Protocol to quantify polyphosphate in human cell lines using a tagged PPBD peptide.

Polyphosphate (polyP) is an evolutionarily conserved polymer of phosphates that is difficult to study in human cells because of its low concentration and high lability. First, we described how to express and purify Xpress-tagged PPBD (Ppx1 PolyP Binding Domain). We describe the detection and quantification of nuclear polyP in HEK293T cells using Xpress-PPBD, Xpress antibody, and Alexa-conjugated secondary antibodies. We have also used this protocol in SH-SY5Y HeLa and HEK293 cells. For complete details on the use and execution of this protocol, please refer to Samper-Martín et al. (2021).

Polyphosphate degradation by Nudt3-Zn2+ mediates oxidative stress response.

Polyphosphate (polyP) is a polymer of hundreds of phosphate residues present in all organisms. In mammals, polyP is involved in crucial physiological processes, including coagulation, inflammation, and stress response. However, after decades of research, the metabolic enzymes are still unknown. Here, we purify and identify Nudt3, a NUDIX family member, as the enzyme responsible for polyP phosphatase activity in mammalian cells. We show that Nudt3 shifts its substrate specificity depending on the cation; specifically, Nudt3 is active on polyP when Zn2+ is present. Nudt3 has in vivo polyP phosphatase activity in human cells, and importantly, we show that cells with altered polyP levels by modifying Nudt3 protein amount present reduced viability upon oxidative stress and increased DNA damage, suggesting that polyP and Nudt3 play a role in oxidative stress protection. Finally, we show that Nudt3 is involved in the early stages of embryo development in zebrafish.

Low-dose vaginal misoprostol vs vaginal dinoprostone insert for induction of labor beyond 41st week: A randomized trial.

INTRODUCTION: The aim of this study was to compare the efficacy and safety of a low-dose protocol of vaginal misoprostol and vaginal dinoprostone insert for induction of labor in women with post-term pregnancies. MATERIAL AND METHODS: We designed a prospective, randomized, open-labeled trial with evaluators blinded to the end-point, including women of at least 41 weeks of gestational age with uncomplicated singleton pregnancies and a Bishop score <6. They were randomized into dinoprostone or misoprostol groups in a 1:1 ratio. Baseline maternal data and perinatal outcomes were recorded for statistical analysis. Successful vaginal delivery within 24 hours was the primary outcome variable. A P value <0.05 was considered statistically significant. This study was registered in ClinicalTrials.gov (number NTC03744364). RESULTS: We included 198 women for analysis (99 women in each group). Vaginal birth rate within 24 hours did not differ between groups (49.5% vs 42.4%; P = 0.412). When the Bishop score was <4, dinoprostone insert showed a higher probability of vaginal delivery within 12 hours (17.8% vs 4%; P = 0.012). In the dinoprostone group, removal of the insert was more likely to be due to an adverse event (5.1% vs 14.1%; P = 0.051) and an abnormal fetal heart rate pattern during active labor (44.4% vs 58.6%; P = 0.047). Both groups were similar in neonatal outcomes including Apgar score, umbilical cord pH and neonatal intensive care unit admission. CONCLUSIONS: Low-dose vaginal misoprostol and vaginal dinoprostone insert seem to be equally effective and safe for induction of labor in pregnant women with a gestational age beyond 41 weeks.

Horner's Syndrome due to a Spontaneous Internal Carotid Artery Dissection after Deep Sea Scuba Diving.

Internal carotid artery dissection (ICAD) is a rare entity that either results from traumatic injury or can be spontaneously preceded or not by a minor trauma such as sporting activities. It represents a major cause of stroke in young patients. The diagnosis should be suspected with the combination of Horner's syndrome, headache or neck pain, and retinal or cerebral ischaemia. The confirmation is frequently made with a magnetic resonance angiography (MRA). Although anticoagulation with heparin followed by vitamin-K-antagonists is the most common treatment, there is no difference in efficacy of antiplatelet and anticoagulant drugs at preventing stroke and death in patients with symptomatic carotid dissection. We describe a patient with ICAD following deep sea scuba diving, who presented with Horner's syndrome and neck pain and was successfully treated with anticoagulants.