Objective:To investigate the clinicopathological characteristics and prognostic factors of sporadic mismatch repair deficient (dMMR) colorectal cancer.Methods:A total of 120 cases of sporadic dMMR colorectal cancer from July 2015 to April 2021 were retrospectively collected in Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Patients with Lynch syndrome; synchronous multiple colorectal cancers; preoperative anti-tumor treatments such as chemotherapy and radiotherapy; and those with incomplete follow-up information were excluded based on family history and next-generation sequencing (NGS) test results. Immunohistochemical stains were used to detect the expression of mismatch repair proteins, methylation-specific PCR for methylation testing, and fluorescent PCR for BRAF V600E gene mutation detection. The clinical and pathological data, and gene mutation status were analyzed. Follow-up was done to assess survival and prognosis including progression-free survival and overall survival rate.Results:Sporadic dMMR colorectal cancer occurred more frequently in the right side of the colon, in females, and in the elderly. Morphologically, it was mostly moderately-differentiated, and most patients had low-grade tumor budding. In terms of immunohistochemical expression, MLH1 and PMS2 loss were dominant, and there were age and location-specificities in protein expression. MLH1 methylation was commonly detected in elderly female patients and rare in young male patients; while MLH1 and PMS2 deficiency, and BRAF V600E mutation occurred more often on the right side ( P<0.05). The 3-year and 5-year progression-free survival rates were 90.7% and 88.7% respectively, and the 3-year and 5-year overall survival rates were 92.8% and 90.7% respectively. Tumor budding status was an independent risk factor affecting patient recurrence (hazard ratio=3.375, 95% confidence interval: 1.060-10.741, P=0.039), patients with low-grade tumor budding had better prognosis, and those with medium or high-grade tumor budding had poor prognosis. Conclusion:For dMMR colorectal cancer patients, tumor budding status is an independent risk factor for recurrence.

Background There is a lack of evidence on whether exposure to PM_2.5 and its constituents would affect the relationship between the dietary approaches to stop hypertension (DASH) and central obesity. Objective To investigate the effect of exposure to PM_2.5 and its constituents on the correlation between the DASH dietary pattern and the prevalence of central obesity. Methods The data were obtained from the baseline survey of the "Xinjiang Multi-Ethnic Natural Population Cohort Construction and Health Follow-Up Study" in Urumqi. A DASH score was calculated according to intake frequency of 8 food groups, and summed from intake frequency of recommended food groups scored from 1 to 5 from low to high, and intake frequency of restricted food groups scored from 1 to 5 from high to low. A higher DASH score indicates better compliance with the DASH dietary pattern. We estimated exposure using satellite-derived PM_2.5 and a chemical transport model (GEOS-Chem) for its constituents, including organic carbon (OC), black carbon (BC), sulfate (SO₄²⁻), nitrate (NO₃⁻), ammonium (NH₄⁺), and soil dust. Central obesity was defined by waist circumference: ≥90 cm for men or ≥85 cm for women according to Criteria of weight for adults (WS/T 428—2013). A logistic regression model was used to analyze the effects of the DASH dietary pattern as well as PM_2.5 and its constituents on central obesity, and a stratified analysis was used to explore the effects of PM_2.5 and its constituents on the association between the DASH dietary pattern and central obesity. Results The study included 9 565 urban residents, aged (62.30±9.42) years, with a central obesity prevalence rate of 60.75%. After adjusting for selected confounders, the DASH score Q5 group had a 17.5% lower risk of central obesity than the Q1 group (OR=0.825, 95%CI: 0.720-0.947). PM_2.5 and its constituents OC, BC, SO₄²⁻, NH₄⁺, and soil dust were positively associated with the prevalence of central obesity, but no association was observed between constituent NO₃⁻ exposure and central obesity. The stratified analysis revealed that the prevalence of central obesity was reduced in the DASH score Q5 group in participants exposed to low concentrations of PM_2.5 and its constituents NO₃⁻, NH₄⁺, and soil dust, while the protective effect of the DASH pattern on central obesity disappeared in subjects exposed to high concentrations of PM_2.5 and its constituents NO₃⁻, NH₄⁺, and soil dust. Conclusion Exposure to PM_2.5 and its constituents NO₃⁻, NH₄⁺, and soil dust could attenuate the protective effect of the DASH pattern on central obesity.

Using novel virtual reality (VR) technology to carry out the construction of clinical medical examination question bank, while deepening the reform of clinical medical course examination, it continues to innovate the medical professional evaluation system and improve the flexibility, diversity and scientificity of clinical medicine in teaching and assessment. It is of great and far-reaching significance to improve the teaching level and the quality of medical education in medical colleges and universities. This paper analyzes and discusses the necessity and feasibility of building a clinical medical examination question bank, and the advantages and prospects of integrating VR technology to carry out the construction of clinical medical examination question bank. At the same time, the exploration and practice of the examination question bank construction based on VR technology disscussed in detail would provide innovative thinking and reference for the clinical medical teaching and evaluation, medical personnel training and other aspects in China.

