Optimal trade-off between boosted tolerance and growth fitness during adaptive evolution of yeast to ethanol shocks.

BACKGROUND: The selection of Saccharomyces cerevisiae strains with higher alcohol tolerance can potentially increase the industrial production of ethanol fuel. However, the design of selection protocols to obtain bioethanol yeasts with higher alcohol tolerance poses the challenge of improving industrial strains that are already robust to high ethanol levels. Furthermore, yeasts subjected to mutagenesis and selection, or laboratory evolution, often present adaptation trade-offs wherein higher stress tolerance is attained at the expense of growth and fermentation performance. Although these undesirable side effects are often associated with acute selection regimes, the utility of using harsh ethanol treatments to obtain robust ethanologenic yeasts still has not been fully investigated. RESULTS: We conducted an adaptive laboratory evolution by challenging four populations (P1-P4) of the Brazilian bioethanol yeast, Saccharomyces cerevisiae PE-2_H4, through 68-82 cycles of 2-h ethanol shocks (19-30% v/v) and outgrowths. Colonies isolated from the final evolved populations (P1c-P4c) were subjected to whole-genome sequencing, revealing mutations in genes enriched for the cAMP/PKA and trehalose degradation pathways. Fitness analyses of the isolated clones P1c-P3c and reverse-engineered strains demonstrated that mutations were primarily selected for cell viability under ethanol stress, at the cost of decreased growth rates in cultures with or without ethanol. Under this selection regime for stress survival, the population P4 evolved a protective snowflake phenotype resulting from BUD3 disruption. Despite marked adaptation trade-offs, the combination of reverse-engineered mutations cyr1A1474T/usv1Δ conferred 5.46% higher fitness than the parental PE-2_H4 for propagation in 8% (v/v) ethanol, with only a 1.07% fitness cost in a culture medium without alcohol. The cyr1A1474T/usv1Δ strain and evolved P1c displayed robust fermentations of sugarcane molasses using cell recycling and sulfuric acid treatments, mimicking Brazilian bioethanol production. CONCLUSIONS: Our study combined genomic, mutational, and fitness analyses to understand the genetic underpinnings of yeast evolution to ethanol shocks. Although fitness analyses revealed that most evolved mutations impose a cost for cell propagation, combination of key mutations cyr1A1474T/usv1Δ endowed yeasts with higher tolerance for growth in the presence of ethanol. Moreover, alleles selected for acute stress survival comprising the P1c genotype conferred stress tolerance and optimal performance under conditions simulating the Brazilian industrial ethanol production.

Over-the-counter products in tooth bleaching: A scoping review.

OBJECTIVE: To map and summarize the current scientific evidence concerning the active ingredients, effectiveness, and adverse effects of over-the-counter (OTC) bleaching products. DATA AND SOURCE: This study was conducted according to the PRISMA-ScR guidelines for scoping reviews and registered on the Open Science Framework platform. STUDY SELECTION: Database searches were conducted in PubMed/MEDLINE, Embase, and Scopus up to January 2024. All in vitro, in situ, and clinical studies evaluating the effectiveness and adverse effects of OTC bleaching products were included. A descriptive analysis of the included studies was performed. RESULTS: A total of 88 studies were included. Most of them were in vitro studies (n = 49), followed by randomized clinical trials (n = 28). The main OTC bleaching products identified were whitening or stain-removing toothpastes (n = 42), followed by whitening strips (n = 39). Most clinical studies indicate that whitening strips are effective in improving tooth color and providing whitening benefits. In contrast, the bleaching effectiveness of toothpastes, mouth rinses and whitening trays was mainly supported by in vitro studies. The main adverse effects associated with OTC bleaching agents were tooth sensitivity and gingival irritation. CONCLUSION: A wide variety of OTC bleaching products is available for consumer self-administered use. Clinical studies have mainly confirmed the bleaching effectiveness of whitening strips, while the validation for toothpastes, mouth rinses and whitening trays has mainly relied on in vitro studies. Nevertheless, the use of OTC bleaching products may result in adverse effects, including tooth sensitivity, gingival irritation, and enamel surface changes. CLINICAL SIGNIFICANCE: Some over-the-counter bleaching products may have whitening properties supported by clinical studies, particularly those containing hydrogen or carbamide peroxide. Nonetheless, clinicians must be aware of the potential risks associated with excessive self-administration of these products, which may result in adverse effects.

