Pharmacological inhibition of p300 ameliorates steatosis, inflammation, and fibrosis in mice with non-alcoholic steatohepatitis.

The histone acetyltransferase p300 plays a pivotal role in regulating gene expression and cellular phenotype through epigenetic mechanisms. It significantly influences lipid metabolism, which is a key factor in the pathogenesis of non-alcoholic steatohepatitis (NASH), by modulating the transcription of genes involved in lipid synthesis and accumulation. This study aimed to investigate the protective potential of inhibiting p300 in NASH. Male C57BL/6J mice were subjected to a methionine- and choline-deficient (MCD) diet for 4 weeks to induce NASH, and during this period, the p300 inhibitor C646 (10 mg/kg) was administered three times a week. C646 treatment reduced the elevation of p300 expression and histone H3 acetylation, leading to a decrease in liver injury markers in the serum and an improvement in the histological abnormalities observed in MCD diet-fed mice. C646 also reduced lipid accumulation by modulating de novo lipogenesis and suppressed inflammation, including cytokine overproduction and macrophage infiltration. Furthermore, C646 mitigated liver fibrosis and myofibroblast accumulation. This protective effect was achieved through the inhibition of apoptosis by reducing p53 and Bax expression and the suppression of ferroptosis by decreasing lipid peroxidation while enhancing antioxidant defenses. Additionally, C646 alleviated endoplasmic reticulum stress, as evidenced by the downregulation of unfolded protein response signaling molecules. These results highlight the potential of p300 as a therapeutic target for NASH.

Effect of Paxlovid in COVID-19 treatment during the periods of SARS-CoV-2 Omicron BA.5 and BN.1 subvariant dominance in the Republic of Korea: a retrospective cohort study.

BACKGROUND: This study was conducted to assess the efficacy of nirmatrelvir/ritonavir treatment in patients with coronavirus disease 2019 (COVID-19), particularly those aged 60 years and older. Using real-world data, the period during which the BN.1 Omicron variant was dominant was compared to the period dominated by the BA.5 variant. METHODS: In this retrospective cohort study, data were collected regarding 2,665,281 patients infected with severe acute respiratory syndrome coronavirus 2 between July 24, 2022, and March 31, 2023. Propensity score matching was utilized to match patients who received nirmatrelvir/ ritonavir in a 1:4 ratio between BN.1 and BA.5 variant groups. Multivariable logistic regression analysis was employed to assess the effects of nirmatrelvir/ritonavir within these groups. RESULTS: Compared to the prior period, the efficacy of nirmatrelvir/ritonavir did not significantly differ during the interval of Omicron BN.1 variant dominance in the Republic of Korea. Among patients treated with nirmatrelvir/ritonavir, a significantly lower risk of mortality was observed in the BN.1 group (odds ratio [OR], 0.698; 95% confidence interval [CI], 0.557-0.875) compared to the BA.5 group. However, this treatment did not significantly reduce the risk of severe or critical illness, including death, for those in the BN.1 group (OR, 0.856; 95% CI, 0.728-1.007). CONCLUSION: Nirmatrelvir/ritonavir has maintained its effectiveness against COVID-19, even with the emergence of the BN.1 Omicron subvariant. Consequently, we strongly recommend the administration of nirmatrelvir/ritonavir to patients exhibiting COVID-19-related symptoms, irrespective of the dominant Omicron variant or their vaccination status, to mitigate disease severity and decrease the risk of mortality.

Synthesis and Structural Characterization of Macrocyclic α-ABpeptoids and Their DNA-Encoded Library.

The first synthesis of macrocyclic α-ABpeptoids with varying lengths is described. X-ray crystal structures reveal that cyclic trimer displays a chair-like conformation with a cct amide sequence and cyclic tetramer has a saddle-like structure with an uncommon cccc amide arrangement. The creation of a DNA-encoded combinatorial library of macrocyclic α-ABpeptoids is described.

