Prenatal exposure to environmental toxins and comprehensive dental findings in a population cohort of children.

Environmental toxins are known to have many impacts on growth and development in humans, starting in utero. Alterations in amelogenesis, caused by chemical and physical trauma that occur during the antenatal, perinatal and postnatal time periods, may result in developmental defects in deciduous and permanent tooth enamel, as demonstrated in animal studies. These defects can be clinically visible and result in a variety of morphological and functional problems in the dentition. Since enamel does not remodel after formation, it may serve as a permanent record of insults during organ development.Our primary purpose was to investigate any possible relationship between intrauterine exposure to endocrine disrupting chemicals (phenols and phthalates) and developmental defects in enamel in children, while also accounting for fluoride exposure. Our secondary purpose was to report descriptively on findings from comprehensive dental examinations performed on 356 children that were drawn from the general paediatric population. A cohort of children from the Utah Children's Project (N = 356) that had full medical exams, comprehensive medical and family histories and available biospecimens were given extraoral and intraoral examinations. They also completed an oral health questionnaire. Standardized intraoral photographs were taken of the teeth and viewed by standardised examiners and the dental observations were recorded for a full inventory of findings, including: tooth morphology, caries, restorations, colorations, attrition, erosion, fractures and hypomineralization. Perinatal maternal urine samples were assessed for the concentration of fluoride, phenols and phthalates, including bisphenol A (BPA).Pairwise statistical analyses were done to correlate the dental findings with one another and with the presence of environment chemicals found in the urine samples. Hypomineralization was the most common finding (96% of children; 37% of deciduous teeth, 42% of permanent teeth), consistent with molar incisor hypomineralization (MIH) described in other human populations. No consistent correlations were seen between dental findings and the presence of phenols and phthalates in prenatal urine, but the number of samples available for the assessment was limited (n = 35).In conclusion, we found a high proportion of dental hypomineralization in a population based paediatric cohort, but did not find an association with prenatal exposure to phenols and phthalates.

Cross-cultural adaptation of a Spanish version of a previously validated HPV survey that evaluates dental students' knowledge, perception and clinical practices in Latin America.

BACKGROUND: The global incidence of oropharyngeal cancer (OPC) is increasing. Dental professionals play a key role in the detection of oral lesions that could lead to cancer. However, scientific-based HPV-OPC visual inspection guidelines are underdeveloped and HPV knowledge and awareness has been reported to be low among dental students and professionals. The present study adapted and performed pretesting of a multi-scale survey evaluating knowledge, perceptions, and clinical practices regarding HPV and HPV-OPC for Latin American Spanish-speaking populations. METHODS: A previously developed questionnaire for English-speaking dental students was translated to Spanish. The questionnaire was administered to first year dental students at two Latin American universities with dental programs. Internal consistencies were measured using Cronbach Alpha. Analyses were conducted in SAS Version 9.4. RESULTS: Data from a total of 114 students, a majority of the which were female (61%), and Hispanic/Latino(a)/Spanish (91%). The HPV, HPV-OPC, and HPV vaccine knowledge subscales demonstrated good internal consistency, the Cronbach's alpha was 0.83, 0.75, and 0.86 respectively. The Barriers subscale had a Cronbach's alpha of 0.93, showing excellent internal consistency. The Clinical Procedures subscale, focused on factors surrounding dental students' hypothetical clinical practice procedures, had a Cronbach's alpha of 0.86. The Scope of Practice scale had a Cronbach's alpha of 0.93. CONCLUSIONS: Ultimately, this survey demonstrated reliability and applicability for the assessment of dental students' knowledge, perceptions, and clinical practices regarding HPV and HPV-OPC in Latin America.

A Multi-state Evaluation of Oral Health Students' Knowledge of Human Papillomavirus-Related Oropharyngeal Cancer and HPV Vaccination.

