High nitrogen concentration causes G2/M arrest in Hanseniaspora vineae.

Yeasts have been widely used as a model to better understand cell cycle mechanisms and how nutritional and genetic factors can impact cell cycle progression. While nitrogen scarcity is well known to modulate cell cycle progression, the relevance of nitrogen excess for microorganisms has been overlooked. In our previous work, we observed an absence of proper entry into the quiescent state in Hanseniaspora vineae and identified a potential link between this behavior and nitrogen availability. Furthermore, the Hanseniaspora genus has gained attention due to a significant loss of genes associated with DNA repair and cell cycle. Thus, the aim of our study was to investigate the effects of varying nitrogen concentrations on H. vineae's cell cycle progression. Our findings demonstrated that nitrogen excess, regardless of the source, disrupts cell cycle progression and induces G2/M arrest in H. vineae after reaching the stationary phase. Additionally, we observed a viability decline in H. vineae cells in an ammonium-dependent manner, accompanied by increased production of reactive oxygen species, mitochondrial hyperpolarization, intracellular acidification, and DNA fragmentation. Overall, our study highlights the events of the cell cycle arrest in H. vineae induced by nitrogen excess and attempts to elucidate the possible mechanism triggering this absence of proper entry into the quiescent state.

Bacterial community associated with gingivitis and periodontitis in dogs.

Periodontal disease is a chronic condition characterized by bacterial adhesion, followed by biofilm formation, and subsequently by an inflammatory process that progresses to gingivitis and later to periodontitis. The variations in the oral microbiota have been associated with the progression of this disease. This study evaluated the alteration of the cultivable oral microbiota in dogs with different oral health status. Thirty dogs were selected and divided into three groups: healthy, gingivitis, and periodontitis. The collected oral samples were seeded, and colonies with distinct phenotypic characteristics were isolated and classified using sequencing of the 16S rRNA gene. The DNA sequences were aligned, and a phylogenetic tree was constructed. Simpson's diversity index was calculated, and a dissimilarity matrix based on the Jaccard similarity index was used to plot a principal coordinate analysis. A total of 119 bacteria with different colony morphologies were isolated and classified into 4 phyla, 29 genera, and 45 species based on phylogenetic analysis. The results indicated an increase in bacteria belonging to the Proteobacteria phylum and a less extended decrease in Actinobacteria, Firmicutes, and Bacteroidetes phyla in dogs with periodontal disease (gingivitis and periodontitis) compared to healthy dogs. Representatives of the genera Neisseria sp., Corynebacterium sp., Pasteurella sp., and Moraxella sp. increased through the worsening of the periodontal disease, while Staphylococcus sp. decreased. All groups exhibited moderate to high levels of biodiversity index, and the plotted PCoA show a clear separation in the oral microbiome of dogs with periodontitis compared to dogs with gingivitis and the healthy group.

Differences in yeast behaviour during ageing of sparkling wines made with Charmat and Traditional methods.

In this study, we followed the yeast and wine behaviour during the second fermentation and subsequent lees ageing of sparkling wines produced by Traditional and Charmat methods at an industrial scale. During this period, we conducted physicochemical, microbiological, gene expression, and marker analyses of characteristics related to wine ageing. Our results show that the yeast behaviour during the fermentation is similar in both methods. However, after fermentation, there is a faster decrease in yeast vitality and viability in the Charmat method, together with an increase in the expression of autophagy-related genes (AMS1, APE1, and ATG8). We relate these factors to ageing with the continuous homogenization of the liquid practised in the Charmat method, and static ageing with the lees concentrated at the bottom of the bottle performed in the Traditional method. Despite the variation in yeast viability during ageing, there are no differences in soluble proteins, free amino nitrogen, total phenols, antioxidant activity, and colour evolution between the wines produced by the two methods, assuming few differences over the time that monitoring was conducted.

A peculiar cell cycle arrest at g2/m stage during the stationary phase of growth in the wine yeast Hanseniaspora vineae.

