Vulnerable period in heart failure: a window of opportunity for the optimization of treatment - a statement by Mexican experts.

Acute heart failure (HF) is associated with poor prognosis. After the acute event, there is a vulnerable period during which the patient has a marked risk of readmission or death. Therefore, early optimization of treatment is mandatory during the vulnerable period. The objective of this article is to provide recommendations to address the management of patients with HF during the vulnerable period from a practical point of view. A group of Mexican experts met to prepare a consensus document. The vulnerable period, with a duration of up to 6 months after the acute event - either hospitalization, visit to the emergency department or the outpatient clinic/day hospital - represents a real window of opportunity to improve outcomes for these patients. To best individualize the recommendations, the management strategies were divided into three periods (early, intermediate and late vulnerable period), including not only therapeutic options but also evaluation and education. Importantly, the recommendations are addressed to the entire cardiology team, including physicians and nurses, but also other specialists implicated in the management of these patients. In conclusion, this document represents an opportunity to improve the management of this population at high risk, with the aim of reducing the burden of HF.

Cardiovascular Disease in Women With Breast Cancer: A Contemporary Review

Abstract Breast cancer (BC) is the most common malignant neoplasia in women and is responsible for one in six deaths from cancer in the female population. Five years after diagnosis, BC survival rates currently exceed 80%. Cardiovascular disease (CVD) is a frequent cause of morbidity and mortality in BC, mainly in patients receiving cardiotoxic drugs (anthracyclines, immunotherapy) and radiotherapy (RT). CVD and BC have common risk factors (RF), which are related to aging, traditional and cardiometabolic RFs (obesity, dyslipidemia, consumption of alcoholic beverages), and others associated with sex and reproductive women's age, such as early menarche, late menopause, nulliparity, use of oral contraceptives, as well as hormone replacement therapy in postmenopause. Risk stratification and the promotion of an ideal state of cardiovascular (CV) health are fundamental in preventing CVD in survivors. Therapeutic management and follow-up of patients with BC require a multidisciplinary team to reduce complications and mortality of CV origin.

Third National Registry of Cardiac Rehabilitation Programs in Mexico (RENAPREC III-2022) / Tercer Registro Nacional de Programas de Rehabilitación Cardiaca en México (RENAPREC III-2022)

Abstract Introduction: In Mexico, cardiac rehabilitation (CR) as an interdisciplinary intervention with therapeutic impact in patients with heart disease is growing. There is the need to know actual conditions of CR in our country. Objectives: The objective of this National Registry is to follow-up those existing and new CR units in Mexico through the comparison between the two previous registries, RENAPREC-2009 and RENAPREC II-2015 studies. This is a descriptive study focused on diverse CR activities such as assistance training, and certification of health professionals, barriers, reference, population attended, interdisciplinarity, permanence over time, growth prospects, regulations, post-pandemic condition, integrative characteristics, and scientific research. Results: Data were collected from 45 CR centers in the 32 states, 75.5% are private practice units, 67% are new, 33% were part of RENAPREC II-2015, and 17 have continued since 2009. With a better distribution of CR units along the territory, the median reference of candidates for CR programs is 9% with a significant reduction into tiempo of enrollment to Phase II admission (19 ± 11 days). Regarding to previous registries, the coverance of Phases I, II, and III is 71%, 100%, and 93%, respectively; and a coverance increases in evaluation, risk stratification, and prescription, more comprehensive attendance and prevention strategies. Conclusions: CR in Mexico has grown in the past 7 years. Even there is still low reference and heterogeneity in specific processes, there are strengths such as interdisciplinarity, scientific professionalization of specialists, national diversification, and an official society that are consolidated over time.

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In-Silico Selection of Wound-Healing Plant Secondary Molecules and Their Pro-Healing Activities on Experimental Models.

This study explored the potential of plant-derived molecules (PDMs) as a medicinal treatment for skin wounds. To assess their healing properties, 34 potential drug molecules (PDMs) and ten therapeutic targets were subjected to molecular docking and dynamics analysis, with allantoin used as a standard compound. Although aristolochic acid had the most potent inhibitory effect, its toxicity made it unsuitable for testing on cells and mice. Therefore, ß-caryophyllene (BC) and caryophyllene oxide (BCoxide) were chosen for further testing. The results showed that BC-treated HaCat cells had significantly improved scratch area closure, and both BC and BCoxide treatment produced positive effects such as reduced dermal cellularity and mast cells, decreased levels of inflammation markers IL-6 and TNF-α, and an increase in collagen deposition in mice tissues. However, these treatments did not accelerate wound healing. This study suggests that the PDMs selected based on in-silico results have significant potential for pro-healing abilities. It is essential to conduct further research to confirm our findings.