Diversity and assembly patterns of mangrove rhizosphere mycobiome along the Coast of Gazi Bay and Mida Creek in Kenya.

Fungi are among key actors in the biogeochemical processes occurring in mangrove ecosystems. In this study, we investigated the changes of fungal communities in selected mangrove species by exploring differences in diversity, structure and the degree of ecological rearrangement occurring within the rhizospheres of four mangrove species (Sonneratia alba, Rhizophora mucronata, Ceriops tagal and Avicennia marina) at Gazi Bay and Mida Creek in Kenya. Alpha diversity investigation revealed that there were no significant differences in species diversity between the same mangrove species in the different sites. Rather, significant differences were observed in fungal richness for some of the mangrove species. Chemical parameters of the mangrove sediment significantly correlated with fungal alpha diversity and inversely with richness. The fungal community structure was significantly differentiated by mangrove species, geographical location and chemical parameters. Taxonomic analysis revealed that 96% of the amplicon sequence variants belonged to the Phylum Ascomycota, followed by Basidiomycota (3%). Predictive FUNGuild and co-occurrence network analysis revealed that the fungal communities in Gazi Bay were metabolically more diverse compared to those of Mida Creek. Overall, our results demonstrate that anthropogenic activities influenced fungal richness, community assembly and their potential ecological functions in the mangrove ecosystems investigated.

Technical comparison of MinIon and Illumina technologies for genotyping Chikungunya virus in clinical samples.

New-generation sequencing (NGS) techniques have brought the opportunity for genomic monitoring of several microorganisms potentially relevant to public health. The establishment of different methods with different mechanisms provides a wide choice, taking into account several aspects. With that in mind, the present aim of the study was to compare basic genomic sequencing metrics that could potentially impact genotyping by nanopores from Oxford Nanopore Technologies and by synthesis from Illumina in clinical samples positive for Chikungunya (CHIKV). Among the metrics studied, running time, read production, and Q score were better represented in Illumina sequencing, while the MinIOn platform showed better response time and greater diversity of generated files. That said, it was possible to establish differences between the studied metrics in addition to verifying that the distinctions in the methods did not impact the identification of the CHIKV virus genotype.

Glutaraldehyde-based desensitizer does not influence postoperative sensitivity and clinical performance of posterior restorations: A 24-month randomized clinical trial.

OBJECTIVES: To evaluate the influence of a glutaraldehyde-based desensitizer (GL) on postoperative sensitivity (POS) in posterior bulk-fill resin composite restorations using an adhesive applied in the self-etch (SE) and etch-and-rinse (ER) strategies; and to assess the clinical performance of the restorations. METHODS: Posterior resin composite restorations (n = 228) at least 3 mm deep were inserted in 57 subjects using a split-mouth design. The adhesive was applied with/without prior application of a GL. A resin composite was used for all restorations. Spontaneous POS (risk and intensity), as well as POS caused by stimulation with an air blast and assess the response to horizontal and vertical percussion was assessed using two scales in the baseline and after 7, 14, and 30 days. In addition, some parameters were evaluated using FDI criteria up to 24 months of clinical service. RESULTS: No significant POS was observed (p > 0.05). A higher absolute risk and intensity of spontaneous POS was observed within 7 days (35.1%), without statistically significant differences among groups. At 24 months 5 restorations were considered clinically unsatisfactory, and 73 restorations showed minor discrepancies in adaptation, with no significant differences between groups (p > 0.05). SIGNIFICANCE: A GL agent does not influence POS in posterior restorations with bulk-fill resin composite. It may be considered a dispensable clinical step in the restorative protocol.

