Enhanced chromium and nitrogen removal by constructing a biofilm reaction system based on denitrifying bacteria preferential colonization theory

Understanding the developmental characteristics of microbial communities in biofilms is crucial for designing targeted functional microbial enhancements for the remediation of complex contamination scenarios. The strong prioritization effect of microorganisms confers the ability to colonize strains that arrive first dominantly. In this study, the auto-aggregating denitrifying bacterial Pseudomonas stutzeri strain YC-34, which has both nitrogen and chromium removal characteristics, was used as a biological material to form a stable biofilm system based on the principle of dominant colonization and biofortification. The effect of the biofilm system on nitrogen and chromium removal was characterized by measuring the changes in the quality of influent and effluent water. The pattern of biofilm changes was analyzed by measuring biofilm content and thickness and characterizing extracellular polymer substances (EPS). Further analysis of the biofilm microbiota characteristics and potential functions revealed the mechanism of strain YC-34 biofortified biofilm. The results revealed that the biofilm system formed could achieve 90.56% nitrate-nitrogen removal with an average initial nitrate-nitrogen concentration of 51.9 mg/L and 40% chromium removal with an average initial hexavalent chromium Cr(VI) concentration of 7.12 mg/L. The biofilm properties of the system were comparatively analyzed during the biofilm formation period, the fluctuation period of Cr(VI)-stressed water quality, and the stabilization period of Cr(VI)-stressed water quality. The biofilm system may be able to increase the structure of hydrogen bonds, the type of protein secondary structure, and the abundance of amino acid-like components in the EPS, which may confer biofilm tolerance to Cr(VI) stress and allow the system to maintain a stable biofilm structure. Furthermore, microbial characterization indicated an increase in microbial diversity in the face of chromium stress, with an increase in the abundance of nitrogen removal-associated functional microbiota and an increasing trend in the abundance of nitrogen transfer pathways. These results demonstrate that the biofilm system is stable in nitrogen and chromium removal. This bioaugmentation method may provide a new way for the remediation of heavy metal-polluted water bodies and also provides theoretical and application parameters for the popularization and application of biofilm systems.

[Effect of duodenal stump reinforcement on postoperative complications in patients undergoing laparoscopic radical gastrectomy]

Objective: To evaluate the influence of duodenal stump reinforcing on the short-term complications after laparoscopic radical gastrectomy. Methods: A retrospective cohort study with propensity score matching (PSM) was conducted. Clinical data of 1204 patients with gastric cancer who underwent laparoscopic radical gastrectomy at the First Affiliated Hospital of Army Medical University from April 2009 to December 2018 were collected. The digestive tract reconstruction methods included Billroth II anastomosis, Roux-en-Y anastomosis and un-cut-Roux- en-Y anastomosis. A linear stapler was used to transected the stomach and the duodenum. Among 1204 patients, 838 were males and 366 were females with mean age of (57.0±16.0) years. Duodenal stump was reinforced in 792 cases (reinforcement group) and unreinforced in 412 cases (non-reinforcement group). There were significant differences in resection range and anastomotic methods between the two groups (both P<0.001). The two groups were matched by propensity score according to the ratio of 1∶1, and the reinforcement group was further divided into purse string group and non-purse string group. The primary outcome was short-term postoperative complications (within one month after operation). Complications with Clavien-Dindo grade ≥ III a were defined as severe complications, and the morbidity of complication between the reinforcement group and the non-reinforcement group, as well as between the purse string group and the non-purse string group was compared. Results: After PSM, 411 pairs were included in the reinforcement group and the non-reinforcement group, and there were no significant differences in baseline data between the two groups (all P>0.05). No perioperative death occurred in any patient.The short-term morbidity of postoperative complication was 7.4% (61/822), including 14 cases of anastomotic leakage (23.0%), 11 cases of abdominal hemorrhage (18.0%), 8 cases of duodenal stump leakage (13.1%), 2 cases of incision dehiscence (3.3%), 6 cases of incision infection (9.8%) and 20 cases of abdominal infection (32.8%). Short-term postoperative complications were found in 25 patients (6.1%) and 36 patients (8.8%) in the reinforcement group and the non-reinforcement group, respectively, without significant difference (χ²=2.142, P=0.143). Nineteen patients (2.3%) developed short-term severe complications (Clavien-Dindo grade ≥IIIa), while no significant difference in severe complications was found between the two groups (1.7% vs. 2.9%, χ²=1.347, P=0.246). Sub-group analysis showed that the morbidity of short-term postoperative complication of the purse string group was 2.6% (9/345), which was lower than 24.2% (16/66) of the non-purse string group (χ²=45.388, P<0.001). Conclusion: Conventional reinforcement of duodenal stump does not significantly reduce the incidence of duodenal stump leakage, so it is necessary to choose whether to reinforce the duodenal stump individually, and purse string suture should be the first choice when decided to reinforce.

[Comparison of clinical efficacy and quality of life between uncut Roux-en-Y and Billroth II with Braun anastomosis in laparoscopic distal gastrectomy for gastric cancer]