Comparison of the transgenic rodent mutation assay, error corrected next generation duplex sequencing, and the alkaline comet assay to detect dose-related mutations following exposure to N-nitrosodiethylamine.

N-Nitrosodiethylamine (NDEA), a well-studied N-nitrosamine, was tested in rats to compare the dose-response relationship of three genotoxicity endpoints. Mutant / mutation frequencies were determined using the transgenic rodent (TGR) gene mutation assay and error corrected next generation sequencing (ecNGS) (i.e., duplex sequencing (DS)), and genetic damage was detected by the alkaline comet assay. Big Blue® (cII Locus) animals (n = 6 per dose group) were administered doses of 0.001, 0.01, 0.1, 1, 3 mg/kg/day NDEA by oral gavage. Samples were collected for cII mutation and DS analyses following 28-days of exposure and 3 days recovery. In a separate study, male Sprague-Dawley (SD) rats (n = 6 per dose group) were administered the same doses by oral gavage for two consecutive days and then samples collected for the alkaline comet assay. A dose-related increase in mutant / mutation frequencies of the liver but not duodenum was observed using the TGR assay and DS with DS resulting in a slightly more sensitive response, with a lower benchmark dose (BMD). In addition, a dose-related increase in percent tail DNA was observed in the liver using the alkaline comet assay. Therefore, DS and comet assays showed good utility for hazard identification and dose-response analysis of a representative N-nitrosamine comparable to the TGR gene mutation assay.

Error-corrected next generation sequencing - Promises and challenges for genotoxicity and cancer risk assessment.

Error-corrected Next Generation Sequencing (ecNGS) is rapidly emerging as a valuable, highly sensitive and accurate method for detecting and characterizing mutations in any cell type, tissue or organism from which DNA can be isolated. Recent mutagenicity and carcinogenicity studies have used ecNGS to quantify drug-/chemical-induced mutations and mutational spectra associated with cancer risk. ecNGS has potential applications in genotoxicity assessment as a new readout for traditional models, for mutagenesis studies in 3D organotypic cultures, and for detecting off-target effects of gene editing tools. Additionally, early data suggest that ecNGS can measure clonal expansion of mutations as a mechanism-agnostic early marker of carcinogenic potential and can evaluate mutational load directly in human biomonitoring studies. In this review, we discuss promising applications, challenges, limitations, and key data initiatives needed to enable regulatory testing and adoption of ecNGS - including for advancing safety assessment, augmenting weight-of-evidence for mutagenicity and carcinogenicity mechanisms, identifying early biomarkers of cancer risk, and managing human health risk from chemical exposures.

Next Generation Sequencing Workshop at the Royal Society of Medicine (London, May 2022): how genomics is on the path to modernizing genetic toxicology.

The use of error-corrected Next Generation Sequencing (ecNG) to determine mutagenicity has been a subject of growing interest and potentially a disruptive technology that could supplement, and in time, replace current testing paradigms in preclinical safety assessment. Considering this, a Next Generation Sequencing Workshop was held at the Royal Society of Medicine in London in May 2022, supported by the United Kingdom Environmental Mutagen Society (UKEMS) and TwinStrand Biosciences (WA, USA), to discuss progress and future applications of this technology. In this meeting report, the invited speakers provide an overview of the Workshop topics covered and identify future directions for research. In the area of somatic mutagenesis, several speakers reviewed recent progress made with correlating ecNGS to classic in vivo transgenic rodent mutation assays as well as exploring the use of this technology directly in humans and animals, and in complex organoid models. Additionally, ecNGS has been used for detecting off-target effects of gene editing tools and emerging data suggest ecNGS potential to measure clonal expansion of cells carrying mutations in cancer driver genes as an early marker of carcinogenic potential and for direct human biomonitoring. As such, the workshop demonstrated the importance of raising awareness and support for advancing the science of ecNGS for mutagenesis, gene editing, and carcinogenesis research. Furthermore, the potential of this new technology to contribute to advances in drug and product development and improve safety assessment was extensively explored.

