Limitation in Controlling the Morphology of Mammalian Vero Cells Induced by Cell Division on Asymmetric Tungsten-Silicon Oxide Nanocomposite.

Engineered nanomaterials are often used in tissue engineering applications to influence and manipulate the behavior of cells. Recently, a number of tungsten-silicon oxide nanocomposite devices containing equal width (symmetric) tungsten and silicon oxide parallel line comb structures were developed and used by our group. The devices induced over 90% of seeded cells (Vero) to align within ±20° of the axes of 10 µm wide tungsten lines. Furthermore, a mathematical model was successfully developed to predict this alignment behavior and forecast the minimum width of isolated tungsten lines required to induce such behavior. However, the mechanism by which the widths of the symmetrical tungsten and silicon oxide lines induce the alignment behavior is still unknown. Furthermore, the model was never tested on more complex asymmetrical structures. Herewith, experiments were conducted with mammalian cells on complex asymmetrical structures with unequal tungsten and silicon oxide line widths. Results showed that the model could be extended to more complex pattern structures. In addition, cell morphology on the patterned structures reset during cell division because of mitotic rounding, which reduced the population of cells that elongated and aligned on the tungsten lines. Ultimately, we concluded that it was impossible to achieve a 100% alignment with cells having unsynchronized cell cycles because cell rounding during mitosis took precedence over cell alignment; in other words, internal chemical cues had a stronger role in cell morphology than external cues.

Pattern-Dependent Mammalian Cell (Vero) Morphology on Tantalum/Silicon Oxide 3D Nanocomposites.

The primary goal of this work was to investigate the resulting morphology of a mammalian cell deposited on three-dimensional nanocomposites constructed of tantalum and silicon oxide. Vero cells were used as a model. The nanocomposite materials contained comb structures with equal-width trenches and lines. High-resolution scanning electron microscopy and fluorescence microscopy were used to image the alignment and elongation of cells. Cells were sensitive to the trench widths, and their observed behavior could be separated into three different regimes corresponding to different spreading mechanism. Cells on fine structures (trench widths of 0.21 to 0.5 µm) formed bridges across trench openings. On larger trenches (from 1 to 10 µm), cells formed a conformal layer matching the surface topographical features. When the trenches were larger than 10 µm, the majority of cells spread like those on blanket tantalum films; however, a significant proportion adhered to the trench sidewalls or bottom corner junctions. Pseudopodia extending from the bulk of the cell were readily observed in this work and a minimum effective diameter of ~50 nm was determined for stable adhesion to a tantalum surface. This sized structure is consistent with the ability of pseudopodia to accommodate ~4⁻6 integrin molecules.

Shifting paradigms in restoration of the world's coral reefs.

Many ecosystems around the world are rapidly deteriorating due to both local and global pressures, and perhaps none so precipitously as coral reefs. Management of coral reefs through maintenance (e.g., marine-protected areas, catchment management to improve water quality), restoration, as well as global and national governmental agreements to reduce greenhouse gas emissions (e.g., the 2015 Paris Agreement) is critical for the persistence of coral reefs. Despite these initiatives, the health and abundance of corals reefs are rapidly declining and other solutions will soon be required. We have recently discussed options for using assisted evolution (i.e., selective breeding, assisted gene flow, conditioning or epigenetic programming, and the manipulation of the coral microbiome) as a means to enhance environmental stress tolerance of corals and the success of coral reef restoration efforts. The 2014-2016 global coral bleaching event has sharpened the focus on such interventionist approaches. We highlight the necessity for consideration of alternative (e.g., hybrid) ecosystem states, discuss traits of resilient corals and coral reef ecosystems, and propose a decision tree for incorporating assisted evolution into restoration initiatives to enhance climate resilience of coral reefs.

From Moment to Movement: Empowerment and Resilience as a Framework for Collective Action in Hong Kong.

