[Combinational Overexpression of Foxa3 and Hnf4α Enhance the Proliferation and Prolong the Functional Maintenance of Primary Hepatocytes]

In an in vitro culture system, primary hepatocytes usually display a low proliferation capacity, accompanied with a decrease of viability and a loss of hepatocyte-specific functions. Previous studies have demonstrated that the combination introductions of certain hepatocyte-specific transcription factors are able to convert fibroblasts into functional hepatocyte-like cells. However, such combinational usage of transcription factors in primary hepatocytes culture has not yet sufficiently studied. The forkhead box protein A3 (FoxA3) and hepatocyte nuclear factor 4α (Hnf4α) are liver-enriched transcription factors that play vital roles in the differentiation, and maintenance of hepatocytes. Thus, we simultaneously overexpressed the two genes, Foxa3 and Hnf4α, in rat hepatocytes and observed that the combinational augmentation of these two transcription factors have enhanced the proliferation and stabilized the hepatocyte-specific functions of primary hepatocytes over a long-term culture period.

[Global incidence and mortality of renal cell carcinoma in 2020]

Objective: To analyze the global epidemiology of renal cell carcinoma (RCC) in 2020. Methods: The incidence and mortality data of RCC in the cooperative database GLOBOCAN 2020 of International Agency for Research on Cancer of WHO and the human development index (HDI) published by the United Nations Development Programme in 2020 were collated. The crude incidence rate (CIR), age-standardized incidence rate (ASIR), crude mortality rate (CMR), age-standardized mortality rate (ASMR) and mortality/incidence ratio (M/I) of RCC were calculated. Kruskale-Wallis test was used to analyze the differences in ASIR or ASMR among HDI countries. Results: In 2020, the global ASIR of RCC was 4.6/100 000, of which 6.1/100 000 for males and 3.2/100 000 for females and ASIR was higher in very high and high HDI countries than that in medium and low HDI countries. With the rapid increase of age after the age of 20, the growth rate of ASIR in males was faster than that in females, and slowed down at the age of 70 to 75. The truncation incidence rate of 35-64 years old was 7.5/100 000 and the cumulative incidence risk of 0-74 years old was 0.52%. The global ASMR of RCC was 1.8/100 000, 2.5/100 000 for males and 1.2/100 000 for females. The ASMR of males in very high and high HDI countries (2.4/100 000-3.7/100 000) was about twice that of males (1.1/100 000-1.4/100 000) in medium and low HDI countries, while the ASMR of female (0.6/100 000-1.5/100 000) did not show significant difference. ASMR continued to increase rapidly with age after the age of 40, and the growth rate of males was faster than that of females. The truncation mortality rate of 35-64 years old was 2.1/100 000, and the cumulative mortality risk of 0-74 years old was 0.20%. M/I decreases with the increase of HDI, with M/I as 0.58 in China, which was higher than the global average of 0.39 and the United States' 0.17. Conclusion: The ASIR and ASMR of RCC presented significant regional and gender disparities globally, and the heaviest burden was in very high HDI countries.

[Spatiotemporal changes of COVID-19 outbreak in Shanghai]

Objective: To clarify the epidemiological characteristics and spatiotemporal clustering dynamics of COVID-19 in Shanghai in 2022. Methods: The COVID-19 data presented on the official websites of Municipal Health Commissions of Shanghai during March 1, 2022 and May 31, 2022 were collected for a spatial autocorrelation analysis by GeoDa software. A logistic growth model was used to fit the epidemic situation and make a comparison with the actual infection situation. Results: Pudong district had the highest number of symptomatic and asymptomatic infectants, accounting for 29.30% and 35.58% of the total infectants. Differences in cumulative attack rates and infection rates among 16 districts (P<0.001) were significant. The rates were significantly higher in Huangpu district than in other districts. The attack rate of COVID-19 from March 1, 2022 to May 31, 2022 had a global spatial positive correlation (P<0.05). Spatial distribution of COVID-19 attack rate was different at different periods. The global autocorrelation coefficient from March 16 to March 29, April 6 to April 12 and May 18 to May 24 had no statistical significance (P>0.05). Our local autocorrelation analysis showed that 22 high-high clustering areas were detected in eight periods.The high-risk hot-spot areas have experienced a "less-more-less" change process. The growth model fitting results were consistent with the actual infection situation. Conclusion: There was a clear spatiotemporal correlation in the distribution of COVID-19 in Shanghai. The comprehensive prevention and control measures of COVID-19 epidemic in Shanghai have effectively prohibited the growth of the epidemic, not only curbing the spatially spread of high-risk epidemic areas, but also reducing the risk of transmission to other cities.

Tuning Dzyaloshinskii-Moriya interaction via an electric field at the Co/h-BN interface

The Dzyaloshinsky-Moriya interaction (DMI) at the Co/h-BN interface can emerge and be enhanced by applying a downward electric field. The height of the Co atom relative to the h-BN layer with the electric field determines the variation of DMI. One half reduction of J₁ is beneficial to generate skyrmions. Tuning the DMI by an electric field sheds new light for research on skyrmions.

[Impact of obstructive sleep apnea on the long-term cardiovascular outcomes in patients with acute coronary syndrome]

Objective: To investigate the impact of obstructive sleep apnea (OSA) on long-term cardiovascular outcomes in patients with acute coronary syndrome (ACS). Methods: This is a single-center, prospective cohort study. Between June 2015 to January 2020, consecutive ACS patients hospitalized at Beijing Anzhen Hospital, Capital Medical University were enrolled. All patients underwent portable sleep breathing monitoring, and they were then divided into moderate/severe OSA group (apnea-hypopnea index (AHI)≥15 events/hour) and no/mild OSA group (AHI<15 events/hour). The primary endpoint was major adverse cardiac and cerebrovascular event (MACCE), defined as a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, ischemia-driven revascularization and hospital admission for unstable angina or heart failure. MACCE were compared yearly by the log-rank test. Multivariable Cox regression analyses were performed to determine the independent predictors of MACCE. Results: A total of 1 927 patients with ACS were enrolled, including 1 629 males (84.5%), aged (56.4±10.5) years. Moderate/severe OSA was present in 1 014 (52.6%) patients. Compared with no/mild OSA group, moderate/severe OSA group exhibited a higher body mass index (P<0.05). Hypertension, prior PCI were more prevalent in moderate/severe OSA group (both P<0.05). The difference of ACS category between the two groups was statistically significant (P=0.021). The rate of patients who underwent PCI and the number of stents were higher in the moderate/severe OSA group. During a 5-year follow-up (median 2.9 years (IQR 1.5-3.6 years)), the cumulative incidence of MACCE was significantly higher in the moderate/severe OSA group than in the no/mild OSA group (34.0% vs. 24.0%, HR=1.346, 95%CI 1.100-1.646, log-rank P=0.004). The cumulative incidence of MACCE remained statistically higher at 4 and 5 year in the moderate/severe OSA group as compared to the no/mild OSA group (33.3% vs. 22.9%, HR=1.397, 95%CI 1.141-1.710, log-rank P=0.001; 34.0% vs. 24.0%, HR=1.341, 95%CI 1.096-1.640, log-rank P=0.004, respectively). Multivariate analysis showed that moderate/severe OSA (HR=1.312, 95%CI 1.054-1.631, P=0.015) was an independent predictor of long-term MACCE in ACS patients. Conclusions: Moderate/severe OSA is observed in more than 52% ACS patients. Moderate/severe OSA is an independent predictor of long-term MACCE.