Biowaxes from Palm Oil as Promising Candidates for Cosmetic Matrices and Pharmaceuticals for Human Use.

The production of waxes from vegetable oils, such as palm oil, for use as a base material in products for human applications is an alternative to those derived from petroleum and animals. Seven palm oil-derived waxes, called biowaxes (BW1-BW7) in this work, were obtained by catalytic hydrotreating of refined and bleached African palm oil and refined palm kernel oil. They were characterized by three properties: compositional, physicochemical (melting point, penetration value, and pH), and biological (sterility, cytotoxicity, phototoxicity, antioxidant, and irritant). Their morphologies and chemical structures were studied by SEM, FTIR, UV-Vis, and 1H NMR. The BWs presented structures and compositions similar to natural biowaxes (beeswax and carnauba). They had a high concentration of waxy esters (17%-36%) with long alkyl chains (C, 19-26) per carbonyl group, which are related to high melting points (<20-47.9 °C) and low penetration values (2.1-3.8 mm). They also proved to be sterile materials with no cytotoxic, phototoxic, antioxidant, or irritant activity. The biowaxes studied could be used in cosmetic and pharmacological products for human use.

[Third National Registry of Cardiac Rehabilitation Programs in Mexico (RENAPREC III-2022)]. / Tercer Registro Nacional de Programas de Rehabilitación Cardiaca en México (RENAPREC III-2022).

Introduction: In Mexico, cardiac rehabilitation (CR) as an interdisciplinary intervention with therapeutic impact in patients with heart disease is growing. There is the need to know actual conditions of CR in our country. Objectives: The objective of this National Registry is to follow-up those existing and new CR units in Mexico through the comparison between the two previous registries, RENAPREC-2009 and RENAPREC II-2015 studies. This is a descriptive study focused on diverse CR activities such as assistance training, and certification of health professionals, barriers, reference, population attended, interdisciplinarity, permanence over time, growth prospects, regulations, post-pandemic condition, integrative characteristics, and scientific research. Results: Data were collected from 45 CR centers in the 32 states, 75.5% are private practice units, 67% are new, 33% were part of RENAPREC II-2015, and 17 have continued since 2009. With a better distribution of CR units along the territory, the median reference of candidates for CR programs is 9% with a significant reduction into tiempo of enrollment to Phase II admission (19 ± 11 days). Regarding to previous registries, the coverance of Phases I, II, and III is 71%, 100%, and 93%, respectively; and a coverance increases in evaluation, risk stratification, and prescription, more comprehensive attendance and prevention strategies. Conclusions: CR in Mexico has grown in the past 7 years. Even there is still low reference and heterogeneity in specific processes, there are strengths such as interdisciplinarity, scientific professionalization of specialists, national diversification, and an official society that are consolidated over time.

Introducción: En México, la Rehabilitación Cardíaca (RC) como intervención interdisciplinaria con impacto terapéutico en paciente con cardiopatía está en crecimiento. Existe la necesidad de conocer las condiciones actuales de la RC en nuestro país. Objetivo: El objetivo de este Registro es dar seguimiento comparativo de las unidades nuevas y existentes entre los registros anteriores, RENAPREC-2009 y RENAPREC II-2015. Se trata de un estudio descriptivo centrado en diversas actividades de la RC: formación asistencial y certificación de sus profesionales, barreras, referencia, población atendida, interdisciplinariedad, permanencia en el tiempo, perspectivas de crecimiento, normativa, condición pospandemia, características integradoras e investigación. Resultados: Se recolectaron datos de 45 centros en los 32 estados, 67% son nuevos 75.5% son de práctica privada, 33% fueron parte de RENAPREC II-2015 y 17 desde 2009. Con una mejor distribución de las unidades de RC a lo largo del territorio, la mediana de referencia de pacientes candidatos a RC es ahora del 9% con reducción significativa del tiempo de admisión a Fase II (19 ± 11 días). Respecto a registros anteriores las coberturas de las Fases I, II y III son del 71%, 100% y 93%, respectivamente; con un aumento de la cobertura en evaluación, estratificación de riesgo y prescripción, atención más integral y estrategias de prevención. Conclusiones: La RC en México ha crecido en los últimos 7 años. Si bien aún existe baja referencia y heterogeneidad en procesos específicos, existen fortalezas como la interdisciplinariedad, la profesionalización científica de los especialistas, la diversificación nacional y una sociedad oficial que se consolida en el tiempo.

