Establishment and characterization of Lesch-Nyhan syndrome rabbit model.

Lesch-Nyhan syndrome (LNS) is a congenital defect disease that results in defective purine metabolism. It is caused by pathogenic variants of the HPRT gene. Its clinical symptoms mainly include high uric acid levels, gout, and kidney stones and damage. The mechanism of LNS has not been fully elucidated, and no cure exists. Animal models have always played an important role in exploring causative mechanisms and new therapies. This study combined CRISPR/Cas9 and microinjection to knock out the HPRT gene to create an LNS rabbit model. A sgRNA targeting exon 3 of HPRT gene was designed. Subsequently, Cas9 mRNA and sgRNA were injected into rabbit zygotes, and injected embryos were transferred to the uterus. The genotype and phenotype of rabbits were analyzed after birth. Four infant rabbits (named R1, R2, R3 and R4), which showed varying levels of gene modification, were born. The gene-editing efficiency was 100%. No wild-type sequences at the target HPRT gene were detected in R4 rabbit. Next, 6-thioguanine drug testing confirmed that HPRT enzymatic activity was deficient in R4 infant rabbit. HE staining revealed kidney abnormalities in all infant rabbits. Overall, an sgRNA capable of knocking out the HPRT gene in rabbits was successfully designed, and HPRT gene-modified rabbits were successfully constructed by using CRISPR/Cas9 technology and microinjection. This study provides a new nonrodent animal model for studying LNS syndrome.

Microplastic exposure disturbs sleep structure, reduces lifespan, and decreases ovary size in Drosophila melanogaster.

The organ-specific toxicity resulting from microplastic (MP) exposure has been extensively explored, particularly concerning the gut, liver, testis, and lung. However, under natural conditions, these effects are not restricted to specific organs or tissues. Investigating whether MP exposure presents a systemic threat to an entire organism, impacting factors such as lifespan, sleep, and fecundity, is essential. In this study, we investigated the effects of dietary exposure to two different doses of MPs (1-5 µm) using the terrestrial model organism Drosophila melanogaster. Results indicated that the particles caused gut damage and remained within the digestive system. Continuous MP exposure significantly shortened the lifespan of adult flies. Even short-term exposure disrupted sleep patterns, increasing the length of daytime sleep episodes. Additionally, one week of MP exposure reduced ovary size, with a trend towards decreased egg-laying in mated females. Although MPs did not penetrate the brain or ovaries, transcriptome analysis revealed altered gene expression in these tissues. In the ovary, Gene Ontology (GO) analysis indicated genotoxic effects impacting inflammation, circadian regulation, and metabolic processes, with significant impacts on extracellular structure-related pathways. In the brain, GO analysis identified changes in pathways associated with proteolysis and carbohydrate metabolism. Overall, this study provides compelling evidence of the systemic negative effects of MP exposure, highlighting the urgent need to address and mitigate environmental MP pollution.

Radiofrequency Catheter Ablation Versus Cryoballoon Ablation in the Treatment of Paroxysmal Atrial Fibrillation: A Cost-effectiveness Analysis in China.

PURPOSE: The aim of this study was to evaluate the cost-effectiveness of radiofrequency catheter ablation (RFCA) compared with cryoballoon (CB) ablation in the treatment of patients with paroxysmal atrial fibrillation (PAF) from the payer's perspective in China. METHODS: We constructed a cohort model, combining a 12-month decision-tree model with a lifetime Markov state-transition model, in a hypothetical cohort of patients with drug-refractory PAF managed with either RFCA or CB ablation, to compare the cost-effectiveness of the 2 procedures. Data related to clinical outcomes and costs in this model were obtained from a retrospective 12-month follow-up study in patients in China and from related literature. The incremental cost-effectiveness ratio (ICER) over a 10-year time period was calculated and compared against the willingness-to-pay (WTP) threshold. We used a 1-way sensitivity analysis and a probabilistic sensitivity analysis (PSA) to access the structural uncertainty and the parameter uncertainty, respectively. FINDINGS: Over a 10-year time horizon, the total costs per patient of RFCA and CB ablation were ¥98,164.04 (US $15,339.57; €13,058.94) and ¥107,542.37 ($16,805.07; €14,306.55), respectively, and quality-adjusted life-years (QALYs) gained were 5.47 and 5.43, respectively. The ICER ratio was -¥224,365.01 (-$35,060.32; -€29,847.68) per QALY, indicating that RFCA is associated with greater QALYs and lower costs than CB ablation. The 1-way sensitivity analysis demonstrated that the model results were most sensitive to the odds ratio of the atrial fibrillation recurrence within 12 months in the RFCA group versus the CB ablation group, the cost of RFCA, and the perioperative stroke risk with RFCA. According to the results of the PSA, RFCA was associated with a high probability of being cost-effective (99.48%) compared with CB ablation at a WTP threshold of ¥161,940 ($25,305.50; €21,543.17) per QALY. IMPLICATIONS: Our analysis indicates that RFCA is cost-saving compared with CB ablation in the treatment of patients with PAF in China, based on better QALYs and lower costs over a 10-year time horizon, from the payer's perspective.