Lithographically defined uniform worm-shaped polymeric nanoparticles

We report a nanoimprint lithography method combined with photolithography on a bi-layer polymer setup to define nano-worms laterally in nano-gratings and produce uniform worm-shaped polymeric nanoparticles in aqueous solution by dissolving water soluble sacrificial layer poly(vinyl alcohol) (PVA). Process control of the thin residue layer, SU-8 curing using broadband UV source, and warm development to remove any residue are necessary to ensure success of this technique. The use of water soluble PVA as a releasing layer and elimination of an invasive plasma etching for the releasing process makes this protocol highly compatible with biomaterials. Direct release and suspension of fluorescent worm-shaped nanoparticles (length to width ratio up to 75) in aqueous solution were demonstrated. Compared to the worm-shaped nanoparticles made by self-assembly, these lithographically defined nano-worms have much better controllability and uniformity on the shape, size, and aspect ratio. The availability of these precisely defined non-spherical particles would be important to develop a comprehensive understanding of the shape effects of nanoparticles on their efficacy in nanomedicine applications.

Single-mode delivery of 250 nm light using a large mode area photonic crystal fiber

We demonstrate that large mode area (LMA) photonic crystal fibers (PCFs) can be used as single-mode patch-cords for 250 nm laser light. We have studied the transmission of the 250 nm output beam of a frequency-quadrupled diode laser through a triangular structure LMA PCF with 10 microm core. We have achieved single-mode output with coupling loss of 1.8 +/- 0.6 dB and transmission loss of 1.5 +/- 0.2 dB/m. The critical bend loss radius is approximately 6 cm. The transmission loss is compared with published bulk silica measurements. Effects of optically induced damage were observed after prolonged operation and have been studied as function of laser power and time. The optical damage occurs primarily at the fiber input and can be partly ameliorated by cleaving the fiber input. For input power levels of < approximately 0.3 mW stable operation can be achieved for periods of >40 hours which is sufficient for many laboratory based applications. The results show the utility of these fibers for single-mode beam delivery in a spectral region where step-index single-mode fibers are not readily available.

Perfluorinated contaminants in fur seal pups and penguin eggs from South Shetland, Antarctica

Perfluorinated compounds (PFCs) have emerged as a new class of global environmental pollutants. In this study, the presence of perfluorochemicals (PFCs) in penguin eggs and Antarctic fur seals was reported for the first time. Tissue samples from Antarctic fur seal pups and penguin eggs were collected during the 2003/04 breeding season. Ten PFC contaminants were determined in seal and penguin samples. The PFC concentrations in seal liver were in the decreasing order, PFOS>PFNA>PFHpA>PFUnDA while in Adélie penguin eggs were PFHpA>PFUnDA>PFDA>PFDoDA, and in Gentoo penguin eggs were PFUnDA>PFOS>PFDoDA>PFHpA. The PFC concentrations differed significantly between seals and penguins (p<0.005) and a species-specific difference was found between the two species of penguins (p<0.005). In our study we found a mean concentration of PFOS in seal muscle and liver samples of 1.3 ng/g and 9.4 ng/g wet wt, respectively, and a mean concentration in Gentoo and Adélie penguin eggs of 0.3 ng/g and 0.38 ng/g wet wt, respectively. PFCs detected in penguin eggs and seal pups suggested oviparous and viviparous transfer of PFOS to eggs and off-springs.