Influence of bioceramic intracanal medication on the bond strength of bioceramic root canal sealer.

To investigate the influence of the remaining volume of a new intracanal medication based on bioceramic compounds on the bond strength (BS) and formation of an adhesive interface between calcium silicate-based and epoxy resin-based root canal sealers. For this purpose, the specimens were distributed according to the intracanal medication (n = 26): Bio-C Temp (BCT) and Ultracal XS (UXS). The roots were scanned in microCT, and after 7 days, the medication was removed. Then a new scan was performed to evaluate the volume of medication remaining. Subsequently, 40 specimens were redistributed into 2 subgroups (n = 10) and filled according to the sealer used: AH Plus (AHP) and Bio-C Sealer (BCS), to assess the bond strength by using the push-out test, and the adhesive interface by confocal laser fluorescence microscopy (CLSM) and scanning electron microscopy (SEM). The t test showed a smaller remainder of BCT (1.77 ± 0.86) compared with UXS (10.47 ± 5.78), irrespective of the root third evaluated. The BS showed that teeth with BCT + BCS had higher bond strength values (3.70 ± 1.22) when compared to the other groups: BCT + AHP (2.15 ± 1.07), UXS + BCS (3.18 ± 1.09) and UXS + AHP (2.11 ± 1.02) (p<0.001). The cervical third had higher BS when compared with the middle and apical thirds (p < 0.001), and higher number of adhesive failures. The adhesive interface in SEM and CLSM images showed better adaptation for the association between BCT + BCS. Intracanal medication and silicate-based endodontic sealer appeared to interact chemically by forming a biomineralizing layer, allowing for an increase in the bond strength and forming an adhesive interface between the materials, with no or less gap formation.

Essential Oils Distilled from Colombian Aromatic Plants and Their Constituents as Penetration Enhancers for Transdermal Drug Delivery.

The study aimed to determine the enhanced effects of essential oils (EOs) and plant-derived molecules (PDMs) as penetration enhancers (PEs) for transdermal drug delivery (TDD) of caffeine. A 1% w/w solution of eight EOs and seven PDMs was included in the 1% caffeine carbopol hydrogel. Franz diffusion cell experiments were performed using mice with full-thickness skin. At various times over 24 h, 300 µL of the receptor were withdrawn and replaced with fresh medium. Caffeine was analyzed spectrophotometrically at 272 nm. The skin irritation effects of the hydrogels applied once a day for 21 days were investigated in mice. The steady-state flux (JSS) of the caffeine hydrogel was 30 ± 19.6 µg cm-2 h-1. An increase in caffeine JSS was induced by Lippia origanoides > Turnera diffusa > eugenol > carvacrol > limonene, with values of 150 ± 14.1, 130 ± 47.6, 101 ± 21.7, 90 ± 18.4, and 86 ± 21.0 µg cm-2 h-1, respectively. The Kp of caffeine was 2.8 ± 0.26 cm h-1, almost 2-4 times lower than that induced by Lippia origanoides > Turnera diffusa > limonene > eugenol > carvacrol, with Kp values of 11 ± 1.7, 8.8 ± 4.2, 6.8 ± 1.7, 6.3 ± 1.2, and 5.15 ± 1.0 cm h-1, respectively. No irritating effects were observed. Lippia origanoides, Turnera diffusa, eugenol, carvacrol, and limonene improved caffeine's skin permeation. These compounds may be as effective as the PE in TDD systems.

Influence of bioceramic intracanal medication on the bond strength of bioceramic root canal sealer

