 0.62 y 0.59, respectivamente. Los resultados mostraron una acción antiproliferativa in vitro prometedora de las muestras obtenidas de A. arenaria , con los mejores resul tados para NCI/ADR - RES, HT29 y OVCAR - 3, y valores de TGI que van desde 5.95 a 28.71 µg.mL - 1, demostrando que los compuestos de esta clase pueden ser prototipos potenciales para el descubrimiento de nuevos agentes terapéuticos

Virus adsorbent systems based on Amazon holocellulose and nanomaterials.

The environment preservation has been an important motivation to find alternative, functional, and biodegradable materials to replace polluting petrochemicals. The production of nonbiodegradable face masks increased the concentration of microplastics in the environment, highlighting the need for sustainable alternatives, such as the use of local by-products to create efficient and eco-friendly filtering materials. Furthermore, the use of smart materials can reduce the risk of contagion and virus transmission, especially in the face of possible mutations. The development of novel materials is necessary to ensure less risk of contagion and virus transmission, as well as to preserve the environment. Taking these factors into account, 16 systems were developed with different combinations of precursor materials (holocellulose, polyaniline [ES-PANI], graphene oxide [GO], silver nanoparticles [AgNPs], and activated carbon [AC]). Adsorption tests of the spike protein showed that the systems containing GO and AC were the most efficient in the adsorption process. Similarly, plate tests conducted using the VSV-IN strain cultured in HepG2 cells showed that the system containing all phases showed the greatest reduction in viral titer method. In agreement, the biocompatibility tests showed that the compounds extracted from the systems showed low cytotoxicity or no significant cytotoxic effect in human fibroblasts. As a result, the adsorption tests of the spike protein, viral titration, and biocompatibility tests showed that systems labeled as I and J were the most efficient. In this context, the present research has significantly contributed to the technological development of antiviral systems, with improved properties and increased adsorption efficiency, reducing the viral titer and contributing efficiently to public health. In this way, these alternative materials could be employed in sensors and devices for filtering and sanitization, thus assisting in mitigating the transmission of viruses and bacteria. RESEARCH HIGHLIGHTS: Sixteen virus adsorbent systems were developed with different combinations of precursor materials (holocellulose, polyaniline (ES-PANI), graphene oxide (GO), silver nanoparticles (AgNPs), and activated carbon (AC)). The system that included all of the nanocomposites holocellulose, PANI, GO, AgNPs, and AC showed the greatest reduction in viral titration. The biocompatibility tests revealed that all systems caused only mild or moderate cytotoxicity toward human fibroblasts.

Effect of an exercise-based cardiac rehabilitation program on quality of life of patients with chronic Chagas cardiomyopathy: results from the PEACH randomized clinical trial.

To investigate the effect of an exercise-based cardiac rehabilitation program on the quality of life (QoL) of patients with chronic Chagas cardiomyopathy (CCC). PEACH study was a single-center, superiority randomized clinical trial of exercise training versus no exercise (control). The sample comprised Chagas disease patients with CCC, left ventricular ejection fraction < 45%, without or with HF symptoms (CCC stages B2 or C, respectively). QoL was assessed at baseline, after three months, and at the end of six months of follow-up using the SF-36 questionnaire. Patients randomized for the exercise group (n = 15) performed exercise training (aerobic, strength and stretching exercises) for 60 min, three times a week, during six months. Patients in the control group (n = 15) were not provided with a formal exercise prescription. Both groups received identical nutritional and pharmaceutical counseling during the study. Longitudinal analysis of the effects of exercise training on QoL, considering the interaction term (group × time) to estimate the rate of changes between groups in the outcomes (represented as beta coefficient), was performed using linear mixed models. Models were fitted adjusting for each respective baseline QoL value. There were significant improvements in physical functioning (ß = + 10.7; p = 0.02), role limitations due to physical problems (ß = + 25.0; p = 0.01), and social functioning (ß = + 19.2; p < 0.01) scales during the first three months in the exercise compared to the control group. No significant differences were observed between groups after six months. Exercise-based cardiac rehabilitation provided short-term improvements in the physical and mental aspects of QoL of patients with CCC.Trial registration: ClinicalTrials.gov Identifier: NCT02517632; August 7, 2015.

