IFN-γ affects pancreatic cancer properties by MACC1-AS1/MACC1 axis via AKT/mTOR signaling pathway

BACKGROUND

Metastasis-related in colon cancer 1 (MACC1) is highly expressed in a variety of solid tumours, but its role in pancreatic cancer (PC) remains unknown. Interferon gamma (IFN-γ) affecting MACC1 expression was explored as the potential mechanism following its intervention.

METHODS

Expressions of MACC1 treated with IFN-γ gradient were confirmed by quantitative real-time PCR (qRT-PCR) and western blot (WB). Proliferation, migration, and invasion abilities of PC cells treated with IFN-γ were analysed by CCK8, EDU, colony formation, Transwell (with or without matrix gel) and wound-healing assays. Expression of antisense long non-coding RNA of MACC1, MACC1-AS1, and proteins of AKT/mTOR pathway, (pho-)AKT, and (pho-)mTOR was also assessed by qRT-PCR and WB. SiRNA kit and lentiviral fluid were conducted for transient expression of MACC1 and stable expression of MACC1-AS1, respectively. Rescue assays of cells overexpressing MACC1-AS1 and of cells silencing MACC1 were performed and cellular properties and proteins were assessed by the above-mentioned assays as well.

RESULTS

IFN-γ inhibited MACC1 expression in a time- and dose-dependent manner; 100 ng/mL IFN-γ generally caused downregulation of most significant (p ≤ 0.05). In vitro experiments revealed that IFN-γ decreased cellular proliferation, migration, and invasion abilities and downregulated the expression of pho-AKT and pho-mTOR (p ≤ 0.05). Conversely, overexpression of MACC1-AS1 upregulated pho-AKT and pho-mTOR proteins, and reversed cellular properties (p ≤ 0.05). Rescue assays alleviated the above changes of pho-AKT/ mTOR and cellular properties.

CONCLUSION

IFN-γ affected PC properties by MACC1-AS1/MACC1 axis via AKT/mTOR signaling pathway, which provides novel insight for candidate targets for treating PC.

[The expression and clinical significance of Bmi-1 gene in oral leukoplakia with different prognosis]

Objective: To detect the expression of Bmi-1 in oral leukoplakia (OL) cells and tissues, and analyze its role and clinical significance in the malignant transformation of OL. Methods: Immunohistochemistry was used to evaluate Bmi-1 expression in OL samples from 109 patients (51 males, 58 females, age range: 18-74 years) who were treated in the Department of Stomatology, the Affiliated Wuxi People's Hospital of Nanjing Medical University and the Center of Stomatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, between 1996 and 2018. The correlation between Bmi-1 expression level and clinicopathological parameters and prognosis in patients with OL was analyzed. The mRNA and protein expression levels of Bmi-1 gene in normal oral mucosal epithelial cells, OL cells, oral squamous cell carcinoma (OSCC) cells, OL tissues and paired adjacent normal tissues were detected by real-time PCR and Western blotting. The effects of Bmi-1 on the proliferation, colony formation and apoptosis were investigated by silencing expression of Bmi-1 in OL cell lines Leuk-1. Results: The protein level of Bmi-1 in OL tissue with severe and mild dysplasia was statistically different (6 819±994 vs 4 713±372, P=0.017). The OSCC-free survival rate of OL patients with high Bmi-1 expression was 65.5% (36/55), which was lower than that of OL patients with low Bmi-1 expression (88.9%, 48/54, P=0.003). Multivariate Cox proportional analysis indicated that Bmi-1 expression was the independent predictor for malignant transformation of OL (HR=2.522, 95%CI: 1.128-5.640, P=0.024). The mRNA level of Bmi-1 in OL specimens was 0.455±0.120, which was higher than that in paired adjacent normal tissues (0.063±0.009, P=0.014). The Bmi-1 mRNA level in malignant transformed OL specimens was (1.405±0.397), which was higher than that in untransformed OL specimens (0.145±0.017, P<0.001). After transfection of Bmi-1-shNC and Bmi-1-shRNA2 adenovirus into OL cell line Leuk-1, there were significant differences in the number of clone formation (824±40 vs 414±38, P=0.002) and apoptosis rate (17.7%±2.3% vs 36.0%±2.0%, P=0.004). Conclusions: The up-regulation of Bmi-1 expression promotes the malignant biological behavior of OL cells. Bmi-1 expression can be used as a predictor for malignant transformation of OL.

[Study of abnormal lipid metabolism analysis and significance of fatty acid binding protein expression in patients with hepatocellular carcinoma]

Objective: Hepatocellular carcinoma (HCC) is the fourth most dominant cancer in the world and the second leading cause of cancer-related deaths in the China. With the increase in the incidence of metabolic syndrome (MS) in the population, the correlation between MS and HCC has gradually been recognized. MS manifests as non-alcoholic fatty liver disease (shortly known as NAFLD) in the liver. A large number of research results has shown that the development of fatty liver is closely related to the occurrence of HCC, in which lipid metabolism plays a key regulatory role, and lipid metabolism is regulated by fatty acid binding protein (FABP). This study signifies the lipid metabolism analysis and the key FABP expression conditions in HCC. Methods: Data of patients who were first diagnosed with primary HCC between January 2016 to July 2019 were collected, and were divided into two groups according to the etiology, namely the viral and non-viral hepatitis-related HCC group. The relationship between MS-related factors and HCC was analyzed by t-test and chi square test. The expressions of FABP1, FABP4 and FABP5 were detected in cancer and adjacent tissues by immunohistochemistry, and the expressions of FABP1, FABP4 and FABP5 in HCC with fatty liver were detected by immunofluorescence. Finally, the expressional characteristics of the above-mentioned FABPs in HCC patients were analyzed with different clinicopathological features. Results: There were statistically significant differences in the rate of abnormal lipid metabolism and the number of abnormalities in MS-related factors between the viral and non-viral hepatitis-related HCC group. FABP1, FABP4, and FABP5 expression in HCC tissues were lower than the corresponding adjacent tumor tissues. Compared with simple HCC, FABP1, FABP4, FABP5 expression were increased in HCC tissues with steatosis, and the expression of FABP was closely related to the clinical characteristics of patients. Conclusion: Abnormal lipid metabolism is closely related to non-viral hepatitis-related HCC. The expression of lipid metabolism regulatory proteins FABP1, FABP4, and FABP5 are down-regulated in HCC tissues, but up-regulated in HCC with fatty liver, suggesting that the relationship between MS, especially dyslipidemia, and HCC should be paid attention to in clinical practice for early intervention. FABP1, FABP4, FABP5 may regulate HCC occurrence and development.

Current status and distribution of hip fractures among older adults in China

China is a middle-risk country for hip fracture at present, which differs from previous data that it was low-risk. By 2050, the total number of hip fractures in people older than 65 years is predicted to be 1.3 million.

INTRODUCTION

To assess hip fracture incidence in China and examine the heterogeneity of hip fracture in seven geographical regions of China.

METHODS

There were 238,230 hip fracture patients aged 65 years or older from 2013 to 2016 from a large national in-patients database (HQMS) involving 30.6 million hospitalizations. Taking into account the total national hospitalization rate per calendar year, we estimated the incidence of hip fracture per 100,000 residents older than 65 years in China overall and in seven geographical Chinese regions.

RESULTS

The proportion of men and women older than 65 years with hip fractures was 1.00:1.95. Between 2013 and 2016, the number of hip fractures per 100,000 people age 65+ was 278. China has vast territories; the number of hip fractures per 100,000 people over 65 years old was 202 in Northeast China and 374 in Northwest China. Northwest has higher altitude, lower population density, is less developed with lower urbanization than Northeast China which is low altitude, and highly urbanized.

CONCLUSIONS

China should no longer be regarded as a low-risk country for hip fracture. By 2050, the total number of hip fractures in people older than 65 years in China is predicted to be 1.3 million. Higher altitude areas had higher hip fracture rates than lower altitude, higher urbanized areas.

