Combinatorial analysis of population dynamics, metabolite levels and malolactic fermentation in Saccharomyces cerevisiae/ Lachancea thermotolerans mixed fermentations.

The outcome of co- or sequential inoculation of Lachancea thermotolerans in winemaking remains unpredictable due to a lack of integrated data regarding the impact of grape juice composition on L. thermotolerans fermentation behaviour. Here, we investigate the impact of nitrogen composition on fermentation characteristics and aroma compound production in grape juice sequentially inoculated with commercial L. thermotolerans and S. cerevisiae strains. Subsequently, all treatments were subjected to malolactic fermentation (MLF) using two commercial strains of Oenococcus oeni. Addition of amino acids led to faster growth for S. cerevisiae fermentations, compared to the nitrogen-equivalent addition of diammonium phosphate (DAP). L. thermotolerans persistence in the mixed fermentations was significantly higher following DAP addition, with higher glycerol and lactic acid production. Interestingly, the lower total Nitrogen content in DAP-treated musts compared to other treatments did not alter the subsequent growth of S. cerevisiae. MLF was more similar between musts fermented with L. thermotolerans, regardless of nutrient regime, whereas significant differences in MLF completion times were observed for different nitrogen treatments in S. cerevisiae fermentations. Collectively, the data present an integrated view of the impact of nitrogen treatment on multispecies co-inoculation (growth kinetics and aromatic outcomes) and the downstream impact on MLF.

Influence of sugars and pH on the citrate metabolism of different lactic acid bacteria strains in a synthetic wine matrix.

AIMS: This study investigated the influence of sugars (glucose and fructose) and pH on the gene expression of citE (citrate lyase ß-subunit) and the subsequent formation of metabolites associated with citrate metabolism. METHODS AND RESULTS: Different levels of glucose (2·5, 50 and 115 g l-1 ), fructose (2·5, 50 and 115 g l-1 ) and pH (3·0, 3·5, 4·0 and 5·0) were evaluated for their effect on citE expression in four different lactic acid bacteria strains. Two Oenococcus oeni strains and two Lactobacillus plantarum strains were used, of which one strain of each species screened positive for the citE gene. Among the factors tested, fructose had the biggest influence on the relative expression of citE in O. oeni. In addition, the citrate-positive strains produced high concentrations of diacetyl and acetoin. CONCLUSIONS: This study gives an overview of how sugar, pH and different lactic acid bacteria strains influence citE gene expression and the formation of metabolites associated with citrate metabolism closely linked to malolactic fermentation (MLF). SIGNIFICANCE AND IMPACT OF THE STUDY: These results can be used to make informed decisions regarding MLF when aiming to create a wine with a buttery aroma or not.

Neutrophil and monocyte responses to downhill running: Intracellular contents of MPO, IL-6, IL-10, pstat3, and SOCS3.

High-intensity exercise results in immune activation. This study determined whether (a) there is concordance between serum MPO and neutrophil and/or monocyte intracellular MPO content; (b) peripheral blood mononuclear cells respond to inflammatory interleukins (ILs) by increasing intracellular signaling. Healthy male (n = 12) volunteers participated in high-intensity running (12 × 5 min, 10% decline, 15 km/h). Blood sample (pre, post, 4 h) analyses included serum concentrations of IL-1ß, IL-1ra, IL-4, IL-6, IL-8, IL-10, matrix metalloprotease-9 (MMP-9) and creatine kinase (CK). Intracellular IL-6, IL-10, MPO and STAT3/SOCS3 signaling were assessed in mononuclear cells. CK (1573 ± 756 u/L), MMP-9 (101 ± 27 ng/mL), neutrophil (9.89 ± 0.76 × 10(9) cells/L) and monocyte counts (1 ± 0.08 × 10(9) cells/L) increased at 4 h. At 4 h serum (7.1 ± 1.3 ng/mL) and monocyte MPO (1.7-fold) increased, whereas neutrophil MPO decreased (0.8-fold). Intracellular monocyte IL-10 and IL-6 decreased by 15% and 20-30%, respectively, coinciding with elevations in serum IL-10 of 14.5 ± 4.7 pg/mL and IL-6 of 5.4 ± 2.9 pg/mL, suggesting immune cell cytokine release in response to exercise. Intracellular PBMC p-STAT3 to total STAT3 ratio increased from pre to 4 h. Circulating monocytes are responsive to increased serum IL-6 suggesting a negative feedback loop via STAT3 signaling.

Mechanical plasticity of collagen directs branch elongation in human mammary gland organoids.