The Transconceptual Model of Empowerment and Resilience (American Journal of Community Psychology, 52, 2013, 333) suggests that a set of resilience and empowerment resources fuel both initial and sustained participation in collective action. Using the case study of a prodemocracy movement in Hong Kong, the present study focused on the subset of those resources that are relevant in ongoing collective action: efficacy, skills, and maintenance. As individuals possess varying combinations of these resources, the present study utilized latent profile analysis to test how patterns of empowerment and resilience resources influence initial and long-term collective action. Five groups were identified: (a) Uncommitted/Uninspired; (b) Committed to Status Quo; (c) Mainstream Populist; (d) Empowered; and (e) Ambivalent. ANOVA and ANCOVA analyses found that there are significant group differences in initial and long-term participation. Groups with higher level of resources reported greater levels of initial participation than their counterparts; however, high resource groups did not uniformly report greater levels of intention to participate in future collective action. Of the maintenance processes tested, collective identity emerged as a particularly important predictor differentiating initial and sustained participation. Findings from the present study raise questions about how individuals with multiple identities can come together and participate in collective action.

Effects of long-term rofecoxib on gastric intestinal metaplasia: results of a randomized controlled trial.

PURPOSE: Gastric cancer and its premalignant gastric lesion, intestinal metaplasia (IM), frequently express cyclooxygenase-2 (COX-2) at high levels. We tested whether long-term use of specific COX-2 inhibitors regress gastric IM. EXPERIMENTAL DESIGN: This is a double-blind, randomized, placebo-controlled trial. Individuals with confirmed IM and Helicobacter pylori clearance were randomized to receive rofecoxib 25 mg daily or placebo. Endoscopy was done at baseline, at the end of year 1, and at the end of year 2, with multiple biopsies taken from the antrum and corpus. The primary end point was the proportion of subjects with regression of IM. Secondary end points were the severity of other histologic variables and the proportion of subjects with complete regression of IM. RESULTS: Two-hundred and thirteen subjects with confirmed IM were randomized. The proportion of subjects with the regression of IM did not differ significantly between rofecoxib and placebo groups (antrum, 24.5% versus 26.9%; P = 0.74; corpus, 4.3% versus 2.2%; P = 0.68). Patients on rofecoxib (19.1%) and on placebo (16.1%) had no IM detected in the stomach (P = 0.59). There was also no significant difference in the severity of IM between the two treatment groups (P >or= 0.3). CONCLUSIONS: There was no trend to suggest that treatment with rofecoxib for 2 years resulted in the regression of gastric IM. Although our findings cast doubt on the reversibility of gastric IM by COX-2 inhibitor, further studies are needed to establish the role of COX-2 inhibitors in different stages of gastric carcinogenesis.

Helicobacter pylori infection in 1st degree relatives of Chinese gastric cancer patients.

OBJECTIVE: Familial aggregation of gastric cancer has been linked to familial clustering of Helicobacter pylori infection. Patterns and risk factors associated with H. pylori infection were investigated in 1st degree relatives of Chinese gastric cancer patients. MATERIAL AND METHODS: Gastric cancer relatives were invited for screening endoscopy. H. pylori infection was diagnosed by endoscopic and serological methods. RESULTS: Among the 270 cancer relatives examined, 161 (59.6%) were found to be infected with H. pylori. The prevalence of infection in cancer relatives was significantly higher than age- and gender-matched dyspeptic control (45.5%, p=0.0006). The mean age of H. pylori-infected relatives was significantly older than that of non-infected relatives (43.9 versus 38.3 years; p<0.001). The prevalence of H. pylori infection was higher in those with more siblings (p=0.013, chi(2) test for trend). Moreover, individuals whose siblings had stomach cancer were more likely to have H. pylori infection than those with a parental history of cancer (68.2% versus 51.8%, p=0.007). In contrast, the youngest sibling had a significantly lower H. pylori infection rate than other siblings (39.2% versus 64.2%, p=0.001). Using multiple logistic regression, it was found that age >45 years (OR=1.8; 95% CI, 1.02-3.3) and a history of gastric cancer in siblings (OR=1.9; 95% CI, 1.06-3.3) were independent risk factors for H. pylori infection, and that the youngest sibling in the family had a reduced risk (OR=0.45; 95% CI, 0.24-0.84). CONCLUSIONS: This study identifies the patterns and risk factors for H. pylori in gastric cancer relatives, which may shed light on the evolving epidemiology of H. pylori infection in Chinese patients.

