Absence of Ductus Venosus: A Comparison of 2 Distinctive Fetal Autopsy Cases and Embryologic Perspectives.

In fetal circulation, oxygenated blood from the placenta flows through the umbilical vein into the ductus venosus (DV), then enters the inferior vena cava, and subsequently reaches the right atrium of the heart. The DV serves as a shunt, allowing this oxygen-rich blood to bypass the liver. The absence of the DV (ADV), also known as agenesis of the DV, is a rare congenital anomaly. Without a DV, blood from the umbilical vein must follow alternative routes to the heart. In ADV cases, blood from the umbilical vein must follow 1 of 2 primary drainage patterns: either an extrahepatic shunt or an intrahepatic shunt. This report details the antenatal ultrasound and postmortem findings of 2 fetuses diagnosed with ADV by prenatal imaging studies. The first case involved a fetus with a persistent right umbilical vein connected directly to the suprahepatic IVC, accompanied by early obliteration of the left umbilical vein and true agenesis of the DV. This fetus also had additional congenital anomalies. In contrast, the second case involved a fetus with a normal left umbilical vein that entered the liver. However, despite an ultrasound diagnosis of "absence" of the DV, a DV was present, though markedly hypoplastic and probably minimally functional or non-functional. In this case, blood from the umbilical vein likely followed an alternate intrahepatic route through the portal and hepatic veins, before reaching the heart (intrahepatic shunt). These contrasting cases emphasize the heterogeneity of vascular anomalies and embryologic origins captured by the term "ADV." Additionally, the terminology of "absence" or "agenesis" may be misleading in some purported ADV cases. Specifically, in the second case, the DV was not absent; it was markedly hypoplastic instead. This also appears to be the first reported case of a hypoplastic DV in a fetus. Both cases underscore the importance of effective collaboration and clear communication between maternal-fetal medicine specialists and pathologists.

What are the experiences of non-invasive ventilation for sleep-disordered breathing in children and young people and what outcomes matter? Perspectives of children and young people, their parents and the staff who care for them.

BACKGROUND: Non-invasive ventilation (NIV) for sleep-disordered breathing (SDB) in children and young people (CYP) can result in multiple health outcomes; however, adherence to NIV can be challenging. Suboptimally treated SDB may increase the risk of adverse consequences. Placing children's and parents' goals at the core of their SDB treatment may support adherence to NIV. To identify these health outcomes, it is necessary to gain a greater understanding of CYP's experiences of using NIV, whether they perceive any benefits from NIV use, as well as the outcomes that their parents and NIV staff identify as important. METHODS: Semi-structured qualitative interviews were conducted with nine CYP (aged 4-16 + years), 13 parents and nine healthcare professionals (HCPs); verbatim transcripts were analysed using Framework Analysis. RESULTS: CYP predominantly reported an improvement in levels of energy, focus and ability to concentrate whereas parents also identified outcomes of mood and behaviour. The majority of children showed understanding of the reasons for being prescribed NIV. A subset of children did not notice their SDB. The health outcomes identified by HCPs and parents that could result from improved overnight gas exchange are subjective measures that rely on parent and child report. Measuring these health outcomes focussed on the impact of improved sleep rather than measuring improved sleep itself. CONCLUSIONS: It is important for HCPs administering NIV to ascertain whether CYP have noticed any of their sleep-disordered breathing symptoms and any improvements from using NIV, including the relationship between benefits and side effects. Focussing on promoting understanding for CYP who are unable to link their wellbeing to their previous night's sleep may be futile and HCP strategies should concentrate on the process of tolerating the device. Parents, CYP and HCPs should collaborate to identify treatment goals specifically tailored for the child and monitor any progress against these goals.

Mycolyltransferase is important for biofilm formation and pathogenesis of Tsukamurella keratitis.

Tsukamurella, a group of multi-drug resistant, Gram-positive, aerobic, and partially acid-fast bacteria, are emerging causes of bacterial conjunctivitis and keratitis. However, the pathogenesis of Tsukamurella keratitis is largely unknown. To address this, we used New Zealand White rabbits to develop the first eye infection model and conducted in vitro tests to study the pathogenesis mechanisms of Tsukamurella. There is increasing evidence that biofilms play a significant role in ocular infections, leading us to hypothesize that biofilm formation is crucial for effective Tsukamurella infection. In order to look for potential candidate genes which are important in biofilm formation and Tsukamurella keratitis. We performed genome sequencing of two ocular isolates, T. pulmonis-PW1004 and T. tyrosinosolvens-PW899, to identify potential virulence factors. Through in vitro and in vivo studies, we characterized their biological roles in mediating Tsukamurella keratitis. Our findings confirmed that Tsukamurella is an ocular pathogen by fulfilling Koch's postulates, and using genome sequence data, we identified tmytC, encoding a mycolyltransferase, as a crucial gene in biofilm formation and causing Tsukamurella keratitis in the rabbit model. This is the first report demonstrating the novel role of mycolyltransferase in causing ocular infections. Overall, our findings contribute to a better understanding of Tsukamurella pathogenesis and provide a potential target for treatment. Specific inhibitors targeting TmytC could serve as an effective treatment option for Tsukamurella infections.