Pro-inflammatory immune profile mediated by TNF and IFN-γ and regulated by IL-10 is associated to IgG anti-SARS-CoV-2 in asymptomatic blood donors.

The SARS-CoV-2 virus has infected and killed millions of people, but little is known about the risk factors that lead to the development of severe, mild or asymptomatic conditions after infection. The individual immune response and the balance of cytokines and chemokines have been shown to be important for the prognosis of patients. Additionally, it is essential to understand how the production of specific antibodies with viral neutralizing capacity is established. In this context, this study aimed to identify positive individuals for IgG anti-SARS-CoV-2 in a large population of blood donors (n = 7837) to establish their immune response profile and to evaluate its viral neutralization capacity. The prevalence found for IgG anti-SARS-CoV-2 was 5.6% (n = 441), with male blood donors (61.9%) being more prevalent among the positive ones. The results showed that positive individuals for IgG anti-SARS-CoV-2 have high serum concentrations of chemokines, TNF, IFN-γ and IL-10. The analyses showed that the positivity index for IgG anti-SARS-CoV-2 is associated with the neutralizing capacity of the antibodies, which, in turn, is significantly related to lower serum concentrations of CCL5 and CXCL10. The results allow us to hypothesize that the development and maintenance of IgG anti-SARS-CoV-2 antibodies in infected individuals occurs in a pro-inflammatory microenvironment well regulated by IL-10 with great capacity for recruiting cells from the innate and adaptive immune systems.

SARS-CoV-2 IgG Seroprevalence among Blood Donors as a Monitor of the COVID-19 Epidemic, Brazil.

During epidemics, data from different sources can provide information on varying aspects of the epidemic process. Serology-based epidemiologic surveys could be used to compose a consistent epidemic scenario. We assessed the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG in serum samples collected from 7,837 blood donors in 7 cities of Brazil during March-December 2020. Based on our results, we propose a modification in a compartmental model that uses reported number of SARS-CoV-2 cases and serology results from blood donors as inputs and delivers estimates of hidden variables, such as daily values of SARS-CoV-2 transmission rates and cumulative incidence rate of reported and unreported SARS-CoV-2 cases. We concluded that the information about cumulative incidence of a disease in a city's population can be obtained by testing serum samples collected from blood donors. Our proposed method also can be extended to surveillance of other infectious diseases.

Postoperative sensitivity in posterior resin composite restorations with prior application of a glutaraldehyde-based desensitizing solution: A randomized clinical trial.

OBJECTIVES: To evaluate the effect of a glutaraldehyde-based desensitizer on the postoperative sensitivity (POS) in posterior resin composite restorations up to 12 months using a universal adhesive (Tetric N-Bond Universal) with selective enamel etching (SE) or an etch-and-rinse (ER) strategy. METHODS: Class I and class II resin composite restorations (n = 220) at least 3 mm deep were inserted in 55 subjects. The universal adhesive was applied using the SE (self-etch strategy on dentin with selective enamel etching) or the ER strategy, with or without prior application of a glutaraldehyde-based desensitizer (Gluma Desensitizer - GL) to form groups SEGL and ERGL. A bulk-fill resin composite (Tetric NCeram Bulk Fill) was used for all restorations. Spontaneous POS was assessed 7 days after the restorative procedure using the Visual Analog Scale (VAS) and the Numeric Rating Scale (NRS). After 7, 14, and 30 days of completing each restoration, the subjects were reassessed to evaluate POS caused by stimulation with an air blast, horizontal and vertical percussion. In addition, marginal discoloration, marginal adaptation, fracture, and recurrence of caries were evaluated using the FDI (World Dental Federation) criteria after 7 days and at 12 months. RESULTS: No significant spontaneous or stimuli-induced POS was observed when restorations with or without GL were compared (p>0.05). A higher risk of spontaneous POS was observed within 7 days (40.0%; 95% CI 28.1 to 53.1), without statistically significant differences among groups. None of the participants reported POS at 12 months, however five restorations were considered clinically unsatisfactory (p > 0.05). CONCLUSIONS: The previous application of GL did not significantly reduce spontaneous or stimuli-induced POS in posterior resin composite restorations at any time, regardless of the adhesive strategy used. CLINICAL SIGNIFICANCE: The use of a glutaraldehyde-based desensitizing agent did not generate lower incidence of postoperative sensitivity in resin composite posterior restorations.