Abstract To investigate the influence of the remaining volume of a new intracanal medication based on bioceramic compounds on the bond strength (BS) and formation of an adhesive interface between calcium silicate-based and epoxy resin-based root canal sealers. For this purpose, the specimens were distributed according to the intracanal medication (n = 26): Bio-C Temp (BCT) and Ultracal XS (UXS). The roots were scanned in microCT, and after 7 days, the medication was removed. Then a new scan was performed to evaluate the volume of medication remaining. Subsequently, 40 specimens were redistributed into 2 subgroups (n = 10) and filled according to the sealer used: AH Plus (AHP) and Bio-C Sealer (BCS), to assess the bond strength by using the push-out test, and the adhesive interface by confocal laser fluorescence microscopy (CLSM) and scanning electron microscopy (SEM). The t test showed a smaller remainder of BCT (1.77 ± 0.86) compared with UXS (10.47 ± 5.78), irrespective of the root third evaluated. The BS showed that teeth with BCT + BCS had higher bond strength values (3.70 ± 1.22) when compared to the other groups: BCT + AHP (2.15 ± 1.07), UXS + BCS (3.18 ± 1.09) and UXS + AHP (2.11 ± 1.02) (p<0.001). The cervical third had higher BS when compared with the middle and apical thirds (p < 0.001), and higher number of adhesive failures. The adhesive interface in SEM and CLSM images showed better adaptation for the association between BCT + BCS. Intracanal medication and silicate-based endodontic sealer appeared to interact chemically by forming a biomineralizing layer, allowing for an increase in the bond strength and forming an adhesive interface between the materials, with no or less gap formation.

Changes in COVID-19 Vaccine Intent Among a Diverse Population of Older Adults, June 2021-February 2022.

Introduction COVID-19 vaccination rates remain suboptimal in the United States. Clinicians and policymakers need to better understand how likely vaccine-hesitant individuals are to ultimately accept vaccination and what is associated with such changes. This study's aims were to 1) describe changes between vaccine intentions and actual uptake from June 2021 through February 2022, and 2) identify modifiable factors associated with vaccine uptake among those with initial hesitancy. Methods This cohort study included a stratified random sample of adults aged 65 years and older in an integrated health care system. The survey, conducted June through August 2021, elicited intent and perceptions regarding COVID-19 vaccination. Subsequent vaccine uptake through February 2022 was analyzed using electronic health records. Results Of 1195 individuals surveyed, 66% responded; 213 reported not yet having received a COVID-19 vaccine and were further analyzed. At baseline, most individuals said they would definitely not (42%) or probably not (5%) get the COVID-19 vaccine or were not sure (26%). During follow-up, 61 individuals (29%) were vaccinated, including 19% of those who initially said they would definitely not be vaccinated. Among vaccine-hesitant individuals, the rate of vaccination was highest for those who initially considered COVID-19 less dangerous than the vaccine (46%) or named short-term side effects (36%) as their most important concern. Conclusions COVID-19 vaccine intent among older adults was malleable during the pandemic's second year, even among those who initially said they would definitely not be vaccinated. Vaccine uptake could be enhanced by increasing awareness of COVID-19 risks and by addressing vaccine side effects.

Use of the bacterial reverse mutation assay to predict carcinogenicity of N-nitrosamines.

Under ICH M7, impurities are assessed using the bacterial reverse mutation assay (i.e., Ames test) when predicted positive using in silico methodologies followed by expert review. N-Nitrosamines (NAs) have been of recent concern as impurities in pharmaceuticals, mainly because of their potential to be highly potent mutagenic carcinogens in rodent bioassays. The purpose of this analysis was to determine the sensitivity of the Ames assay to predict the carcinogenic outcome with curated proprietary Vitic (n = 131) and Leadscope (n = 70) databases. NAs were selected if they had corresponding rodent carcinogenicity assays. Overall, the sensitivity/specificity of the Ames assay was 93-97% and 55-86%, respectively. The sensitivity of the Ames assay was not significantly impacted by plate incorporation (84-89%) versus preincubation (82-89%). Sensitivity was not significantly different between use of rat and hamster liver induced S9 (80-93% versus 77-96%). The sensitivity of the Ames is high when using DMSO as a solvent (87-88%). Based on the analysis of these databases, the Ames assay conducted under OECD 471 guidelines is highly sensitive for detecting the carcinogenic hazards of NAs.

Effect of Electronic and Mail Outreach From Primary Care Physicians for COVID-19 Vaccination of Black and Latino Older Adults: A Randomized Clinical Trial.

