Probing the occurrence, sources and cancer risk assessment of polycyclic aromatic hydrocarbons in PM2.5 in a humid metropolitan city in China.

Fifty-two consecutive PM2.5 samples from December 2021 to February 2022 (the whole winter) were collected in the center of Chongqing, a humid metropolitan city in China. These samples were analysed for the 16 USEPA priority polycyclic aromatic hydrocarbons (16 PAHs) to explore their composition and sources, and to assess their cancer risks to humans. The total concentrations of the 16 PAHs (ng m-3) ranged from 16.45 to 174.15, with an average of 59.35 ± 21.45. Positive matrix factorization (PMF) indicated that traffic emissions were the major source (42.4%), followed by coal combustion/industrial emission (31.3%) and petroleum leakage/evaporation (26.3%). The contribution from traffic emission to the 16 PAHs increased from 40.0% in the non-episode days to as high as 46.2% in the air quality episode during the sampling period. The population attributable fraction (PAF) indicates that when the unit relative risk (URR) is 4.49, the number of lung cancer cases per million individuals under PAH exposure is 27 for adults and 38 for seniors, respectively. It was 5 for adults and 7 for seniors, when the URR is 1.3. The average incremental lifetime cancer risk (ILCR) for children, adolescents, adults and seniors was 0.25 × 10-6, 0.23 × 10-6, 0.71 × 10-6, and 1.26 × 10-6, respectively. The results of these two models complemented each other well, and both implied acceptable PAH exposure levels. Individual genetic susceptibility and exposure time were identified as the most sensitive parameters. The selection and use of parameters in risk assessment should be further deepened in subsequent studies to enhance the reliability of the assessment results.

Identification of key genes in Gram­positive and Gram­negative sepsis using stochastic perturbation.

Sepsis is an inflammatory response to pathogens (such as Gram­positive and Gram­negative bacteria), which has high morbidity and mortality in critically ill patients. The present study aimed to identify the key genes in Gram­positive and Gram­negative sepsis. GSE6535 was downloaded from Gene Expression Omnibus, containing 17 control samples, 18 Gram­positive samples and 25 Gram­negative samples. Subsequently, the limma package in R was used to screen the differentially expressed genes (DEGs). Hierarchical clustering was conducted for the specific DEGs in Gram­negative and Gram­negative samples using cluster software and the TreeView software. To analyze the correlation of samples at the gene level, a similarity network was constructed using Cytoscape software. Functional and pathway enrichment analyses were conducted for the DEGs using DAVID. Finally, stochastic perturbation was used to determine the significantly differential functions between Gram­positive and Gram­negative samples. A total of 340 and 485 DEGs were obtained in Gram­positive and Gram­negative samples, respectively. Hierarchical clustering revealed that there were significant differences between control and sepsis samples. In Gram­positive and Gram­negative samples, myeloid cell leukemia sequence 1 was associated with apoptosis and programmed cell death. Additionally, NADH:ubiquinone oxidoreductase subunit S4 was associated with mitochondrial respiratory chain complex I assembly. Stochastic perturbation analysis revealed that NADH:ubiquinone oxidoreductase subunit B2 (NDUFB2), NDUFB8 and ubiquinol­cytochrome c reductase hinge protein (UQCRH) were associated with cellular respiration in Gram­negative samples, whereas large tumor suppressor kinase 2 (LATS2) was associated with G1/S transition of the mitotic cell cycle in Gram­positive samples. NDUFB2, NDUFB8 and UQCRH may be biomarkers for Gram­negative sepsis, whereas LATS2 may be a biomarker for Gram­positive sepsis. These findings may promote the therapies of sepsis caused by Gram­positive and Gram­negative bacteria.

[Percutaneous endoscopic gastrostomy for home nutrition support in patients with stroke and post-traumatic brain].

OBJECTIVE: To evaluate the application value of percutaneous endoscopic gastrostomy (PEG) for home nutrition support in patients with stroke and post-traumatic brain. METHODS: We retrospectively analyzed the clinical data of the 16 patients with stroke and post-traumatic brain, including cerebral infarction (n = 9), cerebral hemorrhage ( n = 5), subarachnoid hemorrhage (n = 1), and cerebral trauma (n = 1). All these patients underwent PEG in our hospital because they were not able to be orally fed. RESULTS: The weight, triceps skinfold thickness, mid-upper arm muscle circumference, and serum albumin, hemoglobin, and lympholeukocyte cell counts 30, 60, and 120 days after hospital discharge were significantly higher than those at hospital discharge (P <0.05 or P <0.01). The NIHSS scores 30, 60, and 120 days after hospital discharge were 14.0 +/- 1.3, 14.0 +/- 1.1, and 3.0 +/- 1.2, respectively, which were significantly lower than 16.0 +/- 1.2 at hospital discharge (all P <0.05). Complications included gastric contents retention (n = 1), backstreaming (n = 1), aspirated pneumonia (n = 1), and intra-cushion syndrome (n = 1). CONCLUSIONS: PEG for home nutrition support is useful for the treatment of patients with stroke and post-traumatic brain with dysphagia and malnutrition after long-term coma. It can help to avoid the deterioration of nutritional status and improve the quality of life.