Objective:To analyze the microsatellite instability (MSI) status in endometrioid endometrial carcinoma (EEC) with deficient mismatch repair (dMMR) and to explore the concordance between MSI next generation sequencing (NGS)/PCR and MMR immunohistochemistry (IHC) results.Methods:Sixty dMMR EEC cases by IHC from November 2017 to February 2019 were selected in the Department of Pathology, Peking Union Medical College Hospital. Two pathologists reviewed the IHC results. The MSI status and the germline/somatic mutational status of MMR genes were analyzed by NGS. MLH1 promoter methylation status was determined by methylation-specific PCR (MSP) in cases with MLH1 protein deficiency. In cases with discrepant results between MMR IHC and MSI NGS, the MSI status was detected again by PCR, and the reasons for the discrepancy were discussed with gene mutation and MLH1 promoter methylation results.Results:Among 60 dMMR EEC specimens, 3 samples were re-assigned as proficient mismatch repair (pMMR) after pathological review, and identified as MSS by NGS. Another 3 dMMR cases showed MSI-uncertainty (MSI-U) by NGS due to insufficient tumor content. In the remaining 54 cases, the concordance between MMR IHC and MSI NGS was 87% (47/54). The seven discrepant cases was further analyzed: in 5 discrepant cases with MLH1/PMS2 protein loss, one case did not have enough samples for detection, one case was MSI-H, and the remaining three cases were MSS by PCR. All these 5 cases with MLH1/PMS2 protein loss showed the MLH1 promoter hypermethylation, two of which also had a somatic mutation in the MSH2 gene. The two discrepant cases with MSH6 protein loss were both MSS by PCR, one of which was considered to have Lynch syndrome with germline mutation in MSH6 gene.Conclusions:Although the overwhelming majority of dMMR EEC cases by IHC shows MSI-H by NGS/PCR, there are uncommon discrepant dMMR EEC cases with MSS. They are mostly found in cases with MLH1/PMS2 protein loss caused by MLH1 promoter hypermethylation and rarely related to Lynch syndrome. Both MMR IHC and MSI NGS/PCR tests have their advantages and disadvantages, complimentary to each other.

Objective We aimed to investigate the overexpression of succinic dehydrogenase (SDH) B and MIB-1 in patients with pheochromocytoma/paraganglioma(PHEO/PGLs) and its significance for predicting the clinical malignant behavior.Methods From August 2008 to April 2016,the clinical characteristics of 93 patients with PHEO/PGLs were analyzed retrospectively.There were 57 males and 36 females,with an average of 34 years,ranging 8-73 years old.There were 68 cases of adrenal pheochromocytoma and 25 cases of paraganglioma.There were 79 cases with hypertension and 14 cases of adrenal accidental tumors.Sixty-six cases with typical hyper-catecholamine secretion symptoms and 27 cases with non-functional PHEO/PGL.Benign PHEO/PGLs were 77 cases and malignant 16 cases.The tumor was located on the left side in 39 cases,on the right side in 32 cases and multiple lesions in 22 cases.The diameter of the PHEO/PGL tumor was (6.8 ± 2.7) cm.The 24 h urine catecholamine was measured before operation,which showed epinephrine was (42.6 ± 5.1) μg/24 h,norepinephrine was (167.5 ± 13.5) μg/24h and dopamine was (246.4 ± 71.2)μg/24h.Six cases wihtout hereditary diseases of urinary system were selected as normal control group.SDHB,SDHAF2,SDHC,SDHD,VHL and RET gene mutations were detected in all patients.Immunohistochemical panel has been performed to detect the expression of SDHB,MIB-1,EPAS1,VEGF-1 receptor (VEGF-1 R),and chromain A (CgA) in 93 specimens of PHEO/PGL tissue.The positive granular cytoplasm staining ＞ 50％ was strongly positive (+ + +),11％ to 50％ was moderately positive (+ +),1％ to 10％ was weak positive (+) and the negative was compared with the known positive internal reference,that is,there was less than 1％ or no stain completely.Results SDHB,SDHAF2,SDHC,SDHD,VHL and RET gene mutations in 27 cases (29.5％).Nine patients with SDHB gene mutation (9.7％).RET proto-oncogene mutations in 8 cases (8.6％).3 cases had VHL mutation (3.2％).Immunohistochemical staining showed that MIB-1 positive expression was found in 7 of 9 patients with SDHB gene mutation.Six cases in the control group were negative for gene detection and MIB-1,EPAS1,CgA and VEGF-1R immunohistochemical results.EPAS1 showed moderately positive in patients with PHEO/PGL and strong positive in patients with malignant PHEO/PGL.In 9 cases with SDHM mutation,EPAS1 was noticed positive in seven cases,which showed the relationship with CgA,MIB-1 and VEGF-1R.Conclusions The SDHB gene mutation is usually shown as a paraganglioma focus outside the adrenal gland.And 9.8％ of the paragangliomas were associated with a mutation of the SDHB gene with an increase in malignant risk.The SDHB mutation caused over-expression of MIB-1 and the positive expression of EPAS1 and VEGF-1R in PHEO/PGL tissues,which was associated with invasion and metastasis of malignant PHEO/PGL.

