T­lymphoblastic lymphoma in a child diagnosed by metagenomic sequencing: A case report.

T-lymphoblastic lymphoma (T-LBL) is a rare subtype of non-Hodgkin's lymphoma with a higher incidence in children than adults. T-LBL often presents with multiple lymph node enlargements or mediastinal masses, which can cause local compression symptoms, and is frequently misdiagnosed as an infectious disease at an early stage. By summarizing a recently experienced case of T-LBL in a patient with a suspected infection, with an analysis of clinical features and diagnostic methods, the aim of the present study was to provide more information on the early diagnosis of tumors in patients suspected to have an infection. An 8-year-old boy presented at a local hospital with abdominal pain, chest tightness and shortness of breath for >5 days, and bilateral pleural, abdominal and pericardial effusion were considered. Following hospitalization without significant improvement under treatment with an anti-infection regimen and closed chest cavity drainage, the patient was transferred to another hospital. Once admitted, ultrasound examination indicated a large amount of pericardial and pleural effusion. Pericardiocentesis and closed chest cavity drainage were performed immediately. The initial pericardial drainage, which was bloody in appearance, gradually changed to a pale-yellow fluid. The patient continued to present with a temperature and remained under active anti-infection treatment. With repeated drainage procedures, it was observed that the volume of fluid obtained from the closed chest cavity exhibited an increasing trend. The cytological and tumor marker analysis of the idiopathic effusion specimens detected no abnormalities. Metagenomic next-generation sequencing (mNGS) of the pericardial drainage fluid was performed to identify the infectious pathogen. No pathogen was detected in the specimens, but the copy number variation (CNV) found in multiple chromosomes was highly suggestive of cancer development and progression. Lung imaging revealed no mediastinal lesions or tumors. The fluid from a subsequent closed chest drainage procedure was evaluated by mNGS for diagnostic purposes, and multiple CNVs were again noted, with similar results to those from the pericardial effusion. To determine the tumor type, immunophenotyping of the fluid was performed using flow cytometry and a diagnosis of T-LBL was confirmed. The patient was subsequently transferred to the hematology department for chemotherapy. The present case indicates that mNGS can not only differentiate between infections and tumors but also rapidly determine disease etiology.

P311 knockdown alleviates hyperoxia-induced injury by inactivating the Smad3 signaling pathway in type II alveolar epithelial cells.

P311 is associated with alveolar formation and development. However, the role and possible mechanism of P311 in hyperoxia-induced injury in type II alveolar epithelial cells (AEC II) need to be elucidated. In our study, rat AEC II (RLE-6TN) were exposure to normoxia (21% O2 and 5% CO2) or hyperoxia (95% O2 and 5% CO2) for 24 h, followed by determination of P311 expression. After knockdown of P311 and hyperoxic treatment, cell viability, cell cycle progression, apoptosis and the Smad3 signaling pathway were examined. Rat AEC II were pretreated with SIS3 HCl for 4 h and then subjected to P311 overexpression plasmid transfection and hyperoxic exposure. Then, cell viability, apoptosis and the Smad3 signaling pathway were determined. The results showed that hyperoxic exposure significantly elevated P311 levels in rat AEC II. P311 knockdown increased cell viability, accelerated cell cycle progression and inhibited apoptosis, as well as suppression of the Smad3 signaling pathway in hyperoxia-exposed AEC II. Additionally, we found that P311 overexpression enhanced the effects of hyperoxia. Interestingly, SIS3 HCl incubation blocked the effects of P311 overexpression on rat AEC II function under hyperoxic condition, as evidenced by an increase in cell viability, and suppressions of apoptosis and the Smad3 signaling pathway. These results indicate that P311 knockdown may ameliorate hyperoxia-induced injury by inhibiting the Smad3 signaling pathway in rat AEC II. P311 may be a novel target for the treatment of hyperoxia-induced lung injury and even bronchopulmonary dysplasia (BPD).

Hyperoxia induces alveolar epithelial cell apoptosis by regulating mitochondrial function through small mothers against decapentaplegic 3 (SMAD3) and extracellular signal-regulated kinase 1/2 (ERK1/2).

Oxygen therapy and mechanical ventilation are widely used to treat and manage neonatal emergencies in critically ill newborns. However, they are often associated with adverse effects and result in conditions such as chronic lung disease and bronchopulmonary dysplasia. Hence, aclear understanding of the mechanisms underlying hyperoxia-induced lung damage is crucial in order to mitigate the side effects of oxygen-based therapy. Here, we have established an in vitro model of hyperoxia-induced lung damage in type II alveolar epithelial cells (AECIIs) and delineated the molecular basis of oxygen therapy-induced impaired alveolar development. Thus, AECIIs were exposed to a hyperoxic environment and their cell viability, cell cycle progression, apoptosis, mitochondrial integrity and dynamics, and energy metabolism were assessed. The results showed that hyperoxia has no significant effect as an inhibitor of SMAD3 and ERK1/2 in AECIIs, but leads to significant inhibition of cell viability. Further, hyperoxia was found to promote AECII apoptosis and mitochondrial, whereas chemical inhibition of SMAD3 or ERK1/2 further exacerbated the detrimental effects of hyperoxia in AECIIs. Overall, these findings presented herein demonstrate the critical role of SMAD/ERK signaling in the regulation of AECII behavior in varying oxygen environments. Thus, this study offers novel insights for the prevention of neonatal lung dysfunction in premature infants.

[Mormorphological and functional changes of lung cells in hyperoxia environment].

OBJECTIVE: To observe the morphological and functional changes of different lung cells in hyperoxia environment. METHODS: Type II alveolar epithelial cells (AEC II) and lung fibroblasts (LFs) of fetal rats with 18 days old were isolated and cultured in vitro, and divided into air group (placed in an atmospheric incubator, and culturing with oxygen volume fraction of 0.21) and hyperoxia group (placed in a high oxygen culture chamber, and culturing with oxygen volume fraction of 0.90). Morphological changes of two kinds of cells were observed under microscope. Cell migration was observed by scratch test. The levels of reactive oxygen species (ROS) and apoptosis in cells were detected by flow cytometry. RESULTS: After 8 hours of hyperoxia, the volume of AEC II increased and the cells were loosely arranged; the clearance of LFs cells was increased and arranged in disorder. Scratch test showed that, compared with air group, the immigration rate of AEC II was inhibited at 6 hours hyperoxia [migration rate: (38.67±1.15)% vs. (58.67±2.31)%, P < 0.01], the immigration rate of LFs was promoted at 12 hours after hyperoxia [migration rate: (55.37±1.50)% vs. (46.90±1.20)%, P < 0.01]. With the increase of hyperoxia time, intracellular ROS contents of two cells were gradually increased, which were significantly higher than those of the air group (fluorescence intensity: 130.67±4.04 vs. 54.67±2.51, 85.00±2.00 vs. 60.33±1.52, both P < 0.01). Both two kinds of cells showed apoptosis after exposure to high oxygen, the apoptosis rate of AEC II at 2 hour exposure were significantly higher than that of air group [(1.93±0.28)% vs. (1.07±0.11)%, P < 0.05], the apoptosis rate of LFs at 6 hour exposure was significantly higher than that of air group [(1.66±0.09)% vs. (1.46±0.09)%, P < 0.05]. CONCLUSIONS: High concentration of oxygen can cause poor growth of lung cells, reduce AEC II migration level and increase LFs migration, and the production of intracellular ROS eventually leads to apoptosis of lung cells.