Soil bacteria and fungi communities are shaped by elevation influences in Colombian forest and páramo natural ecosystems

The influence of elevation on natural terrestrial ecosystems determines the arrangements of microbial communities in soils to be associated with biotic and abiotic factors. To evaluate changes of fungi and bacteria at the community level along an elevational gradient (between 1000 and 3800 m.a.s.l.), physicochemical measurements of soils, taxonomic identifications of plants, and metabarcoding sequences of the 16S rRNA gene for bacteria and the ITS1 region for fungi were obtained. The bacterial taxonomic composition showed that Acidobacteriota increased in abundance with elevation, while Actinobacteriota and Verrucomicrobiota decreased. Furthermore, Firmicutes and Proteobacteria maintained maximum levels of abundance at intermediate elevations (1200 and 2400 m.a.s.l.). In fungi, Ascomycota was more abundant at higher elevations, Basidiomycota tended to dominate at lower elevations, and Mortierellomycota had a greater presence at intermediate sites. These results correlated with the edaphic parameters of decreasing pH and increasing organic carbon and available nitrogen with elevation. In addition, the Shannon index found a greater diversity in bacteria than fungi, but both showed a unimodal pattern with maximum values in the Andean Forest at 2400 m.a.s.l. Through the microbial characterization of the ecosystems, the elevational gradient, soil properties, and vegetation were found to exert significant effects on microbial communities and alpha diversity indices. We conclude that the most abundant soil microorganisms at the sampling points differed in abundance and diversity according to the variations in factors influencing ecological communities. (AU)

Computational methods in the analysis of SARS-CoV-2 in mammals: A systematic review of the literature.

SARS-CoV-2 is an enveloped RNA virus that causes severe respiratory illness in humans and animals. It infects cells by binding the Spike protein to the host's angiotensin-converting enzyme 2 (ACE2). The bat is considered the natural host of the virus, and zoonotic transmission is a significant risk and can happen when humans come into close contact with infected animals. Therefore, understanding the interconnection between human, animal, and environmental health is important to prevent and control future coronavirus outbreaks. This work aimed to systematically review the literature to identify characteristics that make mammals suitable virus transmitters and raise the main computational methods used to evaluate SARS-CoV-2 in mammals. Based on this review, it was possible to identify the main factors related to transmissions mentioned in the literature, such as the expression of ACE2 and proximity to humans, in addition to identifying the computational methods used for its study, such as Machine Learning, Molecular Modeling, Computational Simulation, between others. The findings of the work contribute to the prevention and control of future outbreaks, provide information on transmission factors, and highlight the importance of advanced computational methods in the study of infectious diseases that allow a deeper understanding of transmission patterns and can help in the development of more effective control and intervention strategies.

Color matching and color recovery in large composite restorations using single-shade or universal composites.

This study assessed the color-matching ability and color recovery of unprepared teeth when using single-shade composites and a universal composite in large restorations. Buccal and palatine surface colors of molars were measured with a spectrophotometer (CIELAB) before preparing round cavities (6 mm in diameter, 2 mm in depth). The cavities were randomly filled with a single-shade composite (Omnichroma, Diamond One, or Vittra APS Unique) or a universal composite (Filtek Universal). Color measurements of the restored cavities were taken, and overall color differences (ΔEab and ΔE00) and differences in the whitening index for dentistry (ΔWID) from baseline were calculated. Additionally, visual assessments of a color match to the surrounding enamel were performed by forty evaluators (laypersons and undergraduate students of dentistry) in a viewing booth under illuminant D65, with rating scores from 0 (no color mismatch) to 4 (not acceptable). Data were analyzed using RM or one-way ANOVA (α = 0.05). Results showed that the restorations generally exhibited whiter colors (WID ranged from 27.9 to 41.3) than the unprepared teeth (WID ranged from 15.9 to 19.3). The composite Filtek Universal demonstrated the lowest color discrepancy (ΔWID = 8.6; ΔE00 = 10.8; and ΔE00 = 6.2), and no significant differences were observed among the evaluated single-shade composites. Furthermore, all composites showed similar and adequate color matches to the surrounding enamel. However, it is important to note that despite their ability to match the surrounding enamel reasonably, none of the composites evaluated in large restorations fully recovered the color observed in unprepared teeth.