Objective: To compare the clinical efficacy and quality of life between uncut Roux-en-Y and Billroth II with Braun anastomosis in laparoscopic distal gastrectomy for gastric cancer patients. Methods: A retrospective cohort study was performed. Inclusion criteria: (1) 18 to 75 years old; (2) gastric cancer proved by preoperative gastroscopy, CT and pathological results and tumor was suitable for D2 radical distal gastrectomy; (3) postoperative pathological diagnosis stage was T1-4aN0-3M0 (according to the AJCC-7th TNM tumor stage), and the margin was negative; (4) Eastern Cooperative Oncology Group (ECOG) physical status score <2 points, and American Association of Anesthesiologists (ASA) grade 1 to 3; (5) no mental illness; (6) able to answer questionnaires independently; (7) patients agreed to undergo laparoscopic distal gastrectomy and signed an informed consent. Exclusion criteria: (1) patients with severe chronic diseases and American Association of Anesthesiologists (ASA) grade >3; (2) patients with other malignant tumors; (3) patients suffered from serious mental diseases; (4) patients received neoadjuvant chemotherapy or immunotherapy. According to the above criteria, clinical data of 200 patients who underwent laparoscopic distal gastrectomy at the Department of General Surgery of the First Affiliated Hospital of Army Medical University from January 2016 to December 2019 were collected. Of the 200 patients, 108 underwent uncut Roux-en-Y anastomosis and 92 underwent Billroth II with Braun anastomosis. The general data, intraoperative and postoperative conditions, complications, and endoscopic evaluation 1 year after the surgery were compared. Besides, the quality of life of two groups was also compared using the Chinese version of the European Organization For Research and Treatment of Cancer (EORTC) quality of life questionnaire-Core 30 (QLQ-C30) and quality of life questionnaire-stomach 22 (QLQ-STO22). Results: There were no significant differences in baseline data between the two groups (all P>0.05). All the 200 patients successfully underwent laparoscopic distal gastrectomy without intraoperative complications, conversion to open surgery or perioperative death. There were no significant differences between two groups in operative time, intraoperative blood loss, postoperative complications, time to flatus, time to removal of gastric tube, time to liquid diet, time to removal of drainage tube or length of postoperative hospital stay (all P>0.05). Endoscopic evaluation was conducted 1 year after surgery. Compared to Billroth II with Braun group, the uncut Roux-en-Y group had a significantly lower incidences of gastric stasis [19.8% (17/86) vs. 37.0% (27/73), χ(2)=11.199, P=0.024], gastritis [11.6% (10/86) vs. 34.2% (25/73), χ(2)=20.892, P<0.001] and bile reflux [1.2% (1/86) vs. 28.8% (21/73), χ(2)=25.237, P<0.001], and the differences were statistically significant. The EORTC questionnaire was performed 1 year after surgery, there were no significant differences in the scores of QLQ-C30 scale between the two groups (all P>0.05), while the scores of QLQ-STO22 showed that, compared to the Billroth II with Braun group, the uncut Roux-en-Y group had a lower pain score (median: 8.3 vs. 16.7, Z=-2.342, P=0.019) and reflux score (median: 0 vs 5.6, Z=-2.284, P=0.022), and the differences were statistically significant (all P<0.05), indicating milder symptoms. Conclusion: The uncut Roux-en-Y anastomosis is safe and reliable in laparoscopic distal gastrectomy, which can reduce the incidences of gastric stasis, gastritis and bile reflux, and improve the quality of life of patients after surgery.

Effects of Non-Invasive Brain Stimulation on Alzheimer's Disease

BACKGROUND

Previous meta-analyses did not explore the immediate and long-term effect of non-invasive brain stimulation (NIBS) on different cognitive domains in Alzheimer's disease (AD). The meta-analysis aimed to assess the therapy effect of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) on different cognitive domains in AD in randomized controlled trials (RCTs).

METHODS

Studies published before December 2021 and exploring therapy effect of rTMS, tDCS on different cognitive domains in AD were searched in the following databases: PubMed and Web of Science. We used STATA 12.0 software to compute the standard mean difference (SMD) and a 95% confidence interval (CI).

RESULTS

The present study included 16 articles (including 372 AD patients treated with rTMS and 310 treated with sham rTMS) for rTMS and 11 articles (including 152 AD patients treated with tDCS and 134 treated with sham tDCS) for tDCS. The present study showed better immediate and long-term general cognitive function increase effects in AD given rTMS, compared to those given sham rTMS with random effects models (immediate effect: SMD = 2.07, 95% CI = 0.37 to 3.77, I2 = 97.8%, p < 0.001; long-term effect: SMD = 5.04, 95% CI = 2.25 to 7.84, I2 = 97.8%, p < 0.001). The present study showed no significant immediate and long-term effects of rTMS on attention, executive, language and memory functions. In addition, the present study showed no significant difference in immediate or long-term effects of tDCS on general cognitive function, attention, language or memory functions between tDCS group and sham tDCS group.

CONCLUSIONS

RTMS was an effective treatment technique for general cognitive function in AD, whereas tDCS showed no significant therapy effect on cognitive function in AD. More large-scale studies were essential to explore the effect of NIBS on various cognitive function in AD.

Efficacy of auto-aggregating aerobic denitrifiers with coaggregation traits for bioaugmentation performance in biofilm-formation and nitrogen-removal

To promote efficiency nitrogen-rich wastewater treatment from a sequencing batch biofilm reactor (SBBR), three aerobic denitrifiers (Pseudomonas mendocinaIHB602, Methylobacterium gregansDC-1 and Pseudomonas stutzeriIHB618) with dual-capacities of strong auto-aggregation and high nitrogen removal efficiency were studied. The aggregation index analysis indicated that coaggregation of the three strains co-existed was better when compared with one or two strains grown alone. Optimal coaggregation strains were used to bioaugmente a test reactor (SBBR_T), which exhibited a shorter time for biofilm-formation than uninoculated control reactor (SBBR_C). With different influent ammonia-N loads (150, 200 and 300 mg·L^-1), the average ammonia-N and nitrate-N removal efficiency were all higher than that in SBBR_C, as well as a lower nitrite-N accumulation. Microbial community structure analysis revealed coaggregation strains may successfully colonize in the bioreactor and be very tolerant of high nitrogen concentrations, and contribute to the high efficiency of inorganic nitrogen-removal and biofilm-formation.

[Dibenzyl trisulfide inhibits proliferation and induces apoptosis of HN30 cells via Akt/ p53 signaling pathway]

OBJECTIVE

To explore the effect of dibenzyl trisulfide (DTS) on cell proliferation and apoptosis in human head and neck squamous cell carcinoma (HNSCC) HN30 cells.

OBJECTIVE

The effects of DTS on proliferation of HNSCC cell lines HN30, HN12, and SCC25 were examined by assessing colony formation ability of the treated cells. The effect of different concentrations of DTS on viability of HN30 cells was assessed using MTT assay. HN30 cells were treated with 3, 10, or 30 μmol/L DTS for 24 h, and the cell apoptosis and mitochondrial membrane potential (MMP) were detected using flow cytometry with annexin Ⅴ-FITC/PI double staining and JC-1 fluorescent probe staining. Western blotting was performed to determine the protein expressions of caspase-3, cleaved caspase-3 and Bcl-2 in the treated cells. The phosphorylation levels of Akt and p53 in HN30 cells were detected using Western blotting after treatment with 10 μmol/L DTS for 0.5, 1, 2, 4, 8, or 16 h.