Effectiveness of Molnupiravir Treatment in Patients with COVID-19 in Korea: A Propensity Score Matched Study.

BACKGROUND: The MOVe-OUT (efficacy and safety of molnupiravir [MK-4482] in non-hospitalized adult participants with COVID-19 [MK-4482-002]) trial reported that the administration of molnupiravir in unvaccinated patients with coronavirus disease 2019 (COVID-19) before the Omicron epidemic showed a preventive effect of 31% against hospitalization and death. However, studies on the preventive effect of molnupiravir against progression to severe disease and death in patients with COVID-19 during the Omicron epidemic are limited. This study aimed to evaluate the preventive effect of molnupiravir against severe/critical illness or death and death in Korean patients with COVID-19 who were vaccinated mostly during the Omicron epidemic. MATERIALS AND METHODS: This study used large-scale retrospective cohort data to select patients with COVID-19 who were either treated or not treated with molnupiravir, between August 2022 and March 2023, at a ratio of 1 : 4 using the propensity score matching method. In total, 762,768 patients comprised the non- administered group, and 190,692 patients comprised the molnupiravir-administered group. The preventive effect of molnupiravir against severe/critical illness or death and death was analyzed using logistic regression analysis. RESULTS: The preventive effect of molnupiravir against severe/critical illness or death and death, represented by the odds ratio (OR) and 95% confidence interval (CI), in the molnupiravir-administered and non-administered group was (OR: 0.714; CI: 0.667 - 0.764) and (OR: 0.749; CI: 0.682 - 0.823), respectively. As age increased, the preventive effect against severe/critical illness or death and death increased. The preventive effect against severe/critical illness or death at ≥60 years was (OR: 0.669; CI: 0.624 - 0.717), at ≥70 years was (OR: 0.614; CI: 0.570 - 0.661), and at ≥80 years was (OR: 0.563; CI: 0.515 - 0.615). The preventive effect against death at ≥60 years was (OR: 0.729; CI: 0.663 - 0.802), at ≥70 years was (OR: 0.676; CI: 0.612 - 0.747), and at ≥80 years was (OR: 0.622; CI: 0.554 - 0.698). CONCLUSION: Although molnupiravir showed a relatively weak preventive effect against severe/critical illness or death (29%) and death (25%) among patients with COVID-19, it exhibited a stronger protective effect in older patients than in younger patients. In particular, the preventive effect against severe/critical illness or death (44%) and death (38%) in those aged ≥80 years was pronounced. This study strongly suggests that molnupiravir administration can alleviate the burden on the medical system, and treat patients with COVID-19 effectively by reducing its progression to severe disease and death.

Integrated High-Temporal-Resolution and High-Density Subretinal Prosthesis Using a Correlated Double-Sampling Technique.

This paper presents a 1600-pixel integrated neural stimulator with a correlated double-sampling readout (DSR) circuit for a subretinal prosthesis. The retinal stimulation chip inserted beneath the photoreceptor layer comprises an array of an active pixel sensor (APS) and biphasic pulse shaper. The DSR circuit achieves a high signal-to-noise ratio (SNR) of the APS with a short integration time to simultaneously improve the temporal and spatial resolutions of restored vision. This DSR circuit is adopted along with a 5 × 5-pixel tile, which reduces pixel size and improves the SNR by increasing the area occupied by storage capacitors. Moreover, a low-mismatch reference generator enables a low standard deviation between individual pulse shapers. The 1600-pixel retinal chip, fabricated using the 0.18 µm 1P6M CMOS process, occupies a total area of 4.3 mm × 3.3 mm and dissipates an average power of 3.4 mW; this was demonstrated by determining the stimulus current patterns corresponding to the illuminations of an LCD projector. Experimental results show that the proposed high-density stimulation array chip can achieve a high temporal resolution owing to its short integration time.

Microbiome Engineering Using Probiotic Yeast: Saccharomyces boulardii and the Secreted Human Lysozyme Lead to Changes in the Gut Microbiome and Metabolome of Mice.