Human papillomavirus-related oropharyngeal cancers (HPV-OPCs) are on the rise, yet HPV knowledge among dental professionals remains low. The purpose of this multi-state study was to examine sociodemographic factors associated with final year dental hygiene (DH), third year dental (DS3), and fourth year dental (DS4) students' knowledge regarding HPV, HPV-OPC, and HPV vaccination. Twenty dental programs in the USA were approached in the implementation phase to complete an online, 153-item, self-administered questionnaire that was developed and tested in a previous study. Descriptive statistics and chi-square analyses were conducted in SAS version 9.4 to examine the relationship between sociodemographic variables with HPV, HPV-OPC, and HPV vaccination knowledge levels. This study included the participation of students from 15 dental programs (n = 380) with an overall response rate of 28%. Although the results cannot be generalized to the entire population of dental students in the USA, most students had inadequate overall HPV knowledge (65%), HPV-OPC knowledge (80%), and HPV vaccination knowledge (55%). While all student groups displayed adequate general HPV knowledge levels (≥ 70% correct responses), gender, racial, religious, age, and regional differences were observed. Future dental professionals need to have adequate levels of HPV knowledge to aid in reducing the HPV-OPC burden. This study identified sociodemographic factors related to lower knowledge of HPV, HPV-OPC, and HPV vaccination, and highlights groups of students with greater needs for HPV education. This study provides a foundation for future research and interventions to be developed. Dental institutions can use findings to strengthen curricula development.

Multiplex navigation of global regulatory networks (MINR) in yeast for improved ethanol tolerance and production.

Multiplex navigation of global regulatory networks (MINR) is an approach for combinatorially reprogramming gene expression to manipulate complex phenotypes. We designed, constructed, and mapped MINR libraries containing 43,020 specific mutations in 25 regulatory genes expected to perturb the yeast regulatory network. We selected growth competition experiments for library mutants conferring increased ethanol and/or glucose tolerance. We identified specific mutants that not only possessed improved ethanol and/or glucose tolerance but also produced ethanol at concentrations up to 2-fold higher than those produced by the wild-type strain. We further determined that mutations increasing ethanol tolerance were transferable to a diploid industrial yeast strain. The facile construction and mapping of 43,020 designer regulatory mutations provide a roadmap for how to access and engineer complex phenotypes in future synthetic biology and broader efforts.

PROTAC-induced BET protein degradation as a therapy for castration-resistant prostate cancer.

Prostate cancer has the second highest incidence among cancers in men worldwide and is the second leading cause of cancer deaths of men in the United States. Although androgen deprivation can initially lead to remission, the disease often progresses to castration-resistant prostate cancer (CRPC), which is still reliant on androgen receptor (AR) signaling and is associated with a poor prognosis. Some success against CRPC has been achieved by drugs that target AR signaling, but secondary resistance invariably emerges, and new therapies are urgently needed. Recently, inhibitors of bromodomain and extra-terminal (BET) family proteins have shown growth-inhibitory activity in preclinical models of CRPC. Here, we demonstrate that ARV-771, a small-molecule pan-BET degrader based on proteolysis-targeting chimera (PROTAC) technology, demonstrates dramatically improved efficacy in cellular models of CRPC as compared with BET inhibition. Unlike BET inhibitors, ARV-771 results in suppression of both AR signaling and AR levels and leads to tumor regression in a CRPC mouse xenograft model. This study is, to our knowledge, the first to demonstrate efficacy with a small-molecule BET degrader in a solid-tumor malignancy and potentially represents an important therapeutic advance in the treatment of CRPC.

Pilot Test of Survey to Assess Dental and Dental Hygiene Student Human Papillomavirus-Related Oropharyngeal Cancer Knowledge, Perceptions, and Clinical Practices.

This was the first study to develop and pilot test an assessment tool for the examination of human papillomavirus (HPV)-related oropharyngeal cancer (OPC) knowledge, perceptions, and clinical practices of oral health students. An interdisciplinary team developed the tool using surveys that examined this topic in other populations. The tool was then pilot tested at two different dental programs. Results from the pilot informed revisions to the final version of the tool. Of the 46 student participants, 18 were first-year dental hygiene and 28 were first-year dental students. The majority of participants were female (N = 29, 63%) and ages 18 to 29 years old (N = 41, 89%). Four scales used in the questionnaire were analyzed for reliability. Of these, the HPV and HPV-OPC knowledge and the HPV vaccination knowledge scales had Cronbach alphas of 0.71 and 0.79, respectively. Questions assessing HPV and the role of dental professionals had a correlation coefficient of 0.71. Questions assessing willingness to administer vaccines in the dental office had a correlation coefficient of 0.85. Assessing oral health students' HPV-OPC knowledge, perceptions, and clinical practices are important for future assessment of possible HPV-OPC cases. Dental professionals may be optimally positioned to provide HPV patient education. The tool developed and pilot tested in this study can help schools assess their students' knowledge and guide their dental curriculum to address deficiencies. Since this topic has not been effectively examined with dental health students, the results could help improve dental education and dental care.