OBJECTIVE

DTS at 1 μmol/L significantly inhibited the proliferation of HN30, HN12 and SCC25 cells as shown by colony formation assay. MTT assay showed that DTS dose-dependently decreased HN30 cell viability as compared with the solvent control group, and 100 μmol/L DTS produced the strongest inhibitory effect (P < 0.0001). Treatment with DTS below 30 μmol/L concentrationdependently promoted apoptosis (P < 0.01) and lowered the MMP (P < 0.01) of HN30 cells, and after treatment for 24 h, the cells showed significantly increased cleaved caspase-3 (P < 0.01) and decreased Bcl-2 expression (P < 0.01). Treatment with 10 μmol/L DTS for 16 h significantly inhibited Akt phosphorylation (P < 0.001) and enhanced p53 phosphorylation (P < 0.01) in HN30 cells.

OBJECTIVE

DTS inhibits proliferation and induces apoptosis of HN30 cells possibly through mechanisms involving the inhibition of Akt and the activation of p53.

Accuracy of cold sensibility testing on teeth with full-coverage restorations: a clinical study

AIM

This clinical study evaluated the reliability of the 1,1,1,2-tetrafluoroethane (Endo Ice) cold test to determine the pulpal diagnosis of teeth with full-coverage restorations (FCR). The effect of several variables on its reliability was also investigated.

METHODOLOGY

Data collected from 825 patients treated in the Advanced Education Program in Endodontics at the University of Iowa, USA were analysed. The experimental group included 425 teeth with FCR, whilst the control group consisted of 400 teeth with natural crowns (NC). The pulp sensibility test results, tooth type, tooth number, type of crown, age, gender, presence or absence of caries and recent use of analgesics were recorded. Bivariate analyses were performed to assess the variables associated with the accuracy of dental pulp sensibility tests for either teeth with crowns or teeth without crowns using chi-square tests, Fisher's exact tests, Cochran-Mantel-Haenszel tests, and the Wilcoxon rank-sum tests. A P-value of less than 0.05 was used as a criterion for statistical significance, and a P-value in 0.05 < P < 0.10 was used as a criterion for marginal relevance.

RESULTS

The sensibility test results for FCR teeth had an accuracy of 0.866; sensitivity of 0.835; specificity of 0.879; a positive predictive value of 0.746; and a negative predictive value of 0.926. The data indicated a significant difference in the accuracy of pulp sensibility test results between the experimental and control groups (P < 0.001). Although the cold test in FCR teeth still had high accuracy, teeth with NC were significantly more likely to have true-positive and true-negative results (91.5% NC vs. 86.6% FCR, P = 0.024). No significant differences between FCR and NC were found concerning gender, tooth type, type of crown, the presence of abutment and recent use of analgesic (P > 0.05).

CONCLUSION

Pulp sensibility cold testing with 1,1,1,2-tetrafluoroethane (TFE) on teeth with FCR was less accurate than on teeth without full-coverage crowns. However, the use of TFE cold testing is still a relevant and reliable diagnostic tool, particularly for teeth with a pulpal diagnosis of symptomatic irreversible pulpitis. Clinicians should routinely carry out cold pulp sensibility testing on teeth when making a pulpal diagnosis.

Baicalin attenuates endometritis in a rabbit model induced by infection with Escherichia coli and Staphylococcus aureus via NF-κB and JNK signaling pathways

In this study, a rabbit endometritis model was developed to study cow endometritis. In addition, the protective effects of baicalin (a flavonoid) against endometritis were investigated. Clinical symptoms, differential leukocyte counting, uterine secretion smear microscopy and chemical examination, urine testing, and signs of necropsy showed abnormal changes and inflammatory responses in the uterus of rabbits. Histopathological results revealed visible inflammatory exudates and blood spots between intercellular spaces which confirmed that the rabbit endometritis model was successfully developed. Most importantly, these inflammatory signs were partially attenuated with baicalin treatment. The data revealed that the increased body temperature and leukocyte cells, pus, and the detachment of epithelial cells were alleviated with baicalin administration in a dose-dependent manner. Histopathological tissue changes such as inflammatory cells infiltrates, hyperemia, hemorrhages, and shedding of epithelial cells were partially attenuated with baicalin treatment. In addition, the mRNA expression of inflammation-related genes (iNOS, IL-1β, TNF-α, IL-10, IL-4, and IL-6) was significantly altered in RAW264.7 cells after LPS treatment. Further, the phosphorylated protein expression of JNK, p65, and IκBα were significantly reduced with LPS treatment. Intriguingly, baicalin pretreatment reversed the alteration in mRNA expression of inflammation-related genes and significantly reduced the phosphorylation of JNK, p65, and IκBα. In summary, our results suggest that baicalin has protective effects on bacterial-induced endometritis in rabbits that involve the suppression of NF-κB and JNK signaling pathways and pro-inflammatory cytokines.

[Long-term efficacy of robotic radical total gastrectomy for gastric cancer and analysis of prognostic factors]

