Screening and identification of a polyurethane-degrading bacterium G-11 and its plastic degradation characteristics / 生物工程学报

Polyurethane (PUR) plastics is widely used because of its unique physical and chemical properties. However, unreasonable disposal of the vast amount of used PUR plastics has caused serious environmental pollution. The efficient degradation and utilization of used PUR plastics by means of microorganisms has become one of the current research hotspots, and efficient PUR degrading microbes are the key to the biological treatment of PUR plastics. In this study, an Impranil DLN-degrading bacteria G-11 was isolated from used PUR plastic samples collected from landfill, and its PUR-degrading characteristics were studied. Strain G-11 was identified as Amycolatopsis sp. through 16S rRNA gene sequence alignment. PUR degradation experiment showed that the weight loss rate of the commercial PUR plastics upon treatment of strain G-11 was 4.67%. Scanning electron microscope (SEM) showed that the surface structure of G-11-treated PUR plastics was destroyed with an eroded morphology. Contact angle and thermogravimetry analysis (TGA) showed that the hydrophilicity of PUR plastics increased along with decreased thermal stability upon treatment by strain G-11, which were consistent with the weight loss and morphological observation. These results indicated that strain G-11 isolated from landfill has potential application in biodegradation of waste PUR plastics.

Effects of social isolation on cognitive function and phenotypic transition of hippocampal astrocytes in mice / 中华行为医学与脑科学杂志

Objective:To explore the effect of social isolation (SI) on cognitive function and the phenotypic transition of hippocampal astrocytes in mice.Methods:Twenty male C57BL/6 mice aged 3-4 weeks were randomly divided into normal group house (GH group) and social isolation group (SI Group). The mice in SI group were fed one per cage for 8 weeks to establish a social isolation model, and the mice in GH group were fed five per cage. The cognitive function of mice was detected by the novel object recognition test and novel location recognition test. The expression of astrocyte marker glial fibrillary acidic protein (GFAP) was detected by immunohistochemistry, RT-PCR and Western blot.The astrocyte morphology change was quantitatively analyzed by Sholl Analysis.The expression of the hippocampal A1-A2 astrocytes markers proteasome subunit beta 8(PSMB8) and a member of the S100 family of Ca 2+ -binding proteins (S100A10) were determined by RT-PCR and Western blot. Statistical analysis was performed using GraphPad Prism 6.0 software, and t-test was used for comparison between two groups. Results:The results of cognitive function showed that the exploration index of novel object ((-5.54±3.30)%, (33.42±7.14)%; t=4.680, P=0.001) and the exploration index of novel location((-7.96±4.81)%, (23.55±8.20)%; t=3.670, P=0.008) in SI group were both lower than those in GH group.Immunohistochemical results showed that the number of GFAP positive cells in hippocampus of SI group was significantly lower than that of GH group((369.90±42.97), (544.90±57.64); t=2.480, P=0.023). The results of Sholl analysis showed that the protuberance of hippocampal astrocytes in SI Group retracted.There were significant differences in the number of intersections between the two groups at 6, 8, 10, 12, 14 and 16 μm away from astrocyte cell body(all P<0.05). Western blot showed that the expression of GFAP protein in SI group was lower than that in GH group((0.85±0.05), (1.03±0.06); t=2.527, P=0.028). The results of PCR showed that the expression of GFAP mRNA in SI group was lower than that in GH group ((0.83±0.05), (1.00±0.03); t=2.970, P=0.018). The expression of A1 phenotypic marker PSMB8 mRNA ((1.58±0.17), (1.00±0.06); t=2.931, P=0.011) and A2 phenotypic marker S100A10 mRNA ((1.52±0.14), (1.00±0.07); t=3.121, P=0.007) in the hippocampus of SI group were higher than those in GH group.Compared with the GH group, the expression of the neurotrophic factors IGF-1 mRNA in the SI group was down-regulated ((0.73±0.07), (1.00±0.08); t=2.327, P<0.05), while the expression of LCN2 mRNA((1.12±0.03), (1.00±0.03), t=2.575, P<0.05), IL-1β mRNA(1.76±0.19), (1.00±0.07), t=3.460, P<0.01) and TNF-α mRNA((2.18±0.42), (1.00±0.07), t=2.427, P<0.05) were up-regulated in the SI group. Conclusion:The pathological mechanism of social isolation-induced cognitive impairment in mice may be related with the phenotypic changes of astrocytes.

Survival after intraoperative or postoperative radiotherapy in early breast cancer: an analysis of the SEER database / 中华放射肿瘤学杂志