Long noncoding RNA MAFG-AS1 facilitates the progression of hepatocellular carcinoma via targeting miR-3196/OTX1 axis

OBJECTIVE

Hepatocellular carcinoma (HCC) is an invasive malignant tumor with high mortality rate. Long non-coding RNA (lncRNA) MAFG-AS1 has been showed to play an oncogenic role in several malignant tumors. Nonetheless, the exact role of MAFG-AS1 in the progression of HCC has not been fully elucidated.

PATIENTS AND METHODS

Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot were used to detect the mRNA and protein expression of MAFG-AS1 in HCC tissues and cells. Cell counting kit-8 (CCK-8), transwell and tubule formation assays were applied to uncover the proliferation, migration, invasion and tumor angiogenesis of HCC cells, respectively. RNA binding protein immunoprecipitation (RIP) assay and Luciferase reporter gene assay were employed to explore the molecular mechanism. In addition, Xenograft assay was used to investigate the effect of MAFG-AS1 in vivo.

RESULTS

MAFG-AS1 was highly expressed in HCC tissues and cells. Attenuation of MAFG-AS1 evidently suppressed the proliferation, migration, invasion and tumor angiogenesis of HCC cells, suggesting that MAFG-AS1 played an oncogenic role in HCC. MiR-3196 was sponged by MAFG-AS1, and OTX1 was a downstream target of miR-3196 in HCC. In addition, OTX1 expression was negatively associated with miR-3196 but positively associated with MAFG-AS1 in HCC tissues. Overexpression of OTX1 could abolish the repressive influence of MAFG-AS1 inhibition on the proliferation, migration, invasion and tumor angiogenesis of HCC cells.

CONCLUSIONS

MAFG-AS1 facilitated the progression of HCC via targeting miR-3196/OTX1 axis, which might be used as a new insight for HCC treatment.

[Effects of oxygen saturation on all-cause mortality among the elderly over 65 years old in 9 longevity areas of China]

Objective: To investigate the association between oxygen saturation (SpO₂) and risk of 3-year all-cause mortality among Chinese older adults aged 65 or over. Methods: The participants were enrolled from Healthy Aging and Biomarkers Cohort Study in year of 2012 to 2014 in 9 longevity areas in China. In this prospective cohort study, 2 287 participants aged 65 or over were enrolled. Data on SpO₂ and body measurements were collected at baseline in 2012, and data on survival outcome and time of mortality were collected at the follow-up in 2014. Participants were divided into two groups according to whether SpO₂ was abnormal (SpO₂<94% was defined as abnormal). Results: The 2 287 participants were (86.5±12.2) years old, 1 006 were males (44.0%), and 315 (13.8%) were abnormal in SpO₂. During follow-up in 2014, 452 were died, 1 434 were survived, and 401 were lost to follow-up. The all-cause mortality rate was 19.8%, and the follow-up rate was 82.5%. The mortality rate of SpO₂ in normal group was 21.1%, and that of abnormal group was 41.6% (P<0.001). After adjusting for confounding factors, compared to participants with normal SpO₂, participants with abnormal SpO₂ had increased risk of all-cause mortality with HR (95%CI) of 1.62 (1.31-2.02); HR (95 % CI) was 1.49 (0.98-2.26) for males and 1.71 (1.30-2.26) for females in abnormal SpO₂ group, respectively; HR (95%CI) was 2.70 (0.98-7.44) for aged 65-79 years old, 1.22 (0.63-2.38) for aged 80-89 years old, and 1.72 (1.35-2.19) for aged over 90 years old in abnormal SpO₂ group, respectively. Conclusion: Abnormal SpO₂ was responsible for increased risk of 3-year all-cause mortality among Chinese elderly adults.

MiR-142 inhibits lung cancer cell proliferation and promotes apoptosis by targeting XIAP

OBJECTIVE

The X-linked inhibitor of apoptosis protein (XIAP) is associated with the development of various tumors. The abnormal miR-142 expression is associated with the onset of lung cancer. Bioinformatics analysis revealed a targeted relationship between miR-142 and XIAP. This report investigated whether miR-142 plays a role in regulating XIAP expression and affecting the biological processes of lung cancer cells.

PATIENTS AND METHODS

The tumor tissues of lung cancer patients were collected, and the adjacent tissues were used as controls. The dual luciferase reporter gene assay validated the targeted regulation between miR-142 and XIAP. Using BEAS-2B cells as control, qRT-PCR was used to detect the expression of miR-142 and XIAP in lung cancer cells A549 and H1650. Lung cancer H1650 cells were cultured and divided into miR-NC group and miR-142 mimic group followed by an analysis of cell proliferation by EdU staining.

RESULTS

Compared with those in adjacent tissues, miR-142 expression was significantly decreased and XIAP expression was increased in lung cancer tissues. The Dual-Luciferase Reporter Assay confirmed a targeted regulation relationship between miR-142 and XIAP. Compared with BEAS-2B cells, miR-142 expression in lung cancer A549 and H1650 cells was significantly decreased, and XIAP expression was significantly increased. Transfection of miR-142 mimic significantly inhibited the expression of XIAP in H1650 cells, promoted apoptosis and inhibited cell proliferation.

CONCLUSIONS

Decreased miR-142 expression and increased XIAP expression is associated with the onset of lung cancer. MiR-142 can inhibit lung cancer cell proliferation and induce apoptosis through inhibition of XIAP expression.

[Comparative study of ultrasound-guided percutaneous microwave ablation and surgical resection for colorectal cancer with liver metastasis]

Objective: To study the clinical efficacy of ultrasound-guided percutaneous microwave ablation and surgical resection for liver metastases from colorectal cancer. Methods: Retrospective analysis of 184 patients with liver metastases from colorectal cancer in Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology from January 2012 to June 2017.Percutaneous microwave ablation or surgical resection for liver metastases were selected under ultrasound guidance. Subgroup analysis was performed according to the treatment of liver metastases. There were 98 patients in the microwave-only group (56 males and 42 females, aged (59±11) years) and 86 cases in the surgery-only group (56 males and 30 females, aged (56±11) years). The baseline data of the two groups were compared, and the results showed that the size of the metastatic lesions in the microwave-only group was smaller than that in the surgery-only group, and the remaining data didn't had statistical differences.The survival time of the two groups of patients was analyzed separately.According to the size of the metastases, the metastases were divided into groups with a diameter of<3 cm and a group of ≥3 cm. The survival time of patients in the microwave-only group and the surgery-only group were analyzed respectively.According to the different primary tumor grades of colorectal cancer, the survival time of patients in the simple microwave-only group and the surgery-only group in the primary tumors Duck A, Duck B, and Duck C were analyzed. Results: In the microwave-only group, the overall survival rates at 1, 3, and 5 years were 100%, 50.9%, and 20.9%; in the surgery-only group, the overall survival rates at 1, 3, and 5 years were 100%, 42.8%, and 20.8%, respectively. There was no significant difference in overall survival between the groups (P=0.972).Metastatic focus diameter ≥3 cm: the overall survival rates of 1, 3, and 5 years with microwave-only were 100%, 65.4%, and 12.1%; the overall survival rates of 1, 3, and 5 years with surgery-only were 100%, 59.5%, and 30.9%. There was no significant difference in overall survival between the groups (P=0.067). The long-term survival rate of the surgery-only group was greater than that of the microwave-only group (P=0.018).Metastasis diameter<3 cm: there was no significant difference in overall survival between the surgery-only group and the microwave-only group (P=0.103).In the treatment of Duck B and C liver metastases of primary colorectal cancer, there was no significant difference in overall survival between microwave alone and surgery alone (P=0.376, P=0.385).Multivariate analysis showed that the size of colorectal cancer metastases was an independent risk factor affecting the prognosis of patients with colorectal cancer liver metastases. Conclusions: Percutaneous microwave ablation has a good effect on colorectal cancer liver metastases and has a similar survival prognosis as surgery.For livers with color ≥ 3 cm in colorectal cancer, the long-term survival rate of the surgery-only group is greater than that of the microwave-only group.