Objective: To analyze long-term outcomes and prognostic factors of gastric cancer patients after robotic radical total gastrectomy. Methods: A retrospective case-control study was conducted. Inclusion criteria: (1) receiving robotic radical total gastrectomy; (2) gastric adenocarcinoma was confirmed by postoperative pathology; (3) no previous history of other malignant tumors; (4) no preoperative chemotherapy or radiation therapy performed. Exclusion criteria: (1) age <18 years old or age >80 years old;(2)distant metastasis before surgery, or palliative surgery; (3) conversion to laparotomy;(4) R1 or R2 resection; (5)emergency surgery; (6) remnant gastric cancer or recurrence; (7)died of severe complications during hospitalization or within 1 month after surgery. Overall survival rates (OS) and disease-free survival rates (DFS) were evaluated using the Kaplan-Meier method. Cox regression analysis was used to identify prognosis factors for overall survival. Results: According to the above criteria, 166 gastric cancer patients who underwent robotic radical total gastrectomy between March 2010 and November 2018 were included in this study. Roux-en-Y reconstruction was performed in all patients. Reconstruction were achieved using extracorporeal method through a minilaparotomy in 149 case and intracorporeal anastomosis in 17 cases. The number of harvested lymph nodes was (34.8±17.5), and the number of harvested lymph nodes at group 2 was (10.1±6.7). The number of patients with lymph node metastasis of group 2 was 73 (44.0%). The median follow-up time was 25 months (range 2-109). There were 55 (33.1%) cases of recurrence during follow-up. The 3- and 5-year overall survival rates were 55.8% and 46.2% respectively. The 3- and 5-year disease-free survival rates were 53.4% and 45.4% respectively. The 5-year overall survival rates grouped based on TNM stage were 78.9% for stage I, 58.5% for stage II, and 37.1% for stage III. The 5-year disease-free survival rates grouped based on TNM stage were 78.9% for stage I, 59.2% for stage II, and 34.6% for stage III. Univariate analysis suggested that TNM stage, the number of harvested lymph nodes and number of harvested lymph nodes at group 2 were associated with overall survival rates (all P<0.05). Multivariate analyses revealed that TNM stage (P<0.001; stage IIIB: HR=5.357, 95%CI:1.182 to 24.275; stage IIIC: HR=11.937, 95%CI: 2.677 to 53.226) and number of harvested lymph nodes at group 2 (P=0.034; 6-10: HR=0.562,95%CI:0.326 to 0.969; >10: HR=0.388, 95%CI: 0.176 to 0.857) were independent prognostic factors for overall survival. Conclusion: The long-term outcomes of robotic radical total gastrectomy were satisfactory. TNM stage and number of harvested lymph nodes at group 2 were independent prognostic factors for overall survival.

[Comparison of clinical efficacy between proximal gastrectomy with double tract reconstruction and total gastrectomy with Roux-en-Y reconstruction for proximal gastric cancer]

Objective: To compare the clinical efficacy of proximal gastrectomy with double tract reconstruction (PG-DT) and total gastrectomy with Roux-en-Y reconstruction (TG-RY) for proximal gastric cancer. Methods: The retrospective study was conducted. Clinicopathological data of 132 patients with proximal gastric cancer confirmed by pathology who underwent PG-DT (n=51) or TG-RY (n=81) by the same surgeon team in Southwest Hospital of Army Military Medical University between January 2006 and December 2016 were collected. Patients with preoperative neoadjuvant therapy, non-R0 resection and non-adenocarcinoma confirmed by pathology were excluded. Observation indicators included intraoperative (operation time and blood loss); postoperative (time to flatus, hospital stay, total complications, metastasis of lymph nodes around distal side of stomach from cases undergoing TG-RY), follow-up (long-term hemoglobin level, incidence of anemia, and survival) parameters. Survival analysis was conducted using the Kaplan-Meier method, and Log-rank test was used to compare survival difference between two groups. Results: No statistically significant differences were found between two groups in the baseline data, including age, gender, BMI, hemoglobin level before operation, postoperative TNM stage, tumor size and histological differentiation between two groups (all P>0.05). There were no significant differences between PG-DT and TG-RY in intraoperative blood loss [200 (200) ml vs. 200 (195) ml, Z=-1.860, P=0.063], time to flatus [(2.7±1.0) days vs. (2.6±1.1) days, t=0.225, P=0.823], postoperative hospital stay [10(3) days vs. 10 (4) days, Z=-0.449, P=0.654] and morbidity of perioperative complications [5.9% (3/51) vs. 8.6% (7/81), χ(2)=0.081, P=0.775]. Compared with the TG-RY group, PG-DT group had longer total operative time [294 (97) minutes vs. 255 (71) minutes, Z=-3.148, P=0.002]. The hemoglobin data of 42 patients with PG-DT and 56 patients with TG-RY were collected 1 year after operation. The incidence of anemia in PG-DT group was lower than that of TG-RY group [64.2%(27/42) vs. 82.1% (46/56), χ(2)=4.072, P=0.045], and PG-DT group had higher level of hemoglobin than TG-RY group [(114.4±16.3) g/L vs. (106.6±15.0) g/L, t=2.435, P=0.017]. There were 4 cases (4/81, 4.9%) with metastasis of lymph nodes around distal side of stomach in TG-RY group. All of these 4 tumors were T4 in depth and were more than 5 cm in diameter. The median follow-up period was 26 (1 to 110) months. One-year, 3-year and 5-year survival rates were 93.2%, 65.3% and 55.0% in PG-DT group, and 85.8%, 63.8% and 47.2% in TG-RY group, respectively without significant difference (χ(2)=0.890, P=0.345). Conclusions: Compared with TG-RY, PG-DT has the same safety and feasibility for proximal gastric cancer. Although the operative time is a little longer than TG-RY, PG-DT has advantages in improving the postoperative hemoglobin level.

[Comparative study on clinical efficacy of two surgical methods for gastric gastrointestinal stromal tumors at unfavorable position]

