Utilizing metagenomic next-generation sequencing for pathogen detection and diagnosis in lower respiratory tract infections in real-world clinical practice.

BACKGROUND: Infectious etiologies of lower respiratory tract infections (LRTIs) by the conventional microbiology tests (CMTs) can be challenging. Metagenomic next-generation sequencing (mNGS) has great potential in clinical use for its comprehensiveness in identifying pathogens, particularly those difficult-to-culture organisms. METHODS: We analyzed a total of 205 clinical samples from 201 patients with suspected LRTIs using mNGS in parallel with CMTs. mNGS results were used to guide treatment adjustments for patients who had negative CMT results. The efficacy of treatment was subsequently evaluated in these patients. RESULTS: mNGS-detected microorganisms in 91.7% (188/205) of the clinical samples, whereas CMTs demonstrated a lower detection rate, identifying microorganisms in only 37.6% (77/205) of samples. Compared to CMT results, mNGS exhibited a detection sensitivity of 93.5% and 95.4% in all 205 clinical samples and 180 bronchoalveolar lavage fluid (BALF) samples, respectively. A total of 114 patients (114/201; 56.7%) showed negative CMT results, among which 92 received treatment adjustments guided by their positive mNGS results. Notably, 67.4% (62/92) of patients demonstrated effective treatment, while 25% (23/92) experienced a stabilized condition. Subgroup analysis of cancer patients revealed that 41.9% (13/31) exhibited an effective response to treatment, and 35.5% (11/31) maintained a stable condition following medication adjustments guided by mNGS. CONCLUSION: mNGS demonstrated great potential in identifying microorganisms of clinical significance in LRTIs. The rapid turnaround time and reduced susceptibility to the impact of antimicrobial administration make mNGS a valuable supplementary tool for diagnosis and treatment decision-making for suspected LRTIs in clinical practice.

Dietary supplementation of coated sodium butyrate improves growth performance of laying ducks by regulating intestinal health and immunological performance.

Introduction: This study was conducted to assess the effects of dietary supplementation of coated sodium butyrate (CSB) on the growth performance, serum antioxidant, immune performance, and intestinal microbiota of laying ducks. Methods: A total of 120 48-week-old laying ducks were randomly divided into 2 treatment groups: the control group (group C fed a basal diet) and the CSB-treated group (group CSB fed the basal diet + 250 g/t of CSB). Each treatment consisted of 6 replicates, with 10 ducks per replicate, and the trial was conducted for 60 days. Results: Compared with the group C, the group CSB showed a significant increase in the laying rate (p<0.05) of the 53-56 week-old ducks. Additionally, the serum total antioxidant capacity, superoxide dismutase activity and immunoglobulin G level were significantly higher (p<0.05), while the serum malondialdehyde content and tumor necrosis factor (TNF)-a level were significantly lower (p<0.05) in the serum of the group CSB compared to the group C. Moreover, the expression of IL-1b and TNF-a in the spleen of the group CSB was significantly lower (p<0.05) compared to that of the group C. In addition, compared with the group C, the expression of Occludin in the ileum and the villus height in the jejunum were significantly higher in the group CSB (p<0.05). Furthermore, Chao1, Shannon, and Pielou-e indices were higher in the group CSB compared to the group C (p<0.05). The abundance of Bacteroidetes in the group CSB was lower than that in the group C (p<0.05), while the abundances of Firmicutes and Actinobacteria were higher in the group CSB compared to the group C (p<0.05). Conclusions: Our results suggest that the dietary supplementation of CSB can alleviate egg-laying stress in laying ducks by enhancing immunity and maintaining the intestinal health of the ducks.

Synthesis of Cu2O-Modified Reduced Graphene Oxide for NO2 Sensors.

Nowadays, metal oxide semiconductors (MOS)-reduced graphene oxide (rGO) nanocomposites have attracted significant research attention for gas sensing applications. Herein, a novel composite material is synthesized by combining two p-type semiconductors, i.e., Cu2O and rGO, and a p-p-type gas sensor is assembled for NO2 detection. Briefly, polypyrrole-coated cuprous oxide nanowires (PPy/Cu2O) are prepared via hydrothermal method and combined with graphene oxide (GO). Then, the nanocomposite (rGO/PPy/Cu2O) is obtained by using high-temperature thermal reduction under Ar atmosphere. The results reveal that the as-prepared rGO/PPy/Cu2O nanocomposite exhibits a maximum NO2 response of 42.5% and is capable of detecting NO2 at a low concentration of 200 ppb. Overall, the as-prepared rGO/PPy/Cu2O nanocomposite demonstrates excellent sensitivity, reversibility, repeatability, and selectivity for NO2 sensing applications.

