An Atlas of Dietary Intakes and Medication Uses on Risk of Bladder Cancer: A Wide-Angle Mendelian Randomization Analysis

BACKGROUND

Observational studies suggests that diets and medications affect bladder cancer (BC) development, which are subject to confounding and difficult to make causal inference. Here we aimed to investigate whether those observational associations are causal and determining the potential directions and pathways.

METHODS

We used 2-sample Mendelian randomization (MR) analysis to assess associations of dietary intakes, medication uses and molecules with BC risk. Genetic summary data were derived from participants of predominantly European ancestry with rigorous instruments selection, where univariable MR, mediation MR and multivariable MR were performed.

RESULTS

The results of univariable MR showed 4 dietary intakes and 4 medication uses having a protective effect on BC, while 4 circulating metabolites, 440 circulating proteins and 2 gut microbes were observed to be causally associated with BC risk. Through mediation MR, we found 572 analytes showing consistent mediating effects between dietary intakes or medication uses and BC risk. Furthermore, 9 out of 16 diet-medication pairs showed significant interactions and alterations on BC when consumed jointly.

CONCLUSION

In summary, the findings obtained from the current study have important implications for informing prevention strategies that point to potential lifestyle interventions or medication prescriptions to reduce the risk of developing BC. HighlightsThe current study extends observational literature in showing the importance of diets and medications on bladder cancer prevention.The associations of diets and medications on bladder cancer prevention might be through circulating metabolites, circulating proteins and gut microbiotaOur results provide a new understanding of interactions in certain diet-medication pairs which should be taken into account by both physicians and patients during the development of a treatment strategy.

Genome-wide exploration of genetic interactions for bladder cancer risk

Although GWASs have been conducted to investigate genetic variation of bladder tumorigenesis, little is known about genetic interactions that may influence bladder cancer (BC) risk. By leveraging large-scale participants from UK Biobank, we established a discovery database with 4000 Caucasian participants (2000 cases vs 2000 non-cases), a database with 1648 Caucasian participants (824 cases vs 824 non-cases) and 856 non-Caucasian participants (428 cases vs 428 non-cases) as validation. We then performed a genome-wide SNP-SNP interaction investigation related to BC risk based a machine learning approach (ie, GenEpi). Moreover, we used the selected interactions to build a BC screening model with an integrated interaction-empowered polygenic risk score (iPRS) based on Cox proportional hazard model. With Bonferroni correction, we identified 10 statistically significant pairs of SNPs, which located in 17 chromosomes. Of these, four SNP-SNP interactions were found to be positively associated with BC risk among Caucasian participants (ORs 1.57-2.03), while six SNP-SNP interactions showed negatively associated with BC risk (ORs 0.54-0.65). Only four of the SNP-SNP interactions were consistently identified in non-Caucasian participants located in ST7L-ADSS2, FHIT-CHDH, LARP4B-LHPP and RBFOX3-MPRIP. In addition, the iPRS showed a HR of 1.81 (95% CI: 1.46-2.09) compared the highest tertile to the lowest tertile, with an enhanced AUC (0.91; 95% CI:0.85-0.97) than PRS (AUC: 0.86; 95% CI:0.76-0.95; P-DeLong test  = 2.2 × 10-4 ). In summary, this study identified several important SNP-SNP interactions for BC risk, and developed an iPRS model for BC screening, which may help to identify the people at high-risk state of BC before early manifestation.

[Efficacy, prognosis and influencing factors of transcatheter arterial embolization in the treatment of neuroendocrine neoplasm liver metastases]