Objective: To investigate the safety and feasibility of laparoscopic operation in thetreatment of gastric gastrointestinal stromal tumor (GIST) at unfavorable positions. Methods: A retrospective cohort study was conducted to analyze the clinical data of patients with gastric GIST at unfavorable positions confirmed by pathology after surgery (laparoscopy or laparotomy) at the Southwest Hospital of the Army Medical University and the Minda Hospital of Hubei Minzu University from June 2008 to June 2018. The unfavorable positions of stomach are defined as the esophagogastric junction, the proximal cardia of gastric lesser curvature, the pylorus of stomach, the posterior wall of stomach and the antrum of stomach.Exclusion criteria:(1) preoperative chemotherapy or imatinib therapy; (2) diameter of tumor > 10 cm; (3) tumor metastasis or concurrence of other malignant tumors. A total of 244 patients (238 in Southwest Hospital and 6 in Minda Hospital) were enrolled, including 122 males and 122 females with age of 41-70years. Operative methods should be adopted according to patients' wishes. There were 146 cases in the laparoscopic surgery group and98 cases in the open surgery group. The intraoperative blood loss, operative time, postoperative first flatus time, postoperative firstfeeding time,average hospital stay, morbidity of postoperative complication,1-,3-,and 5-year recurrence free survival(RFS) and overall survival (OS)rate were compared between the two groups. Results: There were no significant differences in sex, age, tumor size, tumor risk grade or growth pattern between the laparoscopic and the open surgery groups (all P>0.05),and these two groups were comparable. Compared with open group, laparoscopic group had less intraoperative blood loss [(31.4±2.3) ml vs. (143.9±3.7) ml, t=292.800, P<0.001], shorter postoperative first flatus time [(2.1±0.7) days vs.(3.8±0.8) days, t=17.550,P<0.001], shorter postoperative first feeding time [(2.1±0.5) days vs.(2.3±1.7) days, t=1.339,P=0.020], shorter hospital stay [(8.6±2.6) days vs. (13.6±3.2) days, t=13.410, P<0.001], and lower morbidity of postoperative complication [16(11.0%) vs. 21(21.4%),χ²=4.996,P=0.025], whose differences were statistically significant. While the operation time was similar in two groups [(124.7±15.8) minutes vs. (120.9±14.5) minutes, t=1.903,P=0.058]. The median follow-up of all the patients was 43 (1 to 119) months.In laparoscopic group and open group, the 1-, 3- and 5-year RFS were 94.5% vs. 93.9%, 91.1% vs. 90.8%,and 82.2% vs. 81.6%, respectively, and 1-, 3- and 5-year OS were 98.6% vs. 95.9%, 95.9% vs. 94.9%,and 91.1% vs. 88.8%, respectively, whose differences were not statistically significant (all P>0.05). Conclusion: In the experienced gastrointestinal surgery center, laparoscopic resection of gastric GIST at unfavorable position is safe and feasible, achieving the same efficacy of open surgery.

The glycosyltransferase ST6Gal-I is enriched in cancer stem-like cells in colorectal carcinoma and contributes to their chemo-resistance

PURPOSE

Presence of cancer stem cells (CSCs) contributes to tumor outgrowth, chemo-resistance and relapse in some cancers including colorectal carcinoma (CRC). The current characterization methods of CSCs in CRC only allows enrichment of CSCs but not their purification. Recent reports showed that ST6 beta-galactoside alpha-2,6-sialyltransferase 1 (ST6Gal-I) plays an essential role in protecting tumor cells against harsh environment like oxidative stress and nutrient deprivation. Therefore, whether ST6Gal-I may be highly expressed in CSCs or whether it may enhance resistance of tumor cells to chemotherapy deserves exploration.

METHOD

ST6Gal-I levels were determined in CRC specimens, compared to paired normal colorectal tissue, and examined in CD133+ vs CD133- CRC cells, and CD44+ vs CD44- CRC cells. ST6Gal-I levels and their association with patient survival were examined. In vivo, 2 CRC cell lines Caco-2 and SW48 were transduced with two lentiviruses, one lentivirus carrying a green fluorescent protein reporter and a luciferase reporter under a cytomegalovirus promoter to allow tracing tumor cells by both fluorescence and luciferase activity, and one lentivirus carrying a nuclear red fluorescent protein under the control of ST6Gal-I promoter to allow separation of ST6Gal-I+ vs ST6Gal-I- CRC cells. Tumor sphere formation, resistance to fluorouracil-induced apoptosis, and frequency of tumor formation after serial adoptive transplantation were done on ST6Gal-I+ vs ST6Gal-I- CRC cells.

RESULT

ST6Gal-I levels were significantly upregulated in clinically obtained CRC specimens, compared to paired normal colorectal tissue. Poorer patient survival was detected in ST6Gal-I-high CRC, compared to ST6Gal-I-low subjects. Higher levels of ST6Gal-I were detected in CD133+ CRC cells than CD133- CRC cells, and in CD44+ CRC cells than in CD44- CRC cells. Compared to ST6Gal-I- CRC cells, ST6Gal-I+ CRC cells generated significantly more tumor spheres in culture, were more resistant to fluorouracil-induced apoptosis likely through upregulating cell autophagy, and generated tumor more frequently after serial adoptive transplantation.

CONCLUSION

ST6Gal-I may be highly expressed in the cancer stem-like cells in CRC and enhances cancer cell resistance to chemotherapy.

Role of secreted protein acidic in hematogenous metastasis of gastric cancer

OBJECTIVE

To investigate tumor microenvironment of metastasis (TMEM) and the expression of SPARC (secreted protein acidic and rich in cysteine) in gastric cancer, and their relationships with hematogenous metastasis.

PATIENTS AND METHODS

Twenty-six pairs of cases with gastric cancer were enrolled, in which there were 26 cases with distant organ metastases and 26 cases of gastric cancer without organ metastases as controls. TMEM (by double-stained immunohistochemistry) and the expression of SPARC were determined in twenty-six pairs of cases. In addition, we selected 48 patients to detect the expression of SPARC, VEGF (vascular endothelial growth factor), and evaluated TAMs (tumor associated macrophages), MVD (the microvessel density), MPI (microvessel pericyte coverage index), and TMEM in gastric cancer tissues by immunohistochemistry.

RESULTS

TMEM count was significantly higher in the metastatic gastric cancer tissues than that in non-metastatic cancer tissues in a case-control study (p<0.01). On the contrary, SPARC expression was lower in the metastatic gastric cancer tissues than that in non-metastatic cancer tissues. TMEM count, TAMs, and MVD were significantly correlated with invasion depth, histological type and TNM stage (p<0.05 or p<0.01). Expression of SPARC and VEGF were significantly correlated with tumor histological types, invasion depth, differentiation and lymph node metastasis of patients (p<0.05). SPARC and VEGF expression in stromal cells of gastric cancer tissues were significantly correlated with TAMs, MVD and MPI (p<0.05). In addition, SPARC expression was significantly inversely correlated with VEGF expression in gastric cancer tissues (p<0.05).

CONCLUSIONS

TMEM was detected in initial gastric cancer resection and closely correlated with hematogenous metastasis. Furthermore, SPARC may be involved in gastric cancer metastasis by effecting on tumor microenvironment.