Importance: COVID-19 morbidity is highest in Black and Latino older adults. These racial and ethnic groups initially had lower vaccination uptake than others, and rates in Black adults continue to lag. Objectives: To evaluate the effect of outreach via electronic secure messages and mailings from primary care physicians (PCPs) on COVID-19 vaccination uptake among Black and Latino older adults and to compare the effects of culturally tailored and standard PCP messages. Design, Setting, and Participants: This randomized clinical trial was conducted from March 29 to May 20, 2021, with follow-up surveys through July 31, 2021. Latino and Black individuals aged 65 years and older from 4 Kaiser Permanente Northern California (KPNC) service areas were included. Data were analyzed from May 27, 2021, to September 28, 2021. Interventions: Individuals who had not received COVID-19 vaccination after previous outreach were randomized to electronic secure message and/or mail outreach from their PCP, similar outreach with additional culturally tailored content, or usual care. Outreach groups were sent a secure message or letter in their PCP's name, followed by a postcard to those still unvaccinated after 4 weeks. Main Outcomes and Measures: The primary outcome was time to receipt of COVID-19 vaccination during the 8 weeks after initial study outreach. KPNC data were supplemented with state data from external sources. Intervention effects were evaluated via proportional hazards regression. Results: Of 8287 included individuals (mean [SD] age, 72.6 [7.0] years; 4665 [56.3%] women), 2434 (29.4%) were Black, 3782 (45.6%) were Latino and preferred English-language communications, and 2071 (25.0%) were Latino and preferred Spanish-language communications; 2847 participants (34.4%) had a neighborhood deprivation index at the 75th percentile or higher. A total of 2767 participants were randomized to culturally tailored PCP outreach, 2747 participants were randomized to standard PCP outreach, and 2773 participants were randomized to usual care. Culturally tailored PCP outreach led to higher COVID-19 vaccination rates during follow-up compared with usual care (664 participants [24.0%] vs 603 participants [21.7%]; adjusted hazard ratio (aHR), 1.22; 95% CI, 1.09-1.37), as did standard PCP outreach (635 participants [23.1%]; aHR, 1.17; 95% CI, 1.04-1.31). Individuals who were Black (aHR, 1.19; 95% CI, 1.06-1.33), had high neighborhood deprivation (aHR, 1.17; 95% CI, 1.03-1.33), and had medium to high comorbidity scores (aHR, 1.19; 95% CI, 1.09-1.31) were more likely to be vaccinated during follow-up. Conclusions and Relevance: This randomized clinical trial found that PCP outreach using electronic and mailed messages increased COVID-19 vaccination rates among Black and Latino older adults. Trial Registration: ClinicalTrials.gov Identifier: NCT05096026.

Discriminator for Cutaneous Leishmaniasis Using MALDI-MSI in a Murine Model.

Cutaneous leishmaniasis is a skin disease caused by flagellate protozoa of the genus Leishmania and transmitted by sandflies of the genus Lutzomyia. Around 1 million new cases occur in the world annually, with a total of 12 million people affected, mainly in rural areas with low access to health services and adequate treatments. In the area of the Americas, Colombia has one of the highest infection rates after Brazil. Topical treatments with pentamidine isethionate (PMD) present an attractive alternative due to their ease of application and low costs. However, cutaneous leishmaniasis lesions present nodules with seropurulent exudate that, when drying, form hyperkeratotic lesions, hindering the effective penetration of drugs for their treatment. The use of molecular histology techniques, such as MALDI-MSI, allow in situ evaluation of the penetration of the treatment to the sections of the dermis where the disease-causing parasite resides. However, the large volume of information generated makes it impossible to process it manually. Machine learning techniques allow the unsupervised processing of large amounts of information, generating prediction models for the classification of new information. This work proposes a low-cost method to generate cutaneous leishmaniasis detection and classification models using MALDI-MSI images taken from murine models. The proposed models allow a 95% efficiency when separating healthy samples from infected samples and an effectiveness of 67% when separating effectively treated samples from unsuccessfully treated samples.

A Collaborative Initiative to Establish Genomic Biomarkers for Assessing Tumorigenic Potential to Reduce Reliance on Conventional Rodent Carcinogenicity Studies.