[Effects of estimated glomerular filtration rate on all-cause mortality in the elderly aged 65 years and older in 8 longevity areas in China]

Objective: To investigate the association between estimated glomerular filtration rate (eGFR) and all-cause mortality in the elderly aged 65 years and older in longevity areas in China. Methods: Data used in this study were obtained from Healthy Aging and Biomarkers Cohort Study, a sub-cohort of the Chinese Longitudinal Healthy Longevity Survey, 1 802 elderly adults were collected in the study during 2012-2017/2018. In this study, the elderly were classified into 4 groups, moderate-to-severe group [<45 ml·min(-1)·(1.73 m(2))(-1)], mild-to-moderate group [45- ml·min(-1)·(1.73 m(2))(-1)], mild group [60- ml·min(-1)·(1.73 m(2))(-1)] and normal group [≥90 ml·min(-1)·(1.73 m(2))(-1)] according to their eGFR levels. Results: After 6 years of follow-up, 852 participants died, with a mortality rate of 47.3%. Multivariate Cox regression analysis showed that the levels of eGFR were negatively correlated with all-cause mortality risk in the elderly (the HR of elderly was 0.993 and the 95%CI was 0.989-0.997 for every unit of eGFR increased, P=0.001), while compared with the group with normal eGFR, the HRs (95%CI) of the elderly in the moderate-to-severe group, mild-to-moderate group, and mild group were 1.690 (1.224-2.332, P=0.001), 1.312 (0.978-1.758, P=0.070), 1.349 (1.047-1.737, P=0.020) respectively [trend test P<0.001]. Conclusion: The decrease in eGFR was associated with higher mortality risk among the elderly in longevity areas in China.

Research on values of GDF-15 level in the diagnosis of primary liver cancer and evaluation of chemotherapeutic effect

OBJECTIVE

To investigate the values of growth differentiation factor-15 (GDF-15) level in the diagnosis of primary liver cancer and evaluation of chemotherapeutic effect.

PATIENTS AND METHODS

92 patients with liver cancer treated from June 2015 to May 2016 were selected as liver cancer group; 53 patients with benign liver lesion were selected as benign liver disease group, and 40 healthy subjects receiving physical examination were selected as healthy control group. Fasting venous blood was drawn from objects of study in the early morning at 1 d after admission and at the last day after chemotherapy (liver cancer group), and the serum GDF-15 level was measured.

RESULTS

The serum GDF-15 levels in patients in liver cancer group and benign liver disease group were significantly higher than those in healthy control group and benign liver disease group (p<0.05). The serum GDF-15 levels in patients with stage III and IV liver cancer were significantly higher than those in patients with stage I and II liver cancer, and the serum GDF-15 level in patients with stage IV liver cancer was significantly higher than that in patients with stage III liver cancer (p<0.05). There was no significant difference in serum GDF-15 level among patients with different clinical data (p>0.05). The ROC curve analysis showed that the threshold value of GDF-15 was 1573.23 ng/L, and the sensitivity, specificity, and accuracy were 81.23%, 83.99%, and 83.62%, respectively. The serum GDF-15 level in patients with progressive disease was significantly higher than those in patients with partial remission and stable disease, and the serum GDF-15 level in patients with stable disease was significantly higher than that in patients with partial remission (p<0.05).

CONCLUSIONS

The serum GDF-15 level has certain clinical values in the diagnosis of primary liver cancer and evaluation of chemotherapeutic effect.

[Postoperative distal tibiofibular synostosis: radiographic characteristics and the influence on ankle mobility]

Objective: To investigate the clinical and imaging characteristics of distal tibiofibular synostosis in postoperative ankle fractures and its effects on the ankle mobility. Methods: The clinical and imaging data of 47 patients with distal tibiofibular synostosis treated surgically from October 1991 to June 2013 were analyzed retrospectively. There were 30 males and 17 females, aged from 15 to 68 years with a mean age of (39±13) years. The original fracture types, internal fixation profiles, imaging features of distal tibiofibular synostosis were recorded. Ankle range of motion (ROM) and complications at the last follow-up were also evaluated.The ROMs of healthy and fractured sides were compared with paired sample rank test. Results: The patients were followed up for 3 to 204 months (mean 25.4 months). Of the patients, 34(72.4%) were ankle fractures, 7(14.9%) were distal tibiofibular fractures, 1(2.1%) was tibiofibular shaft fracture, 2(4.3%) were tibial shaft fractures associated with lateral malleolus fracture and the resting 3(6.4%) were Pilon fractures. In patients with ankle fractures, 76.5%(26/34) of the synostosis occurred at the distal tibiofibular syndesmosis, while 23.5%(8/34) at the proximal of the tibiofibular sydesmosis; in patients with distal tibiofibular fracture, 85.7%(6/7) of the tibiofibular synostoses occurred at the fracture sites. The synostosis occurred at the level of syndesmotic screws in 8 patients (88.9%, 8/9) fixed with distal tibiofibular syndesmotic screws. And synostosis occurred at the sites of the distal locking screws in all (3/3) of the patients fixed with intramedullary nails. At the last follow-up, the active plantarflexion, active dorsiflexion and passive dorsiflexion in the affected side was 0°(0°, 5°), 2°(0°, 5°), 5°(0°, 10°) less than those in the healthy side, respectively (Z=-3.493, -4.491, -5.130, all P<0.05).During the follow-up, 4 patients complained of lateral ankle discomfort with no impact on daily life. Conclusions: Post-operative distal tibiofibular synostosis mainly occurs at the sites of fractures, distal tibiofibular syndesmotic screw sites and the sites of the distal locking screws of tibial intramedullary nails. ROM of the injured ankle decreases in comparison with that at the contralateral side, although no obvious symptoms are observed and no intervention needed.

[The relationship between hazard ratio and median survival time]

The hazard ratio and median survival time are the routine indicators in survival analysis. We briefly introduced the relationship between hazard ratio and median survival time and the role of proportional hazard assumption. We compared 110 pairs of hazard ratio and median survival time ratio in 58 articles and demonstrated the reasons for the difference by examples. The results showed that the hazard ratio estimated by the Cox regression model is unreasonable and not equivalent to median survival time ratio when the proportional hazard assumption is not met. Therefore, before performing the Cox regression model, the proportional hazard assumption should be tested first. If proportional hazard assumption is met, Cox regression model can be used; if proportional hazard assumption is not met, restricted mean survival times is suggested.

[Deltoid ligament augmentation and repairing in ankle fracture associated with deltoid ligament injury and syndesmosis diastasis]

Objective: To evaluate the outcome of the deep component augmentation and superficial component repairing and syndesmosis screw fixation in treating ankle fracture associated with deltoid ligament injury and syndesmosis diastasis. Methods: From January 2014 to December 2017, 16 patients with ankle fracture combined with deltoid ligament injury and syndesmosis diastasis were treated with the deep component augmentation and superficial component repairing in Beijing Jishuitan Hospital.Of the patients, 13 were males and 3 were females, with an average age of (38±10) years (21-57 years). Nine cases were athletic injuries, 4 cases were daily-life injuries and 3 cases were traffic injuries.According to the Weber classification, 6 cases were type B, 10 cases were type C. According to the Lauge-Hansen classification, 6 cases were supination external rotation Ⅳ injury, 9 cases were pronation external rotation Ⅳ injury, 1 case was pronation abduction Ⅲ injury.The surgical treatment method was rigid fixation of the lateral malleolus and deep deltoid ligament augamentation instead of syndesmosis screw fixation.The effect of the surgical method was observed. Results: The average follow up was (24±12) months (6-40 months). The mean degree of dorsiflexion was 17.8°±6.8° (5°-30°), with 3.8°±6.0° (0°-15°) less than that in normal side, the mean degree of plantar flexion was 46.9°±7.9°, with 1.9°±3.9° (0°-10°) less than that in normal side.The mean Philips and Schwartz score was 96.8±5.1 (82-100), the American Orthopaedic Foot and Ankle Society (AOFAS) Score was 97.4±4.6 (84-100). Conclusion: In the treatment of ankle fracture associated with deltoid ligament injury and syndesmosis diastasis, the deep component augmentation and superficial component repairing and proper rehabilitation can benefit the functional recovery.