The probiotic yeast Saccharomyces boulardii has great potential for use as a chassis for microbiome engineering because of its high resistance to environmental stress, well-developed genetic tools, and the ability to secrete recombinant proteins in the intestine. As oral feeding of lysozyme has been reported to change the gut microbiome and fecal metabolites, we engineered S. boulardii to secrete human lysozyme, and investigated the changes in the microbiome and fecal metabolites in response to the administration of the engineered probiotic yeast into mice. Administration of S. boulardii changed the structure of the gut microbiome by promoting the growth of clostridia and increasing the diversity of strains. The human lysozyme secreted by S. boulardii in the intestine resulted in a unique gut microbiome structure through selective growth. In addition, the administration of probiotic yeast S. boulardii affected host energy metabolism and decreased blood urea and fructose levels, suggesting a mechanism of health benefits in mice. IMPORTANCE Our study identified changes in the microbiome by administering wild-type S. boulardii in mice to healthy mice based on long-read sequencing and demonstrated that a recombinant protein secreted by engineered S. boulardii in the intestine could change the microbiome. Our results provide valuable information for the development of therapeutics using engineered S. boulardii that changes the gut microbiome and host physiology.

Effectiveness of Paxlovid, an Oral Antiviral Drug, Against the Omicron BA.5 Variant in Korea: Severe Progression and Death Between July and November 2022.

BACKGROUND: Paxlovid is an oral antiviral drug that received emergency use authorization in South Korea for the treatment of patients with mild-to-moderate coronavirus disease 2019 (COVID-19) on January 14, 2022. Since the onset of the severe acute respiratory syndrome coronavirus 2 pandemic, the virus has continued to evolve. The emergence of new variants has raised concerns about possible reductions in the effectiveness of vaccines and drugs. The effectiveness of Paxlovid in patients infected with the omicron variant and subvariants has not yet been determined. This study assessed the effectiveness of Paxlovid at reducing the risk of severe/critical illness or death and death in patients with mild-to-moderate COVID-19 caused by omicron subvariant BA.5. METHODS: In this nationwide retrospective cohort study, data on 8,902,726 patients were collected from four sources (the Drug Utilization Review database, COVID-19 Patient Information Management System, confirmed patient information, and basic epidemiological investigation data) between July 1 and November 30, 2022. Multivariable logistic regression analysis was conducted, with adjustment for age, sex, severe acute respiratory syndrome coronavirus 2 immunity (vaccination), and comorbidities. RESULTS: A total of 1,936,925 patients with COVID-19 were included in the analysis, including 420,996 patients treated with Paxlovid, and 1,515,959 patients not treated with Paxlovid. Paxlovid treatment in patients aged ≥ 60 years of age was associated with significantly reduced risk of severe/critical illness or death (46.0%), and death rate (32.5%), and its effectiveness was high, regardless of vaccination status. CONCLUSION: Paxlovid is effective at reducing the risk of death due to COVID-19 in patients with omicron BA.5 infection, especially in older patients, regardless of vaccination status. This suggests that older patients with COVID-19-related symptoms should be administered Paxlovid, regardless of their vaccination status, to reduce severity and risk of death.

Identification and Characterization of Diplodia parva and Diplodia crataegicola Causing Black Rot of Chinese Quince.