Olive Oil Components as Novel Antioxidants in Neuroblastoma Treatment: Exploring the Therapeutic Potential of Oleuropein and Hydroxytyrosol.

In this review, we explored the therapeutic potential of oleuropein (OLE) and hydroxytyrosol (HT) in the treatment of neuroblastoma (NB). NB is an extracranial tumour that predominantly affects children aged between 17 and 18 months. Recurrence and drug resistance have emerged as the biggest challenges when treating NB, leading to a crucial need for new therapeutic approaches. Food of the Mediterranean Diet (MD) presents several health benefits, including that of cancer treatment. In this review, we emphasised olive oil since it is one of the main liquid ingredients of the MD. OLE is the principal phenolic compound that constitutes olive oil and is hydrolysed to produce HT. Considering that tumour cells produce increased amounts of reactive oxygen species, this review highlights the antioxidant properties of OLE and HT and how they could result in increased cellular antioxidant defences and reduced oxidative damage in NB cells. Moreover, we highlight that these phenolic compounds lead to apoptosis and cell cycle arrest, reduce the side effects caused by conventional treatments, and activate tumours that become dormant as a resistance mechanism. Future research should explore the effects of these compounds and other antioxidants on the treatment of NB in vivo.

Influence of repositioning guides' color and usage on precision in tooth color measurement with a clinical spectrophotometer.

BACKGROUND: Repositioning guides are commonly employed in clinical studies to ensure consistent tooth color measurements. Yet, their influence on measured color remains uncertain. OBJECTIVE: This study evaluated the impact of repositioning guides' color and usage on tooth color measurement using a clinical spectrophotometer. METHODOLOGY: In total, 18 volunteers participated in this study, in which the color of their upper left central incisor and upper left canine was measured with or without repositioning guides (control). The guides were made from pink, blue, or translucent silicone, as well as an acetate-based bleaching tray. Tooth color was measured in triplicates using a clinical spectrophotometer based on the CIELAB system. The standard deviations of these readings were used to estimate reproducibility, and color differences (ΔE00) between the measurements with guides and the control were calculated. RESULTS: Repositioning guides had a minimal effect on L* values and no effect on b* values. The use of pink silicone increased a* values, whereas blue or translucent silicone reduced them. Irrespective of the evaluated tooth, the lowest ΔE00 values were observed for the translucent silicone and bleaching tray. The usage of guides only affected data variability for the L* color coordinate. CONCLUSION: Using repositioning guides can significantly impact the precision of tooth color measurement with a clinical spectrophotometer.

New races with wider virulence indicate rapid evolution of Puccinia striiformis f. sp. tritici in the Southern Cone of America.

Wheat yellow (stripe) rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat worldwide. Pst populations are composed of multiple genetic groups, each carrying one or more races characterized by different avirulence/virulence combinations. Since the severe epidemics in 2017, yellow rust has become the most economically important wheat foliar disease in Uruguay. A set of 124 Pst isolates collected from wheat fields in Uruguay between 2017 and 2021 were characterized phenotypically and 27 of those isolates were subsequently investigated in-depth by additional molecular genotyping and race phenotyping analyses. Three genetic groups were identified, i.e., PstS7, PstS10 and PstS13, the latter being the most prevalent. Two races previously reported in Europe, Warrior (PstS7) and Benchmark (PstS10), were detected in four and two isolates, respectively. A third race known as Triticale2015 (PstS13), first detected in Europe in 2015 and in Argentina in 2017, was detected at several locations. Additional virulence to Yr3, Yr17, Yr25, Yr27 or Yr32 was detected in three new race variants within PstS13. The identification of these new races, which have not been reported outside South America, provides strong evidence of the local evolution of virulence in Pst during the recent epidemic years.