Objective: To evaluate the efficacy of transcatheter arterial embolization (TAE) in the treatment of neuroendocrine neoplasm liver metastases (NENLM), analyze the prognosis and related factors. Methods: Clinical data of NENLM patients treated with TAE in the First Affiliated Hospital of Nanjing Medical University from January 2018 to March 2022 were retrospectively analyzed. Objective response rate (ORR), disease control rate (DCR), and adverse event rate after TAE were evaluated according to the Response Evaluation Criteria In Solid Tumors and the Common Terminology Criteria for Adverse Events. The prognosis was evaluated by median overall survival (mOS) and median progression-free survival (mPFS). The survival curve was plotted by Kaplan-Meier method. Multivariate Cox regression was used to analyze prognostic factors. Results: A total of 39 NENLM patients were included in this study, aged (53.3±10.3) (23-74) years old, including 23 males and 16 females. Among them, 9 cases had functional neuroendocrine neoplasms. There were 31 cases with primary sites locating in the digestive system, 32 cases with WHO G1 and G2 primary sites, 27 cases with abundant blood supply for liver metastases and 13 cases with liver tumor load >50%. Thirty patients received treatment of long-acting somatostatin analogue(SSA). A total of 123 TAE were performed in 39 cases, with an ORR of 38.5% (15/39) and a DCR of 76.9% (30/39). There were no serious adverse events of level 4-5 during the perioperative period. The median follow-up was 38.7 (95%CI: 31.3-46.1) months, with mOS of 37.3(95%CI: 27.0-47.5) months and mPFS of 12.6 (95%CI: 7.1-18.1) months. Multivariate Cox regression analysis found that the combination of long-term SSA treatment was an influencing factor for overall survival of patients (HR=0.207, 95%CI: 0.076-0.567, P=0.002). Conclusions: TAE can effectively reduce the load of liver metastases in patients with NENLM, and the combination of long-term SSA treatment can improve the ovreall survival of patients.

[Epidemiological characteristics of norovirus acute gastroenteritis outbreaks and influencing factors in China, 2007-2021]

Objective: To analyze the epidemiological characteristics of norovirus-caused acute gastroenteritis outbreaks in China, identify the factors influencing the scale of outbreaks, and provide scientific evidences for early control of norovirus infection outbreaks. Methods: The descriptive epidemiological analysis approach was applied to analyze the incidence of national norovirus infection outbreaks by using the data from the Public Health Emergency Event Surveillance System in China from January 1, 2007 to December 31, 2021. The unconditional logistic regression model was applied to analyze the risk factors that affected the outbreaks' scale. Results: A total of 1 725 norovirus infection outbreaks were recorded in China from 2007 to 2021, with an upward trend in the number of the reported outbreaks. The southern provinces had their annual outbreak peaks from October to March; the northern provinces had two outbreak peaks from October to December and from March to June annually. The outbreaks occurred mainly in southeastern coastal provinces with a trend of gradual spread to central, northeastern and western provinces. The outbreaks mainly occurred in schools and childcare setting (1 539 cases, 89.22%), followed by enterprises and institutions (67 cases, 3.88%) and community households (55 cases, 3.19%). Human to human transmission was the main infection route (73.16%), and norovirus GⅡ genotype was the predominate pathogen causing the outbreaks (899 cases, 81.58%). The time interval between the onset of the primary case and the outbreak reporting M (Q₁, Q₃) was 3 (2, 6) days and the case number of the outbreak M (Q₁, Q₃) was 38 (28, 62). The timeliness of outbreak reporting was improved in recent years and the scale of the outbreaks showed a decreasing trend over the years, the differences in reporting timeliness and outbreak scale among different settings were significant (P<0.001). The factors that affected outbreaks' scale included the outbreak setting, transmission route, outbreak reporting timeliness and type of living areas (P<0.05). Conclusions: From 2007 to 2021, the number of the norovirus-caused acute gastroenteritis outbreaks increased in China and the more areas were affected. However, the outbreak scale showed a decreasing trend and the outbreak reporting timeliness was improved. It is important to further improve the surveillance sensitivity and reporting timeliness for the effective control of the outbreak scale.

[Epidemiological characteristics of typhoid fever and paratyphoid fever in China, 2004-2020]