[Biocompatibility of extracellular matrix hydrogel with human iPSCs differentiated cardiomyocytes]

Objective: To observe the biocompatibility of porcine omental derived extracellular matrix (ECM) hydrogel with human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and the feasibility of ECM hydrogel as a delivery vector of cell transplantation. Methods: A series of chemical, physical and enzymatic methods were applied to acellularize the porcine omentum. Subsequently, the extracted ECM was prepared into thermosensitive hydrogel. The biochemical composition of the hydrogel was identified by histological staining. The microstructure was observed by scanning electron microscopy. The hydrogel was then injected into the myocardium of mice to observe its in situ gelation ability. Differentiation of human induced pluripotent stem cells into cardiomyocytes was achieved by small molecule induction, and then the obtained hiPSC-CMs were cultured. hiPSC-CMs cultured onto the prepared hydrogel were defined as the hydrogel group, while conventionally cultured hiPSC-CMs were defined as the control group. Cardiomyocyte viability and growth patterns were detected using live/dead staining, CCK-8 and phalloidin staining. Immunofluorescence staining and Western blot of cardiomyocytes were used to determine the survival and phenotypic maintenance markers of cardiomyocytes in materials. Results: The results of HE staining, oil red O staining and DAPI fluorescence staining showed that there was no significant cell debris, nucleus and lipid residue in the prepared ECM hydrogel. The Sirius red staining and Alcian blue staining showed that the hydrogel retained collagen and glycolaminoglycan, which were the main components of ECM. The prepared hydrogel behaves as a viscous liquid at 4 ℃ and as a gel state at 37 ℃. Scanning electron microscope results showed that the microstructure of the hydrogel was composed of irregular fibers and pores of different sizes. Under the guidance of ultrasound, the prepared ECM hydrogel could be successfully injected into the myocardium of mice. Immediately after the injection, the hyperechoic signal could be observed under ultrasound, suggesting that the hydrogel remained in the myocardium. HE staining of myocardial tissue evidenced that there was lump of gel in the injection area. The differentiated hiPSC-CMs were co-cultured with the prepared ECM hydrogel, and the results of live/dead staining showed that most of the hiPSC-CMs in the hydrogel group and the control group were alive, dead cells were scanty. The results of CCK-8 test showed that the absorbance values of the two groups were similar (P>0.05). The results of phalloidin staining showed that hiPSC-CMs could extend normally when co-cultured with ECM hydrogel. The cell morphology of the hydrogel group was similar with that of the control group, and there was no statistically significant difference in the F-actin coverage area per cell between the two groups (P>0.05). Immunofluorescence staining of cardiomyocyte markers showed that there was no significant difference in the coverage area of α-actinin and connexin-43 (Cx-43) per field between the hydrogel group and the control group (both P>0.05), the quantitative results of DAPI staining showed that there was no statistically significant difference in the number of cells between the two groups (P>0.05). Meanwhile, the results of Western blot showed that the expression levels of α-actinin and Cx-43 in cardiomyocytes in the hydrogel group were similar as those in the control group (both P>0.05). Conclusions: These results show that preparation of the ECM hydrogel from porcine omentum is successful. The hydrogel has good biocompatibility and no obvious cytotoxicity. Besides, the hydrogel can support the survival of hiPSC-CMs in vitro and maintain its phenotype. These properties make it a promising injectable cardiac tissue engineering material.

[CD44 regulates biological behavior and Ras signaling pathway in nasopharyngeal carcinoma stem cells]

Objective: To study the biological behavior of nasopharyngeal carcinoma stem cells and to explore the activation of Ras signaling pathway regulated by CD44. Methods: CNE2-SC and 5-8F-SC were nasopharyngeal carcinoma stem cells and obtained by serum-free suspension culture. Cell counting kit-8 (CCK-8) assay, colony formation assay, Transwell migration assay, cell adhesion array were used to investigate the growth, proliferation, migration and adhesion of nasopharyngeal carcinoma stem cells. Western blot test was used to detect the expressions of Ras signaling pathway related proteins and siRNA-mediated interference was used to determine the activation of Ras signaling pathway regulated by CD44. Results: The growth rates of CNE2-SC and 5-8F-SC cells were significantly lower than those of nasopharyngeal carcinoma cells at 24, 48 and 72 hours after inoculation (P<0.05). After 14 days of implantation, the colony formation rates of CNE2-SC (44.5±1.9)% and 5-8F-SC (47.4±1.8)% were higher than those of CNE2 (34.9±1.5)% and 5-8F (37.2±1.7)%, respectively(P<0.01). The migration cell number of CNE2-SC was (87.6±7.8), 3.97 times higher than that of CNE2 (P<0.01). The migration cell number of 5-8F-SC was (67.2±5.7), 3.07 times higher than 5-8F (P<0.01). The adhesion rates of CNE2-SC and CNE2 cells were (42.1±7.6)% and (8.9±2.0)%, respectively at 3 hours after inoculation and were (82.4±5.0)% and (12.1±2.2)% at 6 hours after inoculation, respectively. The adhesion rate of CNE2-SC cells was higher than that of CNE2 cells (all P<0.01). The adhesion rates of 5-8F-SC and 5-8F cells were (53.6±6.1)% and (7.3±1.5)% at 3 hours after inoculation, and (90.7±3.6)% and (11.0±1.2)% at 6 hours after inoculation, respectively. The adhesion rate of 5-8F-SC cells was higher than that of 5-8F cells (P<0.01). The expression levels of CD44, Ras and N-cadherin were significantly higher, while phosphatase and tensin homolog deleted on chromosome 10 (PTEN), E-cadherin in nasopharyngeal carcinoma stem cells were lower than those of the nasopharyngeal carcinoma cells. Furthermore, the levels of phosphorylated mitogen extracellular kinase1/2 (p-MEK1/2) and phosphorylated extracellular signal-regulated protein kinase1/2 (p-ERK1/2)were significantly increased in nasopharyngeal carcinoma stem cells (P<0.01). Correlation analysis showed that the protein expression levels of CD44 was highly positively correlated with RAS in nasopharyngeal carcinoma stem cells(r=0.985, P=0.002; r=0.962, P=0.038). Deletion of CD44 in CNE2-SC decreased the expression levels of HER-2, Ras and p-ERK1/2, p-Akt and phosphorylated protein kinase C-δ(p-PKCδ) (P<0.01). Conclusions: Despite compare to the nasopharyngeal carcinoma cell, nasopharyngeal carcinoma stem cells grows at a relatively slow rate, the capacities of clone formation, migration, adhesion are promoted. This may be related to the CD44-regulated abnormal activation of Ras signaling pathway.

Incidence, predictors and prognostic impact of intracranial bleeding within the first year after an acute coronary syndrome in patients treated with percutaneous coronary intervention

Background:

The rate of intracranial haemorrhage after an acute coronary syndrome has been studied in detail in the era of thrombolysis; however, in the contemporary era of percutaneous coronary intervention, most of the data have been derived from clinical trials. With this background, we aim to analyse the incidence, timing, predictors and prognostic impact of post-discharge intracranial haemorrhage in patients with acute coronary syndrome undergoing percutaneous coronary intervention.

Methods:

We analysed data from the BleeMACS registry (patients discharged for acute coronary syndrome and undergoing percutaneous coronary intervention from Europe, Asia and America, 2003–2014). Analyses were conducted using a competing risk framework. Uni and multivariate predictors of intracranial haemorrhage were assessed using the Fine–Gray proportional hazards regression analysis. The endpoint was 1-year post-discharge intracranial haemorrhage.

Results:

Of 11,136 patients, 30 presented with intracranial haemorrhage during the first year (0.27%). The median time to intracranial haemorrhage was 150 days (interquartile range 55.7–319.5). The fatality rate of intracranial haemorrhage was very high (30%). After multivariate analysis, only age (subhazard ratio 1.05, 95% confidence interval 1.01–1.07) and prior stroke/transient ischaemic attack (hazard ratio 3.29, 95% confidence interval 1.36–8.00) were independently associated with a higher risk of intracranial haemorrhage. Hypertension showed a trend to associate with higher intracranial haemorrhage rate. The combination of older age (⩾75 years), prior stroke/transient ischaemic attack, and/or hypertension allowed us to identify most of the patients with intracranial haemorrhage (86.7%). The annual rate of intracranial haemorrhage was 0.1% in patients with no risk factors, 0.2% in those with one factor, 0.6% in those with two factors and 1.3% in those with three factors.

