Long-term taxonomic and functional stability of the gut microbiome from human fecal samples

Appropriate storage of fecal samples is a critical step for unbiased analysis in human microbiome studies. The purpose of this study was to evaluate the stability of the fecal microbial community for up to 18 months. Ten healthy volunteers provided fecal samples at the Jeonbuk National University Hospital. Stool samples were stored under the following six conditions: four different storage temperatures (- 70 °C, - 20 °C, 4 °C, and room temperature [20-25 °C]) and two different collection tubes (OMNIgene-Gut and DNA/RNA shield-fecal collection tubes). The gut microbiome was analyzed with 16S rRNA sequencing. We compared the taxonomic composition, alpha diversity, beta diversity and inferred pathway abundance between the baseline and 18 months after storage. Samples collected in the DNA/RNA Shield-fecal collection tubes showed the best performance in preservation of the taxonomic composition at 18 months. Pairwise differences in alpha diversity metrics showed the least deviation from zero. The PERMANOVA test showed non-significant change of beta diversity metrics (Unweighted Unifrac: q-value 0.268; Weighted Unifrac: q-value 0.848). The functional stability was significantly well preserved in the DNA/RNA Shield-fecal collection tubes (adjusted p value < 0.05). Our results demonstrate the use of the DNA/RNA Shield-fecal collection tube as an alternative storage method for fecal samples to preserve the taxonomic and functional stability of the microbiome over a long term.

Quantitative analysis of acetylsalicylic acid in human blood using volumetric absorptive microsampling

Volumetric absorptive microsampling (VAMS) is a novel sampling technique that allows for the collection of an accurate volume of blood by dipping a microsampler tip. The purpose of this study is to compare the requirement of a stabilizing reagent for the conventional venous blood sampling method versus VAMS in the analytical measurement of the concentration of acetylsalicylic acid. A high-performance liquid chromatography with mass spectrometry (LC-MS/MS) method was developed and validated for the accurate determination of acetylsalicylic acid in human blood. The blood samples spiked with acetylsalicylic acid with and without stabilizing reagent were absorbed into VAMS tips. In the whole blood sample, the same concentration was shown regardless of the addition of the stabilizing reagent, but the concentration decreased when the stabilizing reagent was not added to the VAMS sample. To apply the VAMS technology as a new blood sampling method, stabilizing reagents should be added before the analysis of acetylsalicylic acid concentration.

Interaction between the laser beam and keyhole wall during high power fiber laser keyhole welding

The crucial factor of laser welding is the laser energy conversion. For a better understanding of the process, the interaction process between the laser beam and keyhole wall was investigated by observing the keyhole wall evaporation during high-power fiber laser welding. The results show that the evaporation vapor, induced by the laser beam, discretely distributed on the keyhole wall. A tiny 'hollow' zone was observed at the spot center-action region on the FKW. The evaporation vapor induced by the spot center moved downward along the front keyhole wall (FKW) with a period of about 0.3~0.75 ms, which indicates that the keyhole formation is reminiscent of a periodical laser drilling process on the FKW. The evaporation vapor on the keyhole wall suggest the assumption that the laser energy coupling mode in the keyhole was multiple-reflection, and the keyhole depth was mainly determined by the drilling behavior induced by the first absorption on the FKW.

Effect of epigallocatechin-3-gallate, major ingredient of green tea, on the pharmacokinetics of rosuvastatin in healthy volunteers

Previous in vitro studies have demonstrated the inhibitory effect of green tea on drug transporters. Because rosuvastatin, a lipid-lowering drug widely used for the prevention of cardiovascular events, is a substrate for many drug transporters, there is a possibility that there is interaction between green tea and rosuvastatin. The aim of this study was to investigate the effect of green tea on the pharmacokinetics of rosuvastatin in healthy volunteers. An open-label, three-treatment, fixed-sequence study was conducted. On Day 1, 20 mg of rosuvastatin was given to all subjects. After a 3-day washout period, the subjects received 20 mg of rosuvastatin plus 300 mg of epigallocatechin-3-gallate (EGCG), a major ingredient of green tea (Day 4). After a 10-day pretreatment of EGCG up to Day 14, they received rosuvastatin (20 mg) plus EGCG (300 mg) once again (Day 15). Blood samples for the pharmacokinetic assessments were collected up to 8 hours after each dose of rosuvastatin. A total of 13 healthy volunteers were enrolled. Compared with the administration of rosuvastatin alone, the concomitant use at Day 4 significantly reduced the area under the concentration-time curve from time 0 to the last measurable time (AUC_last) by 19% (geometric mean ratio 0.81, 90% confidence interval [CI] 0.67-0.97) and the peak plasma concentration (C_max) by 15% (geometric mean ratio 0.85, 90% CI 0.70-1.04). AUC_last or C_max of rosuvastatin on Day 15 was not significantly different from that on Day 1. This study demonstrated that co-administration of EGCG reduces the systemic exposure of rosuvastatin by 19%, and pretreatment of EGCG can eliminate that effect of co-administration of EGCG.