Objective: To analyze the incidence trend and epidemiological characteristics of typhoid fever and paratyphoid fever in China from 2004 to 2020, understand the high-incidence population and hotspot areas, and provide evidences to develop more targeted prevention and control measures. Methods: The descriptive epidemiological method and spatial analysis method were applied to analyze the epidemiological characteristics of typhoid fever and paratyphoid fever in China during this period by using the surveillance data collected from the National Notifiable Infectious Disease Reporting System of Chinese Center for Disease Control and Prevention. Results: A total of 202 991 cases of typhoid fever were reported in China from 2004 to 2020. More cases occurred in men than in women (sex ratio: 1.18∶1). Most cases were reported in adults aged 20-59 years (53.60%). The incidence rate of typhoid fever decreased from 2.54/100 000 in 2004 to 0.38/100 000 in 2020. The highest incidence rate was reported in young children aged <3 years after 2011, ranging from 1.13/100 000 to 2.78/100 000, and during this period the proportion of cases in this age group increased from 3.48% to 15.59%. The proportion of the cases in the elderly aged ≥60 years increased from 6.46% in 2004 to 19.34% in 2020. The hotspot areas existed in Yunnan, Guizhou, Guangxi and Sichuan Provinces and expanded to Guangdong, Hunan, Jiangxi, and Fujian Provinces. A total of 86 226 paratyphoid fever cases were reported from 2004 to 2020, the male to female ratio of the cases was 1.21∶1. Most cases were reported in adults aged 20-59 years (59.80%). The incidence rate of paratyphoid fever decreased from 1.26/100 000 in 2004 to 0.12/100 000 in 2020. The highest incidence rate of paratyphoid fever was in young children aged <3 years after 2007, ranging from 0.57/100 000 to 1.19/100 000, and during this period the proportion of the cases in this age group increased from 1.48% to 30.92%. The proportion of the cases in the elderly aged ≥60 years increased from 4.52% in 2004 to 22.28% in 2020. The hotspot areas expanded to the east, including Guangdong, Hunan and Jiangxi Provinces, from Yunnan, Guizhou, Sichuan, and Guangxi Provinces. Conclusions: The results showed a low level of incidence of typhoid fever and paratyphoid fever in China with a trend of decreasing per year. The hotspots were mainly in the of Yunnan, Guizhou, Guangxi and Sichuan Provinces, with an expanding trend to eastern China. It is necessary to strengthen the typhoid fever and paratyphoid fever prevention and control in southwestern China, among young children aged <3 years and the elderly aged ≥60 years.

The effects of the interaction of genetic predisposition with lifestyle factors on bladder cancer risk

OBJECTIVES

To investigate the association of polygenic risk score (PRS) and bladder cancer (BC) risk and whether this PRS can be offset by a healthy lifestyle.

METHODS

Individuals with BC (n = 563) and non-BC controls (n = 483 957) were identified in the UK Biobank, and adjusted Cox regression models were used. A PRS was constructed based on 34 genetic variants associated with BC development, while a healthy lifestyle score (HLS) was constructed based on three lifestyle factors (i.e., smoking, physical activity, and diet).

RESULTS

Overall, a negative interaction was observed between the PRS and the HLS (P = 0.02). A 7% higher and 28% lower BC risk per 1-standard deviation (SD) increment in PRS and HLS were observed, respectively. A simultaneous increment of 1 SD in both HLS and PRS was associated with a 6% lower BC risk. In addition, individuals with a high genetic risk and an unfavourable lifestyle showed an increased BC risk compared to individuals with low genetic risk and a favourable lifestyle (hazard ratio 1.55, 95% confidence interval 1.16-1.91; P for trend <0.001). Furthermore, population-attributable fraction (PAF) analysis showed that 12%-15% of the BC cases might have been prevented if individuals had adhered to a healthy lifestyle.

CONCLUSION

This large-scale cohort study shows that a genetic predisposition combined with unhealthy behaviours have a joint negative effect on the risk of developing BC. Behavioural lifestyle changes should be encouraged for people through comprehensive, multifactorial approaches, although high-risk individuals may be selected based on genetic risk.

[Investigate of the etiology and prevention status of liver cirrhosis]

Objective: To investigate the etiology, prevention and treatment status, and their corresponding regional differences of the patients with liver cirrhosis in China, in order to provide scientific basis for the development of diagnosis and control strategies in China. Methods: Clinical data of patients diagnosed with liver cirrhosis for the first time through January 1, 2018 to December 31, 2020 from 50 hospitals in seven different regions of China were collected and analyzed retrospectively, and the difference of etiology, treatment, and their differences in various regions were analyzed. Results: A total of 11 861 cases with liver cirrhosis were included in the study. Thereinto, 5 093 cases (42.94%) were diagnosed as compensated cirrhosis, and 6 768 cases (57.06%) had decompensated cirrhosis. Notably, 8 439 cases (71.15%) were determined as chronic hepatitis B-caused cirrhosis, 1 337 cases (11.27%) were alcoholic liver disease, 963 cases (8.12%) were chronic hepatitis C, 698 cases (5.88%) were autoimmune liver disease, 367 cases (3.09%) were schistosomiasis, 177 cases (1.49%) were nonalcoholic fatty liver, and 743 cases (6.26%) of other types of liver disease. There were significant differences in the incidence of chronic hepatitis B, chronic hepatitis C, alcoholic liver disease, fatty liver, schistosomiasis liver disease, and autoimmune liver disease among the seven regions (P<0.001). Only 1 139 cases (9.60%) underwent endoscopic therapy, thereinto, 718 cases (6.05%) underwent surgical therapy, and 456 cases (3.84%) underwent interventional therapy treatment. In patients with compensated liver cirrhosis, 60 cases (0.51%) underwent non-selective β receptor blockers(NSBB), including 59 cases (0.50%) underwent propranolol and 1 case (0.01%) underwent carvedilol treatment. In patients with decompensated liver cirrhosis, 310 cases (2.61%) underwent NSBB treatment, including 303 cases (2.55%) underwent propranolol treatment and 7 cases (0.06%) underwent carvedilol treatment. Interestingly, there were significant differences in receiving endoscopic therapy, interventional therapy, NSBB therapy, splenectomy and other surgical treatments among the seven regions (P<0.001). Conclusion: Currently, chronic hepatitis B is the main cause (71.15%) of liver cirrhosis in several regions of China, and alcoholic liver disease has become the second cause (11.27%) of liver cirrhosis in China. The three-level prevention and control of cirrhosis in China should be further strengthened.

