Genetic Ablation of Pyruvate Dehydrogenase Kinase Isoform 4 Gene Enhances Recovery from Hyperoxic Lung Injury: Insights into Antioxidant and Inflammatory Mechanisms.

BACKGROUND: Pyruvate dehydrogenase kinase isoform 4 (PDK4) plays a pivotal role in the regulation of cellular proliferation and apoptosis. The objective of this study was to examine whether the genetic depletion of the PDK4 gene attenuates hyperoxia-induced lung injury in neonatal mice. METHODS: Neonatal PDK4-/- mice and wild-type (WT) mice were exposed to oxygen concentrations of 21% (normoxia) and 95% (hyperoxia) for the first 4 days of life. Pulmonary histological assessments were performed, and the mRNA levels of lung PDK4, monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-6 were assessed. The levels of inflammatory cytokines in lung tissue were quantified. RESULTS: Following convalescence from neonatal hyperoxia, PDK4-/- mice exhibited improved lung alveolarization. Notably, PDK4-/- mice displayed significantly elevated MCP-1 protein levels in pulmonary tissues following 4 days of hyperoxic exposure, whereas WT mice showed increased IL-6 protein levels under similar conditions. Furthermore, neonatal PDK4-/- mice subjected to hyperoxia demonstrated markedly higher MCP-1 mRNA expression at 4 days of age compared to WT mice, while IL-6 mRNA expression remained unaffected in PDK4-/- mice. CONCLUSIONS: Newborn PDK4-/- mice exhibited notable recovery from hyperoxia-induced lung injury, suggesting the potential protective role of PDK4 depletion in mitigating lung damage.

Detection of Pathologic Heart Murmurs Using a Piezoelectric Sensor.

This study aimed to evaluate the capability of a piezoelectric sensor to detect a heart murmur in patients with congenital heart defects. Heart sounds and murmurs were recorded using a piezoelectric sensor and an electronic stethoscope in healthy neonates (n = 9) and in neonates with systolic murmurs caused by congenital heart defects (n = 9) who were born at a hospital. Signal data were digitally filtered by high-pass filtering, and the envelope of the processed signals was calculated. The amplitudes of systolic murmurs were evaluated using the signal-to-noise ratio and compared between healthy neonates and those with congenital heart defects. In addition, the correlation between the amplitudes of systolic murmurs recorded by the piezoelectric sensor and electronic stethoscope was determined. The amplitudes of systolic murmurs detected by the piezoelectric sensor were significantly higher in neonates with congenital heart defects than in healthy neonates (p < 0.01). Systolic murmurs recorded by the piezoelectric sensor had a strong correlation with those recorded by the electronic stethoscope (ρ = 0.899 and p < 0.01, respectively). The piezoelectric sensor can detect heart murmurs objectively. Mechanical improvement and automatic analysis algorithms are expected to improve recording in the future.

A Japanese Patient with Genitopatellar Syndrome Transiently Presenting with Cardiac Intramural Cavity during the Neonatal Period.

Genitopatellar syndrome (GPS) is a rare autosomal dominant disorder caused by de novo pathogenic variants in the KAT6B gene. It is characterized by genital abnormalities, patellar hypoplasia/agenesis, flexion contractures of the hips and knees, corpus callosum agenesis with microcephaly, and hydronephrosis and/or multiple renal cysts. More than half of patients with GPS have congenital heart defects, mostly atrial and/or ventricular septal defects, patent foramen ovale, and patent ductus arteriosus. We report a case of a Japanese neonate with a de novo heterozygous c.3769_3772delTCTA pathogenic variant in the KAT6B gene who presented with a cardiac intramural cavity of the ventricular septum at birth. The cavity unexpectedly disappeared at 1 month of age, but trabecular septal thinning and flash remained. The features of the cavity were not consistent with those of congenital ventricular diverticulum or aneurysm, and its identity and prognosis are still unclear. Because patients with GPS may exhibit various forms of cardiac malformation, careful cardiac examination and follow-up are required from birth in cases of suspected GPS.

Development of a Diagnostic Screening Strategy for Niemann-Pick Diseases Based on Simultaneous Liquid Chromatography-Tandem Mass Spectrometry Analyses of N-Palmitoyl-O-phosphocholine-serine and Sphingosylphosphorylcholine.

Early diagnosis of Niemann-Pick diseases (NPDs) is important for better prognosis of such diseases. N-Palmitoyl-O-phosphocholine-serine (PPCS) is a new NPD biomarker possessing high sensitivity, and with its combination with sphingosylphosphocholine (SPC) it may be possible to distinguish NPD-C from NPD-A/B. In this study, a rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method (method 1) and a validated LC-MS/MS analysis (method 2) of PPCS and SPC were developed, and we have proposed a diagnostic screening strategy for NPDs using a combination of serum PPCS and SPC concentrations. Nexera and API 5000 were used as LC-MS/MS systems. C18 columns with lengths of 10 and 50 mm were used for method 1 and 2, respectively. 2H3-Labeled PPCS and nor-SPC were used as internal standards. Selective reaction monitoring in positive-ion mode was used for MS/MS. Run times of 1.2 and 8 min were set for methods 1 and 2, respectively. In both methods 1 and 2, two analytes showed high linearity in the range of 1-4000 ng/mL. Method 2 provided high accuracy and precision in method validation. Serum concentrations of both analytes were significantly higher in NPD-C patients than those of healthy subjects in both methods. Serum PPCS correlated between methods 1 and 2; however, it was different in the case of SPC. The serum PPCS/SPC ratio was different in healthy subjects, NPD-C, and NPD-A/B. These results suggest that using a combination of the two LC-MS/MS analytical methods for PPCS and SPC is useful for diagnostic screening of NPDs.