Fungal isolates from infected Chinese quince trees were found to cause black rot in Yeongcheon, Gyeongsangbuk Province, Korea. The quince leaves withered and turned reddish-brown and fruits underwent black mummification. To elucidate the cause of these symptoms, the pathogen was isolated from infected leaf and fruit tissues on potato dextrose agar and Levan media. Several fungal colonies forming a fluffy white or dark gray mycelium and two types of fungi forming an aerial white mycelium, growing widely at the edges, were isolated. Microscopic observations, investigation of fungal growth characteristics on various media, and molecular identification using an internal transcribed spacer, ß-tubulin, and translation elongation factor 1-α genes were performed. The fungal pathogens were identified as Diplodia parva and Diplodia crataegicola. Pathogenicity tests revealed that the pathogen-inoculated fruits exhibited a layered pattern, turning brown rotting; leaves showed circular brown necrotic lesions. The developed symptoms were similar to those observed in the field. Fungal pathogens were reisolated to fulfill Koch's postulates. Apples were inoculated with fungal pathogens to investigate the host range. Strong pathogenicity was evident in the fruits, with browning and rotting symptoms 3 days after inoculation. To determine pathogen control, a fungicidal sensitivity test was conducted using four registered fungicides. Thiophanate-methyl, propineb, and tebuconazole inhibited the mycelial growth of pathogens. To the best of our knowledge, this is the first report on the isolation and identification of the fungal pathogens D. parva and D. crataegicola from infected fruits and leaves of Chinese quince, causing black rot disease in Korea.

First Report of Cladosporium cladosporioides Causing Leaf Spot of Aralia cordata var. continentalis in Korea.

Aralia cordata var. continentalis (Kitag), commonly known as Japanese spikenard, is an upright herbaceous perennial medicinal plant effective in relieving pain. It is also consumed as a leafy vegetable. Leaf spots and blight symptoms on A. cordata resulting in defoliation were observed in July 2021 from a research field with a disease incidence of nearly 40-50% from 80 plants in Yeongju, Korea. Brown spots with chlorotic halos first appear on the upper leaf surface (Fig. 1A). In the later stage, spots enlarge and coalesce; resulting in the leaves to dry-off (Fig. 1B). To isolate the causal agent, small pieces of diseased leaves displaying the lesion were surface-sterilized by 70% ethanol for 30 s and rinsed twice with sterile distilled water (SDW). Later, the tissues were crushed in a sterile 2.0-ml Eppendorf tube with a rubber pestle in SDW. The suspension was serially diluted and spread on potato dextrose agar (PDA) medium, incubated at 25°C for 3 days. A total of 3 isolates were obtained from the infected leaves. Pure cultures were obtained by the monosporic culture technique (Choi et al. 1999). After 2 to 3 days of incubation with a 12-h photoperiod, the fungus initially produced gray mold colonies in olive color, and the edges of the mold appeared white with a velvety texture after 20 days (Fig. 1C). Microscopic observations revealed small, single-celled, rounded, and pointed conidia that measured 6.67 ± 0.23 µm × 4.18 ± 0.12 µm (length × width) (n=40 spores) (Fig. 1D). On the basis of its morphology, the causal organism was identified as Cladosporium cladosporioides (Torres et al. 2017). For molecular identification, pure colonies of three single-spore isolates were used for DNA extraction. A fragment of the ITS, ACT, and TEF1-α were amplified using the primers ITS1/ITS4 (Zarrin et al. 2016), ACT-512F/ACT-783R, and EF1-728F/EF1-986R, respectively, by PCR (Carbone et al. 1999). The DNA sequences from all three isolates (GYUN-10727, GYUN-10776, and GYUN-10777) were identical. The resulting ITS (ON005144), ACT (ON014518), and TEF1-α (OQ286396) sequences from the representative isolate GYUN-10727 were 99 to 100% identical to the C. cladosporioides (ITS: KX664404, MF077224; ACT: HM148509; TEF1-α: HM148268, HM148266). The phylogenetic dendrogram was constructed from the comparative analysis of ITS, ACT, and TEF1-α gene sequences, showing the relationship between Cladosporium cladosporioides and related Cladosporium species (Fig. 2). The isolate GYUN-10727 has been deposited in Korean Agricultural Culture Collection (KACC 410009), and used as a representative strain in this study. For the pathogenicity test, healthy fresh leaves (3 leaves per plant) of 3-months-old A. cordata plants in pots were spray inoculated with conidial suspensions (1 × 104 conidia/mL) of GYUN-10727, which was obtained from a 7-day-old PDA culture. Leaves sprayed with SDW were considered as control. After 15 days of incubation at 25°C ± 5°C under greenhouse conditions, necrotic lesions were observed on the inoculated A. cordata leaves, while control leaves did not develop any disease symptoms. The experiment was performed twice with three replicates (pots) per treatment. The pathogen was re-isolated from the symptomatic A. cordata leaves, but not from control plants, to fulfill Koch's postulates. The re-isolated pathogen was identified by PCR. Cladosporium cladosporioides has been reported to cause diseases in sweet pepper (Krasnow et al. 2022) and garden peas (Gubler et al. 1999). To our knowledge, this is the first report of C. cladosporioides causing leaf spots of A. cordata in Korea. The identification of this pathogen will help develop strategies to efficiently control the disease in A. cordata.