Práticas de enfermeiros na prevenção e rastreio do câncer de mama e de colo uterino / Practices performed by nurses in the prevention and screening of breast and cervical cancer / Prácticas de enfermería en la prevención y detección del cáncer de mama y cervicouterino

Objetivo: Identificar como ocorrem as práticas de prevenção e de rastreio do câncer de mama e de colo uterino realizadas por enfermeiros que atuam na Atenção Primária à Saúde do Rio Grande do Sul. Métodos: Trata-se de um estudo de abordagem qualitativa e de natureza analítica e compreensiva. Realizou-se entrevistas semiestruturadas. Os dados foram submetidos à análise de conteúdo do tipo temática proposta por Minayo. Os colaboradores foram 58 enfermeiros atuantes na Atenção Primária à Saúde. Resultados: Os resultados apontam que as práticas se desenvolvem em um contexto de crescente autonomia profissional e de protagonismo da Enfermagem. Aspectos como proximidade e vínculo com a comunidade, outros procedimentos e ações ofertadas nos atendimentos, incluindo a condução clínica/terapêutica, na vigência de sinais e sintomas de infecção, condizem com uma atenção mais ampla às necessidades de saúde e de cuidado às mulheres. Conclusão: O estudo evidencia a importância do respaldo de protocolos para a atuação segura das práticas dos enfermeiros da Atenção Básica, visando a prevenção e rastreio do câncer de mama e de colo uterino. Esses instrumentos devem ser de fácil acesso e constantemente atualizados a fim de garantir a padronização preconizada pelo Ministério da Saúde. (AU)

Objective: To identify how the breast and cervical cancer prevention and screening practices performed by nurses working in Primary Health Care in the state of Rio Grande do Sul occurs. Methods: This is a qualitative study with an analytical and comprehensive nature. The collaborators were 58 nurses working in Primary Health Care. Results: The results indicate that the practices are developed in a context of increasing professional autonomy and the role of Nursing. Aspects such as proximity and bonding with the community, other procedures and actions offered in the consultations, including clinical/therapeutic management in cases of signs and symptoms of infection, are consistent with a broader attention to women's health and care needs. Conclusion: The study highlights the importance of supporting protocols for the safe performance of Primary Care nurses' practices, aiming at the prevention and screening of breast and cervical cancer. These documents must be easily accessible and constantly updated in order to guarantee the standardization recommended by the Ministry of Health. (AU)

Objetivo: Identificar cómo las prácticas de prevención y detección del cáncer de mama y cervicouterino son realizadas por enfermeros que actúan en la Atención Primaria de Salud en Rio Grande do Sul. Métodos: Se trata de un estudio cualitativo de carácter analítico y comprensivo. Los colaboradores fueron 58 enfermeros que actuaban en la Atención Primaria de Salud. Resultados: Los resultados indican que las prácticas se desarrollan en un contexto de aumento de la autonomía profesional y del papel de la Enfermería. Aspectos como la proximidad y el vínculo con la comunidad, otros procedimientos y acciones que se ofrecen en las consultas, incluido el manejo clínico/terapéutico en casos de signos y síntomas de infección, son consistentes con una atención más amplia a las necesidades de salud y cuidado de las mujeres. Conclusión: El estudio destaca la importancia de protocolos para la actuación segura de las prácticas de los enfermeros de Atención Primaria, con el objetivo de la prevención y el tamizaje del cáncer de mama y de cuello uterino. Estos instrumentos deben ser de fácil acceso y constantemente actualizados para garantizar la estandarización recomendada por el Ministerio de Salud. (AU)

Biomarker RIPK3 Is Silenced by Hypermethylation in Melanoma and Epigenetic Editing Reestablishes Its Tumor Suppressor Function.