Cloning and characterization of Thermotoga maritima beta-glucuronidase.

The putative beta-glucuronidase from Thermotoga maritima, comprising 563 amino acid residues conjugated with a Hisx6 tag, was cloned and expressed in Escherichia coli. The enzyme has a moderately broad specificity, hydrolysing a range of p-nitrophenyl glycoside substrates, but has greatest activity on p-nitrophenyl beta-D-glucosiduronic acid (kcat=68 s(-1), kcat/K(M)= 4.5x10(5) M(-1) s(-1)). The enzyme also shows a relatively broad pH-dependence with activity from pH4.5 to 7.5 and a maximum at pH6.5. As expected the enzyme is stable towards heat denaturation, with a half life of 3h at 85 degrees C, in contrast to the mesophilic E. coli enzyme, which has a half life of 2.6h at 50 degrees C. The identity of the catalytic nucleophile was confirmed as Glu476 within the sequence VTEFGAD by trapping the glycosyl-enzyme intermediate using the mechanism-based inactivator, 2-deoxy-2-fluoro-beta-D-glucosyluronic acid fluoride and identifying the labeled peptide in peptic digests by HPLC-MS/MS methodologies. Consistent with this, the Glu476Ala mutant was shown to be hydrolytically inactive. The acid/base catalyst was confirmed as Glu383 by generation and kinetic analysis of enzyme mutants modified at that position, Glu383Ala and Glu383Gln. The demonstration of activity rescue by azide is consistent with the proposed role for this residue. This enzyme therefore appears suitable for use in enzymatic oligosaccharide synthesis in either the transglycosylation mode or by use of glycosynthase and thioglycoligase approaches.

Risk factors associated with the development of intestinal metaplasia in first-degree relatives of gastric cancer patients.

Family relatives of gastric cancer patients have a higher risk of gastric cancer and premalignant gastric lesions. We sought to determine the risk factors associated with the presence of intestinal metaplasia in a large cohort of gastric cancer relatives. First-degree relatives of gastric cancer patients were invited for screening gastroscopy. Endoscopic gastric biopsies were obtained from the antrum and corpus. Gastric biopsies were analyzed for Helicobacter pylori infection, severity of inflammation, and presence of intestinal metaplasia. Stepwise logistic regressions were used to identify for risk factors associated with presence of intestinal metaplasia in cancer relatives. Two hundred seventy cancer relatives underwent screening endoscopy (median age, 42; 47% male and 48% siblings). Among them, 161 (59.6%) were H. pylori positive and 81 (30%) had confirmed intestinal metaplasia. The following factors were found to be associated with the presence of intestinal metaplasia: age, male sex, H. pylori infection, birth order, alcohol use, siblings with stomach cancer, childhood living conditions, and water supply. Individuals with intestinal metaplasia had more severe acute and chronic inflammation in the antrum and corpus (P < 0.003). With multiple logistic regression, H. pylori infection [odds ratio (OR), 3.23], male gender (OR, 2.09), age (OR, 1.07), and a history of gastric cancer in siblings (OR, 1.91) were independent factors associated with the development of intestinal metaplasia in cancer relatives. In conclusion, we have identified risk factors associated with gastric intestinal metaplasia in stomach cancer relatives, which may be useful in the understanding of gastric carcinogenesis in these high-risk individuals.