Benefits of a Recombination-Proficient Escherichia coli System for Adaptive Laboratory Evolution.

Adaptive laboratory evolution typically involves the propagation of organisms asexually to select for mutants with the desired phenotypes. However, asexual evolution is prone to competition among beneficial mutations (clonal interference) and the accumulation of hitchhiking and neutral mutations. The benefits of horizontal gene transfer toward overcoming these known disadvantages of asexual evolution were characterized in a strain of Escherichia coli engineered for superior sexual recombination (genderless). Specifically, we experimentally validated the capacity of the genderless strain to reduce the mutational load and recombine beneficial mutations. We also confirmed that inclusion of multiple origins of transfer influences both the frequency of genetic exchange throughout the chromosome and the linkage of donor DNA. We built a simple kinetic model to estimate recombination frequency as a function of transfer size and relative genotype enrichment in batch transfers; the model output correlated well with the experimental data. Our results provide strong support for the advantages of utilizing the genderless strain over its asexual counterpart during adaptive laboratory evolution for generating beneficial mutants with reduced mutational load. IMPORTANCE: Over 80 years ago Fisher and Muller began a debate on the origins of sexual recombination. Although many aspects of sexual recombination have been examined at length, experimental evidence behind the behaviors of recombination in many systems and the means to harness it remain elusive. In this study, we sought to experimentally validate some advantages of recombination in typically asexual Escherichia coli and determine if a sexual strain of E. coli can become an effective tool for strain development.

Recent advances in the evolutionary engineering of industrial biocatalysts.

Evolutionary engineering has been used to improve key industrial strain traits, such as carbon source utilization, tolerance to adverse environmental conditions, and resistance to chemical inhibitors, for many decades due to its technical simplicity and effectiveness. The lack of need for prior genetic knowledge underlying the phenotypes of interest makes this a powerful approach for strain development for even species with minimal genotypic information. While the basic experimental procedure for laboratory adaptive evolution has remained broadly similar for many years, a range of recent advances show promise for improving the experimental workflows for evolutionary engineering by accelerating the pace of evolution, simplifying the analysis of evolved mutants, and providing new ways of linking desirable phenotypes to selectable characteristics. This review aims to highlight some of these recent advances and discuss how they may be used to improve industrially relevant microbial phenotypes.

Evolved osmotolerant Escherichia coli mutants frequently exhibit defective N-acetylglucosamine catabolism and point mutations in cell shape-regulating protein MreB.

Biocatalyst robustness toward stresses imposed during fermentation is important for efficient bio-based production. Osmotic stress, imposed by high osmolyte concentrations or dense populations, can significantly impact growth and productivity. In order to better understand the osmotic stress tolerance phenotype, we evolved sexual (capable of in situ DNA exchange) and asexual Escherichia coli strains under sodium chloride (NaCl) stress. All isolates had significantly improved growth under selection and could grow in up to 0.80 M (47 g/liter) NaCl, a concentration that completely inhibits the growth of the unevolved parental strains. Whole genome resequencing revealed frequent mutations in genes controlling N-acetylglucosamine catabolism (nagC, nagA), cell shape (mrdA, mreB), osmoprotectant uptake (proV), and motility (fimA). Possible epistatic interactions between nagC, nagA, fimA, and proV deletions were also detected when reconstructed as defined mutations. Biofilm formation under osmotic stress was found to be decreased in most mutant isolates, coupled with perturbations in indole secretion. Transcriptional analysis also revealed significant changes in ompACGL porin expression and increased transcription of sulfonate uptake systems in the evolved mutants. These findings expand our current knowledge of the osmotic stress phenotype and will be useful for the rational engineering of osmotic tolerance into industrial strains in the future.

Phylogenomics and genetic analysis of solvent-producing Clostridium species.