For several decades, cancers have demonstrably been one of the most frequent causes of death worldwide. In addition to genetic causes, cancer can also be caused by epigenetic gene modifications. Frequently, tumor suppressor genes are epigenetically inactivated due to hypermethylation of their CpG islands, actively contributing to tumorigenesis. Since CpG islands are usually localized near promoters, hypermethylation of the promoter can have a major impact on gene expression. In this study, the potential tumor suppressor gene Receptor Interacting Serine/Threonine Protein Kinase 3 (RIPK3) was examined for an epigenetic regulation and its gene inactivation in melanomas. A hypermethylation of the RIPK3 CpG island was detected by bisulfite pyrosequencing and was accompanied by a correlated loss of its expression. In addition, an increasing RIPK3 methylation rate was observed with increasing tumor stage of melanomas. For further epigenetic characterization of RIPK3, epigenetic modulation was performed using a modified CRISPR/dCas9 (CRISPRa activation) system targeting its DNA hypermethylation. We observed a reduced fitness of melanoma cells by (re-)expression and demethylation of the RIPK3 gene using the epigenetic editing-based method. The tumor suppressive function of RIPK3 was evident by phenotypic determination using fluorescence microscopy, flow cytometry and wound healing assay. Our data highlight the function of RIPK3 as an epigenetically regulated tumor suppressor in melanoma, allowing it to be classified as a biomarker.

Effect of gingival barrier brands on operator perception, cervical adaptation, and patient comfort during in-office tooth bleaching: a randomized clinical trial.

BACKGROUND: Light-cured resins are widely used as gingival barriers to protect the gums from highly concentrated peroxides used in tooth bleaching. The impact of barrier brand on clinical outcomes is typically considered negligible. However, there is limited evidence on the effects of different brands on operator experience, barrier adaptation, and patient comfort. OBJECTIVE: This clinical trial assessed the impact of four commercial gingival barrier brands (Opaldam, Topdam, Lysadam, and Maxdam) on operator perception, adaptation quality, and patient comfort. METHODS: Twenty-one undergraduate students placed gingival barriers in a randomized sequence using blinded syringes. Photographs of the barriers were taken from frontal and incisal perspectives. After bleaching procedures, operators rated handling features and safety using Likert scale forms. Two experienced evaluators independently assessed barrier adaptation quality on a scale from 1 (perfect) to 5 (unacceptable). The absolute risk of barrier-induced discomfort was recorded. Data were analyzed using Friedman and Chi-square tests (α = 0.05). RESULTS: Opaldam and Topdam received the highest scores in most handling features, except for removal, which was similar among all brands. No significant difference was observed in barrier adaptation quality between the evaluated brands. Discomforts were mainly reported in the upper dental arch, with Maxdam having the highest absolute risk (35% for this arch and 24% overall). CONCLUSIONS: This study suggests that gingival barrier brands can influence operator perception and patient comfort. Opaldam and Topdam were preferred by operators, but all brands demonstrated comparable adaptation quality. CLINICAL TRIAL REGISTRATION: The study was nested in a randomized clinical trial registered in the Brazilian Clinical Trials Registry under identification number RBR-9gtr9sc.

Comparative histological description of the intestine in platyfish (Xiphophorus maculatus) and swordtail fish (Xiphophorus helleri).

This study aimed to provide a comprehensive analysis of the histological structure of intestinal tissues of platyfish (Xiphophorus maculatus) and swordtail fish (Xiphophorus helleri). Specifically, the objectives were: (1) to compare the structural adaptations of their intestines related to their distinct feeding habits, diet, and digestive strategies; and (2) to explore their potential as animal models for intestinal disease research. Through detailed examination of tissue morphology, cell types, and structural features, this study found that both species lack a stomach, with the intestine directly connected to the esophagus. Additionally, this study proposes a new division of the intestine into anterior and posterior segments based on distinct histological characteristics. The anterior segment may be adapted for temporary food storage and digestion and was characterized by elongated epithelial cells and thin intestinal folds. In contrast, the posterior segment displayed shorter villi and higher concentrations of goblet cells. This study is the first to describe in detail the intestinal morphology of platyfish and swordtail fish. These findings contribute significantly to the understanding of the comparative anatomy and physiology of these fish species, highlighting their potential as valuable models for intestinal biology research.