Microtensile Bond Strength of Bulk-fill Resin Composite Restorations in High C-factor Cavities.

AIM: To evaluate the microtensile bond strength (µTBS) and the fracture modes of four bulk-fill resin composites (Tetric EvoCeram Bulk Fill/Ivoclar Vivadent, Filtek Bulk Fill/3M ESPE, Venus Bulk Fill/Heraus Kulzer, and Filtek Bulk Fill Flow/3M ESPE) and one conventional incrementally filled resin composite (Filtek Z250/3M ESPE) inserted in class I cavities, after 24 hours and 6 months of water storage. MATERIALS AND METHODS: In all, 30 sound human extracted molars were divided into five restorative groups. Standardized class I cavities were prepared and restored following the manufacturer's instructions. The restored teeth were then assigned into one of the storage times (24 hours or 6 months). The molars were then cut into 1 mm2 sticks and submitted to µTBS. All fractured specimens were analyzed under a stereomicroscope (40×). Data were submitted to analysis of variance (ANOVA) and the Tukey post hoc test was applied for comparison between groups; and paired t test for comparison within storage times (p = 0.05). RESULTS: After 24 hours of storage, statistically significant differences were observed between Filtek Z250 and Filtek Bulk Fill Flow groups. However, after 6 months, no statistical differences were observed between groups. Additionally, no differences were observed for the µTBS between the storage times. Adhesive failures were the most frequent fracture mode after 24 hours (54%) and 6 months (43%), the resin cohesive fracture mode showed 16% for 24 hours and 14% for 6 months, the dentin cohesive fracture mode showed 14% for 24 hours and 26% for 6 months, and the mixed fracture mode showed 16% for 24 hours and 17% for 6 months. CONCLUSION: Bulk-fill resin composites obtained similar µTBS in high C-factor cavities as conventional incrementally filled resin composites. No bond strength reduction was observed after 6 months of storage. CLINICAL SIGNIFICANCE: Single increment restorations in high C-factor cavities with bulk-fill resin composites did not reduce µTBS after 24 hours or 6 months of storage. The comparable results to the conventional incrementally filled resin composites and the reduction in the operative time, make the bulk-fill resin composites a restorative option for posterior teeth restorations.

Doppler indices of the equine fetal carotid artery throughout gestation.

Assessment of pregnancy viability in the equine patient is currently based on gestational profiles of limited prognostic value. In recent years Doppler technology has been applied to uterine and umbilical arteries of pregnant mares to monitor fetal responsive haemodynamics, suggestive of compromise. To date, uterine artery Doppler indices failed to provide sufficient evidence of pregnancy viability and the umbilical cord of the equine fetus is inconsistently visualized past 250 days gestation. The objectives of this study were to: i) evaluate intracranial blood flow impedance by Doppler examination of the fetal carotid artery and ii) establish reference values for healthy, uncomplicated pregnancies. The middle cerebral artery (MCA), a branch of the carotid artery, is commonly employed to assess intracranial hemodynamics in the human fetus, exhibiting high resistance to circulation to the fetal brain in uncomplicated pregnancies. For the purpose of this study, 12 pregnant mares were examined at 2-3 weeks interval by B mode and Doppler ultrasonography until delivery and a novel technique was developed for Doppler evaluation of the carotid artery in the equine fetus, in order to provide objective evidence of the hemodynamic status of the equine fetus. Additional biophysical and biochemical parameters were collected to demonstrate appropriate pregnancy development. In this study Doppler waveform analysis of fetal intracranial vasculature demonstrated an elevated blood flow impedance, showing a significant correlation of carotid Doppler indices with gestational age. Results were comparable to human fetal trends for the middle cerebral artery (MCA) from mid gestation to term. Biochemical data showed expected patterns of uncomplicated pregnancies.

