[Analysis of clinical and endoscopic characteristics of colorectal polyps in children]

To analyze the clinical and endoscopic characteristics of colorectal polyps in children, and to explore the detection rate, age and gender distribution characteristics, endoscopic treatment effect and follow-up monitoring of colorectal polyps in children, so as to provide reference for disease management of colorectal polyps in children. The clinical and endoscopic characteristics of children with colorectal polyps in Xi 'an Children's Hospital from January 2019 to December 2019 were retrospectively analyzed. The patients were divided into 5 groups according to age (y): 0<y<1 years, 1≤ y<4 years, 4≤ y<7 years, 7≤ y<12 years, and 12≤ y ≤18 years. Independent sample t test, Pearson Chi-square test (χ²) were used to compare groups' differences. The results showed that a total of 724 colonoscopies were completed in 2019, and 160 colorectal polyps were diagnosed, with a detection rate of 22.10%. Among the children with colorectal polyps, 105 were males, accounting for 65.62%, and 55 were females, accounting for 34.38%. The detection rate of male colorectal polyps was 22.68%, and the detection rate of female colorectal polyps was 21.08%. There was no significant difference in the detection rate of colorectal polyps between males and females (χ² = 0.25, P =0.617). Children with colorectal polyps were most common in the age group of 1≤ y<4 years, 72 cases, accounting for 41.14%(72/175). The detection rate of colorectal polyps in different age groups was statistically significant (χ²=73.929, P<0.05). The main symptom of children with colorectal polyps was hematochezia, accounting for 87.5% (140/160). Colorectal polyps were mainly single polyps in 140 patients, accounting for 87.50%, 15 patients had 2-4 polyps, accounting for 9.38%, and 5 patients had 5 or more polyps, accounting for 3.12%. A total of 210 polyps were removed, and the most common site of polyps was rectum, 123 polyps, accounting for 58.57% (123/210). 111 (52.86%, 111/210) of them were 1 cm to 2 cm in diameter. The Yamada classification was mainly type Ⅲ, 114 pieces, accounting for 54.29% (114/210). Among the 210 polyps with diameter ≥0.5 cm, 165 were removed by endoscopic mucosal resection, accounting for 78.57% (165/210). There were 23 patients with postoperative complications, including hematochezia, abdominal pain, fever, vomiting, diarrhea, dizziness, and no gastrointestinal perforation. Juvenile polyps were the main pathological type, accounting for 88.13% (141/160). The children with juvenile polyps were followed up for 3-30 months, and recurrence was considered in 2 of them. In conclusion, the detection rate of colorectal polyps in children aged 1≤ y<4 years is high, and hematochezia is the main clinical manifestation. Standardized endoscopic treatment and follow-up monitoring are very important for children with colorectal polyps.

[Preoperative serum creatinine as an independent prognostic biomarker in patients with early-stage cervical adenocarcinoma]

Objective: To investigate the effect of preoperative serum creatinine (Scr) level on the prognosis of patients with early cervical adenocarcinoma (ADC) and its predictive value. Methods: A retrospective review was performed on 199 patients with the International Federation of Gynecology and Obstetrics (FIGO) stage ⅠA1-ⅡA1 and pathology-proven invasive ADC from January 2005 to December 2015. Patients were followed up by phone and outpatient, with a median follow-up time 77.5 (57.0, 114.0) months, 11 cases (5.5%) were missing, 19 cases (10.1%) recurred, and 17 cases (9.0%) died. Multivariate analysis was performed by Cox regression model to analyze the related factors of the prognosis of ADC patients. The optimal cut-off point was determined by the analysis of receiver operating characteristics (ROC), and the predictive value of related factors for prognosis was evaluated by the area under the curve (AUC). Results: The median age of 199 patients was 44.0 (39.0-50.0) years. Overall, 16 patients (8.0%) were stage ⅠA1; 4 patients (2.0%) were stage ⅠA2; 147 patients (74.0%) were stage ⅠB1; 13 patients (6.5%) were stage ⅠB2; 19 patients (9.5%) were stage ⅡA1. The multivariate analysis showed that FIGO stage [4.570 (1.625-12.854)] and elevated Scr [1.065 (1.006-1.128)] were correlated with DFS in patients with early ADC, as well as correlated with OS [4.412 (1.458-13.350) and 1.076 (1.012-1.144), respectively (all P<0.05)]. The optimal cut-off point of Scr level was 75.2 μmoI/L. The AUC showed that the Scr level was a predictor of DFS (AUC=0.677, 95%CI: 0.608-0.742, P=0.006) and OS (AUC=0.677, 95%CI: 0.607-0.741, P=0.012). Conclusions: The preoperative Scr level independently predicts the prognosis of early-stage ADC; patients with Scr levels>75.2 μmoL/L might require more follow-up and adjuvant treatment, as they might have a poorer prognosis.

[Multimodal Magnetic Resonance and Fluorescence Imaging of the Induced Pluripotent Stem Cell Transplantation in the Brain]

The understanding of the engrafted cell behaviors such as the survival, growth and distribution is the prerequisite to optimize cell therapy, and a multimodal imaging at both anatomical and molecular levels is designed to achieve this goal. We constructed a lentiviral vector carrying genes of ferritin heavy chain 1 (FTH1), near-infrared fluorescent protein (iRFP) and enhanced green fluorescent protein (egfp), and established the induced pluripotent stem cells (iPSCs) culture stably expressing these three reporter genes. These iPSCs showed green and near-infrared fluorescence as well as the iron uptake capacity in vitro. After transplanted the labeled iPSCs into the rat brain, the engrafted cells could be in vivo imaged using magnetic resonance imaging (MRI) and near-infrared fluorescent imaging (NIF) up to 60 days at the anatomical level. Moreover, these cells could be detected using EGFP immunostaining and Prussian blue stain at the cellular level. The developed approach provides a novel tool to study behaviors of the transplanted cells in a multi-modal way, which will be valuable for the effectiveness and safety evaluation of cell therapy.

Multimodal Magnetic Resonance and Fluorescence Imaging of the Induced Pluripotent Stem Cell Transplantation in the Brain

Abstract

The understanding of the engrafted cell behaviors such as the survival, growth and distribution is the prerequisite to optimize cell therapy, and a multimodal imaging at both anatomical and molecular levels is designed to achieve this goal. We constructed a lentiviral vector carrying genes of ferritin heavy chain 1 (FTH1), near-infrared fluorescent protein (iRFP) and enhanced green fluorescent protein (egfp), and established the induced pluripotent stem cells (iPSCs) culture stably expressing these three reporter genes. These iPSCs showed green and near-infrared fluorescence as well as the iron uptake capacity in vitro. After transplanted the labeled iPSCs into the rat brain, the engrafted cells could be in vivo imaged using magnetic resonance imaging (MRI) and near-infrared fluorescent imaging (NIF) up to 60 days at the anatomical level. Moreover, these cells could be detected using EGFP immunostaining and Prussian blue stain at the cellular level. The developed approach provides a novel tool to study behaviors of the transplanted cells in a multimodal way, which will be valuable for the effectiveness and safety evaluation of cell therapy.