The genus Clostridium is a large and diverse group within the Bacillota (formerly Firmicutes), whose members can encode useful complex traits such as solvent production, gas-fermentation, and lignocellulose breakdown. We describe 270 genome sequences of solventogenic clostridia from a comprehensive industrial strain collection assembled by Professor David Jones that includes 194 C. beijerinckii, 57 C. saccharobutylicum, 4 C. saccharoperbutylacetonicum, 5 C. butyricum, 7 C. acetobutylicum, and 3 C. tetanomorphum genomes. We report methods, analyses and characterization for phylogeny, key attributes, core biosynthetic genes, secondary metabolites, plasmids, prophage/CRISPR diversity, cellulosomes and quorum sensing for the 6 species. The expanded genomic data described here will facilitate engineering of solvent-producing clostridia as well as non-model microorganisms with innately desirable traits. Sequences could be applied in conventional platform biocatalysts such as yeast or Escherichia coli for enhanced chemical production. Recently, gene sequences from this collection were used to engineer Clostridium autoethanogenum, a gas-fermenting autotrophic acetogen, for continuous acetone or isopropanol production, as well as butanol, butanoic acid, hexanol and hexanoic acid production.

First-in-Human Dose-Escalation Study of the Novel Oral Depsipeptide Class I-Targeting HDAC Inhibitor Bocodepsin (OKI-179) in Patients with Advanced Solid Tumors.

(1) Background: Histone deacetylases (HDACs) play a critical role in epigenetic signaling in cancer; however, available HDAC inhibitors have limited therapeutic windows and suboptimal pharmacokinetics (PK). This first-in-human phase I dose escalation study evaluated the safety, PK, pharmacodynamics (PDx), and efficacy of the oral Class I-targeting HDAC inhibitor bocodepsin (OKI-179). (2) Patients and Methods: Patients (n = 34) with advanced solid tumors were treated with OKI-179 orally once daily in three schedules: 4 days on 3 days off (4:3), 5 days on 2 days off (5:2), or continuous in 21-day cycles until disease progression or unacceptable toxicity. Single-patient escalation cohorts followed a standard 3 + 3 design. (3) Results: The mean duration of treatment was 81.2 (range 11-447) days. The most frequent adverse events in all patients were nausea (70.6%), fatigue (47.1%), and thrombocytopenia (41.2%). The maximum tolerated dose (MTD) of OKI-179 was 450 mg with 4:3 and 200 mg with continuous dosing. Dose-limiting toxicities included decreased platelet count and nausea. Prolonged disease control was observed, including two patients with platinum-resistant ovarian cancer. Systemic exposure to the active metabolite exceeded the preclinical efficacy threshold at doses lower than the MTD and was temporally associated with increased histone acetylation in circulating T cells. (4) Conclusions: OKI-179 has a manageable safety profile at the recommended phase 2 dose (RP2D) of 300 mg daily on a 4:3 schedule with prophylactic oral antiemetics. OKI-179 is currently being investigated with the MEK inhibitor binimetinib in patients with NRAS-mutated melanoma in the phase 2 Nautilus trial.

Harnessing recombination to speed adaptive evolution in Escherichia coli.

Evolutionary engineering typically involves asexual propagation of a strain to improve a desired phenotype. However, asexual populations suffer from extensive clonal interference, a phenomenon where distinct lineages of beneficial clones compete and are often lost from the population given sufficient time. Improved adaptive mutants can likely be generated by genetic exchange between lineages, thereby reducing clonal interference. We present a system that allows continuous in situ recombination by using an Esherichia coli F-based conjugation system lacking surface exclusion. Evolution experiments revealed that Hfr-mediated recombination significantly speeds adaptation in certain circumstances. These results show that our system is stable, effective, and suitable for use in evolutionary engineering applications.

Visualizing evolution in real time to determine the molecular mechanisms of n-butanol tolerance in Escherichia coli.