L-Fucose is involved in human-gut microbiome interactions.

L-Fucose is one of the key metabolites in human-gut microbiome interactions. It is continuously synthesized by humans in the form of fucosylated glycans and fucosyl-oligosaccharides and delivered into the gut throughout their lifetime. Gut microorganisms metabolize L-fucose and produce short-chain fatty acids, which are absorbed by epithelial cells and used as energy sources or signaling molecules. Recent studies have revealed that the carbon flux in L-fucose metabolism by gut microorganisms is distinct from that in other sugar metabolisms because of cofactor imbalance and low efficiencies in energy synthesis of L-fucose metabolism. The large amounts of short-chain fatty acids produced during microbial L-fucose metabolism are used by epithelial cells to recover most of the energy used up during L-fucose synthesis. In this review, we present a detailed overview of microbial L-fucose metabolism and a potential solution for disease treatment and prevention using genetically engineered probiotics that modulate fucose metabolism. Our review contributes to the understanding of human-gut microbiome interactions through L-fucose metabolism. KEY POINTS: • Fucose-metabolizing microorganisms produce large amounts of short-chain fatty acids • Fucose metabolism differs from other sugar metabolisms by cofactor imbalance • Modulating fucose metabolism is the key to control host-gut microbiome interactions.

Lacticaseibacillus Casei IDCC 3451 Strengthen Digestibility of Plant-based Proteins in Mice.

The demand for plant-based proteins as alternative meat sources continues to increase because of environmental concerns, animal welfare, and religious reasons. However, plant-based proteins have low digestibility than real meat, which should be overcome. In the present study, the effect of co-administration of legumin protein mixture and the probiotic strain on plasma concentration of amino acids was investigated as a strategy of enhancement in protein digestion. First, the proteolytic activity of the four probiotic strains was compared. As a result, Lacticaseibacillus casei IDCC 3451 was identified as an optimal probiotic strain that efficiently digested the legumin protein mixture by forming the largest halo produced by proteolysis. Next, to investigate whether the co-administration of legumin protein mixture and L. casei IDCC 3451 could synergically improve digestibility, mice were fed either a high-protein diet or a high-protein diet with L. casei IDCC 3451 for 8 weeks. Compared to only in the high-protein diet only group, the concentrations of branched chain amino acids and essential amino acids were 1.36 and 1.41 times higher in the co-administered group, respectively. Therefore, co-supplementation of plant-based proteins with L. casei IDCC 3451 can be suggested to improve protein digestibility based on the this study.

Identification and Characterization of Pseudomonas syringae pv. syringae, a Causative Bacterium of Apple Canker in Korea.