Yeasts of the genus Hanseniaspora gained notoriety in the last years due to their contribution to wine quality, and their loss of several genes, mainly related to DNA repair and cell cycle processes. Based on genomic data from many members of this genus, they have been classified in two well defined clades: the "faster-evolving linage" (FEL) and the "slower-evolving lineage" (SEL). In this context, we had detected that H. vineae exhibited a rapid loss of cell viability in some conditions during the stationary phase compared to H. uvarum and S. cerevisiae. The present work aimed to evaluate the viability and cell cycle progression of representatives of Hanseniaspora species along their growth in an aerobic and discontinuous system. Cell growth, viability and DNA content were determined by turbidity, Trypan Blue staining, and flow cytometry, respectively. Results showed that H. uvarum and H. opuntiae (representing FEL group), and H. osmophila (SEL group) exhibited a typical G1/G0 (1C DNA) arrest during the stationary phase, as S. cerevisiae. Conversely, the three strains studied here of H. vineae (SEL group) arrested at G2/M stages of cell cycle (2C DNA), and lost viability rapidly when enter the stationary phase. These results showed that H. vineae have a unique cell cycle behavior that will contribute as a new eukaryotic model for future studies of genetic determinants of yeast cell cycle control and progression.

Aromatic and sensorial characterization of "Moscato pyments": an innovative beverage.

Pyment is a type of mead that is produced from the alcoholic fermentation of a honey solution with the addition of grape juice. Due to the demand for new beverages, pyment can be a profitable alternative for both grape and honey producers. Therefore, this work aimed to characterize the aromatic and physicochemical composition of pyments. The pyments were prepared with addition of 10, 20 and 30% of Moscato juice, and compared with Moscato wine and traditional mead. The results showed an increase in the fermentation rates of Moscato-pyments, indicating that the addition of Moscato juice reverses the low fermentative vigor often reported in mead fermentations. Physicochemical parameters showed an increase in total acidity and a decrease in residual sugar and alcohol, depending on Moscato juice concentration. Moscato-pyments showed an intermediate concentration of volatile compounds between the traditional mead and Moscato wine, with a better balance between fruity, floral and buttery, manifesting characteristic aromas of wines made with Moscato grapes and simultaneously, exposing characteristic aromas of honey. The sensory analysis reveals a significant difference between mead, pyments and Moscato wine. In general, pyments were considered, by the panelists, as the most equilibrated with intermediary aroma intensity, floral, fruity and honey aromas, and good persistence in the mouth.

Ray-tracing Calculation Using Scheimpflug Tomography of Diffractive Extended Depth of Focus IOLs Following Myopic LASIK.

PURPOSE: To evaluate a ray-tracing formula for intraocular lens (IOL) calculation of diffractive extended depth of focus IOLs after myopic laser in situ keratomileusis (LASIK) compared to formulas from an established online calculator. METHODS: This retrospective, consecutive case series included patients after cataract surgery with implantation of an extended depth of focus (EDOF) IOL (AT LARA, Carl Zeiss Meditec; Symfony, Johnson & Johnson) and a history of myopic LASIK. Preoperative assessments included biometry (IOLMaster; Carl Zeiss Meditec) and corneal tomography, including true net power (TNP) (Pentacam; Oculus Optikgeräte GmbH). To evaluate the measurements, the simulated keratometry values (SimK) were compared to the TNP. Regarding IOL calculation, the mean prediction error, mean and median absolute prediction error (MAE and MedAE), and number of eyes within ±0.50, ±1.00, and ±2.00 diopters (D) from the Haigis-L, Shammas, and Barrett True K No History formulas to the Potvin-Hill and Haigis with TNP (Pentacam) formulas were compared. RESULTS: Thirty-six eyes matched the inclusion criteria with a mean spherical equivalent of -6.26 ± 3.25 diopters (D) preoperatively and -0.79 ± 0.75 D postoperatively. The mean difference from SimK and TNP was significantly different from zero (P < .001; -1.24 ± 0.81 D). The best performing formulas by MedAE were the Potvin-Hill and Barrett True K No History (0.39 ± 0.78 and 0.64 ± 1.00 D). The formula with the most eyes within ±0.50 D was the Potvin-Hill (64%), followed by the Barrett True K No History (44%). For MAE and percentage of eyes within ±0.50 D, the Potvin-Hill formula was significantly better than the Haigis-L, Shammas, and Haigis-TNP formulas (P < .05). CONCLUSIONS: Calculation of IOLs in patients who had LASIK remains less predicable than calculations for virgin eyes. Using ray-tracing to calculate diffractive EDOF IOLs after myopic LASIK, the Potvin-Hill formula outperformed established formulas in terms of the percentage within target refraction and the MAE. [J Refract Surg. 2021;37(4):231-239.].