[Evaluation of the proximal femur geometry in patients with elderly osteoporotic hip fractures]

Objective: To investigate the relationship between the proximal femur geometry and elderly osteoporotic hip fractures. Methods: From May 2015 to December 2015, 137 patients with elderly osteoporotic hip fractures were involved.69 cases were in the fracture group and 68 cases were in the control group.CT scan were performed on all patients and the proximal femur geometry parameters were measured, including the neck width (NW), neck length (NL), neck shaft angle (NSA), femur head diameter (FHD), head height (HH) and Offset.Statistical analysis was performed between two groups. Results: The results of single factor analysis showed that age, sex, NL, FHD, NSA and Offset had significantly differences between two groups (P<0.05). The multiple Logistic regression analysis showed that age, sex, NL and NSA were independent risk factor for the hip fractures.The ROC curve analysis showed that area under curve (AUC) were 0.818, 0.818 and 0.725, respectively. Conclusions: The patients with older age, longer NL and larger NSA might be prone to hip fracture and it was an effective and feasible method to reconstruct and measure the CT data of the proximal femur with Mimics software.

Sex-related variations in cortical and trabecular bone of the femoral neck in an elderly Chinese population

Quantitative computed tomography (QCT) was used to investigate sex-related variations in cortical and trabecular bone of the femoral neck. Cortical bone thickness of women in the superior quadrant was thinner than that of men, and the cortex in all four quadrants was negatively associated with age in women.

INTRODUCTION

This cross-sectional study aimed to investigate sex-related similarities and differences in femoral neck structure in an elderly Chinese population by QCT bone investigational toolkit (BIT) analysis.

METHODS

This study included 207 male (67.9 ± 7.7 years; range, 55-87 years) and 400 female subjects (68.0 ± 8.7 years; range, 55-96 years). BIT module was used to measure cortical and trabecular bone in anatomic quadrants of the femoral neck. Measurements of cortical thickness (Ct.Th), cortical vBMD (Ct.vBMD), trabecular vBMD (Tb.vBMD), and integral vBMD (It.vBMD) at the femoral neck were determined in four anatomical sectors.

RESULTS

The greatest difference between sexes, after adjusting for age, height, and weight, was in Ct.Th of Quadrant Supero-anterior (SA), which was 27.4% lower in women (p<0.001). Ct.Th of Quadrant Supero-posterior (SP) was 15.1% lower in women (p = 0.027). Ct.Th and Tb.vBMD in all four quadrants appeared to be negatively associated with age in females, whereas no significant relationship was observed in males, except Ct.Th of Quadrant SP.

CONCLUSIONS

The superior femoral neck geometry between males and females was significantly different, even after adjustment for body size and age, and the sub-regional cortical and trabecular bone negatively age-related changes in women indicated that women apparently have a more vulnerable geometrical outcome with age for fractures than men.

[The expression and significance of heparanase in oral squamous cell carcinoma with different metastatic potentials]

Objective: To detect the expression of heparanase (HPSE) in oral squamous cell carcinoma (OSCC) with different metastatic potentials and investigate its clinical significance. Methods: Transcriptional and translational status of HPSE in OSCC cell lines with different metastatic capacities, primary OSCC samples and their paired metastatic cancer tissues were determined using real-time polymerase chain reaction (PCR) and Western blotting analysis. Immunohistochemistry was used to evaluate HPSE expression in 131 OSCC samples. The correlation between HPSE expression pattern and clinicopathological parameters and clinical outcome in patients with OSCC were analyzed. HPSE level was reduced using HPSE-siRNAs in OSCC cell lines and its impact on cell migration and invasion was measured by scratch assay and matrigel invasion assay. Results: The mRNA and protein levels of HPSE were remarkably up-regulated in OSCC cell lines with highly metastatic capacity (P<0.000 1) and metastatic OSCC tissues (P<0.000 1). The protein levels of HPSE were strongly associated with lymph node metastasis (P<0.000 1) and tumor node metastasis stage (P=0.012). Survival analyses revealed that high HPSE expression was associated with worse overall survival (P=0.000 3). Multivariate Cox proportional analyses indicated that HPSE expression was strongly associated with clinical outcome in patients with OSCC (HR=2.203, 95% CI: 1.203-3.988, P=0.009). The siRNA-mediated silencing of HPSE could suppress the migration and invasion (P=0.008) of HN12 cells in vitro. Conclusions: The up-regulation of HPSE contributes to invasion and metastasis of OSCC. HPSE may serve as a useful biomarker for patients with OSCC.

[Safety and efficacy of partial nephrectomy for solitary kidney tumor]

Objective: To explore the safety and clinical efficacy of partial nephrectomy for solitary kidney tumor. Methods: Twenty patients with a functional or anatomic solitary kidney who underwent nephron-sparing surgery for one or more renal masses were retrospectively analyzed. There were 15 male and 5 female patients with mean age of 63 years.Patients were divided into open partial nephrectomy(OPN) group and laparoscopic partial nephrectomy(LPN) group, the two groups were followed up.Demographic and clinical characteristics were analyzed using student t-test for continuous variables, and the χ² test for categorical variables. Results: There were 21 tumors whose maximum diameter were 1.5 to 6.0 cm, the mean size was (3.7±1.3)cm, mean operative time was (205.3±81.8)minutes, and median estimated blood loss was 385.6 ml.Five cases accepted blood transfusion intro-operation, 1 case appeared leakage of urine post-operation, none had obvious fever.Eighteen cases were clear cell carcinoma, 2 cases were chromophobe renal carcinoma, 1 case was papillary renal cell carcinoma.Seventeen cases were T1aNxM0, 3 cases were T1bNxM0, 1 case was T3NxM0.One case lost to follow up, the others had completed a mean follow-up of 21.5 months (ranging from 1 to 53 months). One case recurred, no one had metastasis, all patients were alive.The hemoglobin ((114.9±19.6)g/L) and estimated glomerular filtration rate(eGFR) ((46.5±18.2) ml/min) of postoperative day were lesser than pre-operation ((130.7±18.8)g/L, (58.0±16.4) ml/min), while the serum creatinine was higher ((123.8±39.8) μmol/L vs.(90.9±33.2) μmol/L). Three months after operation, hemoglobin, serum creatinine and eGFR had no difference with pre-operative.Compared with OPN group, LPN group gain less blood loss (306 ml vs.510 ml)(t=-2.38, P=0.03), had shorter length of stays (15 d vs.21 d)(t=-3.34, P=0.04), had longer time of renal artery clamping (25.8 min vs.16.5 min)(t=2.60, P=0.02). Conclusions: Partial nephrectomy is secure and effective selection for solitary kidney tumor.The LPN has less trauma, gain less blood loss, recover faster and has shorter length of stays than the OPN, which needs shorter ischaemic time.

Abstract 4929: UbcH10 may represent a potential marker of gastric carcinoma

Gastric cancer is a fatal disease with limited early diagnostic methods available. There is an urgent need to find more effective targets for early diagnosis and therapeutics. UbcH10 is an ubiquitin-conjugating enzyme with a high expression reported in some cancers. Several gastric tumor cell lines with high or low expression of UbcH10 were exploited to study the role of UbcH10 in gastric cancer. Knocking down of UbcH10 expression using siRNA in high expressing gastric cancer cell lines resulted in reduced proliferation, increased cisplatin-induced apoptosis and reduced serum-induced ERK, Akt and p38 phosphorylation signaling. In agreement, overexpression of UbcH10 expression in low-expression gastric cancer cell lines led to enhanced cell proliferation, resistance to cisplatin-induced apoptosis. Most importantly, IHC analyses showed that the UbcH10 protein expressed at a high level in patient gastric cancer tissues, but not in adjacent mesenchyme tissues. These data suggest that UbcH10 may promote gastric cancer growth and can serve as a biomarker for diagnosis or target for new therapeutics in gastric cancer.

Citation Format: Mengxuan Yang, Yingying Qu, Gang Hu, Shiwei Tu, RL Shi, XB Wu, ZQ Hu, QM Zhang, SQ Liu, GF Pan, Ziping Zhang, He Zhou. UbcH10 may represent a potential marker of gastric carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4929.

Bioinformatic analysis of RNA-seq data unveiled critical genes in rectal adenocarcinoma

OBJECTIVE

RNA-seq data of rectal adenocarcinoma (READ) were analyzed with bioinformatics tools to unveil potential biomarkers in the disease.