In the present investigation, bacterial isolates from infected apple trees causing apple canker during winter were studied in the northern Gyeongbuk Province, Korea. The pathogen was identified as Pseudomonas syringae pv. syringae (Pss) through various physiological and biochemical characterization assays such as BIOLOG, gas chromatography of fatty acid methyl esters, and 16S rRNA. Bioassays for the production of phytotoxins were positive for syringopeptin and syringomycin against Bacillus megaterium and Geotrichum candidum, respectively. The polymerase chain reaction (PCR) method enabled the detection of toxin-producing genes, syrB1, and sypB in Pss. The differentiation of strains was performed using LOPAT and GATTa tests. Pss further exhibited ice nucleation activity (INA) at a temperature of -0.7°C, indicating an INA+ bacterium. The ice-nucleating temperature was -4.7°C for a non-treated control (sterilized distilled water), whereas it was -9.6°C for an INA- bacterium Escherichia coli TOP10. These methods detected pathogenic strains from apple orchards. Pss might exist in an apple tree during ice injury, and it secretes a toxin that makes leaves yellow and cause canker symptoms. Until now, Korea has not developed antibiotics targeting Pss. Therefore, it is necessary to develop effective disease control to combat Pss in apple orchards. Pathogenicity test on apple leaves and stems showed canker symptoms. The pathogenic bacterium was re-isolated from symptomatic plant tissue and confirmed as original isolates by 16S rRNA. Repetitive element sequence-based PCR and enterobacterial repetitive intergenic consensus PCR primers revealed different genetic profiles within P. syringae pathovars. High antibiotic susceptibility results showed the misreading of mRNA caused by streptomycin and oxytetracycline.

Increased Amino Acid Absorption Mediated by Lacticaseibacillus rhamnosus IDCC 3201 in High-Protein Diet-Fed Mice.

The use of dietary protein products has increased with interests in health promotion, and demand for sports supplements. Among various protein sources, milk protein is one of the most widely employed, given its economic and nutritional advantages. However, recent studies have revealed that milk protein undergoes fecal excretion without complete hydrolysis in the intestines. To increase protein digestibility, heating and drying were implemented; however, these methods reduce protein quality by causing denaturation, aggregation, and chemical modification of amino acids. In the present study, we observed that Lacticaseibacillus rhamnosus IDCC 3201 actively secretes proteases that hydrolyze milk proteins. Furthermore, we showed that co-administration of milk proteins and L. rhamnosus IDCC 3201 increased the digestibility and plasma concentrations of amino acids in a high-protein diet mouse model. Thus, food supplementation of L. rhamnosus IDCC 3201 can be an alternative strategy to increase the digestibility of proteins.

Influence of ICU Surge and Capacity on COVID Mortality Across U.S. States and Regions During the COVID-19 Pandemic.

BACKGROUND: To describe the influence of COVID-19 caseload surges and overall capacity in the intensive care unit (ICU) on mortality among US population and census divisions. METHODS: A retrospective analysis of the national COVID ActNow database between January 1, 2021 until March 1, 2022. The main outcome used was COVID-19 weekly mortality rates, which were calculated and incorporated into several generalized estimation of effects models with predictor variables that included ICU bed capacity, as well as ICU capacity used by COVID cases while adjusting for ratios of vaccinations in populations, case density, and percentage of the population over the age of 65. RESULTS: Each 1% increase in general ICU capacity is correlated with approximately 5 more weekly deaths from COVID-19 per 100,000 population and each percentage increase in the number of patients with COVID-19 admitted to the ICU resulted in approximately 10 more COVID-19 deaths per week per 100,000 population. Significant differences in ability to handle caseload surges were observed across US census divisions. CONCLUSIONS: A strong association was observed between COVID-19 ICU surges, overall ICU surge, and increased mortality. Further research is needed to reveal best practices and public health measures to prevent ICU overcrowding amidst future pandemics and disaster responses.

Antioxidant, Anti-Apoptotic, and Anti-Inflammatory Effects of Farrerol in a Mouse Model of Obstructive Uropathy.