Stemness signature of BMI1 and clinical outcome in esophageal cancer patients undergoing neoadjuvant chemoradiotherapy

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Background: The polycomb group (PcG) family BMI1, acting downstream of the hedgehog (Hh) pathway, plays an essential role in the self-renewal of hematopoietic, neural, and intestinal stem cells, and is dysregulated in many types of cancer. Our recent report has demonstrated that Gli-1 nuclear expression indicative of Hh signalling activation can predict very poorer prognosis of esophageal squamous cell carcinomas (ESCCs)(Br J Cancer 2008). As data were not available on the clinical role of BMI1 expression, we analyzed whether it could be also used to predict disease progression and prognosis in ESCC patients undergoing neoadjuvant chemoradiotherapy (CRT). Methods: BMI1, Gli-1, and p16INK4A expressions were evaluated in 78 ESCC patients by immunohistochemical staining. All patients underwent preoperative chemoradiotherapy; 40 Gy irradiation plus FP (5- FU and CDDP) regimen. Results: In total, 24 out of 78 patients (30.8%) showed BMI1 positive expression. All Gli- 1 nuclear positive cancers expressed BMI1. There was no significant correlation between p16INK4A expression and BMI1 expression. Overall survival (OS) was significantly correlated with the absence of BMI1 expression. The patients with BMI1-positive cancers showed significantly poorer prognoses than those without (mean disease-free survival (DFS) time 16.8 vs 71.2 months, P<0.005; mean OS time 21.8 vs 76.6 months, P<0.001). Conclusions: We demonstrated that BMI1 expression indicative of PcG protein chromatin silencing pathway activation was significantly correlated with esophageal cancer recurrence and poor prognosis after CRT, and that it was not inversely correlated with the presence of the downstream target p16INK4A. These findings suggest that the stemness signature including components of Hh and PcG pathways might be involved in promoting cancer regrowth and progression after CRT, and is thus a potential prognostic biomarker and rational therapeutic target for attacking the “more aggressive” cancer cells causing recurrence.

No significant financial relationships to disclose.

The effect of proton pump inhibitors on the human microbiota

Proton pump inhibitors (PPIs) are commonly used to treat acid-related diseases, most notably gastroesophageal reflux disease. PPIs are designed to shut down the gastric proton pump (H+/K+-ATPase) of parietal cells, thereby raising the pH of the stomach. While effective, a number of side effects have been associated with PPI use. Naturally occurring bacteria, some of which are acid-producing and contain ATPase enzymes, have also been found within the stomach, upper gastrointestinal tract, and oral cavity. Likewise, a number of fungi are known to inhabit the human body; some of these fungi contain H+-ATPase enzymes. Recent literature has suggested that PPIs may be inadvertently affecting these bacteria and fungi in two different ways: 1) PPIs may directly target the proton pumps of the bacteria and fungi, and/or 2) PPIs may indirectly affect the microenvironment of the flora via changes in pH. These unintended interactions are exasperated by the systemic distribution of PPIs throughout the body and may potentially lead to some of the side effects observed with PPI use. Herein we summarize what is currently known about the interactions between the PPIs and the natural human microbiota.

Aspisol inhibits tumor growth and induces apoptosis in breast cancer

Nonsteroidal anti-inflammatory drugs inhibit cell proliferation and induce apoptosis in various cancer cell lines, which is considered to be an important mechanism for their anti-tumor activity and cancer prevention. However, the molecular mechanisms through which these compounds induce apoptosis are not well understood.

AIM

to determine the effects of nonselective cyclooxygenase-2 (COX-2) inhibitor, aspisol on breast cancer cells in vitro and in vivo.

METHODS

The cytotoxic activity of aspisol was evaluated by MTT assay. The apoptosis index of cells was measured by flow cytometry. Immunohistochemical staining was used to detect expressions of COX-2 and caspase-3 in MDA-MB-231 cells. The expression of bcl-2 and bax was analyzed by Western blot analysis. The content of prostaglandin E2 (PGE2) in MDA-MB-231 cells was estimated by ELISA. In vivo apoptosis of the tumor cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL).

RESULTS

Our results showed that aspisol reduced viability of MDA-MB-231 cells in time- and dose- dependent fashions and induced apoptosis by increase of caspase-3 and bax expressions while decrease of COX-2 and bcl-2 expression in vitro. In addition, exposure to aspisol decreased the basal release of PGE2. In vivo, aspisol also inhibited the proliferation of breast cancer cells and induced their apoptosis.