Toxicity of products or feedstock components poses a challenge in the biocatalyst-based production of fuels and chemicals. The genetic determinants that are involved in increased resistance to an inhibitor form the adaptive landscape for the phenotype; so in order to engineer more robust biocatalysts, a better understanding of the adaptive landscape is required. Here, we used an adaptive laboratory evolution method called visualizing evolution in real time (VERT) to help map out part of the adaptive landscape of Escherichia coli tolerance to the biofuel n-butanol. VERT enables identification of adaptive events (population expansions triggered by adaptive mutants) via visualization of the relative proportions of different fluorescently-labeled cells. Knowledge of the occurrence of adaptive events allows for a more systematic isolation of adaptive mutants while simultaneously reducing the number of missed adaptive mutants (and the underlying adaptive mechanisms) that result from clonal interference during the course of in vitro evolution. Based on the evolutionary dynamics observed, clonal interference was found to play a significant role in shaping the population structure of E. coli during exposure to n-butanol, and VERT helped to facilitate the isolation of adaptive mutants from the population. We further combined adaptive laboratory evolution with genome shuffling to significantly enhance the desired n-butanol tolerance phenotype. Subsequent transcriptome analysis of the isolated adaptive mutants revealed different mechanisms of n-butanol resistance in different lineages. In one fluorescently-marked subpopulation, members of the Fur regulon were upregulated; which was not observed in the other subpopulation. In addition, genome sequencing of several adaptive mutants revealed the genetic basis for some of the observed transcriptome profiles. We further elucidated the potential role of the iron-related gene in n-butanol tolerance via overexpression and deletion studies and hypothesized that the upregulation of the iron-related genes indirectly led to modifications in the outer membrane, which contributed to enhanced n-butanol tolerance.

Preclinical Development of the Class-I-Selective Histone Deacetylase Inhibitor OKI-179 for the Treatment of Solid Tumors.

Histone deacetylases (HDACs) play critical roles in epigenomic regulation, and histone acetylation is dysregulated in many human cancers. Although HDAC inhibitors are active in T-cell lymphomas, poor isoform selectivity, narrow therapeutic indices, and a deficiency of reliable biomarkers may contribute to the lack of efficacy in solid tumors. In this article, we report the discovery and preclinical development of the novel, orally bioavailable, class-I-selective HDAC inhibitor, OKI-179. OKI-179 and its cell active predecessor OKI-005 are thioester prodrugs of the active metabolite OKI-006, a unique congener of the natural product HDAC inhibitor largazole. OKI-006, OKI-005, and subsequently OKI-179, were developed through a lead candidate optimization program designed to enhance physiochemical properties without eroding potency and selectivity relative to largazole. OKI-005 displays antiproliferative activity in vitro with induction of apoptosis and increased histone acetylation, consistent with target engagement. OKI-179 showed antitumor activity in preclinical cancer models with a favorable pharmacokinetic profile and on-target pharmacodynamic effects. Based on its potency, desirable class I HDAC inhibition profile, oral bioavailability, and efficacy against a broad range of solid tumors, OKI-179 is currently being evaluated in a first-in-human phase I clinical trial with plans for continued clinical development in solid tumor and hematologic malignancies.

Novel Escherichia coli hybrids with enhanced butanol tolerance.

Hybrids between Escherichia coli and Lactobacillus brevis were generated via protoplast fusion. Growth kinetics of five hybrid strains and E. coli were used to evaluate the butanol tolerance of the novel strains under different conditions. The hybrid strains tolerated up to 2% (v/v) butanol compared to the 1% (v/v) maximum for E. coli. The growth inhibitory effects of butanol were also significantly less in several of the hybrids compared to E. coli. These results demonstrate the potential use of protoplast fusion to generate butanol-tolerant strains.

An unusual case of generalized severe gingival enlargement during pregnancy.

Increased hormone levels that are present during puberty and pregnancy are associated with localized or generalized gingival enlargement. This article reviews the gingival alterations that can occur during pregnancy and describes a case of generalized severe gingival enlargement associated with pregnancy and its management. A 36-year-old woman had severe bilateral gingival enlargement of short duration. The patient denied taking any medications. The laboratory report revealed no systemic abnormalities; however, the report disclosed that she was pregnant. Surgical therapy for the gingival enlargement included gingivectomy and gingivoplasty of all quadrants, which reduced the size of the enlarged gingiva. Postoperative visits demonstrated uneventful healing, with no recurrence seen at the one-year follow-up appointment. It appears that the English literature includes only one other case report that discusses generalized gingival enlargement during pregnancy. Pregnancy-related gingival enlargement should be included as a differential diagnosis in women who have non-drug-induced generalized gingival enlargement.