High Throughput Isolation and Data Independent Acquisition Mass Spectrometry (DIA-MS) of Urinary Extracellular Vesicles to Improve Prostate Cancer Diagnosis

Proteomic profiling of extracellular vesicles (EVs) represents a promising approach for early detection and therapeutic monitoring of diseases such as cancer. The focus of this study was to apply robust EV isolation and subsequent data-independent acquisition mass spectrometry (DIA-MS) for urinary EV proteomics of prostate cancer and prostate inflammation patients. Urinary EVs were isolated by functionalized magnetic beads through chemical affinity on an automatic station, and EV proteins were analyzed by integrating three library-base analyses (Direct-DIA, GPF-DIA, and Fractionated DDA-base DIA) to improve the coverage and quantitation. We assessed the levels of urinary EV-associated proteins based on 40 samples consisting of 20 cases and 20 controls, where 18 EV proteins were identified to be differentiated in prostate cancer outcome, of which three (i.e., SERPINA3, LRG1, and SCGB3A1) were shown to be consistently upregulated. We also observed 6 out of the 18 (33%) EV proteins that had been developed as drug targets, while some of them showed protein-protein interactions. Moreover, the potential mechanistic pathways of 18 significantly different EV proteins were enriched in metabolic, immune, and inflammatory activities. These results showed consistency in an independent cohort with 20 participants. Using a random forest algorithm for classification assessment, including the identified EV proteins, we found that SERPINA3, LRG1, or SCGB3A1 add predictable value in addition to age, prostate size, body mass index (BMI), and prostate-specific antigen (PSA). In summary, the current study demonstrates a translational workflow to identify EV proteins as molecular markers to improve the clinical diagnosis of prostate cancer.

Integrative Multi-Omics Analysis for the Determination of Non-Muscle Invasive vs. Muscle Invasive Bladder Cancer: A Pilot Study

Objectives: The molecular landscape of non-muscle-invasive (NMIBC) and muscle-invasive (MIBC) bladder cancer based on molecular characteristics is essential but poorly understood. In this pilot study we aimed to identify a multi-omics signature that can distinguish MIBC from NMIBC. Such a signature can assist in finding potential mechanistic biomarkers and druggable targets. Methods: Patients diagnosed with NMIBC (n = 15) and MIBC (n = 11) were recruited at a tertiary-care hospital in Nanjing from 1 April 2021, and 31 July 2021. Blood, urine and stool samples per participant were collected, in which the serum metabolome, urine metabolome, gut microbiome, and serum extracellular vesicles (EV) proteome were quantified. The differences of the global profiles and individual omics measure between NMIBC vs. MIBC were assessed by permutational multivariate analysis and the Mann–Whitney test, respectively. Logistic regression analysis was used to assess the association of each identified analyte with NMIBC vs. MIBC, and the Spearman correlation was used to investigate the correlations between identified analytes, where both were adjusted for age, sex and smoking status. Results: Among 3168 multi-omics measures that passed the quality control, 159 were identified to be differentiated in NMIBC vs. MIBC. Of these, 46 analytes were associated with bladder cancer progression. In addition, the global profiles showed significantly different urine metabolome (p = 0.029), gut microbiome (p = 0.036), and serum EV (extracellular vesicles) proteome (p = 0.039) but not serum metabolome (p = 0.059). We also observed 17 (35%) analytes that had been developed as drug targets. Multiple interactions were obtained between the identified analytes, whereas for the majority (61%), the number of interactions was at 11–20. Moreover, unconjugated bilirubin (p = 0.009) and white blood cell count (p = 0.006) were also shown to be different in NMIBC and MIBC, and associated with 11 identified omics analytes. Conclusions: The pilot study has shown promising to monitor the progression of bladder cancer by integrating multi-omics data and deserves further investigations.