CONCLUSIONS

Our in vitro and in vivo data indicated that the antitumor effects of aspisol on breast cancer cells was probably mediated by the induction of apoptosis, and it could be linked to the downregulation of the COX-2 or bcl-2 expression and up-regulation of caspase-3 or bax expression.

Cavity ring-down spectroscopy sensor for ion beam etch monitoring and end-point detection of multilayer structures

This contribution reports on the development of in situ sputter monitoring and end-point detection for ion beam etch systems using continuous-wave cavity ring-down spectroscopy (cw-CRDS). The demonstrated system is based on the detection of sputtered manganese atoms using a tunable external cavity diode laser in the vicinity of 403.07 nm. The cw-CRDS system is described and measurements from a manganese-iron target are presented. End-point detection is demonstrated by monitoring the time dependence of manganese concentration for a multilayer target comprised of alternating layers of manganese/iron and titanium. Detection limits are shown to be adequate for today's commercial ion beam sputter systems.

Prediction of antibiotic resistance proteins from sequence-derived properties irrespective of sequence similarity

Increasing antibiotic resistance has become a worldwide challenge to the clinical treatment of infectious diseases. The identification of antibiotic resistance proteins (ARPs) would be helpful in the discovery of new therapeutic targets and the design of novel drugs to control the potential spread of antibiotic resistance. In this work, a support vector machine (SVM)-based ARP prediction system was developed using 1308 ARPs and 15587 non-ARPs. Its performance was evaluated using 313 ARPs and 7156 non-ARPs. The computed prediction accuracy was 88.5% for ARPs and 99.2% for non-ARPs. A potential application of this method is the identification of ARPs non-homologous to proteins of known function. Further genome screening found that ca. 3.5% and 3.2% of proteins in Escherichia coli and Staphylococcus aureus, respectively, are potential ARPs. These results suggest the usefulness of SVMs for facilitating the identification of ARPs. The software can be accessed at SARPI (Server for Antibiotic Resistance Protein Identification).

Hedgehog signal activation in oesophageal cancer patients undergoing neoadjuvant chemoradiotherapy

The zinc finger protein glioma-associated oncogene homologue 1 (Gli-1) is a critical component of the Hedgehog (Hh) signalling pathway, which is essential for morphogenesis and stem-cell renewal, and is dysregulated in many cancer types. As data were not available on the role of Gli-1 expression in oesophageal cancer progression, we analysed whether it could be used to predict disease progression and prognosis in oesophageal cancer patients undergoing neoadjuvant chemoradiotherapy (CRT). Among 69 patients with histologically confirmed oesophageal squamous cell carcinomas (ESCCs), 25 showed a pathological complete response after preoperative CRT. Overall survival (OS) was significantly associated with lymph-node metastasis, distant metastasis, and CRT, and was further correlated with the absence of both Gli-1 nuclear expression and residual tumour. All patients with Gli-1 nuclear expression (10.1%) had distant or lymph-node metastasis, and six out of seven died within 13 months. Furthermore, patients with Gli-1 nuclear-positive cancers showed significantly poorer prognoses than those without (disease-free survival: mean DFS time 250 vs 1738 months, 2-year DFS 0 vs 54.9%, P=0.009; OS: mean OS time 386 vs 1742 months, 2-year OS 16.7 vs 54.9%, P=0.001). Our study provides the first evidence that Gli-1 nuclear expression is a strong and independent predictor of early relapse and poor prognosis in ESCC after CRT. These findings suggest that Hh signal activation might promote cancer regrowth and progression after CRT.