Magnetic Fluctuations, Precursor Phenomena, and Phase Transition in MnSi under a Magnetic Field

The reference chiral helimagnet MnSi is the first system where Skyrmion lattice correlations have been reported. At a zero magnetic field the transition at T_{C} to the helimagnetic state is of first order. Above T_{C}, in a region dominated by precursor phenomena, neutron scattering shows the buildup of strong chiral fluctuating correlations over the surface of a sphere with radius 2π/ℓ, where ℓ is the pitch of the helix. It has been suggested that these fluctuating correlations drive the helical transition to first order following a scenario proposed by Brazovskii for liquid crystals. We present a comprehensive neutron scattering study under magnetic fields, which provides evidence that this is not the case. The sharp first order transition persists for magnetic fields up to 0.4 T whereas the fluctuating correlations weaken and start to concentrate along the field direction already above 0.2 T. Our results thus disconnect the first order nature of the transition from the precursor fluctuating correlations. They also show no indication for a tricritical point, where the first order transition crosses over to second order with increasing magnetic field. In this light, the nature of the first order helical transition and the precursor phenomena above T_{C}, both of general relevance to chiral magnetism, remain an open question.

Abstract P5-09-02: Breast cancer risk prediction using a polygenic risk score in women of African ancestry: Findings from GWAS in breast cancer in the African diaspora

Background: Multiple common susceptibility loci for breast cancer (BC) have been identified/confirmed in Caucasian women. Combination of these SNPs into a polygenic risk score (PRS) could improve risk stratification and provide guidance for preventive and screening strategies. However, due to differences in allele frequencies of genetic variants, tumor characteristics between women of African and European ancestries, we sought to evaluate the association of PRS with BC in a large consortium of African women.

Methods: The GWAS in BC in the African Diaspora (ROOT consortium) included 3686 participants of African ancestry from Nigeria, USA, and Barbados (1657 cases, 2029 controls). PRS was constructed from the published odds ratios (ORs) from 90 susceptibility loci for BC. Logistic regression was used to examine its association with overall BC risk as well as associations by hormone receptor status, family history and other clinical features.

Results: One unit change in the PRS was associated with an OR of 1.13 (95% CI: 1.01-1.28, P=0.042) for overall BC risk, 1.15 (95%CI: 0.95-1.41, P=0.160) for ER+ BC risk, and 1.17 (95%CI: 0.95-1.44, P=0.133) for ER- BC risk. The ORs for developing BC by percentiles of the PRS, relative to women in the middle quintile, showed weak linear trend. The discriminative accuracy of the PRS, as measured by the C-statistic, was 0.524 (95% CI: 0.505-0.542) for overall BC, 0.511(95% CI: 0.479-0.543) for ER+ BC, and 0.513 (95% CI: 0.481-0.545) for ER- BC. There was a statistically significant interaction between PRS and age, the association between PRS and overall BC risk were stronger in two age groups (aged &lt;40 years and ≥60 years). The PRS was also more strongly associated with PR+ (OR=1.26, 95%CI: 1.01-1.58) compared to PR- (OR=1.08, 95%CI: 0.95-1.44) BC. Association between PRS and BC were similarly non-significant across different strata of family history of BC, BMI, alcohol consumption, oral contraceptive use, menopausal, ER and HER2 status.

Table 1. Performance of the 90-SNP polygenic risk score (PRS) in the GWAS in Breast Cancer in the African DiasporaPercentile of PRS (%) OR (95%CI)  Overall BC (n=1657) vs Ctrl (n=2029)ER+ BC (n=403) vs Ctrl (n=2029)ER- BC (n=374) vs Ctrl (n=2029)&lt;51.01 (0.73-1.41)1.32 (0.28-2.13)0.89 (0.51-1.55)5-100.83 (0.59-1.15)0.71 (0.40-1.26)0.63 (0.34-1.17)10-200.74 (0.57-0.95)0.69 (0.44-1.07)0.72 (0.46-1.12)20-400.97 (0.79-1.19)0.80 (0.56-1.14)0.98 (0.69-1.39)40-601.00 (ref)1.00(ref)1.00(ref)60-800.89 (0.73-1.10)0.94 (0.66-1.33)0.90 (0.63-1.28)80-901.14 (0.89-1.47)0.87 (0.56-1.34)0.90 (0.63-1.28)90-951.14 (0.82-1.58)1.54 (0.92-2.58)0.88 (0.48-1.61)&gt;951.10 (0.79-1.52)1.15 (0.67-1.99)1.34 (0.79-2.25)Note: Odds ratios are for different percentiles of the PRS relative to the middle quintile (40% to 60%). Odds ratios were adjusted for study site and the first ten eigenvectors from principal components analysis.

Conclusion: BC PRS obtained from prior GWASs conducted in Caucasian women didn't provide a comparable degree of risk stratification for African Americans. Additional studies are needed to identify SNPs specific to women of African ancestry that could provide improved risk prediction. Further studies can also combine the PRS with lifestyle/environmental factors.

Citation Format: Wang S, Qian F, Zheng Y, Ogundiran T, Ojengbede O, Zheng W, Blot W, Nathanson KL, Hennis A, Nemesure B, Ambs S, Olopade OI, Huo D. Breast cancer risk prediction using a polygenic risk score in women of African ancestry: Findings from GWAS in breast cancer in the African diaspora [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-09-02.

High tumor-infiltrating FoxP3+ T cells predict poor survival in estrogen receptor-positive breast cancer: A meta-analysis

AIMS

Tumor-infiltrating FoxP3⁺ T cells and FoxP3⁺ tumor cells have been reported in breast cancer (BC), which impaired immunity and promoted tumors progression. However, their prognostic value for survival in patients with breast BC remains controversial.

METHODS

A meta-analysis was performed. Original data included the hazard ratios (HR) of overall survival (OS), relapse-free survival and odds ratio (OR) in BC patients. We pooled HR/OR with 95% confidence intervals (CI) to estimate the hazard.