[Focused dilemmas in the diagnosis and treatment of digestive system neuroendocrine neoplasms]

Neuroendocrine neoplasms (NENs) originate from neuroendocrine cells diffusely distributed throughout the body. NENs are liable to be misdiagnosed and missed clinically, which brings great difficulties to clinical diagnosis and treatment, and seriously affects their prognosis. This article will introduce the difficulties and hot spots in the diagnosis and treatment of NENs from the aspects of laboratory and pathological examinations, anatomical and functional imaging examinations, including endoscopy, peptide receptor radionuclide therapy, somatostatin analogue and immune checkpoint inhibitor therapy. It aims to provide more ideas for the early diagnosis and early treatment of NENs, standardized diagnosis and treatment of high-grade NENs in the middle and late stages, and to provide more strategies for clinical multidisciplinary experts towards the management of focused dilemmas in NENs.

[Efficiency and safety of peptide receptor radionuclide therapy in the treatment of metastatic neuroendocrine tumors]

The clinical data of 14 patients with neuroendocrine tumors who received Peptide Receptor Radionuclide Therapy (PRRT) from December 2018 to May 2021 were retrospectively analyzed. Among them, 2 patients demonstrated proprogressive disease, 2 patients had partial response, and 10 patients had stable disease. Grade 1-2 myelosuppression occurred in 5 patients. and 1 patient became grade 3 myelosuppression，which recovered to grade 2 after symptomatic treatment. No grade 2 or higher treatment-related renal toxicity was observed in any of the patients. PRRT is efficacy and no significant side effects for unresectable metastatic neuroendocrine tumors.

[Comparison of clinical features between sporadic pancreatic neuroendocrine tumors and those associated with multiple endocrine neoplasia type 1]

Objective: To compare the clinical features of multiple endocrine adenoma type 1 (MEN-1) associated pancreatic neuroendocrine neoplasms (pNENs) as well as sporadic pNENs. Methods: The clinical data of 28 sporadic pNENs patients and 10 MEN-1-related pNENs patients admitted to the First Affiliated Hospital of Nanjing Medical University from January 2010 to June 2021 were collected. Meanwhile, by searching PubMed database and reviewing the clinical data of 20 foreign patients with MEN-1-related pNENs which were reported at the same time.Compare and analyze the similarities and differences between MEN1-associated pNENs and sporadic pNENs in clinical features, such as family history, blood tests, pathological diagnostic indicators, tumor grade, stage and metastasis, treatment and prognosis and so on. Results: A total of 58 pNENs patients were included, and there were 30 MEN1-related pNENs patients and 28 sporadic pNENs patients. Eighteen patients (60%) had a family history of MEN1-related pNENs, and the mean age of onset was (35.3±13.0)years. There were no patients (0) with family history of sporadic pNENs, and the mean age of onset was(55.3±13.4)years. In contrast, the differences in family history, age of onset and NSE were statistically significant(all P<0.05).Among the pathological diagnostic indicators, there were 19 patients (63.3%) with Grade G2 of MEN1-related pNENs, and 25 patients (83.3%) with somatostatin receptor 2(SSTR2) negative. In sporadic pNENs, there were 16 patients (57.1%) with Grade G2 and 9 patients (32.1%) with SSTR2 negative. The differences in pathological grade, immunohistochemistry (Chromogranin A, CD56, and somatostatin receptor 2, SSTR2) between the two groups were statistically significant(all P<0.05). In terms of tumor staging and metastasis, 21 patients with MEN-1-related pNENs had metastasis (70%) and 20 patients with stage Ⅰ and Ⅱ AJCC (71%) in all. Eight patients with sporadic pNENs had metastasis (26.7%) and 8 patients were with stage Ⅰ and Ⅱ AJCC (28.6%). By contrast, the differences in total metastasis rate, AJCC stage and distant metastasis between the two groups were statistically significant(all P<0.05). In terms of treatment and prognosis, there was no statistical significance in the differences between surgical treatment and prognosis (P>0.05), and the difference was also not statistically significant in survival rate between them (P>0.05). Conclusions: There are no significant differences between MEN1-related pNENs and sporadic pNENs in terms of treatment, prognosis, and survival rate, but there are significant differences in clinical features, pathological features and the staging and grading of tumors. The rate of tumor grade, stage and metastasis of sporadic pNENs is higher.