[Transoral endoscopic resection of benign tumors in parapharyngeal space via medial pterygomandibular raphe approach]

Objective: To explore the surgical methods and effects of transoral endoscopic resection of benign tumors in parapharyngeal space via medial pterygomandibular raphe approach. Methods: The clinical data of 23 patients who underwent resection of benign tumors in parapharyngeal space by endoscopic medial pterygomandibular raphe approach from January 2016 to July 2020 in the Department of Otorhinolaryngology Head and Neck Surgery, the Affiliated Hospital of Qingdao University were analyzed retrospectively. There were 14 males and 9 females with a median age of 43 years. The tumors were located in the anterior space of the styloid process in 13 cases and in the posterior space in 10 cases. The smallest tumor volume was 7.3 ml and the largest was 80.2 ml. The preoperative imaging features, the characteristics and risks of this approach in the operation were analyzed, and the feasible mode of operation was explored. Results: All patients completed the operation successfully. The intraoperative blood loss was 20 to 50 ml, with an average of 28.3 ml. The operation time was 40 to 110 min, with an average of 75.4 min. The incision length was 2 to 4 cm, with an average of 3.0 cm. The postoperative pain score was 2 to 4, with an average of 3.2. The postoperative hospital stay was 4 to 9 d, with an average of 6.7 d. Postoperative pathological diagnosis included pleomorphic adenoma (n=12), neurilemmoma (n=10) and basal cell adenoma (n=1). The patients were followed up for 6 to 60 months. There was no postoperative complication such as infection or serious bleeding, and there was no tumor recurrence after operation. Conclusion: Endoscopic resection of benign tumor in parapharyngeal space via medial pterygomandibular raphe approach is a safe, effective, and minimally invasive surgical method for the treatment of tumors in parapharyngeal space.

[Clinical application of expanded noninvasive prenatal testing for fetal chromosome abnormalities]

To assess the positive predictive value (PPV) of extended noninvasive prenatal testing (NIPT-plus) for fetal chromosomal abnormalities. This retrospective research enrolled 511 cases of pregnant women with positive NIPT-plus results at the Obstetrics and Gynecology Hospital of Fudan University from May 2017 to January 2021. Karyotype analysis and chromosome microarray analysis (CMA) techniques was applied for verification. All cases were followed to determine their pregnancy outcome. The Chi-square test was used in PPV. 63 out of 511 refused prenatal diagnosis after counseling, 448 pregnant women with prenatal diagnosis showed that the PPVs of NIPT-plus test for fetal trisomy 21, 18 and 13 (T21, T18, T13), sex chromosome aneuploidy (SCAs) and chromosome microdeletion/microduplication syndrome (MMS) were 86.0% (92/107), 79.5% (35/44), 54.5% (12/22), 39.5% (75/190), and 41.7% (30/72), respectively. The results revealed that the PPV was higher among older pregnant women compared to young pregnant women (77.8% vs. 51.9%,P<0.01). With increasing maternal age, the PPV of NIPT-plus presented increasing trends for T21, T13, and composite PPV except for T18 or SCAs. In addition, the termination rates for confirmed SCAs fetal karyotypes 45, X; 47, XXX; 47, XXY and 47, XYY were 11/11, 3/15, 91.7% (22/24) and 1/14, respectively. NIPT-plus can safely and effectively detect fetal chromosomal abnormalities and can be extended to MMS screening, significantly reducing the proportion of interventional prenatal diagnoses, and those with positive screening still require further confirmation.

[Application of artificial intelligence-assisted diagnosis for cervical liquid-based thin-layer cytology]

Objective: To explore the application value of artificial intelligence-assisted diagnosis system for TBS report in cervical cancer screening. Methods: A total of 16 317 clinical samples and related data of cervical liquid-based thin-layer cell smears, which were obtained from July 2020 to September 2020, were collected from Southern Hospital, Guangzhou Huayin Medical Inspection Center, Shenzhen Bao'an People's Hospital(Group) and Changsha Yuan'an Biotechnology Co., Ltd. The TBS report artificial intelligence-assisted diagnosis system of cervical liquid-based thin-layer cytology jointly developed by Southern Medical University and Guangzhou F. Q. PATHOTECH Co., Ltd. based on deep learning convolution neural network was used to diagnose all clinical samples. The sensitivity,specificity and accuracy of both artificial intelligence-assisted diagnosis system and cytologists using artificial intelligence-assisted diagnosis system were analyzed based on the evaluation standard(2014 TBS). The time spent by the two methods was also compared. Results: The sensitivity of artificial intelligence-assisted diagnosis system in predicting cervical intraepithelial lesions and other lesions (including endometrial cells detected in women over 45 years old and infectious lesions) under different production methods, different cytoplasmic staining and different scanning instruments was 92.90% and 83.55% respectively, and the specificity of negative samples was 87.02%, while that of cytologists using artificial intelligence-assisted diagnosis system was 99.34%, 97.79% and 99.10%, respectively. Moreover, cytologists using artificial intelligence-assisted diagnosis system could save about 6 times of reading time than manual. Conclusions: Artificial intelligence-assisted diagnosis system for TBS report of cervical liquid-based thin-layer cytology has the advantages of high sensitivity, high specificity and strong generalization. Cytologists can significantly improve the accuracy and work efficiency of reading smears by using artificial intelligence-assisted diagnosis system.

[Epidemiological characteristics and risk factors of Blastocystis hominis infection among patients with HIV/AIDS in Fuyang City Anhui Province]

OBJECTIVE

To investigate the prevalence and risk factors of Blastocystis hominis infections among patients with HIV/AIDS in Fuyang City, Anhui Province.

METHODS

A cross-sectional study was conducted in Fuyang City, Anhui Province in 2016. The demographic and socioeconomic status, and the lifestyle and production style were collected using a questionnaire survey. B. hominis DNA was detected in subjects'stool samples using a PCR assay, and the CD4+ T lymphocyte count and HIV viral load were measured in the subjects' blood samples. The risk factors of B. hominis infections among patients with HIV/AIDS were identified using univariate and multivariate logistic regression analyses.

RESULTS

A total of 398 HIV/AIDS patients were enrolled in this study, with a mean age of 49.3 years, a mean body weight of 55.9 kg and a mean height of 164.4 cm. The prevalence of B. hominis infection was 6.78% in the study subjects, and no gender- (χ² = 1.589, P = 0.207), education level- (χ² =0.508, P = 0.776), marital status- (χ² = 0.419, P = 0.811) or occupation-specific prevalence (χ² = 2.744, P = 0.615) was detected. Among the patients with HIV/AIDS, there were no significant differences in the age (t = 0.370, P = 0.712), height (t = 1.587, P =0.113), body weight (t = 0.516, P = 0.606), CD4⁺ T lymphocyte count (t = 1.187, P = 0.230) or HIV viral load (t = 0.193, P =0.496) between B. hominis-infected and uninfected individuals. Dinking non-tap water [OR = 6.554, 95% CI: (1.876 to 22.903)] and keeping dogs [OR = 5.895, 95% CI: (2.017 to 17.225)] were identified as risk factors for B. hominis infection in patients with HIV/AIDS.

CONCLUSIONS

The prevalence of B. hominis infection is high in HIV/AIDS patients, and drinking non-tap water and keeping dogs are risk factors for B. hominis infection among HIV/AIDS patients.

CAFs secreted exosomes promote metastasis and chemotherapy resistance by enhancing cell stemness and epithelial-mesenchymal transition in colorectal cancer

BACKGROUND

Cancer associated fibroblasts (CAFs) are key stroma cells that play dominant roles in tumor progression. However, the CAFs-derived molecular determinants that regulate colorectal cancer (CRC) metastasis and chemoresistance have not been fully characterized.

METHODS

CAFs and NFs were obtained from fresh CRC and adjacent normal tissues. Exosomes were isolated from conditioned medium and serum of CRC patients using ultracentrifugation method and ExoQuick Exosome Precipitation Solution kit, and characterized by transmission electronic microscopy, nanosight and western blot. MicroRNA microarray was employed to identify differentially expressed miRNAs in exosomes secreted by CAFs or NFs. The internalization of exosomes, transfer of miR-92a-3p was observed by immunofluorescence. Boyden chamber migration and invasion, cell counting kit-8, flow cytometry, plate colony formation, sphere formation assays, tail vein injection and primary colon cancer liver metastasis assays were employed to explore the effect of NFs, CAFs and exosomes secreted by them on epithelial-mesenchymal transition, stemness, metastasis and chemotherapy resistance of CRC. Luciferase report assay, real-time qPCR, western blot, immunofluorescence, and immunohistochemistry staining were employed to explore the regulation of CRC metastasis and chemotherapy resistance by miR-92a-3p, FBXW7 and MOAP1.