MATERIALS AND METHODS

RNA-seq data of READ were downloaded from The Cancer Genome Atlas (TCGA) database. Differential analysis was performed with package edgeR. False discovery rate (FDR) < 0.05 and |log2 (fold change)|>1 were set as cut-off values to screen out differentially expressed genes (DEGs). Gene coexpression network was constructed with package Ebcoexpress. Gene Ontology enrichment analysis was performed for the DEGs in the gene coexpression network with DAVID online tool. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis was also performed for the genes with KOBASS 2.0.

RESULTS

A total of 620 DEGs, 389 up-regulated genes, and 231 down-regulated genes, were identified from 163 READ samples and 9 normal controls. A gene coexpression network consisting of 71 DEGs and 253 edges were constructed. Genes were associated with ribosome and focal adhesion functions. Three modules were identified, in which genes were involved in muscle contraction, negative regulation of glial cell proliferation and extracellular matrix organization functions, respectively. Several critical hub genes were disclosed, such as RPS2, MMP1, MMP11 and FAM83H. Thirteen relevant small molecule drugs were identified, such as scriptaid and spaglumic acid. A total of 8 TFs and 5 miRNAs were acquired, such as MYC, NFY, STAT5A, miR-29, miR-200 and miR-19.

CONCLUSIONS

Several critical genes and relevant drugs, TFs and miRNAs were revealed in READ. These findings could advance the understanding about the disease and benefit therapy development.

[Epidemiological analysis of hospitalized patients with femoral neck fracture in a first-class hospital of Beijing]

OBJECTIVE

To analyze the clinical parameters of the patients with femoral neck fracture such as general condition, therapy method, hospitalized expense so as to provide more effective management plan for the clinical work.

METHODS

The patients with femoral neck fracture above 50 years who received in-patient treatment from 2008 January to 2012 December were admitted into this study. We collected and analyzed the information, such as age, chronic medical disease, therapy method, hospitalized duration and expense and so on.

RESULTS

There were 1 794 femoral neck fracture patients above 50 years (male/female=1/2.06) in our hospital in recent 5 years and the annual average rate of increase was 7.3%. The average age of the patients was (69.9±10.7) years and the annual average rate of increase was 0.6%. The chronic medical disease diagnosis ratio was 55.0%. The average waiting time for operation was (6.8±4.2) days and the average hospitalized duration was (12.9±4.9) days which showed downward trend in recent years. The most popular operations were cannulated screw internal fixation (41.8%) and artificial femoral head replacement (34.1%). In the study, 146 cases (7.9%) received nonsurgical treatment which showed downward trend. The average hospitalized expense was (35 075.7±11 343.2) yuan which showed no obvious change in recent years. The cost for the females was more than that for the males. The expense for hemiarthroplasty and total hip arthroplasty increased while that for cannulated screw internal fixation decreased gradually.

CONCLUSION

The cannulated screw internal fixation and artificial femoral head replacement were the most important operations for the patients with femoral neck fracture. The number and the average age of the patients were on the rise while the expense showed no obvious change in recent years.

[Anterior dislocation of the fibula resulting from surgical malreduction: a case report]

Ankle joint fracture is one of the most common types of fracture. There are many researches on the injury mechanism, treatment principles and surgical techniques. A type of injury which combines posterior dislocation of fibula, known as the Bosworth injury, is relatively rare. In 1947, Bosworth first described this type of injury as an unusual ankle fracture dislocation with fixed posterior fracture dislocation of the distal part of the fibula. In this type of fracture, the proximal fibular shaft fragment locks behind the tibialis posterior tubercle. This rare ankle fracture variant is often not recognized in initial radiographs and requires a computed tomographic (CT) scan for verification. But there are already many reports, discussing the injury mechanism, treatment principles and surgical techniques. However, there are few reports of anterior dislocation of the fibula, caused by either injury or surgery. The mechanism of the injury is still not clear. This article reports a case of anterior dislocation of the fibula. We report a patient with left ankle open fracture (Lauge-Hansen pronation-external rotation stage III, Gustilo IIIA). Open reduction and internal fixation was done in the initial surgery, but ended up with poor reduction, resulting in fibula anterior dislocation, anterior dislocation of talus and tibia fibular dislocation. The fibula was dislocated anteriorly of the tibia, which rarely happened. The patient suffered severe ankle joint dysfunction. The second operation took out the original internal fixation, reduced the fracture, and reset the internal fixation. The function of ankle joint was improved obviously after operation. But because of the initial injury and the two operations, the soft tissue around the fracture was greatly damaged. 6 months after the second operation, and the fracture still not healed, so the bone graft was carried out in the third surgery. Two months after the third surgery, the function of the ankle was significantly better than before, but the fracture healing was poor, which needed further review. Through this case, we understand the rare type of ankle fracture with anterior dislocation of the fibula, and recognize that the timing and quality of initial surgery has a great impact on the patient's prognosis and rehabilitation period.

Cloning and sequence analysis of the coding sequence of β-actin cDNA from the Chinese alligator and suitable internal reference primers from the β-actin gene

β-Actin is an essential component of the cytoskeleton and is stably expressed in various tissues of animals, thus, it is commonly used as an internal reference for gene expression studies. In this study, a 1731-bp fragment of β-actin cDNA from Alligator sinensis was obtained using the homology cloning technique. Sequence analysis showed that this fragment contained the complete coding sequence of the β-actin gene (1128 bp), encoding 375 amino acids. The amino acid sequence of β-actin is highly conserved and its nucleotide sequence is slightly variable. Multiple alignment analyses showed that the nucleotide sequence of the β-actin gene from A. sinensis is very similar to sequences from birds, with 94-95% identity. Ten pairs of primers with different product sizes and different annealing temperatures were screened by PCR amplification, agarose gel electrophoresis, and DNA sequencing, and could be used as internal reference primers in gene expression studies. This study expands our knowledge of β-actin gene phylogenetic evolution and provides a basis for quantitative gene expression studies in A. sinensis.

[Management of pelvic injury associated with complete anterior sacroiliac joint dislocation]

OBJECTIVE

To investigate the management of pelvic injury associated with complete anterior sacroiliac joint dislocation.

METHODS

In the study, 6 cases of pelvic injury associated with complete anterior sacroiliac joint dislocation treated in Beijing Jishuitan Hospital from February 2008 to June 2014 were analyzed. We described the history and severity of injury, emergency treatment, and fracture radiology. In all the cases, the surgical treatment and postoperative functional exercise were performed. We followed up all the cases on an average of 1.6 years, assessed the postoperative recovery and summed up the treatment experience.

RESULTS

All the 6 patients with fractures recovered without infection and nerve symptoms after surgery. Their X-rays showed good reduction of sacroiliac joints. All the cases were followed up on an average of 1.6 years. Six months after surgery, the Majeed scores were perfect in 2 cases, good in 2, fair in 1, and poor in 1. The patients with poor scores suffered persistent pain, and decreased physical activity, and when walking long distances, they needed a walking stick. The 2 patients with low scores could not resume the original work.

CONCLUSION

Pelvic injury associated with complete anterior sacroiliac joint dislocation is a special type of the pelvic injury since the managements during the emergency phase are difficult.The surgery should be done as early as possible, and the anterior approach is available for the reduction and fixation.

[Pregnancy-related pelvic ring disease and its treatment]

Pregnancy-related pelvic ring disease brings great suffering to pregnant women, including the separation of the pubic symphysis and sacroiliac joint pain. Hormonal changes leading to ligamentous laxity is the main reason for Pregnancy-related pelvic ring disease. In normal pregnant cases, and the physiologic widening at the symphysis is about 3-7 mm. When the widening of the symphysis is more than 10 mm, it may lead to symptoms and need active treatment. Currently the diagnosis of the pubic symphysis separation is based on the clinical symptoms and signs. The treatment of acute pubic symphysis separation bases on conservative therapy, includes bed rest and physical therapy. But when the widening of the symphysis is more than 4 cm, the surgery intervention may be a good treatment. If the conservative treatment is not obviously effective, the surgery consists of plate fixation in the pubic symphysis and sacroiliac screw fixation. Other indications for the surgical intervention include inadequate reduction, recurrent diastasis, intractable symptoms, and open rupture.