Phospholipids and their metabolites play an important role in a variety of cellular processes including cell-cell adhesion, cell growth and differentiation, apoptosis, phagocytosis as well as storage of energy. In this study, the phospholipid composition of cancer tissue and adjacent normal tissue from humans and animals were analyzed by internal extractive electrospray ionization mass spectrometry ( iEESI-MS ) . Extractive solvent at high voltage (+5. 5 kV) was injected into tissue samples using a fused silica capillary at a flow rate of 0. 5-1 μL/min, producing fine charged droplets containing analytes of tissue samples at the tip of the sample. Charged droplets were directly sampled to the atmospheric inlet of a mass spectrometer. Out of 21 different ratios of CH3 OH ∶H2 O solvent mixture, the ratio CH3 OH ∶ H2 O=30∶70 ( V/V ) showed the optimal phospholipids extraction and visibility in MS. A large number of phospholipids from different tissue samples ( such as cancer tissue and adjacent normal tissue of lung cancer, esophageal cancer tissue, pork, beef, porcine heart and porcine lung) were obtained simultaneously by iEESI-MS analysis. The experimental results demonstrated that iEESI-MS was characterized by minimal sample pretreatment, low sample consumption, and rapid analysis ( the analysis time per sample was less than 1 min) , and the selectivity and sensitivity of iEESI-MS could be improved by choosing proper solvent. Importantly, the experimental results provided new information for further studies of phospholipids in biological tissues.

OBJECTIVETo investigate the role of sphingosine kinase 1 (SphK1) in regulating the proliferation of hypoxia-exposed glioma cells in vitro and explore the possible molecular mechanisms.

METHODSHuman glioblastoma U87MG cells was transfected with specific small interfering RNA (siRNA) constructs targeting SphK1, and the efficiency of SphK1 knockdown was validated by real-time PCR and Western blotting. The cells transfected with SphK1 siRNA and with a negative control siRNA were then exposed to 3% oxygen or 150 µmol/L CoCl2 to induce hypoxia. The cell proliferation and cell cycle changes following the exposure were evaluated with the Cell Counting Kit-8 and flow cytometry, respectively, and the intracellular Ca(2+) changes were monitored using Flou-4/AM under an inverted laser scanning confocal microscope.

RESULTSSphK1 knockdown significantly reduced hypoxia-induced calcium reflux and suppressed the cell proliferation. Application of OAG, an activator of calcium channels, however, obviously enhanced the cell proliferation under hypoxia.

CONCLUSIONSphK1 promotes the proliferation of glioma cells under hypoxia via regulating calcium signaling.

Calcium Signaling ; Cell Cycle ; Cell Hypoxia ; Cell Line, Tumor ; Cell Proliferation ; Glioblastoma ; Glioma ; pathology ; Humans ; Phosphotransferases (Alcohol Group Acceptor) ; metabolism ; RNA, Small Interfering

Objective To investigate the role of sphingosine kinase 1 (SphK1) in regulating the proliferation of hypoxia-exposed glioma cells in vitro and explore the possible molecular mechanisms. Methods Human glioblastoma U87MG cells was transfected with specific small interfering RNA (siRNA) constructs targeting SphK1, and the efficiency of SphK1 knockdown was validated by real-time PCR and Western blotting. The cells transfected with SphK1 siRNA and with a negative control siRNA were then exposed to 3%oxygen or 150μmol/L CoCl2 to induce hypoxia. The cell proliferation and cell cycle changes following the exposure were evaluated with the Cell Counting Kit-8 and flow cytometry, respectively, and the intracellular Ca2+changes were monitored using Flou-4/AM under an inverted laser scanning confocal microscope. Results SphK1 knockdown significantly reduced hypoxia-induced calcium reflux and suppressed the cell proliferation. Application of OAG, an activator of calcium channels, however, obviously enhanced the cell proliferation under hypoxia. Conclusion SphK1 promotes the proliferation of glioma cells under hypoxia via regulating calcium signaling.

Objective To investigate the role of sphingosine kinase 1 (SphK1) in regulating the proliferation of hypoxia-exposed glioma cells in vitro and explore the possible molecular mechanisms. Methods Human glioblastoma U87MG cells was transfected with specific small interfering RNA (siRNA) constructs targeting SphK1, and the efficiency of SphK1 knockdown was validated by real-time PCR and Western blotting. The cells transfected with SphK1 siRNA and with a negative control siRNA were then exposed to 3%oxygen or 150μmol/L CoCl2 to induce hypoxia. The cell proliferation and cell cycle changes following the exposure were evaluated with the Cell Counting Kit-8 and flow cytometry, respectively, and the intracellular Ca2+changes were monitored using Flou-4/AM under an inverted laser scanning confocal microscope. Results SphK1 knockdown significantly reduced hypoxia-induced calcium reflux and suppressed the cell proliferation. Application of OAG, an activator of calcium channels, however, obviously enhanced the cell proliferation under hypoxia. Conclusion SphK1 promotes the proliferation of glioma cells under hypoxia via regulating calcium signaling.