Identification of the heterogeneous nuclear ribonucleoprotein A2/B1 as the antigen for the gastrointestinal cancer specific monoclonal antibody MG7.

MG7 is an early gastrointestinal cancer specific monoclonal antibody. It can detect gastric cancer with high sensitivity and specificity. However, the target antigen for MG7 has not been identified. Western blot analysis revealed that the MG7 antibody reproducibly recognized two approximately 35 kDa proteins in the total cell lysates of human gastric carcinoma cell lines KATO III and MKN-45. Using a proteomic approach, we identified these MG7 immunoreactive proteins as the human heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1). Western blot analysis of nuclear and cytosolic fraction of KATO III cells using either MG7 or hnRNP A2/B1 antibodies confirmed that the target antigen is located exclusively in the nucleus. With the use of archival samples, we also found that the level of hnRNP A2/B1 protein was increased in gastric cancer tissues (4 out of 5 patients), when compared to their corresponding matching normal stomach tissue.

AKT plays a role in the survival of the tumor cells of extranodal NK/T-cell lymphoma, nasal type.

Phosphorylated AKT has been detected in extranodal NK/T-cell lymphoma, nasal type (ENTL). Either interleukin-2 (IL-2) or interleukin-15 (IL-15) could prevent AKT dephosphorylation and apoptosis in the NK-92 cell line model. IL-15, but not IL-2, was preferentially elevated in patients' serum. AKT and IL-15 may be important in ENTL tumor survival.

Association of human-leukocyte-antigen class I (B*0703) and class II (DRB1*0301) genotypes with susceptibility and resistance to the development of severe acute respiratory syndrome.

Severe acute respiratory syndrome (SARS) is a public health concern worldwide. By studying the human leukocyte antigen (HLA) types A, B, DR, and DQ alleles in 90 Chinese patients with serologically confirmed SARS infections, we identified a strong association between HLA-B*0703 (OR, 4.08; 95% CI, 2.03-8.18; P=.00072 [Bonferroni-corrected P value, P(c) <.0022]) and -DRB1*0301 (OR, 0.06; 95%, 0.01-0.47; P=.00008 [after Bonferroni correction, P<.0042]) and the development of SARS. Moreover, the frequency of B*0703 and B60 coinheritance (9.6%; 95% CI, 4.6%-19.0%) in our SARS group was significantly higher (P=3x10(-9)) than that expected in the general population (0.4%). These genetic data will critically affect both the study of the pathogenesis of SARS and the design of vaccination programs.

Allelic imbalance mapped to 6q14.1 is associated with loss of expression of 5-HT receptor 1B in non-Hodgkin lymphomas.

Previous studies on lymphomas suggested that the long arm of chromosome 6 harbors 1 or more tumor suppressor genes. This study analyzed the status of 25 microsatellite markers in 39 cases, including 9 nodal and 30 extranodal, of non-Hodgkin lymphomas. Thirty of the 39 cases (77%) showed abnormality in at least 1 of the markers. Of the 655 informative results, 135 (20%) were abnormal. These included 5 homozygous deletions, 91 allelic imbalances (AI), and 38 microsatellite instability. The 2 commonest regions of abnormality were mapped to 6q14.1 and 6q27. There was no significant difference in the frequency of these regional losses between nodal and extranodal lymphomas, B-or T-cell lineage, and association with Epstein-Barr virus. The first common deletion region at 6q14.1 is flanked by the HTR1B (5-hydroxytryptamine receptor 1B) gene proximally and a novel unknown gene. AI in the region was found associated with loss of expression HTR1B by RT-PCR. The deletion region at 6q27 was narrowed to approximately 3Mb and maximal at marker D6S386. This locus includes the recently identified SMOC2 (secreted modular calcium-binding protein 2), AF6, and DLL1 (human delta-like 1 protein) genes. RT-PCR analyses of AF6 and DLL1 expression showed poor correlation with the AI results.