Changes in the Ginsenoside Content During Fermentation Using an Appliance for the Preparation of Red Ginseng

The total amount of ginsenoside in fermented red ginseng (FRG) is increased by microbial fermentation. The aim of this study was to evaluate whether fermentation time and temperature affect the ginsenoside content during fermentation using an appliance for the preparation of red ginseng. The FRG and fermented red ginseng extracts (FRG-e) were prepared using an appliance for the preparation of red ginseng. The temperature was recorded and time points for sampling were scheduled at pre-fermentation (0[Formula: see text]h) and 18, 36, 48, 60 and 72[Formula: see text]h after the addition of the microbial strains. Samples of FRG and FRG-e were collected to identify changes in the ginsenoside contents at each time point during the fermentation process. The ginsenoside content was analyzed using high performance liquid chromatography (HPLC). The levels of ginsenoside Rh1, Rg3, and compound Y, which are known to have effective pharmacological properties, increased more than three-fold in the final products of FRG relative to samples prior to fermentation. Although the ginsenoside constituents of FRG-e decreased or increased and then decreased during fermentation, the total amount of ginsenoside in FRG-e was even higher than those in FRG; the total amounts of ginsenoside in FRG-e and FRG were 8282.8 and 738.0[Formula: see text]mg, respectively. This study examined the changes in composition of ginsenosides and suggests a method to manufacture high-content total ginsenosides according to the fermentation temperature and process time. Reducing the extraction time is expected to improve the decrease of ginsenosides in FRG-e as a function of the fermentation time.

Frações solúveis e insolúveis do hidrolisado proteico de resíduo de sardinha na alimentação do jundiá: consumo de ração e excreção de amônia

RESUMO O hidrolisado proteico de pescado é produzido por meio da hidrólise enzimática de resíduos da indústria de pescado, resultando em um ingrediente de excelente qualidade para ser utilizado na alimentação de peixes. O objetivo deste estudo foi determinar o efeito das frações do hidrolisado proteico de resíduo de sardinha sobre o consumo de ração e excreção de amônia de juvenis de jundiá. Foram testadas as frações solúveis e insolúveis do hidrolisado de músculo de sardinha, avaliadas individualmente e combinadas entre si. Juvenis de jundiás (9,76±0,55g) foram divididos em 12 aquários de 20L, na densidade de quatro peixes por aquário, resultando em uma biomassa média de 1,90±0,17g/L. O hidrolisado proteico foi produzido com carcaças limpas de sardinhas mediante o uso da enzima protease bacteriana Protamex(r) (Novozymes A/S) e dele derivaram as frações solúveis e insolúveis. As dietas foram isoproteicas (39% PB) e isoenergéticas (4450kcal EB/kg), e as frações do hidrolisado foram incluídas de forma a fornecerem 50% da proteína das rações. A fração solúvel apresentou grau de hidrólise mais elevado (20,1%) em relação à fração insolúvel (9,97%). As duas dietas contendo a fração solúvel do hidrolisado foram as mais consumidas. Com cinco horas de avaliação, a dieta contendo a fração solúvel do hidrolisado aumentou a excreção de amônia em relação à dieta contendo a fração insolúvel. Após 25 horas, a fração solúvel também aumentou a excreção de amônia, mas, desta vez, em relação à dieta contendo a combinação das duas frações. Conclui-se que a inclusão da fração solúvel do hidrolisado de músculo de sardinha estimula o consumo de ração, todavia, quando a inclusão é elevada, pode haver aumento da excreção de amônia de juvenis de jundiá.

Fusions with histone H3 result in highly specific alteration of gene expression

Hap1 is a yeast transcriptional activator which controls expression of genes such as CYC1 and CYC7. Our results show that Hap1 activity is dependent on a functional chromatin remodeling complex SWI/SNF. Using a modified two-hybrid screen with Hap1 as bait, we recovered expression vectors encoding the Gal4 activation domain fused to histone H3 [Gal4(AD)-H3]. Hap1 activity at CYC1 or CYC7 was increased by Gal4(AD)-H3 and the effect was dependent on the presence of the activation domain of Hap1 and a functional SWI complex. Importantly, overexpression of H3 alone had no effect on Hap1 activity. Analysis of Gal4(AD)-H3 revealed that the fusion is not incorporated into the nucleosome while a functional Gal4 activation domain is dispensable. Activity of many other transcriptional activators was unchanged or slightly affected in the presence of Gal4(AD)-H3. Thus, our results identify a new class of histone H3 variants that cause highly specific alteration of gene expression. Hap1 may interact directly with H3 favoring chromatin remodeling by the SWI/SNF complex.

Mutations in target DNA elements of yeast HAP1 modulate its transcriptional activity without affecting DNA binding

The yeast zinc cluster protein HAP1, a member of the GAL4 family, is a transcriptional activator that binds as a homodimer to target DNA sequences. These targets include the upstream activating sequences of the CYC1 and CYC7 genes, which have no obvious sequence similarity. Even though both sites have the same affinity for HAP1, activation differs at these two sites, even when the sequences are placed in an identical promoter context. In addition, mutants of HAP1 that can bind to both sites but are specifically transcriptionally inactive at CYC7 have been previously isolated. In order to identify nucleotides that are responsible for this differential activity, we have performed random and site-directed mutagenesis of these target sites and assayed their binding to HAP1 in vitro and their activity in vivo in reporter plasmids. Our results show that HAP1 binding sites are degenerate forms of the direct repeat CGG N3 TA N CGG N3 TA. Moreover, we show that activity of HAP1 mutants defective for activation of the CYC7gene is restored by specific mutations in the CYC7 binding site. Conversely, other mutations of the target sites prevent activation by HAP1, without interfering with DNA binding. The results suggest that the sequence of the target sites influences the conformation and, hence, the activity of DNA-bound HAP1.