Conventional and contrast-enhanced ultrasound assessment of craniocerebral gunshot wounds

This study aimed to investigate the characteristic features of craniocerebral gunshot wounds by conventional ultrasound (CUS) and evaluate the efficacy of contrast-enhanced ultrasound (CEUS) in differentiation of tissue condition in wounds. Twenty crossbreed dogs (treatment: N = 15; control: N = 5) were used in the study. Pipe-shaped hyperechoes of varying size were found by CUS in most of the treated animals. The echoic areas were distinct from the neighboring brain tissue and did not change with time. CEUS revealed that the pipe-shaped echo was unenhanced in majority of the injured brains and the surrounding tissue was either heterogeneously enhanced or unenhanced. Pathological analysis confirmed that the contrast-filling-defect area indicated necrotic tissue and the heterogeneous minimally enhanced areas indicated degenerative tissue. CUS imaging enabled detection of hematomas and CEUS indicated that the filling defect was in the center of the hematoma, with enhancement gradually increasing towards the periphery. CUS could effectively detect a wound tract, hematoma, and the craniocerebral area injured by a gunshot, while CEUS could accurately reveal necrotic tissue in the injured area and differentiate the degenerative from normal tissue.

Agrocybe aegerita polysaccharide combined with chemotherapy improves tumor necrosis factor-α and interferon-γ levels in rat esophageal carcinoma

Natural compounds have generated great interest as alternative treatments of diseases like cancer. Here, we investigated the anti-tumor mechanism of one such compound, Agrocybe aegerita polysaccharide, by assessing expression of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in rat esophageal carcinoma (EC). EC was induced in healthy Wistar rats by methyl-n-amyl nitrosamine. Subsequently, rats were administered cancer treatment daily for 4 weeks, as follows: the normal control group (the only group not treated with methyl-n-amyl nitrosamine) and model group received only distilled water; the chemotherapy group received tegafur treatment; and the combination group received tegafur combined with A. aegerita polysaccharide. In normal and combination groups, body weight increased gradually after each week of treatment (P < 0.05), while body weights did not change in model and chemotherapy groups. Using enzyme linked immunosorbent assay, we found serum TNF-α was lower in the combination group (31.56 ± 7.20 pg/L) than either the model (46.24 ± 8.52 pg/L) or chemotherapy (52.39 ± 9.16 pg/L) group, and, while higher, was more similar to the normal controls (25.08 ± 2.93 pg/L; P < 0.05), a finding that was confirmed by the immunohistochemistry of esophageal samples. In contrast, serum IFN-γ was higher in the combination group (97.20 ± 10.92 pg/L) than in either the model (76.11 ± 11.92 pg/L) or chemotherapy (76.04 ± 9.85 pg/L) group, but lower than in the normal group (117.56 ± 10.88; P < 0.05), also confirmed by immunohistochemistry. Therefore, Agrocybe aegerita polysaccharide, when combined with chemotherapy, can regulate immune function in EC, potentially by modulating cytokine activity, specifically downregulation of TNF-α and upregulation of IFN-γ.

Genetic variation in thrombin-activatable fibrinolysis inhibitor is associated with the risk of diabetic nephropathy

Diabetic nephropathy is a kidney disease or damage that results as a complication of diabetes, especially Type 2 diabetes, while albuminuria is an early marker for diabetic nephropathy as it can predict cardiovascular events and mortality in diabetic patients. A potent inhibitor of fibrinolysis, the thrombin-activatable fibrinolysis inhibitor (TAFI) has been isolated and characterized from human plasma. We investigated the associations of the activity-related variants in the TAFI coding gene (505A/G,1040C/T) with the risk of diabetic nephropathy by examining 297samples including 140 health controls and 157 confirmed diabetic nephropathy patients. Diabetic nephropathy grades were further categorized by the urine albumin excretion (UAE)-to-creatinine ratios (ACR). We found little difference that was statistically significant in terms of 505A/G among patients and controls. While at 1040C/T, the detected frequency for the T allele in the group of diabetic nephropathy patients was significantly smaller than that of the control group (15.6% vs 25.7%, respectively; p<0.05). This was due to the relative decrease of T/T homozygotes in the patients (p<0.05, 95% odds ratio 0.28, confidence interval 0.11-0.70). Surprisingly, the difference was only observed with initial diabetic nephropathy stages. This study clearly indicates that, at 1040C/T, the frequency for the T allele is strongly associated with increased risk for diabetic nephropathy in a subset of the general population, implying that the T allele confers protection against the onset of diabetic nephropathy only in homozygosity and may function as a recessive trait.

Development and characterization of microsatellite markers for the endangered Chinese yew Taxus chinensis var. mairei (Taxaceae)

We isolated and characterized 11 microsatellite loci for the Chinese yew, Taxus chinensis var. mairei, an endangered tree species in China, by constructing a (CA)(12)-enriched library. The number of alleles per locus ranged from 5 to 10. The observed heterozygosities ranged from 0.2500 to 0.8333 and the expected heterozygosities ranged from 0.5196 to 0.8680. No significant linkage disequilibrium was detected at these loci. However, four loci significantly deviated from Hardy-Weinberg equilibrium. The null alleles were found to be present at locus Tach9 and locus Tach11 by the Micro-checker test (P < 0.001). These polymorphic loci could be employed in research of gene flow and spatial genetic patterns of T. chinensis var. mairei.

Empirical assessment of state-and-transition models with a long-term vegetation record from the Sonoran Desert

Resilience-based frameworks, including state-and-transition models (STM), are being increasingly called upon to inform policy and guide ecosystem management, particularly in rangelands. Yet, multiple challenges impede their effective implementation: (1) paucity of empirical tests of resilience concepts, such as alternative states and thresholds, and (2) heavy reliance on expert models, which are seldom tested against empirical data. We developed an analytical protocol to identify unique plant communities and their transitions, and applied it to a long-term vegetation record from the Sonoran Desert (1953-2009). We assessed whether empirical trends were consistent with resilience concepts, and evaluated how they may inform the construction and interpretation of expert STMs. Seven statistically distinct plant communities were identified based on the cover of 22 plant species in 68 permanent transects. We recorded 253 instances of community transitions, associated with changes in species composition between successive samplings. Expectedly, transitions were more frequent among proximate communities with similar species pools than among distant communities. But unexpectedly, communities and transitions were not strongly constrained by soil type and topography. Only 18 transitions featured disproportionately large compositional turnover (species dissimilarity ranged between 0.54 and 0.68), and these were closely associated with communities that were dominated by the common shrub (burroweed, Haplopappus tenuisecta); indicating that only some, and not all, communities may be prone to large compositional change. Temporal dynamics in individual transects illustrated four general trajectories: stability, nondirectional drift, reversibility, and directional shifts that were not reversed even after 2-3 decades. The frequency of transitions and the accompanying species dissimilarity were both positively correlated with fluctuation in precipitation, indicating that climatic drivers require more attention in STMs. Many features of the expert models, including the number of communities and participant species, were consistent with empirical trends, but expert models underrepresented recent increases in cacti while overemphasizing the introduced Lehmann's lovegrass (Eragrostis lehmanniana). Quantification of communities and transitions within long-term vegetation records presents several quantitative metrics such as transition frequency, magnitude of accompanying compositional change, presence of unidirectional trajectories, and lack of reversibility within various timescales, which can clarify resilience concepts and inform the construction and interpretation of STMs.

Isolation and characterization of tetranucleotide repeat polymorphic microsatellite loci in Larus saundersi (Aves, Laridae)

Nine polymorphic microsatellite loci were isolated, using tetranucleotide repeat oligonucleotide probes from an enriched DNA library of the globally "vulnerable" Saunders's gull (Larus saundersi), collected from the Yancheng coastal wetland, one of the three remaining breeding sites in China. Six breast muscle tissues and 16 blood samples from 22 gulls and eight eggshell membrane tissues were collected for this analysis. The number of alleles per locus ranged from 4 to 15, with a mean of 8.9. The observed and expected heterozygosities ranged from 0.58 to 0.89 and 0.58 to 0.9, with means of 0.77 and 0.81, respectively. No significant linkage disequilibrium and no divergence from Hardy-Weinberg equilibrium were detected among these loci. Based on Micro-Checker tests, no null alleles are present at any of the loci. The microsatellite loci described here will be valuable for exploring population genetic structure and for other relevant genetic studies of Saunders's gull.