Conclusion:

The incidence of intracranial haemorrhage in the first year after an acute coronary syndrome treated with percutaneous coronary intervention is low. Advanced age, previous stroke/transient ischaemic attack, and hypertension are the main predictors of increased intracranial haemorrhage risk.

[Predictors for perioperative blood loss in pediatric patients with congenital scoliosis]

Objective: To identify predictors of massive blood loss after posterior hemivertebra resection for patients with congenital scoliosis. Methods: The data of 106 children with congenital scoliosis were collected from June 2017 to June 2019 in Beijing Children's Hospital. All the cases received posterior hemivertebra resection and internal fixation. The blood volume was estimated by weight and height. The visible blood loss was recorded according to medical record, and the hidden blood loss was calculated by OSTHEO formula. Perioperative information including age, gender, height, weight, Cobb and kyphosis angle, level fused, number of screws, operative time, and laboratory examinations was collected. Then multivariable linear regression was performed to determine the independent risk factors of blood loss. Results: All the surgeries were completed successfully. The mean age of the children was (7.3±2.3) years and the operative time was (162±56) min. The mean fused levels were 3 and the correction rate for deformity was 78.4%. The amount of blood loss was (568±208) ml which accounted for 42.3% of total blood volume. The visible and hidden blood loss was (334±193) ml and (234±199) ml, respectively, and which accounted for 58.8% and 41.2% of total blood loss. Multivariable linear regression analysis indicated that age, preoperative Cobb angle, the time of surgery and the number of fused levels were independent risk factors of total blood loss. Preoperative Cobb angle ≥40°, spinal fusion ≥4 levels and operative duration ≥140 min indicated more blood loss (all P<0.05). Conclusions: The perioperative blood loss of congenital scoliosis is massive with a high percentage of hidden blood loss. The patients with severe deformity, more fused levels and increased operative time brings higher risk of massive blood loss.

[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.

[Effect of moderate or severe obstructive sleep apnea on cardiac structure and function in patients with acute coronary syndrome]

Objective: To investigate the effect of obstructive sleep apnea (OSA) on cardiac structure and function in patients with acute coronary syndrome (ACS). Methods: A total of 767 patients with ACS consecutively hospitalized at the Emergency & Critical Care Center of Beijing Anzhen Hospital from June 2015 to May 2017 were enrolled in this study. There were 637 males and 130 females. Patients who met the inclusion criteria according to the sleep apnea hypopnea index (AHI) were examined with portable sleep respiration monitoring. Patients were divided into moderate or severe OSA group (AHI≥15,n=389) and non or mild OSA group (AHI<15, n=78). The general information and echocar diographic results were analyzed. The data fitted normal distribution were compared between the groups with independent sample t test. Results: The body mass index [(27.8±3.6) vs (25.8±3.4) kg/m(2), t=-7.854, P<0.01], neck circumference [(41.1±4.2) vs (39.3±3.2) cm, t=-6.717, P<0.01] and waist-to-hip ratio (0.99±0.54 vs 0.97±0.53, t=-4.735, P<0.01) at admission were significantly higher in moderate or severe OSA group than those in non or mild OSA group. The left ventricular end-diastolic diameter, inter-ventricular septum thickness, left atrial diameter,right atrial diameter were all significantly higher, and the E/A peak ratio was remarkably lower in the moderate or severe OSA group (t=-2.130, 0.278, -3.045, -2.241, 2.260, all P<0.05). Conclusion: Moderate or severe OSA may aggravate cardiac remodeling and diastolic function in ACS patients.

[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.

Impact of renin-angiotensin system blockade on the prognosis of acute coronary syndrome based on left ventricular ejection fraction

INTRODUCTION AND OBJECTIVES

For patients with acute coronary syndrome (ACS) treated with percutaneous coronary intervention (PCI), it is unclear whether angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) are associated with reduced mortality, particularly with preserved left ventricular ejection fraction (LVEF). The goal of this study was to determine the association between ACEI/ARB and mortality in ACS patients undergoing PCI, with and without reduced LVEF.

METHODS

Data from the BleeMACS registry were used. The endpoint was 1-year all-cause mortality. The prognostic value of ACEI/ARB was tested after weighting by survival-time inverse probability and after adjustment by Cox regression, propensity score, and instrumental variable analysis.

RESULTS

Among 15 401 ACS patients who underwent PCI, ACEI/ARB were prescribed in 75.2%. There were 569 deaths (3.7%) during the first year after hospital discharge. After multivariable adjustment, ACEI/ARB were associated with lower 1-year mortality, ≤ 40% (HR, 0.62; 95%CI, 0.43-0.90; P=.012). The relative risk reduction of ACEI/ARB in mortality was 46.1% in patients with LVEF ≤ 40%, and 15.7% in patients with LVEF> 40% (P value for treatment-by-LVEF interaction=.008). For patients with LVEF> 40%, ACEI/ARB was associated with lower mortality only in ST-segment elevation myocardial infarction (HR, 0.44; 95%CI, 0.21-0.93; P=.031).

CONCLUSION

The benefit of ACEI/ARB in decreasing mortality after an ACS in patients undergoing PCI is concentrated in patients with LVEF ≤ 40%, and in those with LVEF> 40% and ST-segment elevation myocardial infarction. In non-ST-segment elevation-ACS patients with LVEF> 40%, further studies are needed to assess the prognostic impact of ACEI/ARB.

[Association between hypothyroidism and sleep breathing disorders in patients with coronary heart disease]

Objective: To explore the association between hypothyroidism and sleep breathing disorders in patients with coronary heart disease (CHD). Methods: A total of 784 patients with CHD were consecutively enrolled at the Emergency & Critical Care Center of Beijing Anzhen Hospital from June 2015 to May 2017. According to thyroid function test results, patients were divided into hypothyroidism group (79 cases) and non-hypothyroidism group (705 cases). All patients had undergone sleep monitoring. The sleep apnea status was compared between the two groups. Multivariate logistic regression and linear regression models were used to analyze the association between hypothyroidism and sleep breathing disorders in patients with CHD. Results: The proportion of females, mean body weight and body mass index in the hypothyroidism group were higher than those in the non-hypothyroidism group [26.6% vs.16.2%, (78.6±11.6) kg vs. (75.7±12.0) kg, (27.7±3.2) kg/m(2) vs. (26.6±3.5) kg/m(2), all P<0.05]. Patients in hypothyroidism group had a decreased average oxygen saturation (SaO(2)) compared with patients in non-hypothyroidism group [ (93.2±2.9) % vs. (93.9±2.0) %, P=0.030]. In addition, events of hypoventilation in hypothyroidism group were significantly higher than those in non-hypothyroidism group[92.5 (45.8, 758.3) times vs. 68.0 (33.0, 125.0) times, P=0.013]. There were no significant differences in apnea hypopnea index, diagnosis of obstructive sleep apnea and other sleep breathing parameters between the two groups (P>0.05). A multiple linear regression analysis found that in patients with CHD, the correlation between hypothyroidism and average sleep SaO(2) was significant (β=-0.508, 95%CI -0.989--0.026, P=0.039). Conclusions: CHD patients with hypothyroidism had a lower sleep average SaO(2), and a higher sleep hypopnea events. There is a correlation between hypothyroidism and sleep hypoxia in patients with CHD. Clinical trial registration: clinicalTrials.gov, NCT03362385.

Association of Beta-Blockers with Survival on Patients Presenting with ACS Treated with PCI: A Propensity Score Analysis from the BleeMACS Registry

PURPOSE

The aim was to evaluate prognostic value of beta-blocker (BB) administration in acute coronary syndromes (ACS) patients in the percutaneous coronary intervention (PCI) era.

METHODS AND RESULTS

The BleeMACS project is a multicenter, observational, retrospective registry enrolling patients with ACS worldwide in 15 hospitals. Patients discharged with BB therapy were compared to those discharged without a BB before and after propensity score with matching. The primary endpoint was all-cause mortality at 1 year. Secondary endpoints included in-hospital reinfarction, in-hospital heart failure, 1-year myocardial infarction, 1-year bleeding and 1-year composite of death and recurrent myocardial infarction. After matching, 2935 patients for each group were enrolled. The primary endpoint of 1-year death was significantly lower in the group on BB therapy (4.5 vs 7%, p < 0.05), while only a trend was noted for recurrent acute myocardial infarction (4.5 vs 4.9%, p = 0.54). These results were consistent for patients older than 80 years of age, for ST-elevation myocardial infarction (STEMI) patients, and for those discharged with complete versus incomplete revascularization, but not for non-STEMI/unstable angina patients.

