Toxic effects of permethrin on HMC3 microglia and its associated mechanism / 环境与职业医学

Background Permethrin is a commonly used pyrethroid insecticide and has been found to be potentially neurotoxic. Microglia are innate immune cells in the central nervous system and are involved in the development of a range of neurodegenerative diseases. Objective To observe possible toxic effects of permethrin on human microglia clone 3 (HMC3) in vitro and explore associated mechanism. Methods HMC3 were treated with 0, 10, 25, and 55 μmol·L−1 permethrin for 72 h. Cell cycle and apoptosis were measured using flow cytometry. Cyclin-dependent kinase 1 (CDK1), cyclin-dependent kinase inhibitor 1A (CDKN1A), cyclin B2 (CCNB2), cellular tumor antigen p53 (p53), factor-related apoptosis (FAS), caspase 3 (CASP3), and H2A histone family member X (H2AX) were detected by quantitative real-time PCR (qPCR). The differential genes and enrichment pathways of HMC3 after 0 and 25 μmol·L−1 permethrin treatment was analyzed by RNA sequencing. HMC3 was treated by 0, 10, 25, and 55 μmol· L−1 permethrin for 72 h. The content of nitric oxide (NO) in the supernatant was detected using Griess reagent. The secretion level of interleukin-6 (IL-6) was detected by enzyme linked immunosorbent assay (ELISA). The mRNA expression levels of mitogen-activated protein kinase (MAPK) pathway (including MAPK1, MAPK8, and MAPK14), interleukin-1β (IL-1β), IL-6, and matrix metalloproteinase (MMP) families (including MMP1, MMP2, MMP3, and MMP9) were detected by qPCR. The protein expressions of phosphorylated p38 mitogen-activated protein kinase (p-p38), phosphorylated extracellular signal-regulated kinase (p-ERK), IL-1β, IL-6, and MMP1 were detected by Western blot. Results HMC3 was arrested in G2/M phase after 0, 10, 25, and 55 μmol·L−1 permethrin treatment for 72 h, of which there was a statistically significant difference between the 55 μmol·L−1 permethrin treatment group and the control group (P<0.01), and the mRNA expression of CDKN1A was up-regulated according to the qPCR (P<0.05). There was no statistically significant difference in the proportions of apoptosis between the groups (P＞0.05). The RNA sequencing showed that the differential genes were enriched in the MAPK pathway, and the mRNA expressions of MAPK1, MAPK8, and MAPK14 were up-regulated after the permethrin treatment at 55 μmol·L−1 compared to the control group by qPCR (P<0.05). The Western blot revealed that, compared to the control group, the levels of p-p38 and p-ERK were increased after the 10 μmol·L−1 permetrin treatment (P<0.05), the p-ERK level was increased after the 25 μmol·L−1 permetrin treatment (P<0.05), and the p-p38 level was up-regulated after the 55 μmol·L−1 permetrin treatment (P<0.05). The secretion of NO in the supernatant of HMC3 increased after permetrin treatment compared to the control group (P<0.05), the mRNA and protein expressions and the secretion of IL-6 showed an upward trend, the mRNA and protein expressions of IL-1β were up-regulated (P<0.05), and the mRNA and protein expressions of MMP1 were up-regulated in the 25 and 55 μmol·L−1 permethrin groups (P<0.05). Conclusion Permethrin inhibits HMC3 cell proliferation in vitro, induces cell cycle arrest, activates MAPK pathway, and promotes the expression of inflammatory factors IL-1β and MMP1, which may be one of the mechanism of neurotoxicity induced by permethrin.

Cryptic COL1A1-PDGFB fusion in dermatofibrosarcoma protuberans: a clinicopathological and genetic analysis / 中华病理学杂志