Allelic loss of chromosome 6q in gastric carcinoma.

Loss of the long arm of chromosome 6 (6q) has frequently been reported in gastric carcinoma, and most gastric cancer patients have evidence of intestinal metaplasia in the stomach. However, the relationship between loss of chromosome 6q and intestinal metaplasia has not been studied. In the first part of the study, we define the critical deletion region of chromosome 6q using loss of heterozygosity technique (LOH). Seventeen microsatellite markers were used to detect loss of heterozygosity (LOH) in 37 microdissected gastric tumors. We also examined intestinal metaplasia (IM) foci of the stomach in the same cancer patient (17 cases). Losses on chromosome 6q were detected in high frequency (51%) by LOH. Two distinct regions of common allelic loss were identified: one centered on the marker D6S300 (at 6q16.1) and the second on D6S446 (at 6q27), with LOH frequency of 36% and 31.3%, respectively. The deletions fall into 2 discrete regions, suggesting the existence of at least 2 tumor suppressor genes in 6q. The losses at 6q27 were confirmed by fluorescence in situ hybridization study (FISH). In the cases with LOH in the tumor, no LOH were detected in the autologous IM areas, but losses were detected by FISH. In some cases, these genetic changes may be acquired in the transition from normal gastric mucosa to intestinal metaplasia.

Recurrent genomic aberrations in gastric carcinomas associated with Helicobacter pylori and Epstein-Barr virus.

Helicobacter pylori and Epstein-Barr virus (EBV) both have been associated with gastric carcinoma. No specific genomic aberrations have been reported in association with these agents. We studied 20 cases of primary gastric carcinoma (including 11 positive for and 6 for EBV) by comparative genomic hybridization with validation of results by fluorescence in situ hybridization, loss of heterozygosity analysis, and immunohistochemistry. The results were analyzed in respect to presence or absence of and EBV. The tumors were also compared in terms of histologic type, tumor location, and lymph node metastases. The most frequently observed aberrations in the gastric carcinomas were gains of chromosome 19, 17, 1p, 11, 20q, and 22. The more common losses were found in 4q, 6q, 13q, and 15q. Gains in chromosome 19 and losses in 9p23-pter were found more commonly in cases with (P < 0.05). Gains in centromeric region of chromosome 19 were more common in the EBV-negative cases (P < 0.05). Immunohistochemical expression of and correlated with gains in the regions containing these genes. Gains in chromosome 11 and losses in 15q15 were more common in cases with EBV (P < 0.01 and P < 0.001, respectively). There was no significant association between any genomic aberration and histologic type, tumor location, or nodal metastases. and EBV are associated with different genomic imbalances, suggesting that these infectious agents exert different influences in the development of gastric carcinoma.

Changes of interleukin expression correlate with Helicobacter pylori infection and lymph node metastases in gastric carcinoma.

Helicobacter pylori (HP) infection induces expression of IL-8 and IL-10 in benign gastric epithelium. This study compared the expression of cytokines in CD4+ and CD8+ lymphocyte subsets of peripheral blood lymphocytes (PBL), benign mucosal lymphocytes (ML), and tumor infiltrative lymphocytes (TIL) as well as in the benign and malignant epithelial cells of the same patient, with respect to the presence of HP infection, lymph node metastases, and tumor histologic type. The mRNA of the cytokines was measured by a semiquantitative RT-PCR method. The levels were ranked and compared using the Wilcoxon sign-ranked test. Compared with CD8+ ML, the CD8+ TIL expresses higher levels of IL-6 and IL-8 but lower level of IL-4 in patients with lymph node metastases. In patients with HP infection, expression of IL-8 and IL-10 was higher in the gastric carcinoma cells than in the benign epithelial cells while expression of IL-6 and IL-8 were higher in CD8+ TIL than CD8+ ML. Overexpression of IL-8 in HP associated gastric carcinomas suggested that they might have arisen from HP-infected epithelial cells.