RESULTS

The overall survival of high tumor-infiltrating FoxP3⁺ T cells patients was lower than low tumor-infiltrating FoxP3⁺ T cells patients with estrogen receptor (ER)-positive (HR 0.86, 95% CI 0.77-0.96; P = 0.009) but not ER-negative (HR 1.09, 95% CI 0.82-1.45; P = 0.569) BC. And FoxP3⁺ tumor cells were not associated with the overall survival and recurrences of BC patients (P > 0.05). In addition, a significant association was revealed between high tumor-infiltrating FoxP3⁺ T cells and grade (I + II/III: OR 0.31, 95% CI 0.17-0.56; P < 0.001), ER status (present: OR 2.39, 95% CI 1.51-3.76; P < 0.001), HER2 status (present: OR 0.53, 95% CI 0.36-0.78; P = 0.001), PR status (present: OR 1.88, 95% CI 1.31-2.71; P < 0.001). And a significant association was revealed between positive FoxP3⁺ tumor cells and Nodal status (present: OR 0.48, 95% CI 0.23-0.97; P = 0.04), grade (I + II/III: OR 0.44, 95% CI 0.22-0.85; P = 0.01), PR status (present: OR 2.37, 95% CI 1.54-3.36; P < 0.001).

CONCLUSIONS

High tumor-infiltrating FoxP3⁺ T cells were associated with a poorer prognosis for ER-positive BC, but not for ER-negative BC.

Serum Cholesterol Levels within the High Normal Range Are Associated with Better Cognitive Performance among Chinese Elderly

OBJECTIVES

The association between cognitive function and cholesterol levels is poorly understood and inconsistent results exist among the elderly. The purpose of this study is to investigate the association of cholesterol level with cognitive performance among Chinese elderly.

DESIGN

A cross-sectional study was implemented in 2012 and data were analyzed using generalized additive models, linear regression models and logistic regression models.

SETTING

Community-based setting in eight longevity areas in China.

SUBJECTS

A total of 2000 elderly aged 65 years and over (mean 85.8±12.0 years) participated in this study.

MEASUREMENTS

Total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) concentration were determined and cognitive impairment was defined as Mini-Mental State Examination (MMSE) score ≤23.

RESULTS

There was a significant positive linear association between TC, TG, LDL-C, HDL-C and MMSE score in linear regression models. Each 1 mmol/L increase in TC, TG, LDL-C and HDL-C corresponded to a decreased risk of cognitive impairment in logistic regression models. Compared with the lowest tertile, the highest tertile of TC, LDL-C and HDL-C had a lower risk of cognitive impairment. The adjusted odds ratios and 95% CI were 0.73(0.62-0.84) for TC, 0.81(0.70-0.94) for LDL-C and 0.81(0.70-0.94) for HDL-C. There was no gender difference in the protective effects of high TC and LDL-C levels on cognitive impairment. However, for high HDL-C levels the effect was only observed in women. High TC, LDL-C and HDL-C levels were associated with lower risk of cognitive impairment in the oldest old (aged 80 and older), but not in the younger elderly (aged 65 to 79 years).

CONCLUSIONS

These findings suggest that cholesterol levels within the high normal range are associated with better cognitive performance in Chinese elderly, specifically in the oldest old. With further validation, low cholesterol may serve a clinical indicator of risk for cognitive impairment in the elderly.

The pore architecture of the cystic fibrosis transmembrane conductance regulator channel revealed by co-mutation in pore-forming transmembrane regions

The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel contains 12 transmembrane (TM) regions that are presumed to form the channel pore. However, there is no direct evidence clearly illustrating the involvement of these transmembrane regions in the actual CFTR pore structure. To obtain insight into the architecture of the CFTR channel pore, we used patch clamp recording techniques and a strategy of co-mutagenesis of two potential pore-forming transmembrane regions (TM1 and TM6) to investigate the collaboration of these two TM regions. We performed a range of specific functional assays comparing the single channel conductance, anion binding, and anion selectivity properties of the co-mutated CFTR variants, and the results indicated that TM1 and TM6 play vital roles in forming the channel pore and, thus, determine the functional properties of the channel. Furthermore, we provided functional evidence that the amino acid threonine (T338) in TM6 has synergic effects with lysine (K95) in TM1. Therefore, we propose that these two residues have functional collaboration in the CFTR channel pore and may collectively form a selective filter.

Local proliferation initiates macrophage accumulation in adipose tissue during obesity

Obesity-associated chronic inflammation is characterized by an accumulation of adipose tissue macrophages (ATMs). It is generally believed that those macrophages are derived from peripheral blood monocytes. However, recent studies suggest that local proliferation of macrophages is responsible for ATM accumulation. In the present study, we revealed that both migration and proliferation contribute to ATM accumulation during obesity development. We show that there is a significant increase in ATMs at the early stage of obesity, which is largely due to an enhanced in situ macrophage proliferation. This result was obtained by employing fat-shielded irradiation and bone marrow reconstitution. Additionally, the production of CCL2, a pivotal chemoattractant of monocytes, was not found to be increased at this stage, corroborating with a critical role of proliferation. Nonetheless, as obesity proceeds, the role of monocyte migration into adipose tissue becomes more significant and those new immigrants further proliferate locally. These proliferating ATMs mainly reside in crown-like structures formed by macrophages surrounding dead adipocytes. We further showed that IL-4/STAT6 is a driving force for ATM proliferation. Therefore, we demonstrated that local proliferation of resident macrophages contributes to ATM accumulation during obesity development and has a key role in obesity-associated inflammation.

Medical students' child oral-health-related knowledge, practices and attitudes

OBJECTIVE

This study evaluated medical interns' oral health knowledge, and other factors influencing their ability and willingness to perform oral-health-related practices for high-caries-risk children.

METHODS

A 15-item survey was emailed to all eligible graduating fifth-year medical students at King Khalid University Hospital to address these areas of interest. Chi-square statistics and logistic regression models were used to analyse data.

RESULTS

One-hundred and twenty-one (49%) usable surveys were returned from two mailings. On questions regarding comfort levels when performing oral-health-related practices on children under age 3, physicians noted high levels of comfort with all specified oral health practices. Regarding satisfaction of students with medical training, the majority of respondents (87.5%) rated their medical training as fair or poor in preparing them for oral health assessments compared to only 35%, 29% and 7% of respondents giving fair or poor ratings to child abuse identification, caring for special needs patients and primary care paediatric practice, respectively. Additionally, although 90% of respondents noted that the role of primary physicians in counselling/referring children with oral health was important, 60% did not agree with the AAPD and AAP guidelines that state that all children should be referred to a dentist by 12 months of age. Multivariate logistic regression analyses revealed several statistically significant variables that predict the likelihood of performing various oral-health-related practices. The choice of public-health-oriented future clinical goals, the level of oral health knowledge, how interns rated their oral health training in medical school and the average number of children seen per week, all--to varying degrees--proved important predicator variables for the likelihood of performing them once in practice.