Objective:To compare the survival and prognostic factors of intraoperative radiotherapy (IORT) and postoperative radiotherapy (PORT) in female patients, aged≥50 years, diagnosed with node-negative breast cancer (≤ 3 cm in size).Methods:Clinical data of eligible early breast cancer patients between 2010 and 2015 were obtained from the SEER database. Patients were divided into the IORT and PORT groups according to the radiotherapy record and propensity score matching (PSM) was subsequently conducted. Kaplan-Meier curve was used to evaluate the overall survival (OS) and breast cancer-specific survival (BCSS) between two groups and Cox proportional hazard regression analysis was used to explore the risk factors of clinical prognosis.Results:7 068 patients were included after PSM. The median follow-up time was 32.0 months. The 5-year OS rates in the IORT and PORT groups were 96.8% and 93.8%, respectively. Univariate Cox analysis showed that radiotherapy, age, histological grade, T stage, estrogen receptor (ER) status and progesterone receptor (PR) status were the independent risk factors for OS, and histological grade, T stage, ER status, PR status and chemotherapy were the independent risk factors for BCSS. Multivariate Cox regression analysis demonstrated that patients who received IORT had better OS than PORT counterparts ( P=0.020). Besides, patients aged≥60 years obtained worse OS than those aged<60 years ( P=0.003). Patients with T 2 stage or ER-negative tumors had worse OS than those with T 1 stage tumors ( P<0.001) or ER-positive tumors ( P=0.001). Patients with grade Ⅲ-Ⅳ tumors achieved worse BCSS ( P=0.004). Subgroup analysis showed that IORT yielded better OS for elderly patients (≥60 years), grade Ⅲ-Ⅳ tumors, infiltrating duct carcinoma, T 2 stage tumors, ER-positive tumors, PR-positive tumors and patients without chemotherapy. Conclusions:IORT may bring benefit for highly selected patients with low risk of recurrence, which is not inferior to PORT in terms of short-term survival. Prospective studies with longer follow-up time are needed to confirm the findings.

Progress in the study of macrophage activation and ulcerative colitis from the Notch/NF-κB/NLRP3 signaling pathway / 中南大学学报(医学版)

Ulcerative colitis is an intestinal inflammatory disease characterized by diarrhea, abdominal pain and purulent stool. Uncontrolled inflammation caused by macrophage hyper-activation is an important cause of ulcerative colitis. Therefore, inhibiting macrophage hyper-activation is an effective way to treat ulcerative colitis. Notch signaling pathway is involved in regulating the immune response of macrophages and promoting inflammation. NF-κB signaling pathway is the "star pathway" involved in inflammation. NLRP3 inflammatory body is involved in the activation of macrophages. Notch, NF-κB and NLRP3 inflammatory bodies constitute the upstream and downstream signal pathways in the existing immune inflammatory diseases. Notch signal pathway can regulate the activation of macrophage via NF-κB/NLRP3 inflammatory body signaling pathway.

Risk factors of microinvasion in breast ductal carcinoma in situ / 中国肿瘤临床

Objective:To analyze risk factors of breast ductal carcinoma in situ (DCIS) with microinvasion (DCIS-MI) and explore suitable axillary lymph node surgery treatment for patients with DCIS-MI. Methods:The clinical characteristics, such as age, menopausal status at diagnosis, size of breast mass, and pathology reports of 45 patients with breast DCIS or DCIS-MI treated at Jinling Hospital, Medical School of Nanjing University from February 2013 to February 2016, were retrospectively collected and analyzed statistically to deter-mine the risk factors associated with microinvasion. Results:Premenopause (P=0.006), tumor size≥3.15 cm (P=0.006), and family his-tory of malignant tumor (P=0.002) were proven risk factors of DCIS-MI. Conclusion:Patients with clinical palpable axillary mass, pre-menopause, large breast mass, and family history of malignant tumor demonstrated high possibility of DCIS-MI. Hence, sentinel lymph node biopsy should be performed. Axillary lymph node dissection is highly recommended to patients whose main symptom is palpable axillary mass.

Effect of Chaihushugansan on pancreatic fibrosis in mice with chronic pancreatitis induced by DBTC plus ethanol and its anti-oxidation mecha-nism / 中国病理生理杂志

[ ABSTRACT] AIM:To explore the role of superoxide dismutase ( SOD) and malondialdehyde ( MDA) in chronic pancreatitis ( CP) induced by dibutyltin dichloride ( DBTC) combined with ethanol, and the mechanisms for prevention and treatment of pancreatic fibrosis by Chaihushugansan.METHODS: The KM mice were randomly divided into control group, CP group ( DBTC combined with ethanol) and Chaihushugansan group ( CP+Chaihushugansan) .Except for control group, the mice in other groups were intravenously injected in tail with DBTC (8 mg/kg) and drank 10% ethanol.The mice in Chaihushugansan group were administered intragastrically with Chaihushugansan (6 g· kg-1 · d-1 ) at the follow-ing experimenal period.Before modeling and 1 week, 2 weeks, 4 weeks and 8 weeks after modeling, the mice were anes-thetized and sacrificed.The activity of amylase and the content of hyaluronic acid in the serum were measured.The mor-phology and the degree of fibrosis in the pancreas were observed by HE staining.The activity of SOD and the level of MDA in the pancreas homogenate were analyzed.The protein of pancreas was extracted to detect the expression of type I collagen by Western blotting.RESULTS:DBTC combined with ethanol induced CP with increased serum amylase and hyaluronic acid levels, while the serum amylase and hyaluronic acid levels in Chaihushugansan group were significantly lowered ( P<0.05).In 1 week, 2 weeks, 4 weeks and 8 weeks, the pancreas were obviously injured and appeared different degrees of fibrosis.The content of MDA and the expression of type I collagen in the increased significantly, but the SOD was de-creased.In Chaihushugansan group, the pathological damage and the degree of fibrosis of the pancreas were improved.The level of MDA and type I collagen expression in the pancreas were significantly reduced, but the SOD was increased.CON-CLUSION:The oxidative stress may take part in the development of CP.Inhibition of oxidative stress in the pancreas is one of the mechanisms that Chaihushugansan attenuates the development of CP.