RESULTS

CAFs promote the stemness, epithelial-mesenchymal transition (EMT), metastasis and chemotherapy resistance of CRC cells. Importantly, CAFs exert their roles by directly transferring exosomes to CRC cells, leading to a significant increase of miR-92a-3p level in CRC cells. Mechanically, increased expression of miR-92a-3p activates Wnt/β-catenin pathway and inhibits mitochondrial apoptosis by directly inhibiting FBXW7 and MOAP1, contributing to cell stemness, EMT, metastasis and 5-FU/L-OHP resistance in CRC. Clinically, miR-92a-3p expression is significantly increased in CRC tissues and negatively correlated with the levels of FBXW7 and MOAP1 in CRC specimens, and high expression of exosomal miR-92a-3p in serum was highly linked with metastasis and chemotherapy resistance in CRC patients.

CONCLUSIONS

CAFs secreted exosomes promote metastasis and chemotherapy resistance of CRC. Inhibiting exosomal miR-92a-3p provides an alternative modality for the prediction and treatment of metastasis and chemotherapy resistance in CRC.

[Relationship between impaired myocardial untwisting and left ventricular diastolic dysfunction in patients with autoimmune diseases]

Objective: To observe the relationship between impaired myocardial untwisting and left ventricular diastolic dysfunction in patients with autoimmune diseases (AD). Methods: In this retrospective study, 95 AD patients (27 males, (38.6±14.2) years old) were enrolled as AD group and 71 gender and age matched healthy subjects (24 males, (37.6±12.2) years old) were enrolled as control group, all underwent transthoracic echocardiography and two-dimensional speckle-tracking echocardiography (STE) in our hospital between January 2014 and June 2018. Left ventricular untwisting and diastolic function parameters were measured. Multiple logistic regression analysis was used to identify related factors of left ventricular diastolic dysfunction in AD patients. Receiver operating characteristic (ROC) curve was used to identify the diagnosis value of untwisting parameters for left ventricular diastolic dysfunction in AD patients. Results: Compared with control group, left ventricular ejection fraction was lower (58(47, 66)% vs. 67 (62, 71) %, P<0.001), E/e' was higher (10.78 (7.28, 13.65) vs. 6.30 (5.55, 7.25) , P<0.001), isovolumic relaxation time was longer (73.5 (56.5, 88.0) ms vs. 62.0 (58.0, 68.5) ms, P<0.001),and untwist slope during isovolumic relaxation period (USIR) was lower (31.92 (14.09, 54.92) °/s vs. 59.90 (40.09, 87.18) °/s, P<0.001) in AD group than in control group. Multiple logistic regression analysis showed heart rate (OR=0.885, 95%CI 0.840-0.931, P<0.001), E/e' (OR=0.655, 95%CI 0.537-0.798, P<0.001) and USIR (OR=0.986, 95%CI 0.974-0.998, P=0.020) were independently related with left ventricular diastolic dysfunction in AD patients. ROC curve showed that area under the curve (AUC) was 0.919 (P<0.001), sensitivity was 87.6%, and specificity was 88.7%, when combining the heart rate, E/e', and USIR as assessment parameters for the diagnosis of left ventricular diastolic dysfunction in AD patients at a cutoff of 0.51. Conclusions: Impairment of myocardial untwisting indicates the presence of early stage left ventricular diastolic dysfunction in AD patients. USIR may be a sensitive parameter to evaluate early stage left ventricular diastolic dysfunction in AD patients.

[Construction and mechanical analysis of finite element model for bending property of controlled memory wire nickel-titanium rotary file]

OBJECTIVE

To construct a model for a controlled memory (CM) nickel-titanium (NiTi) file and another M-wire NiTi file with the same geometry by using finite element analysis. To evaluate the flexibility of a CM NiTi file by using three dimensional finite element method and to compare its mechanical responses with that M-wire NiTi.

METHODS

Based on the reverse engineering, the 21 mm long, 25#/08 taper Hyflex NT NiTi file and Hyflex CM NiTi file were fixed by the cantilever bending model at a distance of 9.5 mm from the tip of the file. The mechanical tester's indenter was loaded/unloaded at a distance of 3 mm from the tip of the file. The maximum displacement was 3 mm, the load displacement curve was obtained. Subsequently, by using a micro-CT to scan (layer spacing of 8 μm) NiTi files, and ABAQUS (6.10) was introduced to construct a geometric model. Hyflex NT was considered as a shapememory alloy constitutive model, Hyflex CM was considered as a power-hardening plastic constitutive model, respectively. Comparing the load-displacement curve of cantilever bending in the three-dimensional finite element model with the load-displacement curve in the experiment.

RESULTS

Two tetrahedral element models were constructed, the total number of nodes was 99 353 and the total number of cells was 63 744. When the loading displacement was 1 mm, the stress distribution of the cross section at 6.1 mm from the tip of the file was observed. The upper and lower surfaces were subjected to the maximum bending stress and entered the phase transformation yield stage. The finite element simulation could clearly show the deformation of the file. Various information such as deformation characteristics and stress distribution in the process were well fitted to the actual experimental curve.

CONCLUSION

The constitutive behavior of the material has a significant effect on the mechanical behavior of NiTi file. The finite element model established for the NiTi file of the CM wire can accurately capture the characteristics of various deformation processes of the NiTi root canal file, and it has a good fit with the actual experimental curve. The finite element model can be used for study on bending properties of CM wire.

[Surface microstructure and cyclic fatigue resistance of electro discharged machining nickel-titanium endodontic instrument]

OBJECTIVE

To compare the surface microstructures and cyclic fatigue resistance of HyFlex EDM with HyFlex CM and HyFlex NT.

METHODS

Twelve 25 mm-long 25#/- HyFlex EDM and twelve 25 mm-long 25#/0.06 taper HyFlex CM or HyFlex NT were selected. The surface microstructure of the 2 instruments which were randomly selected from each group was observed by using scanning electron microscope (SEM). The remaining 10 instruments from each group were submitted to the cyclic fatigue test by using a simulated stainless steel root canal with 60° angle of curvature and curvature radius of 3.5 mm. The time till fracture was recorded, the number of cyclic fatigue (NCF) was calculated, the length of fracture fragment was evaluated, and the topographic features were analyzed by using SEM. The data were analyzed by using one-way analysis via SPSS 23.0 software. The statistical significance level was set at 0.05.

RESULTS

SEM observation of the surface and microstructural characterization revealed peculiar melting appearance and evenly distributed micropores on the surface of HyFlex EDM while observations of the surface of both HyFlex CM and HyFlex NT demonstrated machining grooves and irregularities. The NCF of HyFlex EDM was 838±223, which was significantly higher than not only that of HyFlex CM (582±99), but also that of HyFlex NT (81±20) (P<0.05), and the difference between the latter two groups was significant, as well (P<0.05). The length of fractured fragments of HyFlex EDM was (7.27±0.28) mm, which was significantly longer than the HyFlex CM and HyFlex NT, with values of (6.72±0.26) mm and (6.62±0.37) mm, respectively (P<0.05). Topographic features demonstrated typical cyclic fatigue for all the three groups while the region of crack origins was more for HyFlex EDM and HyFlex CM than that of HyFlex NT. As far as the dimple area was concerned, that of HyFlex EDM was deeper and larger than that of HyFlex CM and HyFlex NT.

CONCLUSION

Within the limitations of this study, electro-discharge machining leads to peculiar melting appearance with micropores instead of machining grooves and irregularities on the surface of HyFlex EDM, which may be the reason why HyFlex EDM exhibits significantly better cyclicfatigue resistance than HyFlex CM and HyFlex NT.