Obstructive uropathy is a clinical condition that can lead to chronic kidney disease. However, treatments that can prevent the progression of renal injury and fibrosis are limited. Farrerol (FA) is a natural flavone with potent antioxidant and anti-inflammatory properties. Here, we investigated the effect of FA on renal injury and fibrosis in a mouse model of unilateral ureteral obstruction (UUO). Mice underwent a sham or UUO operation and received intraperitoneal injections of FA (20 mg/kg) daily for 8 consecutive days. Histochemistry, immunohistochemistry and immunofluorescence staining, TdT-mediated dUTP nick end labeling assay, Western blotting, gene expression analysis, and biochemical tests were performed. FA attenuated renal dysfunction (p < 0.05) and ameliorated renal tubular injury (p < 0.01) and interstitial fibrosis (p < 0.001) in UUO mice. FA alleviated 4-hydroxynonenal expression (p < 0.001) and malondialdehyde levels (p < 0.01) by regulating pro-oxidant and antioxidant enzymes. Apoptosis in the kidneys of UUO mice was inhibited by FA (p < 0.001), and this action was accompanied by decreased expression of cleaved caspase-3 (p < 0.01). Moreover, FA alleviated pro-inflammatory cytokine production (p < 0.001) and macrophage infiltration (p < 0.01) in the kidneys of UUO mice. These results suggest that FA ameliorates renal injury and fibrosis in the UUO model by inhibiting oxidative stress, apoptosis, and inflammation.

Enhanced production of 3,4-dihydroxybutyrate from xylose by engineered yeast via xylonate re-assimilation under alkaline condition.

To realize lignocellulose-based bioeconomy, efficient conversion of xylose into valuable chemicals by microbes is necessary. Xylose oxidative pathways that oxidize xylose into xylonate can be more advantageous than conventional xylose assimilation pathways because of fewer reaction steps without loss of carbon and ATP. Moreover, commodity chemicals like 3,4-dihydroxybutyrate and 3-hydroxybutyrolactone can be produced from the intermediates of xylose oxidative pathway. However, successful implementations of xylose oxidative pathway in yeast have been hindered because of the secretion and accumulation of xylonate which is a key intermediate of the pathway, leading to low yield of target product. Here, high-yield production of 3,4-dihydroxybutyrate from xylose by engineered yeast was achieved through genetic and environmental perturbations. Specifically, 3,4-dihydroxybutyrate biosynthetic pathway was established in yeast through deletion of ADH6 and overexpression of yneI. Also, inspired by the mismatch of pH between host strain and key enzyme of XylD, alkaline fermentations (pH ≥ 7.0) were performed to minimize xylonate accumulation. Under the alkaline conditions, xylonate was re-assimilated by engineered yeast and combined product yields of 3,4-dihydroxybutyrate and 3-hydroxybutyrolactone resulted in 0.791 mol/mol-xylose, which is highest compared with previous study. These results shed light on the utility of the xylose oxidative pathway in yeast.

Zebrafish EEG predicts the efficacy of antiepileptic drugs.

Background: Pharmacological evaluation of antiepileptic drugs (AEDs) using mammalian animals takes long time and is expensive. The zebrafish is a species commonly used to study brain functions, neurological diseases, and drug toxicity, and attracts more attention as an alternative animal model to substitute or supplement mammalian animals in drug development. Electroencephalogram (EEG) is a key indicator for diagnosing brain diseases such as epilepsy, by directly measuring the brain activity. We propose a novel method for pharmacological evaluation of AEDs based on EEG from adult zebrafish, which allows researchers to select more clinically valuable drugs at the early stage of AED screening. Methods: To evaluate the efficacy of AEDs, zebrafish EEG signals were measured after administering six AEDs (valproate acid, gabapentin, ethosuximide, oxcarbazepine, tiagabine, and topiramate) at various doses to pentylenetetrazol (PTZ)-induced seizure models. The change in seizure activity was investigated according to doses. The antiepileptic effect was determined by observing a significant decrease in at least one out of three indicators of the number, total duration, and mean duration of ictal events. Results: Using EEG signals from adult zebrafish, antiepileptic effects were observed with all six AEDs. Among them, antiepileptic effects depending on dose were confirmed with valproate acid, gabapentin, ethosuximide, and tiagabine. Moreover, the 50% effective doses (ED50) of valproate acid and tiagabine were determined based on zebrafish EEG for the first time, indicating that the quantitative inter-species comparison of the AED efficacy is possible between zebrafish and mammals such as rodents. Significance: The results show that zebrafish can be used to effectively and quantitatively evaluate the efficacy of AEDs based on EEG, the same method to evaluate antiepileptic effects in mammals, suggesting that the proposed method can contribute in reducing the cost and duration of search for AEDs and thus accelerate the drug development cycles.