Influence of the Restorative Strategy on Push-out Bond Strength of the Self-adhesive Composite.

AIM: This study evaluated the influence of the resin composite and bonding strategy on the push-out bond strength of the self-adhesive, Fusio liquid dentin (FUS) (Pentron Clinical), and of two conventional resin composites of different viscosities, Filtek Z250 (3M ESPE) and tetric flow (Ivoclar Vivadent). MATERIALS AND METHODS: Thirty-two bovine incisors were used after disinfection. The roots were sectioned and the buccal and lingual surfaces were polished until a 2-mm slab was achieved, maintaining enamel at the buccal surface and dentin at the lingual surface. Standardized cavities were then prepared (2.0 × 1.5 mm) and restored according to the following bonding strategies: Fusio liquid dentin with selective etching (FUSSE) in enamel, FUS, Filtek Z250, and tetric flow-total etching (TET). All groups were restored in bulk. After 24 hours of storage in distilled water, finishing and polishing were performed. The push-out test was conducted on a universal testing machine (0.05 mm/minute). Data were analyzed through Kruskal-Wallis and Mann-Whitney tests (p = 0.05). The extruded restorations were evaluated under a stereomicroscope (10×) for failure-mode evaluation. RESULTS: There were no statistically significant differences between the groups TET, Z250, and FUS, with 145.59, 108.91, and 104.12 MPa means, respectively. The FUSSE group (40.92 MPa) showed a statistically significant lower bond strength. The predominant failure mode was a mixed failure for all groups. CONCLUSION: The self-adhesive resin composite achieved a satisfactory result on bond strength when compared to conventional composites with regular and low viscosities, except when selective enamel etching was done. CLINICAL SIGNIFICANCE: This study shows that the clinicians must be aware of the viscosity of the phosphoric acid to avoid dentin contamination whenever performing selective enamel etching. And the self-adhesive resin composite studied presented as another restorative alternative.

Effect of dentin pretreatment with potassium oxalate: A 6-year follow-up.

Oxalate-based products are effective against dentine sensitivity and have been studied as an option to improve long-term adhesive bonding strength. Our aim was to evaluate the effect of potassium oxalate on the microtensile bond strength (µTBS) of the dentin/resin interface after 24 h, 1, and 6 years. Dentin on the occlusal surface of 16 human premolars was exposed and etched with 35% phosphoric acid. The teeth were divided into four groups. Two groups received 3% monohydrated potassium oxalate and the following adhesive systems and composites: Adper Scotchbond Multipurpose + FiltekZ350 (3M/ESPE) and Prime & Bond NT + Esthet-X (Dentsply). Two control groups did not receive potassium oxalate. Teeth were cut into sticks and kept in distilled water at 37°C for 24 h, 1, and 6 years. The sticks underwent µTBS testing after storage. ANOVA, Tukey's post hoc test, and paired t test were used to compare storage times (α = 0.05). The fracture mode of the specimens was classified under a stereomicroscope (40×). Morphology of the hybrid layer and the fracture pattern were observed with scanning electronic microscopy (SEM). Mean µTBS was high at 24 h and decreased after 1 and 6 years. After 6 years, the mean µTBS values were similar with no statistically significant difference between the groups (p = .121). SEM images showed proper dentin hybridization. Dentin pretreatment with potassium oxalate did not affect hybrid layer formation, but bond strength decreased over time after 24 h. Therefore, the clinical use of potassium oxalate to increase dentin bond durability is not indicated.

Comparative study between two techniques for alveolar bone loss assessment: A pilot study.