Epithelial branch elongation is a central developmental process during branching morphogenesis in diverse organs. This fundamental growth process into large arborized epithelial networks is accompanied by structural reorganization of the surrounding extracellular matrix (ECM), well beyond its mechanical linear response regime. Here, we report that epithelial ductal elongation within human mammary organoid branches relies on the non-linear and plastic mechanical response of the surrounding collagen. Specifically, we demonstrate that collective back-and-forth motion of cells within the branches generates tension that is strong enough to induce a plastic reorganization of the surrounding collagen network which results in the formation of mechanically stable collagen cages. Such matrix encasing in turn directs further tension generation, branch outgrowth and plastic deformation of the matrix. The identified mechanical tension equilibrium sets a framework to understand how mechanical cues can direct ductal branch elongation.

Anti-inflammatory cellular targets on neutrophils elucidated using a novel cell migration model and confocal microscopy: a clinical supplementation study.

BACKGROUND: In vivo studies have shown grape seed-derived polyphenols (GSP) to benefit in recovery from muscle injury by modulation of neutrophil infiltration into damaged tissue, thereby reducing secondary damage, as well as by facilitating an early anti-inflammatory macrophage phenotype shift. The current study aimed to provide data in this context from human models and to elucidate specific molecular targets of GSP.Using a placebo-controlled, double-blind study design, eighteen normally healthy volunteers between the ages of 18-35 years old (13 female and 5 male) were orally supplemented with 140 mg/day of GSP for 2 weeks.Blood samples (days 0 and 14) were comprehensively analysed for in vitro neutrophil chemokinetic capacity towards a chemotaxin (fMLP) using a novel neutrophil migration assay, in combination with live cell tracking, as well as immunostaining for neutrophil polarisation factors (ROCK, PI3K) at migration endpoint. Macrophage phenotype marker expression was assessed using flow cytometry. RESULTS: fMLP induced significant chemokinesis (P < 0.01), validating our model. GSP did not exert a significant effect on neutrophil chemokinesis in this non-compromised population, but tended to decrease overall ROCK expression in fMLP-stimulated neutrophils (P = 0.06). Macrophage phenotype markers CD274 and MPO - indicators of a pro-inflammatory M1 phenotype - seemed to be normalised relative to baseline expression levels after GSP treatment. CONCLUSIONS: Current data suggest that GSP may have a modulatory effect on the ROCK-PI3K-PTEN system, but results in this normal population is not conclusive and should be confirmed in a larger, more inflamed population. Potential modulation of macrophage phenotype by GSP should be investigated further.

Inhibition of herpes simplex virus type 1 by aqueous extracts from shoots of Helichrysum aureonitens (Asteraceae).

Helichrysum aureonitens, a southern African medicinal plant reported to have antibacterial properties, was evaluated for antiviral activity against herpes simplex virus type 1 (HSV-1) in vitro. The crude aqueous extract from shoots of H. aureonitens at a concentration of 1.35 mg/ml (w/v) showed significant antiviral activity on HSV-1 in human lung fibroblasts as demonstrated by the absence of a cytopathic effect.

The effect of two different visual presentation modalities on the narratives of mainstream grade 3 children.

OBJECTIVE: This study investigated whether a dynamic visual presentation method (a soundless animated video presentation) would elicit better narratives than a static visual presentation method (a wordless picture book). METHOD: Twenty mainstream grade 3 children were randomly assigned to two groups and assessed with one of the visual presentation methods. Narrative performance was measured in terms of micro- and macrostructure variables. Microstructure variables included productivity (total number of words, total number of T-units), syntactic complexity (mean length of T-unit) and lexical diversity measures (number of different words). Macrostructure variables included episodic structure in terms of goal-attempt-outcome (GAO) sequences. RESULTS: Both visual presentation modalities elicited narratives of similar quantity and quality in terms of the micro- and macrostructure variables that were investigated. CONCLUSION: Animation of picture stimuli did not elicit better narratives than static picture stimuli.

Incidence of human calicivirus and rotavirus infection in patients with gastroenteritis in South Africa.

Human caliciviruses (HuCVs) are reportedly responsible for 2.5-4% of nonbacterial sporadic gastroenteritis. The incidence of HuCV infection in South Africa is unknown. Stool specimens from 1,296 South African patients with sporadic gastroenteritis were screened for the presence of HuCVs using electron microscopy, recombinant enzyme immunoassays for Norwalk (NV) and Mexican (MX) viruses, and the reverse transcriptase-polymerase chain reaction (RT-PCR). RT-PCR products were sequenced to ascertain which HuCV genogroups were present. HuCVs were detected in 43/1,296 (3.3%) specimens examined, with RT-PCR proving to be the most sensitive detection method. Genetic analysis of the isolates indicated that 81% were Snow Mountain Agent, or MX-like; 8% were NV-like; and 11% were HuCV/Sapporo-like. This study indicates that a combination of assays is needed for the accurate detection of HuCVs. Comparative data on hospitalised patients showed that the incidence of rotavirus infection was approximately ten times greater than that of HuCV infection.