Yeast biodiversity in honey produced by stingless bees raised in the highlands of southern Brazil.

The physicochemical characteristics and yeasts diversity in honey samples from 17 species of stingless bees of the genera Nannotrigona, Melipona, Plebeia, Scraptotrigona, and Tetragonisca cultivated in Southern Brazil were determined. The sugar content, moisture, water activity, pH, reducing sugars/total sugar ratio, and total yeast population varied significantly among the honey from the different bee species. The highest yeast population was found in the Plebeia's honey samples and correlated with their high water-activity. Sixteen yeast species were identified based on the nuclear large subunit (26S) ribosomal RNA partial sequences. The genera Starmerella and Zygosaccharomyces were found predominant, with a high prevalence of Starmerella sp., S. etchellsii, and S. apicola. Some yeast species were only identified in honey samples from specific bee species indicating a close relationship between the yeasts and the insects. For the first time, Wickerhamomyces sydowiorum in honey is being reported. In general, the yeast species isolated from stingless bee honey samples demonstrated high osmotolerance and low sugar assimilation.

Selection of low nitrogen demand yeast strains and their impact on the physicochemical and volatile composition of mead.

Mead is an ancient alcoholic beverage produced through the fermentation of a diluted solution of honey. Due to the peculiar and varied composition of honey, mead production faces several problems, such as slow or stuck fermentations mainly due to the low nitrogen concentration, lack of uniformity of the final product and the production of unpleasant aromas. In this context, this work aimed to select low nitrogen-demand yeast strains and evaluate their potential for the production of mead. Therefore, among 21 commercial wine yeast strains, 5 were selected based on their fermentative behavior at low assimilable nitrogen concentrations. The selected strains were further evaluated for their contributions in meads produced with limited nitrogen availability, and the results showed significant differences on some physicochemical parameters like biomass production, residual sugars, glycerol concentration, and fermentative rate. Moreover, meads obtained with selected strains differed in the concentration of several volatile compounds. The volatile compounds concentration and the principal component analysis based on odor activity values allowed separating strains into three groups. In general, S. cerevisiae var bayanus strains (QA23, Spark, and AWRI-R2) were the largest producers of aromatic compounds, particularly those with floral and fruity descriptors. The selection of yeast strains with low nitrogen-demand and different volatile compounds production can be explored by mead makers to limit fermentation problems and obtain characteristic products.

[Ophthalmological care of SARS-CoV-2 positive patients in intensive care units]. / Ophthalmologische Betreuung von stationären, intensivpflichtigen SARS-CoV-2-positiven Patienten.

Early ophthalmological care of patients in intensive care with SARS-CoV­2 (Severe-Acute-Respiratory-Syndrom-Corona-Virus-2) infections is very time-consuming; however, this approach might prevent other ophthalmological diseases, such as lagophthalmos. There is no difference in ophthalmological treatment between SARS-CoV­2 positive and other intensive care patients. Due to the small number of cases in our observational study, a specific ophthalmological clinical pattern related to SARS-CoV­2 infections cannot currently be identified; however, the increased occurrence of subconjunctival hemorrhage in intensive care SARS-CoV­2 patients is remarkable. It remains unclear how ocular symptoms in SARS-CoV­2 infections are related or how they occur in different stages of the disease. Therefore, further studies are necessary for representative statements.