Durable diamond-like carbon templates for UV nanoimprint lithography

The interaction between resist and template during the separation process after nanoimprint lithography (NIL) can cause the formation of defects and damage to the templates and resist patterns. To alleviate these problems, fluorinated self-assembled monolayers (F-SAMs, i.e. tridecafluoro-1,1,2,2,tetrahydrooctyl trichlorosilane or FDTS) have been employed as template release coatings. However, we find that the FDTS coating undergoes irreversible degradation after only 10 cycles of UV nanoimprint processes with SU-8 resist. The degradation includes a 28% reduction in surface F atoms and significant increases in the surface roughness. In this paper, diamond-like carbon (DLC) films were investigated as an alternative material not only for coating but also for direct fabrication of nanoimprint templates. DLC films deposited on quartz templates in a plasma enhanced chemical vapor deposition system are shown to have better chemical and physical stability than FDTS. After the same 10 cycles of UV nanoimprints, the surface composition as well as the roughness of DLC films were found to be unchanged. The adhesion energy between the DLC surface and SU-8 is found to be smaller than that of FDTS despite the slightly higher total surface energy of DLC. DLC templates with 40 nm features were fabricated using e-beam lithography followed by Cr lift-off and reactive ion etching. UV nanoimprinting using the directly patterned DLC templates in SU-8 resist demonstrates good pattern transfer fidelity and easy template-resist separation. These results indicate that DLC is a promising material for fabricating durable templates for UV nanoimprint lithography.

Determination of male age at death in Chinese Han population: Using quantitative variables statistical analysis from pubic bones

Determination of age at death by skeletal features is difficult, but important, both in forensic and physical anthropology. Pubic symphysis is a widely accepted morphological indicator, which provides the best result for personal age identification. Age prediction in this study used nine indicators of morphological changes, viz: ridges and furrows on the symphysial surface, ridge of pubic tubercle, lower extremity, ventral beveling, ossific nodules, dorsal margin, ventral rampart, general macroscopic changes of symphysial surface, and bone density of the symphysial surface. Samples were drawn from 262 male individuals. The study procedures are as follows: Firstly, we examined the morphological features of pubic symphysis using criteria similar to Hanihara's and Suchey-Brooks (SB). Secondly, we evaluated each stage with an appropriate score. Thirdly, we deduced four equations of male age assessment of morphological features by statistic analysis. The results were compared with Hanihara's and Suchey-Brooks method; the similarities and differences among them were discussed objectively. The method produced consistent results as well as developing the criteria of Hanihara's and Suchey-Brooks'.

Species diversity and relative abundance of vaginal lactic acid bacteria from women in Uganda and Korea

AIMS

Lactobacilli play an important role in maintaining vaginal health of women. The aim of this study was to compare the species richness and relative abundance of Lactobacillus and other lactic acid bacteria in women of two geographically distant countries, Uganda and Korea.

METHODS AND RESULTS

Vaginal samples were obtained from two women populations in Uganda and Korea. The Lactobacillus Rogosa SL agar was used for initial isolation of lactic acid bacteria. After phenotypic analyses, the 16S rRNA gene was amplified by polymerase-chain reaction and analysed by the BLAST program and phylogenetic tree construction. A total of 338 (128 Korean and 210 Ugandan) vaginal lactic acid bacterial strains were isolated, including five genera: Lactobacillus, Leuconostoc, Pediococcus, Streptococcus and Weissella. While Lactobacillus crispatus was common in both populations, Lactobacillus fermentum was common only in Korean women, and Lactobacillus gasseri, Lactobacillus reuteri and Lactobacillus vaginalis only in Ugandan women. Among other lactic acid bacteria, Weissella was more common in Ugandan, and Pediococcus in Korean women. All Weissella strains produced hydrogen peroxide, and all Pediococcus strains inhibited Candida species.

CONCLUSION

Although many lactic acid bacteria colonize women, their species distributions may be different in women of geographically separated communities.

SIGNIFICANCE AND IMPACT OF THE STUDY

The knowledge of species richness and relative abundance of vaginal lactic acid bacteria, including Lactobacillus, Pediococcus and Weissella, may lead to the design of better probiotic products as bacterial replacement therapy.