Assessing the influence of field- and GIS-based inquiry on student attitude and conceptual knowledge in an undergraduate ecology lab

Combining field experience with use of information technology has the potential to create a problem-based learning environment that engages learners in authentic scientific inquiry. This study, conducted over a 2-yr period, determined differences in attitudes and conceptual knowledge between students in a field lab and students with combined field and geographic information systems (GIS) experience. All students used radio-telemetry equipment to locate fox squirrels, while one group of students was provided an additional data set in a GIS to visualize and quantify squirrel locations. Pre/postsurveys and tests revealed that attitudes improved in year 1 for both groups of students, but differences were minimal between groups. Attitudes generally declined in year 2 due to a change in the authenticity of the field experience; however, attitudes for students that used GIS declined less than those with field experience only. Conceptual knowledge also increased for both groups in both years. The field-based nature of this lab likely had a greater influence on student attitude and conceptual knowledge than did the use of GIS. Although significant differences were limited, GIS did not negatively impact student attitude or conceptual knowledge but potentially provided other benefits to learners.

The formation of neural codes in the hippocampus: trace conditioning as a prototypical paradigm for studying the random recoding hypothesis

The trace version of classical conditioning is used as a prototypical hippocampal-dependent task to study the recoding sequence prediction theory of hippocampal function. This theory conjectures that the hippocampus is a random recoder of sequences and that, once formed, the neuronal codes are suitable for prediction. As such, a trace conditioning paradigm, which requires a timely prediction, seems by far the simplest of the behaviorally-relevant paradigms for studying hippocampal recoding. Parameters that affect the formation of these random codes include the temporal aspects of the behavioral/cognitive paradigm and certain basic characteristics of hippocampal region CA3 anatomy and physiology such as connectivity and activity. Here we describe some of the dynamics of code formation and describe how biological and paradigmatic parameters affect the neural codes that are formed. In addition to a backward cascade of coding neurons, we point out, for the first time, a higher-order dynamic growing out of the backward cascade-a particular forward and backward stabilization of codes as training progresses. We also observe that there is a performance compromise involved in the setting of activity levels due to the existence of three behavioral failure modes. Each of these behavioral failure modes exists in the computational model and, presumably, natural selection produced the compromise performance observed by psychologists. Thus, examining the parametric sensitivities of the codes and their dynamic formation gives insight into the constraints on natural computation and into the computational compromises ensuing from these constraints.

Differential effects of interleukin-6 receptor activation on intracellular signaling and bone resorption by isolated rat osteoclasts

The effects of the related cytokines interleukin-6 (IL-6), leukemia inhibitory factor (LIF) and oncostatin-M on bone resorption and cytosolic Ca(2+) signaling were compared in isolated rat osteoclasts. In the traditional disaggregated osteoclast (pit) assay, IL-6 and LIF, but not oncostatin-M, conserved the bone resorption otherwise inhibited by high extracellular [Ca(2+)] (15 mM). It produced a paradoxical, concentration-dependent stimulation of resorption by elevated extracellular Ca(2+). In the micro-isolated single osteoclast resorption assay, IL-6, high [Ca(2+)] or IL-6 plus high [Ca(2+)] all increased pit formation. In contrast, the IL-6 receptor (IL-6R)-specific agonist antibody MT-18 inhibited bone resorption in a concentration-dependent manner (1:500 to 1:500 000). MT-18 triggered cytosolic Ca(2+) signals in fura 2-loaded osteoclasts within approximately 10 min of application. Each cytosolic Ca(2+) transient began with a peak deflection that persisted in Ca(2+)-free, EGTA-containing extracellular medium, consistent with a release of intracellularly stored Ca(2+). This was followed by a sustained elevation of cytosolic [Ca(2+)] that was abolished in Ca(2+)-free medium, as expected from an entry of extracellular Ca(2+), and by the Ca(2+) channel antagonist Ni(2+). The inclusion of either IL-6 or soluble human (sh) IL-6R specifically reversed both the above effects of MT-18, confirming that both effects were specific for the IL-6R. The findings suggest that IL-6R activation by IL-6 stimulates osteoclastic bone resorption either by reversing the inhibitory effect of high extracellular Ca(2+) in stromal-containing systems or itself stimulating bone resorption along with Ca(2+) by micro-isolated osteoclasts. In contrast, activation of the IL-6R by an agonist antibody produces an inhibition of bone resorption and an associated triggering of the cytosolic Ca(2+) signals previously associated with regulation of bone resorptive function in other situations.

Initial state randomness improves sequence learning in a model hippocampal network

Randomness can be a useful component of computation. Using a computationally minimal, but still biologically based model of the hippocampus, we evaluate the effects of initial state randomization on learning a cognitive problem that requires this brain structure. Greater randomness of initial states leads to more robust performance in simulations of the cognitive task called transverse patterning, a context-dependent discrimination task that we code as a sequence prediction problem. At the conclusion of training, greater initial randomness during training trials also correlates with increased, repetitive firing of select individual neurons, previously named local context neurons. In essence, such repetitively firing neurons recognize subsequences, and previously their presence has been correlated with solving the transverse patterning problem. A more detailed analysis of the simulations across training trials reveals more about initial state randomization. The beneficial effects of initial state randomization derive from enhanced variation, across training trials, of the sequential states of a network. This greater variation is not uniformly present during training; it is largely restricted to the beginning of training and when novel sequences are introduced. Little such variation occurs after extensive or even moderate amounts of training. We explain why variation is high early in training, but not later. This automatic modulation of the initial-state-driven random variation through state space is reminiscent of simulated annealing where modulated randomization encourages a selectively broad search through state space. In contrast to an annealing schedule, the selective occurrence of such a random search here is an emergent property, and the critical randomization occurs during training rather than testing.

[The study of transfected cardiomyocytes by recombinant adenovirus and adeno-associated virus]

AIM AND METHODS

Recombinant adenovirus (rAd) and adeno-associated virus (rAAV) were created, in which beta2-adrenergic receptors (beta2-AR) gene is under control of the cmv promotor, the cultured neonate rat ventricular myocytes were infected by the two vectors, and the expression of beta2-AR on cultured neonate rat ventricular myocytes was assessed.

RESULTS

RT-PCR demonstrated the presence of beta2-AR mRNA, protein immunoblots demonstrated the expression of the beta2-AR gene. According to a ligand binding assay, the density of beta AR in the cardiomyocytes infected by rAd and rAAV had no difference, which was greater than that in the control.

CONCLUSION

The results above demonstrated that adenovirus vector and AAV vector transfected efficiently cardiomyocytes.

Molecular cloning, expression, and functional characterization of a novel member of the CD38 family of ADP-ribosyl cyclases

We report the molecular cloning and functional characterization of a novel member of the CD38 family of cyclic ADP-ribose (cADPr)-generating cyclases. We cloned a cDNA insert that encoded a 298-amino-acid-long protein (M(w) approximately 39 kDa). The predicted protein displayed 69, 61, and 58% similarity, respectively, to mouse, rat, and human CD38. Rabbit CD38 was also 28% homologous to Aplysia ADP-ribosyl cyclase and leukocyte CD157 (another ADP-ribosyl cyclase); the three cyclases shared 10 cysteine and 2 adjacent proline residues. We then transfected CD38-negative NIH3T3 cells with cDNA encoding a CD38-EGFP fusion protein. Epifluorescence microscopy showed intense EGFP fluorescence confirming CD38 expression. We finally confirmed the ADP-ribosyl cyclase activity of the expressed CD38 by measuring its ability to catalyze the cyclization of the nicotinamide adenine dinucleotide (NAD(+)) surrogate, NGD(+), to its fluorescent nonhydrolyzable derivative, cGDPr.