Deletion of the lipid droplet protein kinase gene affects lipid droplets biogenesis, parasite infectivity, and resistance to trivalent antimony in Leishmania infantum.

The Lipid Droplet Protein Kinase (LDK) facilitates lipid droplet (LD) biogenesis, organelles involved in various metabolic and signaling functions in trypanosomatids. As LDK's function has not been previously explored in Leishmania spp., we utilized CRISPR/Cas9 technology to generate LDK-knockout lines of Leishmania infantum to investigate its role in this parasite. Our findings demonstrate that LDK is not an essential gene for L. infantum, as its deletion did not impede parasite survival. Furthermore, removing LDK did not impact the growth of promastigote forms of L. infantum lacking LDK. However, a noticeable reduction in LDs occurred during the stationary phase of parasite growth following LDK deletion. In the presence of myriocin, a LD inducer, LDK-knockout parasites displayed reduced LD abundance during both logarithmic and stationary growth phases compared to control parasites. Moreover, an infection analysis involving THP-1 cells revealed that 72 h post-infection, LDK-knockout L. infantum lines exhibited fewer infected macrophages and intracellular amastigotes than control parasites. LDK-knockout L. infantum lines also displayed 1.7 to 1.8 -fold greater resistance to trivalent antimony than control parasites. There were no observed alterations in susceptibility to amphotericin B, miltefosine, or menadione in LDK-knockout L. infantum lines. Our results suggest that LDK plays a crucial role in the biogenesis and/or maintenance of LDs in L. infantum, as well as in parasite infectivity and resistance to trivalent antimony.

Exploring Genomics and Microbial Ecology: Analysis of Bidens pilosa L. Genetic Structure and Soil Microbiome Diversity by RAD-Seq and Metabarcoding.

Bidens pilosa L., native to South America and commonly used for medicinal purposes, has been understudied at molecular and genomic levels and in its relationship with soil microorganisms. In this study, restriction site-associated DNA markers (RADseq) techniques were implemented to analyze genetic diversity and population structure, and metabarcoding to examine microbial composition in soils from Palmira, Sibundoy, and Bogotá, Colombia. A total of 2,984,123 loci and 3485 single nucleotide polymorphisms (SNPs) were identified, revealing a genetic variation of 12% between populations and 88% within individuals, and distributing the population into three main genetic groups, FST = 0.115 (p < 0.001) and FIT = 0.013 (p > 0.05). In the soil analysis, significant correlations were found between effective cation exchange capacity (ECEC) and apparent density, soil texture, and levels of Mg and Fe, as well as negative correlations between ECEC and Mg, and Mg, Fe, and Ca. Proteobacteria and Ascomycota emerged as the predominant bacterial and fungal phyla, respectively. Analyses of alpha, beta, and multifactorial diversity highlight the influence of ecological and environmental factors on these microbial communities, revealing specific patterns of clustering and association between bacteria and fungi in the studied locations.

Effects of enamel moistening and repositioning guide color on tooth whitening outcomes: A clinical trial.