Visual results after implantation of a trifocal intraocular lens in high myopes.

PURPOSE: To report visual and refractive outcomes after implantation of a trifocal intraocular lens (IOL) in highly myopic patients. SETTING: Department of Ophthalmology, Goethe University, Frankfurt, Germany. DESIGN: Retrospective case series. METHODS: This study included eyes with previous phacoemulsification and implantation of a trifocal IOL (AT LISA tri 839MP or 939MP) with an IOL power between 0.0 diopter (D) and 10.0 D. Postoperative outcomes at 3 months including uncorrected distance (UDVA), intermediate (UIVA), and near visual acuity (UNVA), corrected distance visual acuity, spherical equivalent, and refractive astigmatism were analyzed. Age-matched eyes after implantation of the same trifocal IOL with higher dioptric power (>10.0 D) served as controls. RESULTS: Thirty-six eyes of 19 patients were included: 18 eyes (10 patients) in the highly myopic group (IOL power 0.0 to 10.0 D) and 18 eyes (9 patients) in the age-matched control group (IOL power >10.0 D). Three months postoperatively, the mean UDVA, UIVA, and UNVA in the highly myopic group were 0.06 logarithm of the minimum angle of resolution (logMAR) ± 0.08 (SD), 0.13 ± 0.09 logMAR, and 0.12 ± 0.07 logMAR, and -0.01 ± 0.10 logMAR, 0.04 ± 0.10 logMAR, and 0.04 ± 0.11 logMAR in the control group, respectively (P = .022, P = .033, P = .053, respectively). CONCLUSION: Implantation of a trifocal IOL in highly myopic eyes with low IOL power (0.0 to 10.0 D) provided satisfactory short-term visual and refractive outcomes; however, results were not as good as those obtained in eyes with higher dioptric IOL power.

Short-term complications of femtosecond laser-assisted laser in situ keratomileusis cuts: Review of 1210 consecutive cases.

PURPOSE: To evaluate short-term complications after femtosecond laser cuts for laser in situ keratomileusis (LASIK). SETTING: Department of Ophthalmology, Goethe University, Frankfurt, Germany. DESIGN: Retrospective consecutive case series. METHODS: Consecutive femtosecond laser cuts (1210 cuts in 624 patients) from LASIK performed with the Intralase FS60 between 2006 and 2014 were analyzed. The analysis looked at intraoperative and postoperative complications at 1 day, 1 week, and 1 month and factors with potential impact on the complication rate, such as ablation depth. RESULTS: No irregular, incomplete, or thin flaps, buttonholes, gas breakthrough, or free caps were observed. Intraoperatively, incomplete side cuts were observed in 4 cases (0.3%). Three of the 4 occurred during the first year of femtosecond laser usage and were explained by a software problem. Epithelial defects, limbal bleeding, and decentered flaps without negative impact on outcome were observed in 45 (3.7%), 12 (1.0%), and 5 (0.4%) eyes, respectively, on the treatment date. Diffuse lamellar keratitis (DLK) stage 1 was observed in 69 (5.7%), 36 (3.0%), and 3 (0.2%) eyes at 1 day, 1 week, and 1 month, respectively, and DLK stage 2 in 20 (1.7%), 6 (0.5%), and 2 (0.2%) eyes, respectively. An increase in total ablation depth resulted in a higher incidence of microstriae (P < .01 at 1 day, 1 week, and 1 month). An increase in the optical zone resulted in a significantly higher incidence of epithelial ingrowth at 1 day and 1 week (P < .01). CONCLUSION: No major cut-related complications were observed. The femtosecond laser is a safe option to create a flap in LASIK. FINANCIAL DISCLOSURE: Proprietary or commercial disclosures are listed after the references.