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Biomedical subjects

Mingming Yang

Publications and source records attributed to Mingming Yang.

2 recordsLinked to original sources

A novel biocontrol Pseudomonas species with broad-spectrum antagonistic activity against phytopathogens.

Bacterial and fungal diseases cause significant losses in horticultural crops, and biocontrol using beneficial microorganisms offers a sustainable alternative to chemical pesticides. In this study, a novel Pseudomonas strain D3 was isolated from Actinidiae rhizosphere. D3 exhibited strong antibacterial activity in LB medium but showed no activity against fungi or oomycetes. However, when cultured in KIDO medium, it demonstrated potent antifungal activity. Phylogenetic analysis based on 16S rRNA gene showed that D3 was most closely related to Pseudomonas mosselii CIP_105259T, while whole-genome sequencing revealed ANI values below 95% with eight known P. mosselii strains. Digital DNA-DNA hybridization (dDDH) further confirmed its genomic distinctiveness, with the highest dDDH value (58.2%) against the type strain P. mosselii DSM 17497T, well below the 70% species delineation threshold, supporting D3 as a novel Pseudomonas species. Functional validation via targeted gene knockout revealed a dichotomy in the antagonistic mechanisms of D3. Knockout of individual biosynthetic gene clusters (BGCs) only partially reduced antibacterial activity against Pseudomonas syringae pv. actinidiae, indicating that multiple BGCs contribute to this activity in a partially redundant manner. In contrast, disruption of a specific lipopeptide synthase cluster completely abolished antifungal activity against Valsa mali. LC-MS/MS analysis confirmed that this lipopeptide was produced exclusively in KIDO medium, consistent with the observed medium-dependent antifungal activity. Detached leaf and twig assays showed that D3 provides strong preventive biocontrol against both pathogens. Collectively, strain D3 employs a dual biocontrol mechanism, combining antibacterial activity mediated by multiple BGCs with lipopeptide-dependent antifungal activity, positioning it as a promising agent for sustainable disease management in horticultural crops.

Pseudomonas

Lactate Dehydrogenase and Outcomes in Patients With HF and Reduced Ejection Fraction: Insights From GALACTIC-HF.

BACKGROUND: Lactate dehydrogenase (LDH) is a cytoplasmic enzyme found in most cells. Increased LDH levels are a nonspecific measure of cellular injury and may be prognostically important in heart failure (HF). OBJECTIVES: This study aims to assess the relationship between LDH and clinical characteristics and outcomes in heart failure and reduced ejection fraction (HFrEF). METHODS: Using data from GALACTIC-HF, a phase 3, randomized, placebo-controlled trial evaluating the efficacy and safety of omecamtiv mecarbil (OM) in patients with HFrEF, the relationship between LDH and clinical outcomes was analyzed. The incremental value of LDH added to a validated prognostic model (PREDICT-HF) was also calculated using Harrell's C statistic, integrated discrimination index (IDI), and net reclassification index (NRI). RESULTS: In GALACTIC-HF, baseline LDH data were available for 8,179 patients, including 6,138 outpatients. Patients with higher LDH were more frequently female and had worse HF status. They were also more likely to have elevated serum creatinine, liver enzymes, creatine kinase, NT-proBNP, and high-sensitivity troponin I. Compared with patients in the lowest LDH (Q1: 155 U/L [25th-75th percentile: 144-163 U/L]), the HRs for the primary outcome (first HF event or cardiovascular death) were Q2: 183 U/L (25th-75th percentile: 177-188 U/L); HR: 1.15 [95% CI: 1.02-1.31]; Q3: 207 U/L (25th-75th percentile: 201-215 U/L); HR: 1.39 [95% CI: 1.23-1.58]; and Q4: 253 U/L (25th-75th percentile: 236-280 U/L); HR: 1.84 [95% CI: 1.62-2.08], respectively. Even after adjustment, elevated LDH remained independently associated with higher HR. When added to the PREDICT-HF risk model, baseline LDH improved Harrell's C statistic, IDI, and NRI for the primary outcome. CONCLUSIONS: In GALACTIC-HF, higher LDH levels were independently associated with a higher risk of clinical outcomes in HFrEF. (Global Approach to Lowering Adverse Cardiac Outcomes Through Improving Contractility in Heart Failure [GALACTIC-HF]; NCT02929329; EudraCT number: 2016-002299-28).

Humans