Downregulation of hsa_circ_0000285 serves as a prognostic biomarker for bladder cancer and is involved in cisplatin resistance

Bladder cancer remains a very challenging disease to treat with the high rates of recurrence and progression associated with current therapies. Although the association between bladder cancer pathology and circRNAs remains undetermined, circRNAs signatures may be useful as prognostic and predictive factors and clinical tools for assessing disease state, treatment response and outcome. This study investigates if these circRNAs can be used as biomarkers for bladder cancer diagnosis and predicting treatment response. Herein, qPCR measured the expression of hsa_circRNA_100783, hsa_circ_0000285 and hsa_circRNA_100782 in bladder cancer tissues. It was established that sa_circ_0000285, but not hsa_circRNA_100782 and hsa_circRNA_10078, are significantly reduced in bladder cancer tissues and serum compared to adjacent tissues and healthy controls. Moreover, hsa_circ_0000285 expression was lower in cisplatin-resistant bladder cancer patients than in those who were cisplatin-sensitive. Here, hsa_circ_0000285 was associated with tumor size (p<0.001), differentiation (p<0.001), lymph node metastasis (p=0.038), distant metastasis (p=0.004) and TNM stage (p=0.013). Further analysis showed that hsa_circ_0000285 would be an independent prognostic factor for bladder cancer patient outcome. In conclusion, our study indicates hsa_circ_0000285 may be a novel biomarker for bladder cancer because of its involvement in bladder cancer chemo-sensitivity.

Long non-coding RNA PICART1 suppresses proliferation and promotes apoptosis in lung cancer cells by inhibiting JAK2/STAT3 signaling

Lung cancer remains the most common cause of tumor-related death worldwide. Recent studies have revealed that long non-coding RNAs (lncRNAs) are involved in the development of various cancers, including lung cancer. This study aimed to investigate the effect and the molecular basis of lncRNA PICART1 on lung cancer. We first assessed the PICART1 expression in lung cancer in vitro and vivo by qRT-PCR. Then the expression of PICART1 in SPC-A-1 and NCI-H1975 cell lines was inhibited and overexpressed by transient transfections. Thereafter, cell viability, cell cycle, migration and apoptosis were respectively measured by MTT, Transwell and flow cytometry assay. Furthermore, qRT-PCR and western blot analysis were mainly performed to assess the expression levels of apoptosis- and migration-related proteins and JAK2/STAT3 pathway proteins. Tumor formation was measured by xenograft tumor model assay in vivo. PICART1 expression was down-regulated in human lung cancer tissues and cell lines. Knockdown of PICART1 increased cell viability of lung cancer cell lines. However, PICART1 overexpression inhibited cell cycle progression and promoted apoptosis in SPC-A-1 and NCI-H1975 cell lines. PICART1 overexpression also inhibited migration, as evidenced by up-regulation of E-cadherin, and down-regulation of Twist1, MMP2 and MMP9. Furthermore, we found PICART1 inhibition may regulate cell apoptosis and migration through activating JAK2/STAT3 pathway. In vivo experiments revealed that PICART1 knockdown significantly promoted tumor formation. This study demonstrates that PICART1 overexpression represents an anti-growth and anti-metastasis role in lung cancer cells. Additionally, PICART1 acts as a tumor suppressor may be via regulation of JAK2/STAT3 pathway.

[The value of high resolution diffusion weighted imaging in differentiating benign and malignant epithelial tumors of parotid gland]

Objective: To investigate the diagnostic value of RESOLVE DWI in the evaluation of benign and malignant epithelial tumors of parotid gland. Methods: A total of 106 patients in the First Affiliated Hospital of Zhengzhou University with epithelial tumors of parotid gland confirmed by pathology from July 2015 to October 2017 were retrospectively analyzed. All patients underwent preoperative routine MRI and RESOLVE DWI, the ADC average values were calculated, t test were used to compare the ADC values of benign and malignant epithelial tumors of parotid gland. Diagnostic performance of ADC value was compared using receiver operating characteristic (ROC)curves. Results: All lesions were solitary, including 69 benign epithelial tumors and 37 malignant epithelial tumors. The mean ADC values of pleomorphic adenoma and basal cell adenoma, adenolymphoma and malignant epithelial tumors were (1.47±0.16)×10(-3) mm(2)/s, (0.83±0.19)×10(-3) mm(2)/s and(1.14±0.14)×10(-3) mm(2)/s, the mean ADC value of adenolymphoma lower than the rest of the two groups, there were statistically significant differences among them (P<0.05). Using 0.94×10(-3) mm(2)/s≤ADC value≤1.28×10(-3)mm(2)/s as the critical value for diagnosing malignant epithelial tumors of parotid gland and comparing with pathological results, the result obtained had a sensitivity of 81.1%, specificity of 88.9%. ADC value had high correlations compared with pathological results, kappa value was 0.600. Conclusion: RESOLVE DWI can be applied in differential diagnosis between benign and malignant epithelial tumors of parotid gland.

FMNL2 destabilises COMMD10 to activate NF-κB pathway in invasion and metastasis of colorectal cancer

BACKGROUND

Diaphanous-related formins (DRFs), actin necleator, have been known to participate in the progression of cancer cells. We previously reported that FMNL2 (Formin-like2), a member of DRFs, was a positive regulator in colorectal cancer (CRC) metastasis, yet proteins and pathways required for the function of this pro-invasive DRFs remain to be identified.

METHODS

The relationship between FMNL2 and COMMD10 was examined using Co-IP, GST pull-down, immunofluorescence and in vitro ubiquitination assay. The in vitro and in vivo function of COMMD10 in CRC was evaluated using CCK-8 proliferation assay, plate colony formation, cell cycle, apoptosis and animal models. The inhibition of NF-κB signalling by COMMD10 was detected using dual-luciferase reporter assay and western blotting. Co-IP, GST pull-down and nuclear protein extraction assay were performed to evaluate the effect on p65 by COMMD10. Real-time PCR and western blotting were performed to detect expressions of FMNL2, COMMD10 and p65 in paired tissues.

RESULTS

FMNL2 targets COMMD10 for ubiquitin-mediated proteasome degradation in CRC cells. COMMD10 targets p65 NF-κB (nuclear factor-κB) subunit and reduces its nuclear translocation, thereby leading to the inactivation of NF-κB pathway and suppression of CRC invasion and metastasis. Inhibition of NF-κB signalling by COMMD10 is necessary for FMNL2-mediated CRC cell behaviours. Downregulation of COMMD10 predicts poor prognosis of CRC patients. The expressions of FMNL2, COMMD10 and p65 are highly linked in CRC tissues.

CONCLUSIONS

These data demonstrate that the FMNL2/COMMD10/p65 axis acts as a critical regulator in the maintenance of metastatic phenotypes and is strongly associated with negative clinical outcomes.

[Feasibility and value of index of microcirculatory resistance in patients with acute myocardial infarction after primary percutaneous coronary intervention]

Objective: To evaluate the feasibility of detecting index of microcirculatory resistance (IMR) and the relationship between IMR and left ventricular (LV) systolic function after acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). Methods: The patients with first AMI received primary PCI in Peking University Third Hospital were enrolled from January 2014 to March 2016. IMR were measured immediately after PCI by using pressure/temperature wire. The relationship between IMR and left ventricular ejection fraction (LVEF) assessed by echocardiography at first day and 6 months after admission was evaluated. Results: Twenty-eight patients with anterior wall AMI were enrolled, with an average age (56±13) years. The success rate of IMR detection was 100%. The mean IMR was (33±18 )mmHg·s. There was no complication related to intravenous adenosine triphosphate (ATP) (140 μg· kg(-1)· min(-1)). The IMR was negatively correlated with TIMI blood flow grade after primary PCI (r=-0.386, P=0.043), and positively correlated with female gender, CK peak value and TnT peak value (r=0.430, P=0.022; r=0.431, P=0.025; r=0.434, P=0.024). After 6 months of follow-up, no adverse cardiovascular events (including cardiac death, nonfatal myocardial infarction, malignant arrhythmia, unplanned revascularization, hospitalization for unstable angina pectoris and severe heart failure requiring hospitalization) occurred. LVEF increased significantly compared with the first day after PCI (0.54±0.08 vs 0.47±0.06, P=0.001), and IMR was negatively correlated with LVEF after 6 months (r=-0.477, P=0.014). Multivariable linear regression analysis showed that CK peak and IMR were predictors of LVEF after six months ( β=-0.595, t=-3.814, P=0.01; β=-0.352, t=-2.26, P=0.036). Conclusions: Immediate detection of IMR in patients with anterior wall AMI after PCI is safe and feasible. The immediate IMR after PCI reflects the extent of myocardial necrosis and myocardial perfusion, and is a predictor of LVEF at 6 months after PCI.