Protective Effects of Orexin A in a Murine Model of Cisplatin-Induced Acute Kidney Injury.

Cisplatin is a chemotherapeutic agent widely used in the treatment of various cancers, but its application is often limited due to complications such as acute kidney injury (AKI). Orexins are hypothalamic neuropeptides that modulate the sleep-wake cycle, neuroendocrine function, and the autonomic nervous system. Emerging evidence suggests that orexin A (OXA) has anti-inflammatory and neuroprotective effects in animal models of neuroinflammatory diseases of the central nervous system. However, the effect of OXA on kidney diseases has not been examined. Here, we investigated whether OXA has a protective effect in a murine model of cisplatin-induced AKI. Intraperitoneal administration of OXA ameliorated renal dysfunction, and histological abnormalities in mice injected with cisplatin. OXA inhibited cisplatin-induced oxidative stress through the modulation of prooxidant and antioxidant enzymes. This peptide reduced apoptotic cell death by inhibiting the p53-mediated pathway in mice injected with cisplatin. OXA also alleviated cisplatin-induced cytokine production and macrophage infiltration into injured kidneys. Taken together, these results showed that OXA ameliorates cisplatin-induced AKI via antioxidant, anti-apoptotic, and anti-inflammatory actions. This peptide could be a potential therapeutic agent for cisplatin-induced AKI.

Clinical outcomes of remdesivir-treated COVID-19 patients in South Korea.

OBJECTIVES: This study analyzed the clinical outcomes of remdesivir treatment in coronavirus disease 2019 (COVID-19) patients in South Korea. METHODS: This retrospective cohort study involved the secondary analysis of epidemiological data. Among patients diagnosed with COVID-19 from July 2, 2020 to March 23, 2021 (12 AM), 4,868 who received oxygen therapy and were released from isolation after receiving remdesivir treatment were assigned to the treatment group, and 6,068 patients who received oxygen therapy but not remdesivir were assigned to the untreated group. The study subjects included children under the age of 19. The general characteristics and severity were compared between the groups. Differences in the time to death and mortality were also compared. RESULTS: In the untreated group, the hazard ratio [HR] for mortality was 1.59 among patients aged ≥70 years and 2.32 in patients with severe disease in comparison to the treatment group. In a comparison of survival time among patients with severe disease aged ≥70 years, the HR for mortality before 50 days was 2.09 in the untreated group compared to the treatment group. CONCLUSION: Patients with remdesivir treatment showed better clinical outcomes in this study, but these results should be interpreted with caution since this study was not a fully controlled clinical trial.

Elucidation of the fucose metabolism of probiotic Lactobacillus rhamnosus GG by metabolomic and flux balance analyses.

Lactobacillus rhamnosus GG (LGG) is one of the most widely used probiotics because of its health benefits and safety. Fucose is among the most abundant hexoses in the human intestine, and LGG consumes fucose to produce energy or proliferate. However, no study has elucidated the metabolism by which LGG metabolizes fucose to produce energy, biomass, and extracellular metabolites. We used metabolomics and flux balance analysis to elucidate these mechanisms and highlight how they might affect the host. We found three different metabolic flux modes by which LGG anaerobically metabolizes fucose to produce energy and biomass. These metabolic flux modes differ from homolactic or heterolactic fermentation and account for the production of lactic acid, 1,2-propanediol, acetic acid, formic acid, and carbon dioxide as a result of fucose metabolism in LGG. We also used gas chromatography/time-of-flight mass spectrometry to identify a variety of short-chain fatty acids and organic acids secreted during fucose metabolism by LGG. Our study is the first to elucidate the unique fucose metabolism of LGG in anaerobic condition.