Na(+)/Ca(2+) exchanger 1 (NCX-1) mediates the anti-apoptotic effect of Akt1 in neonatal rat cardiomyocytes during ischemia/reperfusion.

The purpose of this study was to investigate the anti-apoptotic role of Akt1 gene in neonatal rat cardiomyocytes and the relationship with Na(+)/Ca(2+) exchanger 1 (NCX1) during ischemia/reperfusion (IR). The cultured original rat cardiomyocytes were randomly divided into five groups: normal control group (C group), hypoxia/reoxygenation group (HR group), the control vector pLVX-EGFP-3FLAG group (CV group), the gene pLVX-EGFP-3FLAG-Akt1 transfection group (A group), and Akt1 inhibitor LY294002 group (LY group). Cardiomyocyte vitality was determined using MTT, and the apoptosis was determined by TUNEL to verify the anti-apoptotic role of Akt1. The mRNA levels of Akt1 and NCX1 were determined by RT-PCR, the protein expression of Akt1, p-Akt1, NCX1 and the apoptotic proteins of mitochondrial pathway cytochrome C (Cyto C) and caspase-9 were measured by Western blot. As a result, transfected Akt1 (A group) showed increased myocardial cell viability and reduced apoptosis, with increase in Akt1 expression and decrease in NCX1 expression. The levels of apoptotic proteins Cyto C and caspase-9 also declined. This study demonstrated that lentivirus-mediated transfection of Akt1 played an anti-apoptotic role during IR of rat cardiomyocytes, via inhibition of NCX1 and other mitochondrial proteins.

Antibacterial Effects of a Cell-Penetrating Peptide Isolated from Kefir.

Kefir is a traditional fermented milk beverage used throughout the world for centuries. A cell-penetrating peptide, F3, was isolated from kefir by Sephadex G-50 gel filtration, DEAE-52 ion exchange, and reverse-phase high-performance liquid chromatography. F3 was determined to be a low molecular weight peptide containing one leucine and one tyrosine with two phosphate radicals. This peptide displayed antimicrobial activity across a broad spectrum of organisms including several Gram-positive and Gram-negative bacteria as well as fungi, with minimal inhibitory concentration (MIC) values ranging from 125 to 500 µg/mL. Cellular penetration and accumulation of F3 were determined by confocal laser scanning microscopy. The peptide was able to penetrate the cellular membrane of Escherichia coli and Staphylococcus aureus. Changes in cell morphology were observed by scanning electron microscopy (SEM). The results indicate that peptide F3 may be a good candidate for use as an effective biological preservative in agriculture and the food industry.

Lentiviral-mediated overexpression of Akt1 reduces anoxia-reoxygenation injury in cardiomyocytes.

Activated PI3K/Akt signalling exerts a protective effect after myocardial ischemia by phosphorylating various substrates; however, the precise mechanism by which this occurs remains to be elucidated. We have constructed the recombinant lentiviral vector pLVX-Akt1-EGFP- 3FLAG (LV-Akt1) to determine the efficiency of LV-Akt1 infection, explore the protective role of Akt1, and investigate the possible mechanism by which Akt1 signalling acts during anoxia/reoxygenation (A/R) of cardiomyocytes in primary culture. Akt1 gene transfection increased cardiomyocyte pulsation, reduced cell mortality, and decreased the concentration of lactate dehydrogenase (LDH) in myocardial cells supernatants. Akt1 transfection increased the levels of intracellular p-Akt, enhanced the expression of the anti-apoptosis protein Bcl-2, and reduced that of the apoptosis protein Bax (thereby increasing the Bcl-2/Bax ratio), and caused some increase in hypoxia-inducible factor1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression after A/R. The protective role of Akt1 was partly suppressed by adding a phosphoinositide 3-kinase/Akt inhibitor (LY294002). In conclusion, LV-Akt1 was successfully constructed and neonatal rat cardiomyocytes were transfected efficiently. Akt1 overexpression significantly reduced A/R injury in cardiomyocytes, and this could be related to its effects on various targets of the PI3K/Akt signalling pathway, such as Bcl-2, Bax, HIF-1α and VEGF.