Down-regulation of DAB2IP promotes colorectal cancer invasion and metastasis by translocating hnRNPK into nucleus to enhance the transcription of MMP2

DOC-2/DAB2 interacting protein (DAB2IP) is a RasGAP protein that shows a suppressive effect on cancer progression. Our previous study showed the involvement of transcription regulation of DAB2IP in metastasis of colorectal cancer (CRC). However, the molecular mechanisms of DAB2IP in regulating the progression of CRC need to be further explored. Here, we identified heterogeneous nuclear ribonucleoprotein K (hnRNPK) and matrix metalloproteinase 2 (MMP2) as vital downstream targets of DAB2IP in CRC cells by two-dimensional fluorescence difference gel electrophoresis and cDNA microassay, respectively. Mechanistically, down-regulation of DAB2IP increased the level of hnRNPK through MAPK/ERK signaling pathway. Subsequently, translocation of hnRNPK into nucleus enhanced the transcription activity of MMP2, and therefore promoted invasion and metastasis of CRC. Down-regulation of DAB2IP correlated negatively with hnRNPK and MMP2 expressions in CRC tissues. In conclusion, our study elucidates a novel mechanism of the DAB2IP/hnRNPK/MMP2 axis in the regulation of CRC invasion and metastasis, which may be a potential therapeutic target.

[Study on age and white matter neuronal integrity in healthy volunteers based on automating fiber-tract quantification]

Objective: To analyze age-related change in cerebral matter tract, especially fractional anisotropy, based on automating fiber-tract quantification(AFQ). Methods: A total of 64 years old normal persons and 43 young volunteers were enrolled respectively from the Affiliated Drum Tower Hospital of Nanjing University Medical School and community from January 2015 to June 2016.All of them underwent MRI scan, which included DTI and 3D T(1)WI sequence .All cases were divided into 3 groups according to their ages, the young group 20-35 years old, the middle old group 60-75 years old, the old group 76-90 years old.AFQ was used to identify 20 major white matter tracts in brains of all subjects and make measurements at anatomically equivalent locations along their trajectories. Results: The FA change trend of each fiber was similar among three groups. The old and the middle old group had different FA value in both sides of inferior fronto-occipital fasciculus(left t=-2.73, right t=-6.12, P<0.05), thalamic radiation(left t=-4.79, right t=-19.61, P<0.05), arcuate(left t=10.53, right t=-2.72, P<0.05), callosum forceps(genu t=-2.66, splenium t=28.64, P<0.05), cingulum(left t=-4.53, right t=-2.22, P<0.05)and right corticospinal tract(t=3.10, P<0.05), among which each location of callosum forceps minor was different between the old group and the young group, and this area decreased in the middle group. The old group had different FA value in both sides of uncinate fasciculus(left t=-4.52, right t=-4.53, P<0.05), left corticospinal tract(t=-2.19, P<0.05)and right inferior longitudinal fasciculus(t=11.12, P<0.05). Compared to the young group, there was no statistical difference in the FA of both superior longitudinal fasciculus and left inferior longitudinal fasciculus in the old and the middle old group. Conclusion: AFQ has an impact on the further specific study of the age-related white matter tract.

[Change of white matter neuronal integrity associated with spatial navigation impairment in mild cognitive impairment]

Objective: To analyze the correlation between white matter integrity and spatial navigation impairment in patients with mild cognitive impairment (MCI). Methods: A total of 27 MCI subjects and 24 healthy controls were enrolled from the Affiliated Drum Tower Hospital of Nanjing University Medical School from May 2015 to February 2016, who underwent 3.0 T MRI scan and 2D-computer version spatial navigation test.DTI preprocessing and tract-based spatial statistics (TBSS) were performed by PANDA.Two sample t-test and partial correlation coefficients were performed to investigate the correlation of white matter impairments and spatial navigation decline. Results: Relative to controls, MCI showed worse egocentric navigation (t=-2.202, P<0.05). Decreased FA in superior longitudinal fasciculus (left t=2.95, right t=2.95, P<0.05), inferior longitudinal fasciculus and inferior fronto-occipital fasciculus (left t=2.66, right t=2.96, P<0.05), corpus callosum (t=2.09, P<0.05), cingulum (left t=2.76, right t=2.41, P<0.05), fornix (t=4.83, P<0.05), and corticospinal tract (left t=2.33, right t=2.26, P<0.05), were found in the MCI subjects.The decreased FA value of superior longitudinal fasciculus (left r=-0.354, right r=-0.347, P<0.05), inferior longitudinal fasciculus (left r=-0.338, right r=-0.336, P<0.05), cingulum (left r=-0.395, right r=-0.370, P<0.05), right corticospinal tract (r=-0.362, P<0.05) and fornix (r=-0.369, P<0.05) were correlated with increased ego average total error.Allo average total error were negative correlated with FA value of superior longitudinal fasciculus (left r=-0.329, right r=-0.350, P<0.05), inferior longitudinal fasciculus (left r=-0.349, right r=-0.378, P<0.05), splenium of corpus callosum (r=-0.364, P<0.05) and cingulum (left r=-0.340, right r=-0.406, P<0.05). Conclusion: This study implicated the potential white matter structural basis of spatial navigation impairment and will have an impact on the further study of the neurobiological mechanisms of human spatial navigation ability.

FBX8 is a metastasis suppressor downstream of miR-223 and targeting mTOR for degradation in colorectal carcinoma

F-box proteins are critical components of the SKP1-CUL1-F-box (SCF) E3 ubiquitin ligases and involved in the ubiquitin-dependent proteolytic pathway. Dysregulation of F-box protein-mediated proteolysis often leads to human malignancies. F-box only protein 8 (FBX8), a novel component of F-box proteins, is down-regulated in several tumors and closely correlates with tumor progression. However, little is known about its function, regulatory mechanisms and substrates in the progression of colorectal carcinoma (CRC). Combining microRNA (miRNA) assay, functional characterization, mechanistic studies with clinical validation, we identify FBX8 as a CRC metastasis suppressor downstream of miR-223, a metastasis promoting miRNA that is transcriptionally regulated by Myocyte enhancer factor (MEF2A). mTOR is a substrate of FBX8 for ubiquitin-mediated degradation and is required for FBX8 induced cell proliferation and invasion in CRC cells. FBX8 is down-regulated in human CRC tissues and correlates with MEF2A, miR-223 and mTOR expression levels. Notably, low FBX8 expression status in CRC tissues was a significant prognostic factor for poor overall survival of patients. These findings illustrate FBX8 as a metastasis suppressor that functions through mTOR signaling pathway and has significant prognostic power.