Fibrogrowth factor-2 protects against acute lung injury by activating the PI3K/Akt signaling pathway

Acute lung injury (ALI)/Acute respiratory distress syndrome (ARDS) is a very dangerous disease. The purpose of this study was to investigate the effects of fibrogrowth factor-2 (FGF-2) on lipopolysaccharide (LPS)-induced lung injury and its mechanisms. C57/BL6 mice were used in the study and LPS was used to construct the ALI/ARDS model. In addition, human normal lung epithelial cell line BEAS-2B was cultured to investigate the effect of FGF-2 on the lung and its mechanism of action in vitro. FGF-2 significantly reduced wet/dry weight ratio of mice, the number of cells and inflammatory factors in BALF, and MPO activity in lung tissue. In addition, FGF-2 also reduced the level of oxidative stress in mouse lung tissue. In vitro, FGF-2 effectively reduced LPS-induced inflammatory and apoptotic levels of BEAS-2B cells and increased the activity of the PI3K/Akt signaling pathway. However, LY294002, an inhibitor of the PI3K/Akt signaling pathway, alleviated the protective effect of FGF-2 on lung tissue. Therefore, FGF-2 attenuated inflammation, oxidative stress and apoptosis in alveolar epithelial cells by activating the PI3K/Akt signaling pathway.

Saurogobio punctatus sp. nov., a new cyprinid gudgeon (Teleostei: Cypriniformes) from the Yangtze River, based on both morphological and molecular data

A new cyprinid gudgeon, Saurogobio punctatus sp. nov., is described based on specimens collected from the Yangtze River, China. The new species can be distinguished from its congeners by differences in both morphology and the cytochrome b (cytb) gene sequence. Numerous minute blackish spots are scattered on dorsal and caudal fins in S. punctatus sp. nov. v. absent in the other seven valid Saurogobio species. The new species can be further distinguished from its congeners by the following unique combination of characters: a dorsal fin with eight branched rays; absence of scales in chest area before pectoral origin; upper and lower lips thick, covered with papillae; and a papillose mental pad approximately triangular. Morphologically, the new species most resembles the Chinese lizard gudgeon Saurogobio dabryi, but the new species lays yellowish adhesive eggs v. white pelagic eggs in S. dabryi. A phylogenetic analysis of all Saurogobio species based on cytb gene sequences indicated that S. punctatus sp. nov was distinctly separated from its congeners, with mean sequence divergence ranging from 12·6 to 21·0%. Therefore, molecular data further supported the distinctiveness of the new species.

Control of cell migration direction by inducing cell shape asymmetry with patterned topography

In this study, we explored the concept of introducing asymmetry to cell shapes by patterned cell culture substrates, and investigated the consequence of this induced asymmetry to cell migration behaviors. Three patterns, named "Squares", "Grating", and "Arcs" were fabricated, representing different levels of rotational asymmetry. Using time-lapse imaging, we systematically compared the motility and directionality of mouse osteoblastic cells MC3T3-E1 cultured on these patterns. Cells were found to move progressively faster on "Arcs" than on "Grating", and cells on "Squares" were the slowest, suggesting that cell motility correlates with the level of rotational asymmetry of the repeating units of the pattern. Among these three patterns, on the "Arcs" pattern, the least symmetrical one, cells not only moved with the highest velocity but also the strongest directional persistence. Although this enhanced motility was not associated with the detected number of focal adhesion sites in the cells, the pattern asymmetry was reflected in the asymmetrical cell spreading. Cells on the "Arcs" pattern consistently displayed larger cytoplasmic protrusion on one side of the cell. This asymmetry in cell shape determined the direction and speed of cell migration. These observations suggest that topographical patterns that enhance the imbalance between the leading and trailing fronts of adherent cells will increase cell speed and control movement directions. Our discovery shows that complex cell behaviors such as the direction of cell movement are influenced by simple geometrical principles, which can be utilized as the design foundation for platforms that guide and sort cultured cells.