CONCLUSIONS

BB therapy was related to 1-year lower risk of all-cause mortality, independently from completeness of revascularization, admission diagnosis, age and ejection fraction. Randomized controlled trials for patients treated with PCI for ACS should be performed.

Prediction of Post-Discharge Bleeding in Elderly Patients with Acute Coronary Syndromes: Insights from the BleeMACS Registry

BACKGROUND

A poor ability of recommended risk scores for predicting in-hospital bleeding has been reported in elderly patients with acute coronary syndromes (ACS). No study assessed the prediction of post-discharge bleeding in the elderly. The new BleeMACS score (Bleeding complications in a Multicenter registry of patients discharged with diagnosis of Acute Coronary Syndrome), was designed to predict post-discharge bleeding in ACS patients. We aimed to assess the predictive ability of the BleeMACS score in elderly patients.

METHODS

We assessed the incidence and characteristics of severe bleeding after discharge in ACS patients aged ≥ 75 years. Bleeding was defined as any intracranial bleeding or bleeding leading to hospitalization and/or red blood transfusion, occurring within the first year after discharge. We assessed the predictive ability of the BleeMACS score according to age by Fine-Gray proportional hazards regression analysis, calculating receiver-operating characteristic (ROC) curves and the area under the ROC curves (AUC).

RESULTS

The BleeMACS registry included 15,401 patients of whom 3,376/15,401 (21.9%) were aged ≥ 75 years. Elderly patients were more commonly treated with clopidogrel and less often treated with ticagrelor or prasugrel. Of 3,376 elderly patients, 190 (5.6%) experienced post-discharge bleeding. The incidence of bleeding was moderately higher in elderly patients (hazard ratio [HR], 2.31, 95% confidence interval [CI], 1.92-2.77). The predictive ability of the BleeMACS score was moderately lower in elderly patients (AUC, 0.652 vs. 0.691, p = 0.001).

CONCLUSION

Elderly patients with ACS had a significantly higher incidence of post-discharge bleeding. Despite a lower predictive ability in older patients, the BleeMACS score exhibited an acceptable performance in these patients.

Association of obstructive sleep apnea with cardiovascular outcomes after percutaneous coronary intervention: A systematic review and meta-analysis

The relationship between obstructive sleep apnea (OSA) and adverse cardiovascular outcomes in patients undergoing percutaneous coronary intervention (PCI) remains unclear. We performed a systematic review and meta-analysis to assess the impact of OSA on subsequent cardiovascular events after PCI.We searched the PubMed, EMBASE, and Cochrane library from their inceptions to August 5, 2017. We included cohort studies that described the association between OSA (based on apnea-hypopnea index) and cardiovascular outcomes after PCI with stenting. The primary endpoint was major adverse cardiovascular event (MACE), including all-cause or cardiovascular death, myocardial infarction, stroke, repeat revascularization, or heart failure. Outcomes data were pooled using random effects models and heterogeneity was assessed with the I statistic.We identified 9 studies with 2755 participants. The prevalence of OSA in patients treated with PCI ranged from 35.3% to 61.8%. OSA was associated with increased risk of MACE after PCI (pooled risk ratio [RR] 1.96, 95% confidence interval [CI]: 1.36-2.81, P < .001, I = 54%). Between-study heterogeneity was partially explained by sample size (2 studies with ≤100 participants; RR 9.12, 95% CI: 2.69-31.00, I = 0% vs 7 studies with >100 participants; RR 1.64, 95% CI: 1.23-2.18, I = 35%). Moreover, the presence of OSA significantly increased the incidence of all-cause death (4 studies), cardiovascular death (4 studies), and repeat revascularization (7 studies) in patients undergoing PCI.Patients with OSA are at greater risk of subsequent cardiovascular events after PCI. Whether treatment of OSA prevents such events warrants further investigation.

[Impact of concomitant use of P2Y12 inhibitors and proton pump inhibitors on ischemia events in patients with acute coronary syndrome in real world]

Objective: The study aimed to analyze the impact of concomitant administration of P2Y12 inhibitors and PPIs on ischemia events in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). Methods: We retrospectively analyzed data from a international, multi-center registry between 2003 and 2014 in patients with ACS after PCI, grouped the cohort into patients receiving PPIs or no PPIs and assessed 1-year clinical endpoint (all-cause death/re-infarction). Meanwhile, we grouped the cohort into patients receiving clopidogrel or ticagrelor, and compared the impact of concomitant administration of PPIs and clopidogrel or ticagrelor on 1-year clinical endpoint. Results: Of 9 429 patients in the final cohort, 54.8% (n=5 165) was prescribed a PPI at discharge. Patients receiving a PPI were more likely to have comorbidities. No association was observed between PPI use and the clinical endpoint (HR 1.00, 95% CI 0.86-1.18). Meanwhile, no association was found between PPI use and the clinical endpoint in patients receiving either clopidogrel or ticagrelor. And the clinical endpoint in patients administrated of clopidogrel and PPIs had no difference with that of ticagrelor and PPIs. Conclusions: In patients with ACS following PCI, increased risk of ischemia event was not found in the concomitant use of PPIs and P2Y12 inhibitors, and especially, compared with ticagrelor, clopidogrel was found no association with ischemia events when concomitant administrated with PPIs.

Anti-apoptotic function of herpes simplex virus -2 latency-associated transcript RL1 sequence and screening of its encoded microRNAs

BACKGROUND

The latency-associated transcript (LAT) gene of herpes simplex virus (HSV)-2 is the only detectable viral gene expressed during latent infection in neurons. LAT inhibits apoptosis and maintains latency by promoting the survival of infected neurons. However, whether LAT functions during HSV-2 infection via its encoded RNAs or via its encoded proteins remain unknown. Increasing evidence has indicated that LAT is likely to functionally promote the establishment of latent infection via LAT-encoded microRNAs (miRNAs).

AIM

To explore whether the RL1 fragment of the five adjacent miRNAs has an effect on cell apoptosis, then provide supporting evidence to elucidate the potential role of these miRNAs and to aid screening of their cellular targets.

METHODS

A number of techniques, including MTT assay, flow cytometry and DNA ladder analysis, were used to verify the role of the RL1 fragment and the contribution of the individual miRNAs to the anti-apoptotic effect.

RESULTS

Five miRNAs (miR-H3, miR-H4-3p, miR-H4-5p, miR-H24 and miR-H19) were detected by quantitative PCR in PC12 cells stably expressing RL1 after pEGFP-RL1 plasmid transfection in vitro. The data indicated that expression of HSV-2 LAT RL1 seems to provide protection against apoptosis of PC12 cells induced by ActD. Antisense miRNAs specifically inhibiting these five miRNAs could efficiently reduce their expression. Transfection of antisense-miR-H3, antisense-miR-H4-5p and antisense-miR-H19 into PC12 cells stably expressing RL1 were able to partly reverse the anti-apoptotic effect of these miRNAs.

CONCLUSIONS

These findings indicate that the apoptotic role of the RL1 fragment is likely to be related to overexpression of miR-H3, miR-H4-5p and miR-H19 in PC12 cells.

Prevalence and outcome of patients with cancer and acute coronary syndrome undergoing percutaneous coronary intervention: a BleeMACS substudy

BACKGROUND

The prevalence and outcome of patients with cancer that experience acute coronary syndrome (ACS) have to be determined.