Three-layered atmospheric structure in accretion disks around stellar-mass black holes

Modeling of the x-ray spectra of the Galactic superluminal jet sources GRS 1915+105 and GRO J1655-40 reveals a three-layered atmospheric structure in the inner region of their accretion disks. Above the cold and optically thick disk with a temperature of 0.2 to 0.5 kiloelectron volts, there is a warm layer with a temperature of 1.0 to 1.5 kiloelectron volts and an optical depth around 10. Sometimes there is also a much hotter, optically thin corona above the warm layer, with a temperature of 100 kiloelectron volts or higher and an optical depth around unity. The structural similarity between the accretion disks and the solar atmosphere suggests that similar physical processes may be operating in these different systems.

Controlling activity fluctuations in large, sparsely connected random networks

Controlling activity in recurrent neural network models of brain regions is essential both to enable effective learning and to reproduce the low activities that exist in some cortical regions such as hippocampal region CA3. Previous studies of sparse, random, recurrent networks constructed with McCulloch-Pitts neurons used probabilistic arguments to set the parameters that control activity. Here, we extend this work by adding an additional, biologically appropriate, parameter to control the magnitude and stability of activity oscillations. The new constant can be considered to be the rest conductance in a shunting model or the threshold when subtractive inhibition is used. This new parameter is critical for large networks run at low activity levels. Importantly, extreme activity fluctuations that act to turn large networks totally on or totally off can now be avoided. We also show how the size of external input activity interacts with this parameter to affect network activity. Then the model based on fixed weights is extended to estimate activities in networks with distributed weights. Because the theory provides accurate control of activity fluctuations, the approach can be used to design a predictable amount of pseudorandomness into deterministic networks. Such nonminimal fluctuations improve learning in simulations trained on the transitive inference problem.

[Adeno-associated virus vector mediated gene transfer of HSVI-TK and its effect on killing cancer cell]

The plasmid pACTK-19 was constructed by inserting HSVI-TK gene into the multiple cloning sites of the general adeno-associated virus(AAV) vector pACR-Neo. When plasmid pACTK-19 was transfected to recombinant AAV's packaging cell line AE1201, which was exposed to Adenovirus 5 for two hours before transfection, we got rAAV/ACTK at the titer of 3.4 x 10(5) CFU/ml. After infecting human lung cancer cell A549 with rAAV/ACTK, we extracted host cell's chromosome cDNA and amplified part of the HSVI-TK sequence by a pair of HSVI-TK's primers and then hybridized to digoxin labelled HSVI-TK gene probe. We got corresponding positive band and it proved the integration of HSVI-TK into host cell's chromosome cDNA. By reverse transcripting rAAV/ACR-Neo infected A549 total cell RNA, we amplified part of HSVI-TK sequence and hybridized to Neo gene probe. The corresponding positive band demonstrated the expression of HSVI-TK. So through rAAV/ACTK, HSVI-TK was transferred into host cells and was expressed in them, the rAAV's genome was integrated into host cell's chromosome DNA. Connecting with Ganciclovir (GCV), the HSVI-TK gene transfer mediated by rAAV/ACTK, could inhibit the synthesis of chromosome DNA and lead to the killing of the lung cancer cell. This work proved that recombinant AAV could be used as vector for gene transduction to cancer cell, and also laid foundation for further research and application of AAV vector.

Noise-enhanced performance in a cortical associative memory model

Spontaneous neuronal activity and synaptic noise are well-known phenomena, but their biological significance has not yet been assessed. Using a computer model of the olfactory cortex we show that such activity, expressed as temporal noise in the model, can reduce recall time in associative memory tasks. We investigate both additive and multiplicative noise, and find optimal noise levels for which the recall time reaches a minimum. In addition, we demonstrate that noise can induce state transitions, such that the system is pushed from one attractor state to another. For high enough noise levels the dynamics can change dramatically and, for example, switch from an oscillatory to a chaos-like behavior. We discuss these findings in light of their significance for neural information processing.

Using complexity measure to characterize information transmission of human brain cortex

The information transmission among various parts of the cortex are computed with the theory of mutual information from the data of the electroencephalogram (EEG) time series of normal human subjects. The intensities of these transmissions are characterized by the "complexity" measures. These measures have revealed to be sensitively related to the functional conditions of human beings.

[Changes in adhesion features of leukocytes in rats with severe burns]

Twenty-four rats were divided into 3 groups: normal controls (8), simple burned (8), burned plus Polygonum cuspidatum (p.c.)-treated (8). Three hours after burn, 3ml of whole blood was drawn to isolate polymorphonuclear neutrophilic leucocytes (PMNs). Confluent monolayer of rat microvessel endothelial cells was grown in a parallel plate of flow chamber. PMNs were driven through the flow chamber under different wall shear stresses. Leukocyte-endothelia adhesion was observed with an Olympus inverted microscope and recorded with a colour microscopic TV set. The adhesive characteristic curve of leukocyte was significantly different between the normal and burned groups. The number of PMNs adhesive to endothelium increased obviously 3 hours after burn. Under 0.196 Pa of wall shear stress, the adhesion rate of PMNs was 81.2 + 4.1% in the burned group and 58.8 + 4.6% in the normal group. The PNMs adhesion rate was decreased to near normal in p.c.-treated group. The average survival time in the burned group was 4.1 + 1.2 hours, much lower than that in the p.c. treated group (33.2 + 15.8 hours). However, in the simple burned group, one rat survived for 24 hours and its PMNs adhesive curve was similar to that of the normal or p.c.-treated groups. The findings indicate that PMNs adhesion features increase apparently after severe burn, which is closely related to the survival rate.

Efflux of cyclic GMP from activated human platelets

Activation of human platelets is associated with an increased level of cGMP, when total cGMP in individual samples is measured. However, by discriminating between intracellular and extracellular cGMP we were able to demonstrate that cGMP accumulates in the extracellular space only, whereas the level of intraplatelet cGMP actually decreases. Therefore, during the first minutes of platelet aggregation cGMP is released from the cell, and it thereby escapes hydrolysis by intracellular phosphodiesterases. In contrast, during direct activation of soluble guanylyl cyclase by nitrovasodilators, such as sodium nitroprusside, the newly synthesized cGMP remains mainly inside the cells. Elevation of intracellular calcium and activation of protein kinase C are likely to be involved in promoting cGMP efflux. Our results are discussed in contrast to the general hypothesis that the cGMP increase associated with platelet aggregation may represent a feedback mechanism designed to terminate early events of activating signal transduction. According to our data the apparent cGMP increase results from cGMP release from thrombocytes, rather than soluble guanylyl cyclase activation. This cGMP efflux provides a mechanism of decreasing the intracellular cGMP level upon stimulation with platelet agonists and thus favors platelet activation.

Reversible activation of soluble guanylate cyclase by oxidizing agents

Soluble guanylate cyclase of human platelets was stimulated by thiol oxidizing compounds like diamide and the reactive disulfide 4, 4'-dithiodipyridine. Activation followed a bell-shaped curve, revealing somewhat different optimum concentrations for each compound, although in both cases, higher concentrations were inhibitory. Diamide at a concentration of 100 microM transiently activated the enzyme. In the presence of moderate concentrations of diamide and 4,4'-dithiodipyridine, causing a two- to fourfold activation by themselves, the stimulatory activity of NO-releasing compounds like sodium nitroprusside was potentiated. In contrast, higher concentrations of thiol oxidizing compounds inhibited the NO-stimulated activation of soluble guanylate cyclase. Activation of guanylate cyclase was accompanied by a reduction in reduced glutathione and a concomitant formation of protein-bound glutathione (protein-SSG). Both compounds showed an activating potency as long as reduced glutathione remained, leading to inhibition of the enzyme just when all reduced glutathione was oxidized. Activation was reversible while reduced glutathione recovered and protein-SSG disappeared. We propose that diamide or reactive disulfides and other thiol oxidizing compounds inducing thiol-disulfide exchange activate soluble guanylate cyclase. In this respect partial oxidation is associated with enzyme activation, whereas massive oxidation results in loss of enzymatic activity. Physiologically, partial disulfide formation may amplify the signal toward NO as the endogenous activator of soluble guanylate cyclase.