Study of the dispersion and electrical properties of carbon nanotubes treated by surfactants in dimethylacetamide

In this study, the effects of sodium dodecyl benzene sulfonate, polyvinylpyrrolidone, sodium dodecyl benzene sulfonate/polyvinylpyrrolidone, and Triton X-100 on the dispersion of 0.1 wt% carbon nanotubes in dimethylacetamide are reported. Sedimentation results show that except for sodium dodecyl benzene sulfonate, all the surfactant-assisted carbon nanotube solutions have visually-stable dispersions for at least two months, and even the samples without a surfactant gave no obvious deposition. UV-Vis spectra of the dispersions with and without acid-treatment proved that the carboxyl group attached to the carbon nanotubes positively improves the dispersion effect. The states of aggregation of carbon nanotubes treated by different surfactants are distinctive, and the electrical properties of carbon nanotubes are strongly related to these states of aggregation. The best dispersing and stabilizing effect was found in the sodium dodecyl benzene sulfonate/polyvinylpyrrolidone sample, which also gave the lowest resistance (2.15 x 10(4) omega at 20 V) among all the surfactant-treated stable suspensions.

Characterization of a Functionally Expressed Stretch-activated BKca Channel Cloned from Chick Ventricular Myocytes

We have characterized electrophysiological and pharmacological properties of a stretch-activated BKca channel (SAKcaC) that was cloned from cultured chick ventricular myocytes (CCVM) and expressed in chinese hamster ovary cells (CHO) using the patch-clamp technique. Our results indicate that the cloned SAKcaC keeps most of the key properties of the native SAKcaC in CCVM, such as conductance, ion selectivity, pressure-, voltage- and Ca(2+)-dependencies. However, there was a slight difference between these channels in the effects of channel blockers, charybdotoxin (CTX) and gadolinium (Gd(3+)). The native SAKcaC was blocked in an all-or-none fashion characterized as the slow blockade, whereas the conductance of the cloned SAKcaC was gradually decreased with the blockers' concentration, without noticeable blocking noise. As the involvement of some auxiliary components was suspected in this difference, we cloned a BK beta-subunit from CCVM and coexpressed it with the cloned SAKcaC in CHO cells to examine its effects on the SAKcaC. Although the pharmacological properties of the cloned SAKcaC turned out to be very similar to the native one by the coexpression, it also significantly altered the key characteristics of SAKcaC, such as voltage- and Ca(2+)-dependencies. Therefore we concluded that the native SAKca in CCVM does not interact with the corresponding endogenous beta-subunit. The difference in pharmacological properties between the expressed SAKcaC in CHO and the native one in CCVM suggests that the native SAKca in CCVM is modulated by unknown auxiliary components.

[Development of a canine adenovirus type 1 vaccine strain E3-deleted based expression vector]

OBJECTIVE

To evaluate canine adenovirus type 1 vaccine strain (Cannaught Laboratory Limited, CLL) as recombinant vaccine and gene transfer vector.

METHODS

Recombinant virus CLLEGFP which contains enhanced green fluorescent protein(EGFP) reporter gene was constructed. CLLEGFP was used to infect various human derived cell lines(293, Hela, CO, SW, Hep-2 and CAM) by inoculating intraperitoneally(i.p.), intravenously(i.v.) and intramuscularly (i.m.) to Kunming mice other than oral administration. Various tissue samples of the mice were collected at multi-time point for observing EGFP green fluorescence. Anti-EGFP antibodies were detected by Western blot analysis in the sera after 4 weeks.

RESULTS

CLLEGFP can infect various human derived cell lines and express EGFP. EGFP green fluorescence were observed in liver tissue cells after i.p. transducing 3 days. All immune inoculation ways above could induce Kunming mice producing anti-EGFP antibodies which were identified by Western blot analysis.

CONCLUSIONS

These results indicate that CLL possess powerful potential as recombinant vaccine and gene transfer vector.

Total sialic acid as a tumor marker for oral cancer

Serum sialic acid levels were measured in 80 healthy subjects, in 60 patients with benign tumors and in 110 patients with oral cancer. It was shown that these levels were significantly elevated in oral cancer patients compared to healthy controls and patients with benign tumors (p < 0.01); they were higher in patients with stage III and stage IV disease than in those with stage I and II disease (p < 0.01). However, no difference was observed between healthy controls and stage I and II cancer patients. The results of this study suggest that the determination of sialic acid levels may be of value in the diagnosis of oral cancer, but its usefulness as an adjunct in clinical staging is limited.