This clinical trial investigated the effects of pre-application enamel moistening on the impact of a 37% carbamide peroxide whitener on tooth color changes and the influence of repositioning guide colors. Forty participants were randomly assigned to in-office tooth bleaching with either moistened enamel (experimental) or dry enamel (control). The whitener was applied for 45 min over two sessions. Tooth color was visually measured or assessed using a spectrophotometer with purple or green silicone guides. Tooth bleaching was assessed using CIE76 (ΔEab ) and CIEDE2000 (ΔE00 ) formulas and by whitening and bleaching index score changes. Moistening the enamel did not significantly affect tooth color. However, the guide color choice only impacted tooth color when measured instrumentally. At baseline, the green guide resulted in statistically significantly whiter teeth than the purple guide. Less pronounced differences in the b* coordinate between baseline and final measurements were found using the green guide. The green guide also produced lower ΔEab values and less change in indexes. In conclusion, moistening the enamel did not significantly impact tooth color changes. However, the repositioning guide color influenced the tooth bleaching measured instrumentally, except for ΔE00 .

Color matching and color recovery in large composite restorations using single-shade or universal composites

Abstract This study assessed the color-matching ability and color recovery of unprepared teeth when using single-shade composites and a universal composite in large restorations. Buccal and palatine surface colors of molars were measured with a spectrophotometer (CIELAB) before preparing round cavities (6 mm in diameter, 2 mm in depth). The cavities were randomly filled with a single-shade composite (Omnichroma, Diamond One, or Vittra APS Unique) or a universal composite (Filtek Universal). Color measurements of the restored cavities were taken, and overall color differences (ΔEab and ΔE00) and differences in the whitening index for dentistry (ΔWID) from baseline were calculated. Additionally, visual assessments of a color match to the surrounding enamel were performed by forty evaluators (laypersons and undergraduate students of dentistry) in a viewing booth under illuminant D65, with rating scores from 0 (no color mismatch) to 4 (not acceptable). Data were analyzed using RM or one-way ANOVA (α = 0.05). Results showed that the restorations generally exhibited whiter colors (WID ranged from 27.9 to 41.3) than the unprepared teeth (WID ranged from 15.9 to 19.3). The composite Filtek Universal demonstrated the lowest color discrepancy (ΔWID = 8.6; ΔE00 = 10.8; and ΔE00 = 6.2), and no significant differences were observed among the evaluated single-shade composites. Furthermore, all composites showed similar and adequate color matches to the surrounding enamel. However, it is important to note that despite their ability to match the surrounding enamel reasonably, none of the composites evaluated in large restorations fully recovered the color observed in unprepared teeth.

Resumo Este estudo avaliou a habilidade de combinação de cores e recuperação de cor de dentes não preparados ao utilizar resinas compostas de única tonalidade e uma resina composta universal em grandes restaurações. As cores das superfícies bucais e palatinas de molares foram medidas com um espectrofotômetro (CIELAB) antes de preparar cavidades esféricas (6 mm de diâmetro, 2 mm de profundidade). As cavidades foram preenchidas aleatoriamente com uma resina composta de única tonalidade (Omnichroma, Diamond One ou Vittra APS Unique) ou com uma resina composta universal (Filtek Universal). Foram realizadas medições das cores das cavidades restauradas e calculadas as diferenças de cor globais (ΔEab and ΔE00)) e as diferenças no índice de clareamento para odontologia (ΔWID) em relação à cor inicial. Além disso, foram realizadas avaliações visuais da correspondência de cor com o esmalte circundante por quarenta avaliadores (leigos e estudantes de odontologia) em uma cabine de visualização sob iluminante D65, com pontuações de 0 (nenhuma discrepância de cor) a 4 (não aceitável). Os dados foram analisados usando RM ou ANOVA unidirecional (α = 0,05). Os resultados mostraram que as restaurações geralmente apresentavam cores mais brancas (WID variou de 27,9 a 41,3) do que os dentes não preparados (WID variou de 15,9 a 19,3). A resina composta Filtek Universal demonstrou a menor discrepância de cor (ΔWID = 8,6; ΔE00 = 10,8; and ΔE00 = 6,2), e não foram observadas diferenças significativas entre as resinas compostas de única tonalidade avaliadas. Além disso, todas as resinas compostas apresentaram correspondência de cor similar e adequada com o esmalte circundante. No entanto, é importante observar que, apesar de sua capacidade de corresponder razoavelmente com o esmalte circundante, nenhuma das resinas compostas avaliadas em grandes restaurações recuperou completamente a cor observada nos dentes não preparados.