METHODS AND RESULTS

The BleeMACS project is a multicentre observational registry enrolling patients with acute coronary syndrome undergoing percutaneous coronary intervention worldwide in 15 hospitals. The primary endpoint was a composite event of death and re-infarction after one year of follow-up. Bleedings were the secondary endpoint. 15,401 patients were enrolled, 926 (6.4%) in the cancer group and 14,475 (93.6%) in the group of patients without cancer. Patients with cancer were older (70.8±10.3 vs. 62.8±12.1 years, P<0.001) with more severe comorbidities and presented more frequently with non-ST-segment elevation myocardial infarction compared with patients without cancer. After one year, patients with cancer more often experienced the composite endpoint (15.2% vs. 5.3%, P<0.001) and bleedings (6.5% vs. 3%, P<0.001). At multiple regression analysis the presence of cancer was the strongest independent predictor for the primary endpoint (hazard ratio (HR) 2.1, 1.8-2.5, P<0.001) and bleedings (HR 1.5, 1.1-2.1, P=0.015). Despite patients with cancer generally being undertreated, beta-blockers (relative risk (RR) 0.6, 0.4-0.9, P=0.05), angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (RR 0.5, 0.3-0.8, P=0.02), statins (RR 0.3, 0.2-0.5, P<0.001) and dual antiplatelet therapy (RR 0.5, 0.3-0.9, P=0.05) were shown to be protective factors, while proton pump inhibitors (RR 1, 0.6-1.5, P=0.9) were neutral.

CONCLUSION

Cancer has a non-negligible prevalence in patients with acute coronary syndrome undergoing percutaneous coronary intervention, with a major risk of cardiovascular events and bleedings. Moreover, these patients are often undertreated from clinical despite medical therapy seems to be protective. Registration:The BleeMACS project (NCT02466854).

Optimal Medical Therapy in Patients with Malignancy Undergoing Percutaneous Coronary Intervention for Acute Coronary Syndrome: a BleeMACS Sub-Study

OBJECTIVE

Our objective was to define the most appropriate treatment for acute coronary syndrome (ACS) in patients with malignancy.

METHODS AND RESULTS

The BleeMACS project is a worldwide multicenter observational prospective registry in 16 hospitals enrolling patients with ACS undergoing percutaneous coronary intervention. Primary endpoints were death, re-infarction, and major adverse cardiac events (MACE; composite of death and re-infarction) after 1 year of follow-up. The secondary endpoint was bleeding events during follow-up. We performed sub-study analyses according to whether β-blockers (BBs), angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs), statins, or proton pump inhibitors (PPIs) were prescribed at discharge. We also calculated the propensity score for optimal medical therapy (OMT; combination of BB, ACEI/ARB, and statins). The study included 926 patients. According to the multivariate analysis, ACEIs/ARBs (hazard ratio [HR] 0.58, 95 % confidence interval [CI] 0.36-1.94; p = 0.03) and statins (HR 0.37, 95 % CI 0.23-0.61; p < 0.01) reduced the risk of MACE, while the effects of BBs (HR 0.85, 95 % CI 0.55-1.32; p = 0.48) and PPIs (HR 1.33, 95 % CI 0.83-2.12; p = 0.23) were not significant. OMT was prescribed at discharge in 300 (32.4 %) patients; after propensity score analysis, OMT showed a significant reduction in death (3 % vs. 12.5 %, HR 0.21, 95 % CI 0.1-0.4; log-rank p < 0.001) and MACE (6.7 vs. 15.2 %, log-rank p = 0.01).

CONCLUSION

In patients with ACS and malignancy, OMT reduces the risk of adverse events at 1 year; in particular, ACEIs/ARBs and statins were the most protective drugs. (Clinical trials identifier: NCT02466854).

Eight paths of ERK1/2 signalling pathway regulating hepatocyte proliferation in rat liver regeneration

Although it is known that hormones, growth factors and integrin promote hepatocyte proliferation in liver regeneration (LR) through ERK1/2 signalling pathway, reports about regulating processes of its intracellular paths in hepatocytes of LR are limited. This study aims at exploring which paths of ERK1/2 signalling pathway participate in the regulation of rat LR, especially in hepatocyte proliferation, and how they do so. In all, 14 paths and 165 genes are known to be involved in ERK1/2 signalling pathway. Of them, 161 genes are included in Rat Genome 230 2.0 Array. This array was used to detect expression changes of genes related to ERK1/2 signalling pathway in isolated hepatocytes of rat LR, showing that 60 genes were related to hepatocytes of LR. In addition, bioinformatics and systems biology methods were used to analyse the roles of 14 above paths in regenerating hepatocytes. We found that three paths, RTK→SHC→GRB2/SOS→RAS→RAF, IntegrinΒ→FAK→RAC→PAK→RAF and GΒγ→PI3KΒγ→RAC→PAK→RAF, promoted the G1 phase progression of hepatocytes by activating ERK1/2. A further four paths, Gq→PLCΒ→PKC→SRC/PYK2→GRB2/SOS→RAS→RAF, RTK→PLCγ→PKC→SRC/PYK2→GRB2/SOS→RAS→RAF, IntegrinΒ→FAK/SRC→GRB2/SOS→RAS→RAF and IntegrinΒ→FAK→RAC→PAK→RAF, advanced the cell progression of S phase and G(2)/M checkpoint by activating ERK1/2, and so did PP1/2→Mek1/2 by decreasing the negative influence on ERK1/2. At the late phase of LR, Gαs→AC→EPAC→Rap1→Raf blocked hepatocyte proliferation by decreasing the activity of ERK1/2 and so did PP1/2→Mek1/2. In summary, 60 genes and 8 paths of ERK1/2 signalling pathway regulated hepatocyte proliferation in rat LR.

A pre-paid newborn hearing screening programme: a community-based study

OBJECTIVES

To help obstetric hospitals and clinics to implement newborn hearing screening and to test the feasibility of a pre-paid model for screening.

PATIENTS AND METHODS

From July 2005 to August 2008, we organised a coordinated newborn hearing screening team with portable automated auditory brainstem response (AABR) to provide in-patient screening after delivery and out-patient re-screening at one month of age in birthing facilities throughout Changhua County, Taiwan. This was a community-based study organised by otolaryngologists at a tertiary referral centre.

RESULTS

Ten medical facilities participated in our screening programme. 7,139 out of 12,901 neonates delivered in these facilities during the period were screened for hearing loss. 105 (1.47%) babies who did not pass the in-patient screening were re-screened at one month old. Forty (0.56%) babies referred from the re-screening were sent for diagnostic work-up and six of them failed to show up. The overall follow-up rate was 94.3% (99/105). Eleven babies with bilateral hearing loss and eight babies with unilateral hearing loss were diagnosed. The incidence of bilateral hearing loss in our programme was 1.5/1000. The screening rate descended from medical centre to clinic (p < 0.0001). There was no significant difference between the referral rates for different levels of birthing facilities (p = 0.5611).

CONCLUSIONS

Our study demonstrates that a pre-paid model using AABR is feasible at all three levels of medical facilities. Pre-paid community-based screening might be an option for developing countries in the implementation of universal newborn hearing screening.

Lethal sphenoid fungal sinusitis in an immunocompromised elderly patient

Sphenoid fungal balls are rare and typically indolent lesions, unless superinfected by bacteria or invasive to adjacent neurovascular structures. If the identification or treatment of underlying complications is delayed in an immunocompromised patient, a catastrophic outcome may result. We report the case of an elderly female patient with poorly controlled diabetes mellitus suffering from sphenoid fungal sinusitis that is complicated by cavernous sinus thrombophlebitis and carotid artery stenosis. In spite of reasonable diagnosis and therapy, the patient's general condition deteriorated and she eventually died. The clinical presentation, diagnosis, and treatment strategy are discussed.