[Influence of occupational stress and 5-hydroxytryptamine 2A receptor gene polymorphisms on depression in workers in a thermal power plant]

Objective: To investigate the association of occupational stress and 5-hydroxytryptamine 2A (5-HT2A) receptor gene polymorphisms with depression. Methods: In November 2010, cluster sampling was used to select 589 workers in a thermal power plant as study subjects. Questionnaires were used to investigate demographic features and occupational stressors. Polymerase chain reaction-restriction fragment length polymorphism was used to detect the genotypes of T102C and A-1438G in 5-HT2A receptor gene in 589 workers. Results: High-level daily hassles (OR=3.013, 95%CI 1.642~5.530) , more negative emotion (OR=4.808, 95% CI 2.662~8.681) , more body needs (OR=1.890, 95% CI 1.034~3.453) , and severe role conflict (OR=1.815, 95% CI 1.002~3.288) were risk factors for depression, while high rewards (OR=0.424, 95% CI 0.226~0.796) was the protective factor against depression (all P<0.05). There were no significant differences in T102C genotype and allele distributions between the groups with and without depression (P>0.05) ; there was a significant difference in A-1438G genotype distribution between the groups with and without depression (χ²= 9.573, P<0.05) , while there was no significant difference in A-1438G allele distribution between these groups (P>0.05). The risk of depression in the workers with high-level daily hassles who carried TC genotype (OR= 4.473, 95% CI 1.161~17.238) or CC genotype (OR=5.176, 95% CI 1.367~19.593) of T102C was 4.473 and 5.176 times that in those with low-level daily hassles who carried TT genotype, and the risk of depression in the workers with more negative emotions who carried TC genotype (OR=5.667, 95%CI 1.204~26.673) or CC genotype (OR=8.114, 95% CI 1.747~37.677) of T102C was 5.667 and 8.114 times that in those with less negative emotion who carried TT genotype. The risk of depression in the workers with high-level daily hassles who carried AG genotype (OR=4.505, 95% CI 2.215~9.162) or GG genotype (OR=6.484, 95% CI 2.562~ 16.414) of A-1438G was 4.505 and 6.484 times that in those with low-level daily hassles who carried AA genotype, and the risk of depression in the workers with more negative emotion who carried AG genotype (OR= 4.877, 95%CI 2.326~10.223) or GG genotype (OR=9.090, 95%CI 3.491~23.673) of A-1438G was 4.877 and 9.090 times that in those with less negative emotion who carried AA genotype. The risk of depression in the workers with higher rewards who carried AG genotype (OR=0.152, 95%CI 0.074~0.310) or GG genotype (OR= 0.384, 95% CI 0.153~0.964) of A-1438G was 0.152 and 0.384 times that in those with lower rewards who carried AA genotype. Conclusion: Occupational stress is associated with the development of depression and interacts with 5-HT2A receptor gene polymorphisms.

[Effects of myocardial performance index on assessing left ventricular function in patients with primary hypertension]

OBJECTIVE

To investigate the value of myocardial performance index (MPI) in assessing LV function in patients with primary hypertension (HP).

METHODS

We studied 130 patients with HP (mean age 54.9±13.3 years)and 155 healthy control subjects (mean age 52.4±11.6 years). MPI was determined by tissue doppler imaging using the following formula: MPI=(isovolumic contraction time + isovolumic relaxation time)/ ejection time. The HP group was divided into hypertrophy subgroup( LVMI≥115 g/m(2) in males, or ≥95 g/m(2) in females) and normal mass subgroup(LVMI <115 g/m(2) in males, or<95 g/m(2) in females).

RESULTS

MPI was significantly different in control group, normal mass subgroup and hypertrophy subgroup(0.72±0.23 vs. 0.54± 0.17 vs. 0.45±0.11, P<0.001). Hypertrophy subgroup had significant higher MPI than normal mass subgroup(P =0.046), and both the groups had significant higher MPI than control group(all P<0.001). MPI was positively associated with age(r=0.369,P<0.001), Left ventricular end diastolic diameter(r=0.169, P<0.05), Sm(r=-0.211, P<0.001) and Em(r=-0.383, P<0.001) in control group. In multiple linear regression analysis, MPI was independently related to age (β=0.492, t=7.222,P<0.001) in control group. Among the HP patients, MPI was positively associated with left atrial area (r=0.293, P<0.001),intra ventricular septum(IVS) diameter (r=0.453, P<0.001), LVMI (r=0.453, P<0.001), relative wall thickness(r=0.458, P<0.001), and negatively associated with Sm(r=-0.414, P<0.001), Em(r=-0.508, P<0.001), left ventricular ejection fraction (r=-0.305, P<0.001) in bivariate analysis. In the multiple linear regression analysis, MPI was independently related to Em (β=0.401, t=4.256,P<0.001) and IVS diameter (β=-0.365, t=-3.878,P<0.001) in the HP patients.

CONCLUSION

The HP patients had elevated MPI, especially in the ones with LV hypertrophy. Tissue doppler imaging (TDI) derived MPI could be a useful index to evaluate the overall cardiac function in HP patients.

High color rending index and high-efficiency white organic light-emitting diodes based on the control of red phosphorescent dye-doped hole transport layer

We have investigated the transport characteristics of red phosphorescent dye bis(1-(phenyl)isoquinoline) iridium (III) acetylanetonate (Ir(piq)₂acac) doped 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA), and found that the increasing doping ratio was facilitated to improve the ability of hole transporting. A high color rendering index (CRI) and high-efficiency WOLED was achieved by employing Ir(piq)₂acac doped TCTA film as an effective red emissive layer due to the generation of charge transfer complex (CTC) at the interface. The relative proportion in red: green: blue emission intensity can be controlled by the CTC concentration to obtain high CRI WOLEDs. The WOLED with an optimal red dye doping concentration of 5 wt% exhibits a high CRI of 89 and a power efficiency of 31.2 lm/W and 27.5 lm/W at the initial luminance and 100 cd/m², respectively. The devices show little variation of the Commission Internationale de I'Eclairage coordinates in a wide range of luminance.

Does multiple hosts mean multiple parasites? Population genetic structure of Schistosoma japonicum between definitive host species

Multi-host parasites, those capable of infecting more than one species of host, are responsible for the majority of all zoonotic, emerging or persistent human and animal diseases and are considered one of the major challenges for the biomedical sciences in the 21st century. We characterized the population structure of the multi-host parasite Schistosoma japonicum in relation to its definitive host species by genotyping miracidia collected from humans and domestic animals across five villages around the Yangtze River in Anhui Province, mainland China, using microsatellite markers. High levels of polymorphisms were observed and two main genetic clusters were identified which separated water buffalo, cattle and humans from goats, pigs, dogs and cats. We thereby believe that we present the first evidence of definitive host-based genetic variation in Schistosoma japonicum which has important epidemiological, evolutionary, medical and veterinary implications.

Identification of a mouse thiamine transporter gene as a direct transcriptional target for p53

p53 tumor suppressor is a transcription factor that functions, in part, through many of its downstream target genes. We have identified a p53-inducible gene by performing mRNA differential display on IW32 murine erythroleukemia cells containing a temperature-sensitive p53 mutant allele, tsp53(Val-135). Sequence analysis of the full-length cDNA revealed its identity as the mouse homologue of the human thiamine transporter 1 (THTR-1). Induction of the mouse THTR-1 (mTHTR-1) mRNA was detectable as early as 1 h at 32.5 degrees C; upon shifting back to 38.5 degrees C, mTHTR-1 transcript was rapidly degraded with a half-life of less than 2 h. Elevation of mTHTR-1 expression was found in DNA damage-induced normal mouse embryonic fibroblast cells, but not in p53(-/-) mouse embryonic fibroblast cells, suggesting that mTHTR-1 induction was p53-dependent. A region within the first intron of the mTHTR-1 gene bound to p53 and conferred the p53-mediated transactivation. Furthermore, increased thiamine transporter activities were found in cells overexpressing mTHTR-1 and under conditions of DNA damage or p53 activation. Our findings indicate that p53 may be involved in maintaining thiamine homeostasis through transactivation of THTR-1.

