Ozone therapy mitigates parthanatos after ischemic stroke.

BACKGROUND: Stroke is a leading cause of death worldwide, with oxidative stress and calcium overload playing significant roles in the pathophysiology of the disease. Ozone, renowned for its potent antioxidant properties, is commonly employed as an adjuvant therapy in clinical settings. Nevertheless, it remains unclear whether ozone therapy on parthanatos in cerebral ischemia-reperfusion injury (CIRI). This study aims to investigate the impact of ozone therapy on reducing parthanatos during CIRI and to elucidate the underlying mechanism. METHODS: Hydrogen peroxide (H2O2) was utilized to mimic the generation of reactive oxygen species (ROS) in SH-SY5Y cell reperfusion injury in vitro, and an in vivo ischemic stroke model was established. Ozone saline was introduced for co-culture or intravenously administered to mice. Apoptosis and oxidative stress were assessed using flow cytometry and immunofluorescence. Western blotting was utilized to examine the expression of parthanatos signature proteins. The mechanism by which ozone inhibits parthanatos was elucidated through inhibiting PPARg or Nrf2 activity. RESULTS: The findings demonstrated that ozone mitigated H2O2-induced parthanatos by either upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) or activating peroxisome proliferator-activated receptorg (PPARg). Furthermore, through the use of calcium chelators and ROS inhibitors, it was discovered that ROS directly induced parthanatos and facilitated intracellular calcium elevation. Notably, a malignant feedback loop between ROS and calcium was identified, further amplifying the induction of parthanatos. Ozone therapy exhibited its efficacy by increasing PPARg activity or enhancing the Nrf2 translation, thereby inhibiting ROS production induced by H2O2. Concurrently, our study demonstrated that ozone treatment markedly inhibited parthanatos in stroke-afflicted mice. Additionally, ozone therapy demonstrated significant neuroprotective effects on cortical neurons, effectively suppressing parthanatos. CONCLUSIONS: These findings contribute valuable insights into the potential of ozone therapy as a therapeutic strategy for reducing parthanatos during CIRI, highlighting its impact on key molecular pathways associated with oxidative stress and calcium regulation.

Household Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 from Adults to Children.

Knowledge of transmission dynamics of severe acute respiratory syndrome coronavirus 2 from adults to children in household settings is limited. We found an attack rate among 213 children in 137 households to be 6.1% in households with confirmed adult 2019 novel coronavirus disease index case(s). Transmission from adult to child occurred in only 5.2% of households. Young children <5 years old were at lowest risk of infection (1.3%). Children were most likely to be infected if the household index case was the mother.

Effects of sub-minimum inhibitory concentrations of ciprofloxacin on biofilm formation and virulence factors of Escherichia coli.

OBJECTIVE: To evaluate the influence of sub-minimum inhibitory concentrations (MICs) of ciprofloxacin (CIP) on biofilm formation and virulence factors of Escherichia coli clinical isolates. METHODS: Sub-MICs of CIP were determined using growth curve experiments. The biofilm-forming capacity of E. coli clinical isolates and E. coli ATCC 25922 treated or untreated with sub-MICs of CIP was assessed using a crystal violet staining assay. The biofilm structure of E. coli isolate was assessed with scanning electron microscopy (SEM). The expression levels of the virulence genes fim, usp, and iron and the biofilm formation genes of the pgaABCD locus were measured using quantification RT-PCR (qRT-PCR) in E. coli isolates and E. coli ATCC 25922. RESULTS: Based on our results, the sub-MICs of CIP were 1/4 MICs. Sub-MICs of CIP significantly inhibited biofilm formation of E. coli clinical isolates and E. coli ATCC 25922 (p<0.01). SEM analyses indicated that the biofilm structure of the E. coli changed significantly after treatment with sub-MICs of CIP. Expression levels of the virulence genes fim, usp, and iron and the biofilm formation genes of the pgaABCD locus were also suppressed. CONCLUSIONS: The results revealed that treatment with sub-MICs of CIP for 24h inhibited biofilm formation and reduced the expression of virulence genes and biofilm formation genes in E. coli.

Effects of sub-minimum inhibitory concentrations of ciprofloxacin on biofilm formation and virulence factors of Escherichia coli

ABSTRACT Objective: To evaluate the influence of sub-minimum inhibitory concentrations (MICs) of ciprofloxacin (CIP) on biofilm formation and virulence factors of Escherichia coli clinical isolates. Methods: Sub-MICs of CIP were determined using growth curve experiments. The biofilm-forming capacity of E. coli clinical isolates and E. coli ATCC 25922 treated or untreated with sub-MICs of CIP was assessed using a crystal violet staining assay. The biofilm structure of E. coli isolate was assessed with scanning electron microscopy (SEM). The expression levels of the virulence genes fim, usp, and iron and the biofilm formation genes of the pgaABCD locus were measured using quantification RT-PCR (qRT-PCR) in E. coli isolates and E. coli ATCC 25922. Results: Based on our results, the sub-MICs of CIP were 1/4 MICs. Sub-MICs of CIP significantly inhibited biofilm formation of E. coli clinical isolates and E. coli ATCC 25922 (p < 0.01). SEM analyses indicated that the biofilm structure of the E. coli changed significantly after treatment with sub-MICs of CIP. Expression levels of the virulence genes fim, usp, and iron and the biofilm formation genes of the pgaABCD locus were also suppressed. Conclusions: The results revealed that treatment with sub-MICs of CIP for 24 h inhibited biofilm formation and reduced the expression of virulence genes and biofilm formation genes in E. coli.