There is growing recognition across broad sectors of the scientific community that use of genomic biomarkers has the potential to reduce the need for conventional rodent carcinogenicity studies of industrial chemicals, agrochemicals, and pharmaceuticals through a weight-of-evidence approach. These biomarkers fall into 2 major categories: (1) sets of gene transcripts that can identify distinct tumorigenic mechanisms of action; and (2) cancer driver gene mutations indicative of rapidly expanding growth-advantaged clonal cell populations. This call-to-action article describes a collaborative approach launched to develop and qualify biomarker gene expression panels that measure widely accepted molecular pathways linked to tumorigenesis and their activation levels to predict tumorigenic doses of chemicals from short-term exposures. Growing evidence suggests that application of such biomarker panels in short-term exposure rodent studies can identify both tumorigenic hazard and tumorigenic activation levels for chemical-induced carcinogenicity. In the future, this approach will be expanded to include methodologies examining mutations in key cancer driver gene mutation hotspots as biomarkers of both genotoxic and nongenotoxic chemical tumor risk. Analytical, technical, and biological validation studies of these complementary genomic tools are being undertaken by multisector and multidisciplinary collaborative teams within the Health and Environmental Sciences Institute. Success from these efforts will facilitate the transition from current heavy reliance on conventional 2-year rodent carcinogenicity studies to more rapid animal- and resource-sparing approaches for mechanism-based carcinogenicity evaluation supporting internal and regulatory decision-making.

In vitro selection of ketoconazole-pentamidine-resistant Leishmania (Viannia) braziliensis strains.

The use of ketoconazole (KTZ) plus pentamidine (PMD) could be an interesting treatment option for New World cutaneous leishmaniasis. The aim of this work was to generate KTZ- and PMD-resistant strains and to determine some characteristics of the selection process and the resulting parasites. Resistance to one or two drugs was selected on promastigotes by progressively increasing drug concentrations for eleven months. The resistance levels (IC50) to one or two drugs (synergism assay) were determined using a colorimetric resazurin methodology. The stability of the resistance phenotype (without drug pressure or after mouse passage), cross resistance with paromomycin and miltefosine, and resistance transference to intracellular amastigotes were determined. In addition, some parasite attributes compared with WT, such as growth kinetics, amastigogenesis, THP-1 cells, and mouse infection, were determined. Promastigotes resistant to KTZ or PMD were obtained three times earlier than the combined KTZ + PMD-resistant strains. Resistant parasites (promastigotes and intracellular amastigotes) were three to twelve times less susceptible to KTZ and PMD than WT parasites. The resistance phenotype on parasites was unstable, and no cross resistance was observed. Similar parasite fitness related to our evaluated characteristics was observed except for in vivo infection, where a delay of the onset of cutaneous lesions was observed after KTZ + PMD-resistant parasite infection. CONCLUSION: Combined treatment with KTZ and PMD delayed the onset of parasite resistance and was more effective in vitro than each drug separately for WT and all resistant strains. Parasites resistant to KTZ and PMD acquired similar in vitro behaviour to WT parasites, were less virulent to mice and maintained their resistance phenotype on intracellular amastigotes but not without drug pressure or after mouse infection.

Influence of different calcium hydroxide removal protocols on the bond strength of epoxy resin-based sealer in long oval root canals.

This study evaluated the effect of different protocols for Ca(OH)2 removal on the bond strength (BS) of epoxy resin-based sealer in long oval root canals. Forty-eight mandibular incisors with long oval root canals were selected by CBCT. Biomechanical preparation was performed, the samples were filled with Ca(OH)2 paste and distributed in four groups (n = 12): G-without Ca(OH)2 paste (C); G2-syringe/needle (SN); G3-SN + XP-Endo® Finisher (XPF); G4-SN + passive ultrasonic irrigation (PUI). After 7 days, Ca(OH)2 was removed and teeth were filled using AHPlus and guttapercha. In four samples from each group, the sealer was manipulated with 0.1% rhodamine to assess sealer penetration by fluorescent laser confocal microscopy (FLCM). Samples were sectioned in slices for BS, scanning electron microscopy, and FLCM analysis. The BS data were analyzed by ANOVA and Tukey tests (α = 0.05). The lowest BS values were found for the SN group (12.89 ± 4.36) compared to C (35.55 ± 10.05), while PUI group presented intermediate values (28.57 ± 9.35) and the XPF group (31.34 ± 9.8) showed values that were sometimes similar to C group and sometimes similar to PUI group (p > .05). The analysis of the adhesive interface showed evident gaps, with the presence of residues between the dentin and the filling material for the SN group, and for C, XPF and PUI groups juxtaposed adhesive interface. FLCM images showed sealer penetration in the dentinal tubules along the entire perimeter for C, XPF, and PUI groups. Ca(OH)2 removal with XPF and PUI from long oval root canals resulted in higher bond strength values compared to SN, besides better sealer penetration on dentinal tubules and juxtaposed adhesive interface.