Cell encapsulation with alginate and alpha-phenoxycinnamylidene-acetylated poly(allylamine)

In general, microcapsules prepared from alginate and polycations lack mechanical strength because the interaction between alginate and polycations is ionic instead of covalent, which represents a much stronger bond. To increase the mechanical strength of the capsule, we prepared photosensitive microcapsules that could form covalent bonds between polymers in the capsular membrane by light irradiation. Two types of photosensitive poly(allylamine), with 5% and 10% of amino groups modified by alpha-phenoxycinnamylidene acetylchloride, were synthesized. Both photopolymers exhibited an absorption maximum at 325 nm and were capable of crosslinking upon light exposure. These photosensitive polymers were used for the preparation of microcapsules. The capsules formed from this photosensitive poly(allylamine) and alginate were strengthened significantly by light irradiation. Only 28% of the microcapsules prepared from the 5%-modified photopolymer fractured after 48 h of shaking at 150 rpm. This fracture percentage is much lower when compared with the 60% of capsules fractured when prepared from the untreated poly(allylamine). By using poly(allylamine) at 10% modification, the mechanical strength was improved only slightly, with 26% of capsules fractured. Analysis of the permeability test indicated that the photo-crosslinked capsular membrane was freely permeable to cytochrome c and myoglobin, but less permeable to serum albumin. The encapsulation method was used to entrap and culture IW32 mouse leukemia cells. The cells proliferated to a density of about 1.1 x 10(7) cells/mL in the capsules after 7 days of cultivation. Concurrently, the concentration of erythropoietin in the microcapsules increased to 800 mU/mL. This new encapsulation technique has great potential in the application of a bioindustrial cell-culturing process.

Decreased chronic lymphocytic leukemia incidence in Asians in Los Angeles County

Chronic lymphocytic leukemia (CLL) is rare in Asians living in Asia and possibly in US Asians. In contrast, CLL is the most common leukemia in whites. The basis for this ethnic and geographic variation is unknown. We compared average annual age-adjusted incidence rates (AAIR) of CLL diagnosed from 1972 to 1995 among Los Angeles County-resident Asians, non-Spanish-surnamed- and Spanish-surnamed whites (non-Hispanic and Hispanic-whites) and blacks using the University Southern California-Cancer Surveillance Program (USC-CSP), the population-based cancer registry for Los Angeles County. Asian groups studied included Chinese, Japanese, Filipinos and Koreans. Expected numbers of CLL cases were based on the age-adjusted incidence rates in non-Hispanic whites and compared to numbers of cases observed in Chinese, Japanese and Filipinos. Possible association of socioeconomic state (SES) was assessed using AAIRs with SES-specific denominators. In the absence of denominators by birthplace, the association of birthplace and CLL-incidence was evaluated using proportional odds ratios (POR). Los Angeles County Asian males and females had significantly lower AAIRs than non-Hispanic whites (males: AAIR=0.7 per 100000 population, 95% confidence interval (CI), 0.5-1.0 vs. 4.4, 95% CI, 4.3-4.6; and females: AAIR=0.5, 95% CI, 0.3-0.7 vs. 2.3, 95% CI, 2.2-2.4). Fewer Japanese Chinese and Filipinos were diagnosed with CLL than expected (P<0.01). There was no association of birthplace (POR=0.9, 95% CI, 0. 5-1.9) or SES on CLL-risk. CLL-risk was markedly lower in Los Angeles County Asians compared to non-Hispanic whites. Neither birthplace nor socioeconomic state accounted for this difference suggesting a role for genetic or other environmental factors in decreasing CLL-risk.

Induction of IW32 erythroleukemia cell differentiation by p53 is dependent on protein tyrosine phosphatase

The biological activity of p53 in IW32 erythroleukemia cells was investigated. IW32 cells had no detectable levels of p53 mRNA and protein expression. By transfecting a temperature-sensitive mutant p53 cDNA, tsp53val135, into the cells, we have established several clones stably expressing the mutant p53 allele. At permissive temperature, these p53 transfectants were arrested in G1 phase and underwent apoptosis. Moreover, differentiation along the erythroid pathway was observed as evidenced by increased benzidine staining and mRNA expression of beta-globin and the erythroid-specific delta-aminolevulinic acid synthase (ALAS-E). Treatment of cells with protein tyrosine phosphatase inhibitor vanadate blocked the p53-induced differentiation, but not that of cell death or growth arrest. Increased protein tyrosine phosphatase activity as well as mRNA levels of PTPbeta2 and PTPepsilon could be observed by wildtype p53 overexpression. These results indicate that p53 induced multiple phenotypic consequences through separate signal pathways in IW32 erythroleukemia cells, and protein tyrosine phosphatase is required for the induced differentiation.

The collagen-containing alginate/poly(L-lysine)/alginate microcapsules

A method of preparing microcapsules containing collagen fibrous network is reported in this study. This method takes advantage of miscibility of collagen and alginate and the ability of this mixture to form spherical gel beads in the presence of CaCl2. Collagen was then reconstituted within the microcapsules at 37 after alginate was liquefied with citrate. GH3 rat pituitary tumor cell, which can be cultured in both suspended and attached forms, were entrapped within the microcapsules. The cell proliferated faster in the collagen-containing capsule as compared to those in the conventional microcapsules.

A novel cell encapsulation method using photosensitive poly(allylamine alpha-cyanocinnamylideneacetate)

A photosensitive alpha-cyanocinnamylideneacetyl group was coupled to poly(allylamine) to obtain a photosensitive polymer. This photosensitive poly(allylamine alpha-cyanocinnamylideneacetate) can cross-link upon light exposure. Microcapsules were fabricated from alginate in contact with Ca+2 ion, followed by coating with the photosensitive poly(allylamine alpha-cyanocinnamylideneacetate). The microcapsules, thus formed, can be strengthened significantly by the light-induced cross-linking of poly(allylamine alpha-cyanocinnamylideneacetate). Only 16 capsules (out of 50) prepared from the photosensitive poly(allylamine alpha-cyanocinnamylideneacetate) fractured after 48 h of agitation. For microcapsules prepared from the unmodified poly(allylamine), 32 capsules fractured. The photo cross-linked capsular membrane was permeable to cytochrome C, moderately permeable to myoglobin, and least permeable to serum albumin. IW32 (a mouse leukaemia cell line) cells were entrapped and cultured within these microcapsules. The cells proliferated to a density of about 9 x 10(6) cells/ml in the capsules after 7 days of cultivation.

Identification of a novel mouse p53 target gene DDA3

We have identified a novel p53 regulated gene designated DDA3 through differential mRNA display on IW32 erythroleukemia cells containing a temperature sensitive p53 allele, tsp53val-135. DDA3 mRNA induction could be observed in all sublines expressing tsp53val-135 cultured at permissive temperature as well as in NIH3T3 cells undergoing DNA damage. Upregulation of DDA3 could be detected within 2 h after down-shifting the temperature to 32.5 degrees C; upon shifting back to 38.5 degrees C, DDA3 mRNA rapidly degraded with a half-life of less than 2 h. Actinomycin D, but not cycloheximide, inhibited the p53 dependent DDA3 induction, suggesting that the activation is through transcriptional regulation and does not require de novo protein synthesis. DDA3 was expressed in multiple mouse tissues including brain, spleen, lung, kidney and testis. Full-length DDA3 cDNA was cloned and it contained an open reading frame predicted to encode a proline rich protein of 329 amino acids. Overexpression of DDA3 in H1299 lung carcinoma cells suppressed colony formation. These results suggest that DDA3 is a p53-regulated gene that might participate in the p53-mediated growth suppression.