Characterization of a cellulase-free, neutral xylanase from Thermomyces lanuginosus CBS 288.54 and its biobleaching effect on wheat straw pulp

A xylanase purified from the thermophilic fungus Thermomyces lanuginosus CBS 288.54 was characterized and its potential application in wheat straw pulp biobleaching was evaluated. Xylanase was purified 33.6-fold to homogeneity with a recovery yield of 21.5%. It appeared as a single protein band on SDS-PAGE gel with a molecular mass of approx. 26.2 kDa. The purified xylanase had a neutral optimum pH ranging from pH 7.0 to pH 7.5, and it was also stable over pH 6.5-10.0. The optimal temperature of the xylanase was 70-75 degrees C and it was stable up to 65 degrees C. The purified xylanase was found to be not glycosylated. The xylanase was highly specific towards xylan, but did not exhibit other enzyme activity. Apparent Km values of the xylanase for birchwood, beechwood, soluble oat-spelt and insoluble oat-spelt xylans were 4.0, 4.7, 2.0 and 23.4 mg ml-1, respectively. The potential application of the xylanase was further evaluated in biobleaching of wheat straw pulp. The brightness of bleached pulps from the xylanase pretreated wheat straw pulp was 1.8-7.79% ISO higher than that of the control, and showed slightly lower tensile index and breaking length than the control. Although chlorine consumption was reduced by 28.3% during bleaching, the xylanase pretreated pulp (15 U g-1 pulp) still maintained its brightness at the control level. Besides, pretreatment of pulp with the xylanase was also effective at an alkaline pH as high as pH 10.0.

Experimental evidence for the quantum confinement effect in 3C-SiC nanocrystallites

Using electrochemical etching of a polycrystalline 3C-SiC target and subsequent ultrasonic treatment in water solution, we have fabricated suspensions of 3C-SiC nanocrystallites that luminesce. Transmission electron microscope observations show that the 3C-SiC nanocrystallites, which uniformly disperse in water, have sizes in the range of 1-6 nm. Photoluminescence and photoluminescence excitation spectral examinations show clear evidence for the quantum confinement of 3C-SiC nanocrystallites with the emission band maximum ranging from 440 to 560 nm. Tunable, composite polystyrene/SiC film can be made by adding polystyrene to a toluene suspension of the 3C-SiC nanocrystallites and then coating the resulting solution onto a Si wafer.

The Drosophila double-timeS mutation delays the nuclear accumulation of period protein and affects the feedback regulation of period mRNA

The Drosophila double-time (dbt) gene, which encodes a protein similar to vertebrate epsilon and delta isoforms of casein kinase I, is essential for circadian rhythmicity because it regulates the phosphorylation and stability of period (per) protein. Here, the circadian phenotype of a short-period dbt mutant allele (dbt(S)) was examined. The circadian period of the dbt(S) locomotor activity rhythm varied little when tested at constant temperatures ranging from 20 to 29 degrees C. However, per(L);dbt(S) flies exhibited a lack of temperature compensation like that of the long-period mutant (per(L)) flies. Light-pulse phase-response curves were obtained for wild-type, the short-period (per(S)), and dbt(S) genotypes. For the per(S) and dbt(S) genotypes, phase changes were larger than those for wild-type flies, the transition period from delays to advances was shorter, and the light-insensitive period was shorter. Immunohistochemical analysis of per protein levels demonstrated that per protein accumulates in photoreceptor nuclei later in dbt(S) than in wild-type and per(S) flies, and that it declines to lower levels in nuclei of dbt(S) flies than in nuclei of wild-type flies. Immunoblot analysis of per protein levels demonstrated that total per protein accumulation in dbt(S) heads is neither delayed nor reduced, whereas RNase protection analysis demonstrated that per mRNA accumulates later and declines sooner in dbt(S) heads than in wild-type heads. These results suggest that dbt can regulate the feedback of per protein on its mRNA by delaying the time at which it is translocated to nuclei and altering the level of nuclear PER during the declining phase of the cycle.

Immunolocalization of UDP-glucose:glycoprotein glucosyltransferase indicates involvement of pre-Golgi intermediates in protein quality control

The UDP-glucose:glycoprotein glucosyltransferase (GT) is a protein folding sensor and glycosyltransferase that constitutes an important component of the protein quality control machinery. With the use of quantitative immunogold electron microscopy, we established the subcellular distribution of GT in rat liver and pancreas and Drosophila melanogaster salivary gland as well as cell lines and correlated it with that of glucosidase II, calreticulin, and pre-Golgi intermediate markers. Labeling for GT, as well as for glucosidase II and calreticulin, was found in the endoplasmic reticulum (ER), including nuclear envelope and pre-Golgi intermediates located between ER and Golgi apparatus, and in the cell periphery. In the rough ER, labeling for GT was inhomogeneous, with variously sized labeled and unlabeled cisternal regions alternating, indicative of a meshwork of quality control checkpoints. Notably, labeling intensity for GT was highest in pre-Golgi intermediates, corresponding to twice that of rough ER, whereas the Golgi apparatus exhibited no specific labeling. These results suggest that protein quality control is not restricted to the ER and that the pre-Golgi intermediates, by virtue of the presence of GT, glucosidase II, and calreticulin, are involved in this fundamental cellular process.

DNA adducts of 9-anilinoacridine mustards: characterization by NMR

Two types of 9-anilinoacridine-linked mustards, containing aniline mustard side chains linked either at the 4-position of the intercalating acridine chromophore (type A) or at the 1'-position of the 9-anilino group (type B), were reacted with calf thymus DNA. Adducts were isolated by preparative TLC, and their structures were determined by a variety of one-dimensional and two-dimensional NMR experiments. The only isolated product from the reaction of the 4-linked mustard (type A) was a guanine N7 adduct (55% yield), arising from alkylation in the major groove. In contrast, the major product (57% yield) from reaction of the 1'-linked mustard (type B) was an adenine N3 adduct from alkylation in the minor groove, with a smaller proportion (20%) of guanine N7 adduct. Computer modeling studies of drug-DNA alkylation complexes resulted in minimum-energy structures and averaged molecular dynamics structures that agreed with the adduct studies. The models suggest the aniline ring of the carrier is located in the DNA minor groove, with the acridine ring intercalated between two base pairs with the 4-position pointing into the major groove.

Cytotoxicity and DNA interaction of the enantiomers of 6-amino-3-(chloromethyl)-1-[(5,6,7-trimethoxyindol-2-yl)carbonyl]indo- line (amino-seco-CI-TMI)

The enantiomers of the previously reported racemic 6-amino-3-(chloromethyl)-1-[(5,6,7-trimethoxyindol-2-yl)carbonyl] indoline (amino-seco-CI-TMI) were prepared via resolution of a precursor by chiral HPLC. The only detectable product isolated from reaction of the racemic compound with calf thymus DNA, followed by thermal cleavage, was shown by mass spectrometry and two-dimensional NMR spectroscopy to be the adenine N3 adduct. Polyacrylamide gel electrophoresis assays with the racemate and with each enantiomer also showed adenine to be the only site of alkylation. While the racemic amino compound exhibited sequence selectivity identical to that of the previously characterized phenol analogue, the enantiomers exhibited distinctly different sequence selectivities, allowing the (+) enantiomer to be assigned the "natural" S configuration. The (+)-(S) enantiomer is 3-fold more cytotoxic than the (-)-(R) enantiomer (IC(50) values of 240 and 700 nM, respectively, in AA8 cells, after exposure for 4 h).

Cloning and characterization of the merozoite surface antigen 1 gene of Plasmodium berghei

Merozoite surface antigen 1 (MSA1) is a promising candidate for vaccine development against malaria parasites. Here, we report the complete nucleotide sequence of the gene encoding the precursor to this major surface antigen of Plasmodium berghei strain ANKA using cDNA library screening and polymerase chain reaction techniques. A single open reading frame of 5,376 basepairs encoding a protein with a calculated molecular mass of 197 kD was defined. The protein contains a putative signal peptide of 19 amino acids, a membrane anchor sequence of 18 residues, and shows two epidermal growth factor-like domains rich in Cys residues at the C-terminus. There are four repeat sequences of oligopeptides in the molecule: tetrapeptide (Ser-Thr-Thr-Thr), tripeptide (Pro-Thr-Pro and Pro-Ala-Ala), and dipeptide (Ser-Gly). Furthermore, three nine-residue stretches of a motif (Ala-Ser-Asn-Pro-Gly-Ala-Ser-Ala-Ser) are located near each other. All of these repeat sequences are unexceptionally located in the variable regions when compared with other MSA1 molecules. The molecule displays 79% overall identity to the analogous antigen of P. yoelii yoelii strain YM, 70% to that of P. chabaudi chabaudi strain AS, and 38% to that of P. falciparum strain Wellcome.