OBJECTIVE: To conduct a comparative study between two techniques for assessment of alveolar bone loss. MATERIALS AND METHODS: Absolute and relative techniques were evaluated. The sample consisted of 16 radiographs supposed to meet a single criterion: The reference points applied (Cementum-enamel junction (CEJ) alveolar bone crest and root apex) should be visible. Bone height was measured in the selected radiographs as the percentage of root length through both techniques. Data were submitted to the Statistical Package for Social Science software. Results obtained by both methods were converted into bone loss index values and then categorized. Sensitivity and specificity of the relative technique, compared to the absolute technique, were calculated. Wilcoxon test and the Bland and Altman's method were employed for comparisons. Significance level was set at 5%. RESULTS: For the absolute and relative techniques, means of bone loss index were respectively of 4.81 (±2.25) and 4.75 (±1.80). Bone loss index ≥6 (alveolar bone loss ≥50%) was found in 5 (31.2%) teeth, in the absolute technique, and in 4 (25%) teeth, according to the relative technique. There was no statistically significant difference between both methods (P>0.05). According to the Bland and Altman's method, it was verified a bias of 0.06, and limits of upper and lower agreement of, respectively, 1.58 and -1.45. Sensitivity of 0.8 and specificity of 1 were found for the relative technique compared to the absolute one. CONCLUSION: There was no significant difference between the techniques evaluated, and the relative technique was found to be reliable for measuring alveolar bone loss.

Increased incidence of necrotizing enterocolitis in premature infants born to HIV-positive mothers.

OBJECTIVE: To examine if being born to an HIV-positive mother may increase the risk of necrotizing enterocolitis in premature infants. DESIGN: Case-control study. SETTING: Neonatal unit of a level 3 perinatal centre. METHODS: : Over a period of 8.5 years, all cases of necrotizing enterocolitis occurring in premature infants admitted to the neonatal unit were identified. For each case, two controls were retrospectively chosen that matched for postmenstrual age at birth, intrauterine growth and year of birth. Perinatal characteristics were studied in all infants. MAIN RESULTS: There were 79 cases of necrotizing enterocolitis, which were compared with 158 controls. Using multivariate analysis, multiple pregnancy [odds ratio (OR), 2.29; 95% confidence interval (CI), 1.23-4.25; P = 0.009], abnormal umbilical artery velocity (OR, 2.21; 95% CI, 1.08-4.54; P = 0.030), abnormal fetal heart rate (OR, 2.14; 95% CI, 1.05-4.36; P = 0.036) and HIV-positive mother (OR, 6.63; 95% CI, 1.26-34.8; P = 0.025) were significantly more frequent in fetuses who subsequently developed necrotizing enterocolitis. CONCLUSIONS: This preliminary report suggests an association, not previously reported, between maternal HIV-positive status and an increased risk of necrotizing enterocolitis in premature infants. Despite the limitations of this study, we suggest that premature newborn infants of HIV-positive mothers should be monitored very carefully for a possible increased risk of necrotizing enterocolitis.

A single mutated BRCA1 allele leads to impaired fidelity of double strand break end-joining.

Heterozygosity for mutations in the BRCA1 gene in humans confers high risk for developing breast cancer, but a biochemical basis for this phenotype has not yet been determined. Evidence has accumulated implicating BRCA1, in the maintenance of genomic integrity and the protection of cells against DNA double strand breaks (DSB). Here we present evidence that human cells heterozygous for BRCA1 mutations exhibit impaired DNA end-joining, which is the major DSB repair pathway in mammalian somatic cells. Using an in vivo host cell end-joining assay, we observed that the fidelity of DNA end-joining is strongly reduced in three BRCA1(+/-) cell lines in comparison to two control cell lines. Moreover, cell-free BRCA1(+/-) extracts are unable to promote accurate DNA end-joining in an in vitro reaction. The steady-state level of the wild type BRCA1 protein was significantly lower than the 50% expected in BRCA1(+/-) cells and thus may underlie the observed end-joining defect. Together, these data strongly suggest that BRCA1 is necessary for faithful rejoining of broken DNA ends and that a single mutated BRCA1 allele is sufficient to impair this process. This defect will compromise genomic stability in BRCA1 germ-line mutation carriers, triggering the genetic changes necessary for the initiation of neoplastic transformation.