Evidence for the involvement of protein kinase C in the inhibition of prolactin gene expression by transforming growth factor-beta2

We investigated the mechanisms by which transforming growth factor (TGF)-beta2 inhibited prolactin mRNA expression in GH3 rat pituitary tumor cells. Maximal inhibition was observed with cells exposed to 5 ng/ml TGF-beta2 for 24 hr. Continuous presence of the hormone during the entire period was not necessary because exposure of cells to TGF-beta2 for 20 min was sufficient to trigger the same extent of prolactin mRNA inhibition at 24 hr as with its persistent presence. The action of TGF-beta2 could be abolished by cycloheximide or EGTA, suggesting the requirement of a newly synthesized protein and extracellular Ca2+. The response of prolactin mRNA to TGF-beta2 was inhibited by preincubation of cells with phorbol-12-myristate-13-acetate, which down-regulated protein kinase C (PKC). The activities of both the cytosolic and membrane PKC were significantly reduced at 20 min after TGF-beta2 addition, and inhibition continued to 24 hr, the last time point analyzed. However, the ratio of cytosolic to membrane PKC was not altered by TGF-beta2. Inhibition of PKC did not require the sustained presence of TGF-beta2. In vitro kinase assays of the immunoprecipitated PKC demonstrated that the activities of alpha, epsilon, mu, and zeta isozymes were significantly decreased in the TGF-beta2-treated cells, whereas that of PKClambda was not affected. Western blotting did not reveal any change in PKCepsilon steady state protein levels, suggesting TGF-beta2 inhibits PKC activity through a post-translational mechanism. Our results support that inhibition of PKC activity is an early event mediating TGF-beta2-inhibited prolactin mRNA expression in GH3 cells.

Involvement of Ca2+ signalling in the vasoactive intestinal peptide and 8-Br-cAMP induction of c-fos mRNA expression

Vasoactive intestinal peptide (VIP) is known to signal via Gs mediated pathways. VIP stimulated c-fos mRNA expression in a clonal GH3 pituitary tumour cell line, GH3Ca, whereas 8-Br-cAMP only moderately induced c-fos expression. The VIP-induced c-fos expression was inhibited in the presence of EGTA, or the L-type Ca2+ channel blockers verapamil and nifedipine. Measurement of intracellular Ca2+ concentration ([Ca2+]i) by Fura-2 indicates that VIP gradually elevates [Ca2+]i, with the maximum level attained at 4 min following hormone addition. No [Ca2+]i increase could be detected in Ca2+ free buffer or in buffer containing nifedipine or verapamil, which suggests that VIP induced Ca2+ entry from L-type Ca2+ channels. 8-Br-cAMP rapidly increased [Ca2+]i, with a maximum concentration attained within 1 min of its addition and the elevated level maintained for 15 min. In the absence of external Ca2+ or in the presence of verapamil or nifedipine, the sustained Ca2+ increase was abolished whereas the transient Ca2+ peak was unaffected. Depletion of the internal calcium pools by thapsigargin (1 microM, 30 min), on the other hand, blocked the rapid transient [Ca2+], rise, suggesting the biphasic [Ca2+]i elicited by 8-Br-cAMP was due to mobilization from internal Ca2+ pool followed by extracellular flow. Interestingly, pretreatment with thapsigargin greatly potentiated the 8-Br-cAMP-stimulated c-fos expression. Pretreatment of cells with cholera toxin (1 microg/ml, 9 h) to deplete Gs proteins abolished VIP stimulated-[Ca2+] elevation, while it had little effect on the 8-Br-cAMP induced [Ca2+]i rise. Our results show that VIP increased Ca2+ influx from L-type channel through a Gs-mediated mechanism and this Ca2+ entry across the plasma membrane plays a major role in the hormone induced c-fos mRNA expression.

Protein tyrosine phosphatase-dependent activation of beta-globin and delta-aminolevulinic acid synthase genes in the camptothecin-induced IW32 erythroleukemia cell differentiation

Camptothecin, an antitumor drug that specifically targets topoisomerase I, induced IW32 erythroleukemia cells to differentiate along the erythroid pathway, as demonstrated by the increased mRNA and protein expression of hemoglobin. Unlike other chemically induced erythroleukemia cell differentiation, no c-myc mRNA down-regulation was observed in the early phases of drug treatment. Among the heme-synthesizing enzyme mRNAs that were analyzed, only that of the erythroid-specific delta-aminolevulinic acid synthase (ALAS-E) was stimulated. Vanadate or benzylphosphonic acid, which inhibited protein tyrosine phosphatases (PTPase), blocked the camptothecin-induced differentiation. Maximal inhibition was attained if vanadate was added within the first 6 hr of camptothecin treatment, after which vanadate gradually lost its effectiveness. Camptothecin-induced expression of beta-globin or ALAS-E transcript levels was inhibited in the presence of cycloheximide or vanadate. It was also shown that vanadate blocked differentiation of IW32 cells induced by sodium butyrate, VM-26, and p53. Increased PTPase activity could be observed 48 hr after cells were treated with camptothecin, VM-26, or sodium butyrate. Analysis of PTPase activity in the course of camptothecin treatment showed elevated levels of PTPase in the cytosol and the nucleus, with a greater increase demonstrated in the cytosol than in the nucleus. Our results suggest that by stimulating the beta-globin and ALAS-E gene expression, PTPase plays a critical role in the induced differentiation of IW32 erythroleukemia cells.

Differential effect of age on transforming growth factor-beta 1 inhibition of prolactin gene expression versus secretion in rat anterior pituitary cells

Transforming growth factor-beta 1 (TGF-beta 1) synthesized in the pituitary may act as an autocrine/paracrine regulator of lactotrope function. We examined the effects of TGF-beta 1 on PRL messenger RNA (mRNA), PRL synthesis, and PRL secretion in cultured anterior pituitary (AP) cells from rats at different ages. APs excised from ovariectomized female Sprague-Dawley rats, either young(2-3 months old; average serum PRL: 9 ng/ml), middle-aged (11-12 months old; average serum PRL: 133 ng/ml), or old (24 months old; average serum PRL: 159 ng/ml), were dispersed and cultured for 5 days. Then, cells were washed and challenged with increasing doses of TGF-beta 1 (0-100 ng/ml) for 1-48 h in serum-free medium. Northern blot analysis showed an increase in basal PRL mRNA levels, and a decrease in responsiveness to TGF-beta 1 with age. TGF-beta 1 suppressed PRL mRNA in a dose- and time-dependent manner in cells from young rats. Maximum inhibition was observed at 0.5-1 ng/ml of TGF-beta 1. At 0.5 ng/ml TGF-beta 1, significant reduction in PRL mRNA was detected at 6 h, and maximum inhibition was observed at 12-48 h post TGF-beta 1 incubation. Cells from middle-aged rats were less responsive to TGF-beta 1, whereas cells from old rats did not seem to respond under our experimental conditions. In addition to its effect on PRL mRNA in young AP cells, TGF-beta 1 dose dependently inhibited the rate of PRL synthesis, as indicated by reduced [35S]methionine incorporation into immunoprecipitated PRL. Responsiveness of PRL synthesis to TGF-beta 1 inhibition also decreased with age; however, significant inhibition by TGF-beta 1 on PRL synthesis could still be observed in old AP cells. Analysis by RIA demonstrated that young AP cells produced lower levels (15 micrograms/10(6) cells.24 h) of PRL in culture medium than old AP cells (32 micrograms/10(6) cells.24 h). TGF-beta 1 decreased medium PRL levels in old AP cells as efficaciously as in young AP cells. Significant reduction in medium PRL secreted by young AP cells was observed at 3 h when changes in both PRL mRNA and PRL synthesis were not evident. Taken together, our data suggest that TGF-beta 1 affects PRL production at multiple levels. Moreover, its inhibition on PRL synthesis and mRNA expression, but not on PRL secretion, is age-related. Thus, TGF-beta 1 may play an important role in regulating lactotrope function during aging.