DNA minor groove targeted alkylating agents based on bisbenzimidazole carriers: synthesis, cytotoxicity and sequence-specificity of DNA alkylation

A series of bisbenzimidazoles bearing a variety of alkylating agents [ortho- and meta-mustards, imidazolebis(hydroxymethyl), imidazolebis(methylcarbamate) and pyrrolebis(hydroxymethyl)], appended by a propyl linker chain, were prepared and investigated for sequence-specificity of DNA alkylation and their cytotoxicity. Previous work has shown that, for para-aniline mustards, a propyl linker is optimal for cytotoxicity. Alkaline cleavage assays using a variety of different labelled oligonucleotides showed that the preferred sequences for adenine alkylation were 5'-TTTANANAANN and 5'-ATTANANAANN (underlined bases show the drug alkylation sites), with AT-rich sequences required on both the 5' and 3' sides of the alkylated adenine. The different aniline mustards showed little variation in alkylation pattern and similar efficiencies of DNA cross-link formation despite the changes in orientation and positioning of the mustard, suggesting that the propyl linker has some flexibility. The imidazole- and pyrrolebis(hydroxymethyl) alkylators showed no DNA strand cleavage following base treatment, indicating that no guanine or adenine N3 or N7 adducts were formed. Using the PCR-based polymerase stop assay, these alkylators showed PCR blocks at 5'-C*G sites (the * nucleotide indicates the blocked site), particularly at 5'-TAC*GA 5'-AGC*GGA, and 5'-AGCC*GGT sequences, caused by guanine 2-NH2 lesions on the opposite strand. Only the (more reactive) imidazolebis(methylcarbamoyl) and pyrrolebis(hydroxymethyl) alkylators demonstrated interstrand cross-linking ability. All of the bifunctional mustards showed large (approximately 100-fold) increases in cytotoxicity over chlorambucil, with the corresponding monofunctional mustards being 20- to 60-fold less cytotoxic. These results suggest that in the mustards the propyl linker provides sufficient flexibility to achieve delivery of the alkylator to favoured (adenine N3) sites in the minor groove, regardless of its exact geometry with respect to the bisbenzimidazole carrier. The 'targeted' bisbenzimidazole bis(hydroxymethyl)pyrrole- and imidazole analogues showed very similar patterns of alkylation to the corresponding 'untargeted' compounds, with little evidence of additional selectivity imposed by this AT-preferring carrier.

DNA-Directed alkylating agents. 7. Synthesis, DNA interaction, and antitumor activity of bis(hydroxymethyl)- and bis(carbamate)-substituted pyrrolizines and imidazoles

A series of bis(hydroxymethyl)-substituted imidazoles, thioimidazoles, and pyrrolizines and related bis(carbamates), linked to either 9-anilinoacridine (intercalating) or 4-(4-quinolinylamino)benzamide (minor groove binding) carriers, were synthesized and evaluated for sequence-specific DNA alkylation and cytotoxicity. The imidazole and thioimidazole analogues were prepared by initial synthesis of [(4-aminophenyl)alkyl]imidazole-, thioimidazole-, or pyrrolizine dicarboxylates, coupling of these with the desired carrier, and reduction to give the required bis(hydroxymethyl) alkylating moiety. The pyrrolizines were the most reactive alkylators, followed by the thioimidazoles, while the imidazoles were unreactive. The pyrrolizines and some of the thioimidazoles cross-linked DNA, as measured by agarose gel electrophoresis. Strand cleavage assays showed that none of the compounds reacted at purine N7 or N3 sites in the gpt region of the plasmid gpt2Eco, but the polymerase stop assay showed patterns of G-alkylation in C-rich regions. The corresponding thioimidazole bis(carbamates) were more selective than the bis(hydroxymethyl) pyrrolizines, with high-intensity bands at 5'-NCCN, 5'-NGCN and 5'-NCGN sequences in the PCR stopping assay ( indicates block sites). The data suggest that these targeted compounds, like the known thioimidazole bis(carbamate) carmethizole, alkylate exclusively at guanine residues via the 2-amino group, with little or no alkylation at N3 and N7 guanine or adenine sites. The cytotoxicities of the compounds correlated broadly with their reactivities, with the bis(hydroxymethyl)imidazoles being the least cytotoxic (IC50s >1 microM; P388 leukemia) and with the intercalator-linked analogues being more cytotoxic than the corresponding minor-groove-targeted ones. This was true also for the more reactive thioimidazole bis(carbamates) (IC50s 0.8 and 11 microM, respectively), but both were more active than the analogous "untargeted" carmethizole (IC50 20 microM). The bis(hydroxymethyl)pyrrolizine analogues were the most cytotoxic, with IC50s as low as 0.03 microM.

T-Helper 1 and T-helper 2 cytokine responses in gut-associated lymphoid tissue following enteric reovirus infection

Enteric infection of mice with reovirus serotype 1 elicits antibody and cytotoxic T-lymphocytes in gut-associated lymphoid tissue (GALT). This led to the hypothesis that T-helper 1 (Th1) and T-helper 2 (Th2) responses develop in GALT. Reverse transcriptase-polymerase chain reactions on RNA from Peyer's patches (PP), intraepithelial lymphocytes (IEL), and lamina propria (LP) lymphocytes demonstrated that interferon (IFN)-gamma message was increased in PP and IEL, but not in LP following infection. No increase in mRNA for interleukin (IL)-4, IL-5, or IL-6 was detected. IFN-gamma, IL-5, and IL-6 were produced in in vitro cultures of PP 4-10 days postinfection. PP and spleen lymphocytes from infected mice produced IFN-gamma, but no IL-5 following in vitro restimulation. Infection also induced production of mRNA for the beta2 chain of the IL-12 receptor in PP. We conclude that reovirus induces robust Th1 and weak Th2 cell responses in GALT.

Mono- and dysfunctional nitrogen mustard analogues of the DNA minor groove binder pibenzimol. Synthesis, cytotoxicity and interaction with DNA

Two series of mono- and dysfunctional aniline mustards linked to a bisbenzimidazole minor groove binder have been prepared using a new method (polyphosphate ester-mediated direct coupling of appropriate mustard acids with a preformed advanced phenylenediamine intermediate). As the linker chain attaching the mustard was lengthened the binding site size of the compounds to calf thymus DNA remained essentially constant at 2.6 nucleotides, but reversible binding strength declined by a factor of 2. Analogues with longer linker chains alkylated DNA much more rapidly than those with shorter chains, consistent with the electronic factors. The short chain analogues also failed to alkylate a 120 bp HindIII to Bg/II fragment of the gpt gene, as measured by gel electrophoresis cleavage assays. The longer chain analogues (both mono- and dysfunctional mustards) showed patterns of DNA alkylation that varied with chain length. In particular, while most compounds showed substantial N7 alkylation at many guanine residues, the analogue with a (CH2)3 linker chain showed strong alkylation at adenine sites in poly-AT regions. For the longer chain analogues, the bifunctional mustards were substantially (10- to 20-fold) more cytotoxic than the corresponding monofunctional analogues.