CONCLUSIONS

More oral-health-related training of medical students seems warranted and could improve their interest in providing oral-health-related screening and referrals in practice. Increasing student exposure to child patients and increasing exposures to oral health knowledge and problems could be targeted towards students interested in primary care and public health to use resources most efficiently in the effort to combat the growing caries levels amongst young children in Saudi Arabia.

In VitroandIn VivoReversal of Cancer Cell Multidrug Resistance by 2',4'-Dihydroxy-6'-methoxy-3',5'- dimethylchalcone

2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) isolated from the buds of Cleistocalyx operculatus, was investigated for its reversal effects on cancer cell multidrug resistance. DMC potentiated the cytotoxicity of the chemotherapeutic agent doxorubicin to drug-resistant KB-A1 cells. When 5 microM DMC was present simultaneously with doxorubicin, the IC50 of DOX on KB-A1 cells decreased from 13.9 +/- 0.7 microg/ml to 3.6 +/- 0.7 microg/ml. A human carcinoma xenograft model was established with the KB-A1 cell line. DMC could sensitize the tumors to doxorubicin as indicated by a considerable reduction in tumor weight. DMC increased the intracellular accumulation of doxorubicin in KB-A1 cells. When KB-A1 cells were exposed to 10 microg/ml doxorubicin combined with 5, 10, 20 microM DMC for 4 hours, the intracellular concentrations of doxorubicin were increased 1.4-, 1.8-, 3.1-fold, respectively, in comparison with doxorubicin alone treatment. All results indicated that DMC had reversal effects on the multidrug resistance phenotype.

Benign pelvic metastatic leiomyoma: case report

Benign metastasizing leiomyoma is a rare condition characterized by benign soft tissue tumors most frequently involving the lung, and is usually associated with a benign leiomyoma or intravenous leiomyomatosis of the uterus. We present a case of a 58-year-old female patient with abdominal pain and symptoms of urinary tract infection four years after hysterectomy due to uterine fibroid. The results of CT revealed a pelvic mass. Pathological examination confirmed that it was a metastatic pelvic benign metastasizing leiomyoma (BML). BML only involving the pelvis is extremely rare. The patient underwent surgical resection and recovered well.

MicroRNAs as regulators in normal hematopoietic and leukemia stem cells: current concepts and clinical implications

Relapse after current treatment is one of the main limitations to the complete cure of leukemia, and a concept that leukemia stem cell (LSC) is the major cause of relapse has been proposed. LSCs are derived from normal hematopoietic stem cells (HSCs), residing at the apex of leukemia cells and hiding in the bone marrow (BM) niche to evade chemotherapy. Novel therapy is strongly needed based on the unique features of LSCs to directly target these cells. MicroRNAs (miRNAs), a class of small non-coding RNAs, are now known to play important roles on cancer stem cell maintenance and differentiation. Because of the ability of miRNAs to inactivate either specific genes or entire gene families, strategies based on differential expression levels of miRNAs in LSCs as dominant activators or suppressors of gene activity have emerged as promising new candidate approaches for eradicating LSCs. In this review, we highlight new findings regarding the roles of miRNAs in LSC maintenance of quiescence repression, self-renewal, surface marker targeting, and the LSCBM niche interaction. We also discuss recent advances and future challenges to use LSC specific miRNAs as potential therapeutic molecules in eradicating LSCs.

Association between polymorphisms in IL17F and male asthma in a Chinese population

BACKGROUND AND OBJECTIVES

Interleukin (IL) 17F is a marker of type 17 helper T cells and has a proinflammatory role in asthma.The aim of the present study was to assess the possible association between asthma and polymorphisms in the IL17F gene in a Chinese population.

METHODS

A total of 318 asthmatic patients and 352 nonasthmatic controls were recruited. Two single-nucleotide polymorphisms in IL17F (rs763780 and rs13209590) were detected using GenomeLab SNPstream. Logistic regression methods were used to analyze data.

RESULTS

A significantly lower frequency of the C allele in rs763780 was observed in the control group (P = .0148). The rs763780 TC heterozygote was associated with an increased risk of asthma, and a similar trend was observed assuming a codominant genotype effect (adjusted OR, 1.58; 95% CI, 1.06-2.36; P = .0148; adjusted OR, 1.64; 95% CI, 1.10-2.45; P = .0217). Furthermore, a novel finding of the present study was that this association was exclusive to males (adjusted OR, 1.79; 95% CI, 1.06-3.05; P = .0308) and patients with higher immunoglobulin E levels (> or = 1.85 IU/mL) (adjusted OR, 1.88; 95% CI, 1.10-3.22; P = .0213). We also found that the haplotype with minor alleles for rs763780 was associated with an increased risk of asthma (adjusted OR, 1.62; 95% CI, 1.11-2.35; P = .0115).

CONCLUSION

Our findings indicated that polymorphisms might play a role in susceptibility to asthma.

Accuracy of linear measurement in the Galileos cone beam computed tomography under simulated clinical conditions

OBJECTIVES

The aim of this study was to determine the geometric accuracy of cone beam CT (CBCT)-based linear measurements of bone height obtained with the Galileos CBCT (Sirona Dental Systems Inc., Bensheim, Hessen, Germany) in the presence of soft tissues.

METHODS

Six embalmed cadaver heads were imaged with the Galileos CBCT unit subsequent to placement of radiopaque fiduciary markers over the buccal and lingual cortical plates. Electronic linear measurements of bone height were obtained using the Sirona software. Physical measurements were obtained with digital calipers at the same location. This distance was compared on all six specimens bilaterally to determine accuracy of the image measurements.

RESULTS

The findings showed no statistically significant difference between the imaging and physical measurements (P > 0.05) as determined by a paired sample t-test. The intraclass correlation was used to measure the intrarater reliability of repeated measures and there was no statistically significant difference between measurements performed at the same location (P > 0.05).

CONCLUSIONS

The Galileos CBCT image-based linear measurement between anatomical structures within the mandible in the presence of soft tissues is sufficiently accurate for clinical use.