Influence of repositioning guides' color and usage on precision in tooth color measurement with a clinical spectrophotometer

Abstract Repositioning guides are commonly employed in clinical studies to ensure consistent tooth color measurements. Yet, their influence on measured color remains uncertain. Objective This study evaluated the impact of repositioning guides' color and usage on tooth color measurement using a clinical spectrophotometer. Methodology In total, 18 volunteers participated in this study, in which the color of their upper left central incisor and upper left canine was measured with or without repositioning guides (control). The guides were made from pink, blue, or translucent silicone, as well as an acetate-based bleaching tray. Tooth color was measured in triplicates using a clinical spectrophotometer based on the CIELAB system. The standard deviations of these readings were used to estimate reproducibility, and color differences (ΔE00) between the measurements with guides and the control were calculated. Results Repositioning guides had a minimal effect on L* values and no effect on b* values. The use of pink silicone increased a* values, whereas blue or translucent silicone reduced them. Irrespective of the evaluated tooth, the lowest ΔE00 values were observed for the translucent silicone and bleaching tray. The usage of guides only affected data variability for the L* color coordinate. Conclusion Using repositioning guides can significantly impact the precision of tooth color measurement with a clinical spectrophotometer.

Bone mass, fracture risk, and associated factors in postmenopausal women living with HIV.

OBJECTIVE: The aim of this study was to assess the prevalence of low bone mass (osteopenia/osteoporosis), the factors associated with low bone mass, and the risk of fractures in Brazilian postmenopausal women living with HIV (WLH) in the Amazon region. METHODS: This is a cohort study with a cross-sectional assessment at baseline conducted between March 2021 to August 2022 with 100 postmenopausal WLH undergoing antiretroviral therapy (ART) between 45 and 60 years of age and 100 age-matched HIV-negative women. Data on bone mineral density in the lumbar spine (LS) and femoral neck (FN) were collected using dual x-ray absorptiometry and the 10-year risk of hip and major osteoporotic fractures was assessed using the Fracture Risk Assessment tool (FRAX). RESULTS: The age of menopause onset occurred earlier in WLH ( P < 0.001). No differences in prevalence of osteoporosis and osteopenia in LS and FN were observed except for a lower T score in FN in WLH ( P = 0.039). The FRAX for major osteoporotic fracture and hip fracture were low in both groups, despite the mean of both FRAX scores was higher in WLH ( P < 0.001). Multivariate analysis showed that years since menopause onset, higher body mass index and higher FRAX major osteoporotic fracture were associated with the WLH group, while a higher frequency of physical activity was registered in the HIV-negative group. Multivariate analysis also showed that in WLH, a lower T score in FN was associated with years since menopause onset and body mass index and that the number of years since menopause onset was associated with a lower T score in the LS and a higher score in the FRAX hip fracture. CONCLUSIONS: Our findings show a high prevalence of low bone mass (osteopenia/osteoporosis) in Brazilian postmenopausal women from the Amazon region. Women living with HIV have higher FRAX scores than HIV-negative women and a lower T score in the FN.

Construction and validity of educational technology about the human papillomavirus vaccine for adolescents.

OBJECTIVES: to construct and validate an educational technology in comic book format about the human papillomavirus vaccine aimed at adolescents. METHODS: a methodological study, with a quantitative approach, through the agreement method. It was carried out in two phases: educational technology construction and content validity. Participants are expert judges in the health field. Data collection took place in a virtual environment, through a questionnaire. Data analysis was performed by calculating the Content Validity Index. A Content Validity Index of at least 80% was accepted. RESULTS: the comic book's overall Content Validity Index was 82%, reaching the minimum limit established to be validated. CONCLUSIONS: comics are fundamental in the teaching-learning process, aiming to catch adolescents' attention. Therefore, it is characterized as a valid tool to inform, in a playful manner, about the human papillomavirus vaccine.