Interaction of the antitumour antibiotic streptonigrin with DNA and oligonucleotides

The interaction of the aminoquinone antitumour antibiotic streptonigrin with plasmid DNA, calf thymus DNA and oligonucleotides, in the presence and absence of metal ions, has been studied using circular dichroism, NMR spectroscopy and gel electrophoresis experiments. In the absence of metal ions, streptonigrin does not interact with DNA. Incubation of the two enantiomers of streptonigrin with calf thymus DNA, in the presence of excess zinc(II), showed no evidence of selective interaction of the natural enantiomer, (R)-streptonigrin, with the DNA by circular dichroism. The interaction of streptonigrin with the hexanucleotide d(GCATGC)2 was studied by 1H- and 31P-NMR spectroscopy. In the presence of four equivalents of zinc(II) nitrate and one equivalent of streptonigrin, small changes in chemical shifts of the proton resonances associated with T4 and G5 were detected as well as P4 and P5, consistent with a weak interaction of the zinc(II)-streptonigrin complex with the most accessible binding sites, involving the phosphate groups and guanine N7, at either end of the duplex. In contrast, no significant interaction between the metal complex and d(ATGCAT)2 was detected. Gel electrophoresis experiments were carried out to probe the sequence specificity of the interaction of the non-covalent streptonigrin-metal complexes with DNA, the DNA cleavage reaction of supercoiled DNA, and the specificity of the cleavage reaction. DNase I footprinting showed no sequence specific interactions. Zinc(II), copper(II) and manganese(II) enhanced the cleavage of supercoiled DNA into nicked and linear forms of DNA, while magnesium showed no cleavage reactions under identical conditions. The DNA cleavage reaction of streptonigrin and NADH in the presence and absence of metal ions was studied. Overall, little sequence specificity was observed, but slightly different cleavage patterns suggest that the DNA cleavage can be influenced by the nature of the metal ions.

Synthesis, DNA binding and cytotoxicity of 1-[[omega-(9-acridinyl)amino]alkyl]carbonyl -3-(chloromethyl)-6-hydroxyindolines, a new class of DNA-targeted alkylating agents

We report the first synthesis of examples of the seco-CI DNA alkylating moiety 3-(chloromethyl)-6-hydroxyindoline linked to a 9-aminoacridine DNA-intercalating unit (compounds 1a-1c). The sequence-specificity of DNA alkylation by these compounds was studied by the gel electrophoresis cleavage assay. In contrast to the known trimethoxyindole-linked compound (1d), which alkylates exclusively at N3 of adenines in the minor groove, the acridine-linked analogues (1a-1c) alkylate predominantly at the N7 of guanines in the major groove (the first CI analogues reported to do so), although DNase I footprinting experiments show that the initial non-covalent binding of 1a-1c is not base sequence selective. DNA unwinding experiments show that the acridine moiety of 1a-1c remains intercalated after alkylation.

Aniline mustard analogues of the DNA-intercalating agent amsacrine: DNA interaction and biological activity

Two series of analogues of the clinical antileukemic drug and DNA-intercalating ligand amsacrine have been prepared, containing aniline mustard sidechains of varying reactivity, linked either at the 4-position of the intercalating acridine chromophore (type A) or at the 1'-position of the 9-anilino group (type B). DNase I footprinting assays showed that compounds of type B had stronger reversible binding to DNA than did compounds of type A. Compounds of each type showed similar patterns of alkylation-induced cleavage of DNA, and alkylate at the N7 of guanines in runs of guanines (similar to the pattern for untargeted mustards) as well as some adenines. Both classes of compounds crosslinked DNA, although those bearing relatively inactive mustards did so only at high drug/base pair ratios. However, while the patterns of DNA alkylation were broadly similar, the compounds were considerably more cytotoxic than analogous untargeted mustards. Comparison of their cytotoxicities in wild-type and DNA repair-deficient lines indicated this toxicity was due to DNA crosslinks (except for the least reactive SO2-linked mustards). The 4-linked analogues showed slightly higher in vivo antileukemic activity than the corresponding 1'-linked analogues.

Molecular cloning and antigenic mapping of heat-shock protein 70 from the malaria species Plasmodium bergheI

We have isolated a 70-kD heat-shock protein (hsp-70) cDNA from Plasmodium berghei. A cDNA clone encoding the P. berghei hsp-70 was isolated and sequenced, demonstrating that it is highly homologous with other Plasmodium hsp-70s. One of the common features is a series of GGMP amino acid repeats at the carboxy terminus; there is also a long, AT-rich 5' untranslated region, a hallmark of other malarial RNAs. Hydropathy and antigenicity analyses suggest the presence of two hydrophilic domains. Recombinant peptides comprising different fragments of hsp-70 were expressed in Escherichia coli and assessed for antigenicity with antiserum from mice immunized with sonicated extracts of P. berghei. Antigenic sites map to regions that include the two hydrophilic domains.

Determination of the structural role of the internal guanine-cytosine base pair in recognition of a seven-base-pair sequence cross-linked by bizelesin

Bizelesin (formerly U77,779, The Upjohn Co.) is a bifunctional DNA cross-linking antitumor antibiotic consisting of two open-ring homologs of the (+)-CC-1065 cyclopropa[c]pyrrolo[3,2-e]indol-4(5H)-one (CPI) subunits connected by a rigid linking moiety. Previous studies have shown that Bizelesin most often forms an interstrand cross-link through the N3 of two adenines 6 base pairs (bp) apart (inclusive of the modified adenines). However, gel electrophoresis studies have also indicated that Bizelesin forms 7-bp cross-links in specific sequences. In most of these sequences the cross-linked adenines represent the only possible cross-link site (i.e., no 6-bp site is available); however, in several sequences, a 7-bp sequence is selected in overwhelming preference to a possible 6-bp sequence. In this study, we demonstrate the unique requirement for a G.C base pair within this sequence and the critical presence of the exocyclic 2-amino group of guanine. In a subsequent two-dimensional 1H-NMR study that concentrates on the 7-bp cross-link formed with the sequence 5'-TTAGTTA-3', the role of the central G.C base pairs in the formation of a 7-bp cross-link is probed. 1H-NMR analysis coupled with restrained molecular dynamics (rMD) provides evidence for distortion around the covalently modified adenines. Because of this distortion, the modified bases are twisted toward the center of the duplex adduct, effectively reducing the cross-linked distance. The rMD study also indicates that a hydrogen bond is formed between the exocyclic amine of the central guanine and the carbonyl of the ureylene linker. On the basis of the observation of the distortion in the duplex and the hydrogen bonding between the drug and DNA, it is possible to speculate on the role of the central G.C bases in this sequence preference and propose a mechanism by which Bizelesin forms a 7-bp rather than a 6-bp cross-link with this sequence.

Self-assembly of a quinobenzoxazine-Mg2+ complex on DNA: a new paradigm for the structure of a drug-DNA complex and implications for the structure of the quinolone bacterial gyrase-DNA complex

The quinobenzoxazine compounds A-62176 and A-85226 belong to a novel class of antineoplastic agents that are catalytic inhibitors of topoisomerase II and also structural analogs of the antibacterial DNA gyrase inhibitor Norfloxacin. In vitro studies have shown that their antineoplastic activity is dependent upon the presence of divalent metal ions such as Mg2+ and Mn2+, although the precise role of these ions in the mechanism of action is unknown. In this study we have investigated the structures of the binary complex between the quinobenzoxazines and Mg2+ and the ternary complex between quinobenzoxazine-Mg2+ and DNA. The stoichiometry of the binary and ternary complexes and the biophysical studies suggest that a 2:2 drug:Mg2+ complex forms a "heterodimer complex" with respect to DNA in which one drug molecule is intercalated into DNA and the second drug molecule is externally bound, held to the first molecule by two Mg2+ bridges, which themselves are chelated to phosphates on DNA. There is a cooperativity in binding of the quinobenzoxazines to DNA, and a 4:4 drug:Mg2+ complex is proposed in which the two externally bound molecules from two different 2:2 dimers interact via pi-pi interactions. The externally bound quinobenzoxazine molecules can be replaced by the quinolone antibacterial compound Norfloxacin to form mixed-structure dimers on DNA. Based upon the proposed model for the 2:2 quinobenzoxazine:Mg2+ complex on DNA, a parallel model for the antibacterial quinolone-Mg2(+)-DNA gyrase complex is proposed that relies upon the ATP-fueled unwinding of DNA by gyrase downstream of the cleavable complex site. These models, which have analogies to leucine zippers, represent a new paradigm for the structure of drug-DNA complexes. In addition, these models have important implications for the design of new gyrase and topoisomerase II inhibitors, in that optimization for structure-activity relationships should be carried out on two different quinolone molecules rather than a single molecule.