Objective: To investigate the clinicopathological and cytogenetic features of cryptic COL1A1-PDGFB fusion dermatofibrosarcoma protuberans (CC-DFSP). Methods: Three cases of CC-DFSP diagnosed in West China Hospital, Sichuan University, Chengdu, China from January 2021 to September 2021 were studied. Immunohistochemistry for CD34 and other markers, fluorescence in situ hybridization (FISH) for PDGFB, COL1A1-PDGFB and COL1A1, next-generation sequencing (NGS), reverse-transcriptase polymerase chain reaction (RT-PCR) and Sanger sequencing were performed. Results: There were three cases of CC-DFSP, including two females and one male. The patients were 29, 44 and 32 years old, respectively. The sites were abdominal wall, caruncle and scapula. Microscopically, they were poorly circumscribed. The spindle cells of the tumors infiltrated into the whole dermis or subcutaneous tissues, typically arranging in a storiform pattern. Immunohistochemically, the neoplastic cells exhibited diffuse CD34 expression, but were negative for S-100, SMA, and Myogenin. Loss of H3K27me3 was not observed in the tumor cells. The Ki-67 index was 10%-15%. The 3 cases were all negative for PDGFB rearrangement and COL1A1-PDGFB fusion, whereas showing unbalanced rearrangement for COL1A1. Case 1 showed a COL1A1 (exon 31)-PDGFB (exon 2) fusion using NGS, which was further validated through RT-PCR and Sanger sequencing. All patients underwent extended surgical resection. Except for case 3 with recurrence 2 years after surgical resection, the other 2 cases showed no recurrence or metastasis during the follow-up. Conclusions: FISH has shown its validity for detecting PDGFB rearrangement and COL1A1-PDGFB fusion and widely applied in clinical detection. However, for cases with negative routine FISH screening that were highly suspicious for DFSPs, supplementary NGS or at least COL1A1 break-apart FISH screening could be helpful to identify cryptic COL1A1-PDGFB fusions or other variant fusions.

Basic and clinical research progress in pulmonary alveolar microlithiasis / 医学研究生学报

Pulmonary alveolar microlithiasis (PAM) is a rare genetic disease characterized by calcifications within the alveoli in the lung. Mutations in SLC34A2 gene, which encodes a type IIb sodiumphosphate cotransporter, are responsible for PAM, leading to the intra-alveolar accumulation of phosphate which favors the formation of microliths. A "sandstorm" appearance is the typical radiographic presentation of PAM. The hallmark of this disorder is clinical-radiological dissociation, with typical imaging findings, specific pathological findings and closely correlated specific genetic mutations. The disease has an insidious onset, runs a chronic course and the prognosis is poor. There is no effective treatment except for lung transplantation. This article summarizes the epidemiology, molecular genetics and clinical features of pulmonary alveolar calculi.

A multivariate analysis of prognostic determinants for stages II and III colorectal cancer in 141 patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous prognosis analyses of colorectal cancer (CRC) patients with stage II and III disease were done as separate categories. The purpose of this study was to analyze prognostic factors associated with survival in a group of patients who underwent radical resection of stages II and III CRC.</p><p><b>METHODS</b>A retrospective review was performed for 141 consecutive stages II and III patients who had undergone radical resection of colorectal adenocarcinoma between May 2003 and November 2003. Univariate and multivariate analyses were performed to assess the effect of record variables on disease free survival and overall survival.</p><p><b>RESULTS</b>The median follow-up time was 59 months, and the 3- and 5-year survival rates were 76% and 68%, respectively. Four factors were independently associated with a worse disease-free survival: diabetes (hazard ratio (HR) 2.338; 95% confidence interval (CI) 1.011 - 5.407), expression of cyclooxygenase-2 (Cox-2) (HR 0.335; 95%CI 0.126 - 0.888), expression of matrix metalloproteinases 2 (MMP-2) (HR 0.233; 95%CI 0.101 - 0.541), expression of vascular endothelial growth factor (VEGF) (HR 0.295; 95%CI 0.088 - 0.996). Four factors were independently associated with a worse overall survival: lymph nodes metastasis (HR 1.67; 95%CI 1.29 - 2.14), Cox-2 positive (HR 0.056; 95%CI 0.247 - 0.731), MMP-2 positive (HR 0.398; 95%CI 0.190 - 0.836), VEGF (HR 0.364; 95%CI 0.090 - 0.716).</p><p><b>CONCLUSIONS</b>Diabetes, expression of Cox-2, MMP-2 and VEGF were independently associated with a worse disease- free survival. Lymph nodes metastasis, expression of Cox-2, MMP-2 and high level of VEGF predicted a poor overall survival.</p>

Cultivation of Pathogenic Free-living Amoebae / 中国寄生虫学与寄生虫病杂志

The isolation and culture of pathogenic free-living amoebae are useful in the diagnosis and research. This review focuses on the methods of isolation and cultivation of pathogenic free-living amoebae, including sample treatment, culture conditions, passage culture, pathogen detection, and maintenance.