Bilateral vestibuloplasty utilizing palatal soft tissue grafts in an HIV-positive patient.

The dental treatment of HIV-positive individuals has undergone a change from the management of HIV-associated oral lesions to routine comprehensive dental care. To the authors' knowledge, this is the first report in which palatal soft tissue grafts were used for vestibuloplasty in an HIV-positive patient with a shallow mandibular vestibule. No adverse sequelae were seen during follow-up.

US oral health students' willingness to train and administer the HPV vaccine in dental practices.

HPV oropharyngeal cancers have now surpassed cervical cancer rates in the US. Dental providers' engagement in HPV education and vaccination efforts may help reduce the burden of HPV oropharyngeal cancers. We examined factors associated with oral health students' willingness to train and administer the human papillomavirus (HPV) vaccine in dental settings. US students in 15 oral health programs participated in an online survey in 2016. Unadjusted and adjusted multivariable logistic regression were conducted and odds ratios (OR) and 95% confidence intervals (CI) were reported. Analyses were conducted in SAS Version 9.4. Data from a total of N = 306 students were analyzed to examine sociodemographic, educational, practice, and attitudinal factors associated with willingness to train and administer the HPV vaccine. Majority of the participants were female (70.3%), non-Hispanic/Latino (90.8%), and White (62.1%). Perceiving that HPV vaccination recommendation (OR = 1.95, 95% CI = 1.14-3.35) and administration (OR = 3.79, 95% CI = 1.63-8.81) was in the dental professional's scope was positively associated with outcome measures when other factors were held constant. Students with greater patient contact time (OR = 4.47, 95% CI = 1.14-17.58) and lower role conflict (agreed that HPV vaccine administration was in the dental professional's scope) had higher odds of willingness to administer the HPV vaccine when other factors were held constant (OR = 5.9, 95% CI = 2.27-15.3). The major barrier to engaging oral health students in HPV vaccination efforts was role conflict. Professional organizations and oral health programs should strongly support the role of oral health professionals in HPV oropharyngeal prevention.

Clinical experience of MEK inhibitors in cancer therapy.

Finding new therapies to assist in the treatment of cancer is a major challenge of clinical research. Small molecules that inhibit different molecular targets at the different levels of the MAPK pathway have been developed. Several MEK inhibitors have been examined in early-phase clinical trials and the current state of clinical results using these therapies is presented here.

Biological characterization of ARRY-142886 (AZD6244), a potent, highly selective mitogen-activated protein kinase kinase 1/2 inhibitor.

PURPOSE: The Ras-Raf-mitogen-activated protein kinase kinase (MEK) pathway is overactive in many human cancers and is thus a target for novel therapeutics. We have developed a highly potent and selective inhibitor of MEK1/2. The purpose of these studies has been to show the biological efficacy of ARRY-142886 (AZD6244) in enzymatic, cellular, and animal models. EXPERIMENTAL DESIGN: The ability of ARRY-142886 to inhibit purified MEK1 as well as other kinases was evaluated. Its effects on extracellular signal-regulated kinase (ERK) phosphorylation and proliferation in several cell lines were also determined. Finally, the inhibitor was tested in HT-29 (colorectal) and BxPC3 (pancreatic) xenograft tumor models. RESULTS: The IC(50) of ARRY-142886 was determined to be 14 nmol/L against purified MEK1. This activity is not competitive with ATP, which is consistent with the high specificity of compound for MEK1/2. Basal and epidermal growth factor-induced ERK1/2 phosphorylation was inhibited in several cell lines as well as 12-O-tetradecanoylphorbol-13-acetate-induced ERK1/2 phosphorylation in isolated peripheral blood mononuclear cells. Treatment with ARRY-142886 resulted in the growth inhibition of several cell lines containing B-Raf and Ras mutations but had no effect on a normal fibroblast cell line. When dosed orally, ARRY-142886 was capable of inhibiting both ERK1/2 phosphorylation and growth of HT-29 xenograft tumors in nude mice. Tumor regressions were also seen in a BxPC3 xenograft model. In addition, tumors remained responsive to growth inhibition after a 7-day dosing holiday. CONCLUSIONS: ARRY-142886 is a potent and selective MEK1/2 inhibitor that is highly active in both in vitro and in vivo tumor models. This compound is currently being investigated in clinical studies.