A nanomaterial-based breath test for distinguishing gastric cancer from benign gastric conditions

Background:

Upper digestive endoscopy with biopsy and histopathological evaluation of the biopsy material is the standard method for diagnosing gastric cancer (GC). However, this procedure may not be widely available for screening in the developing world, whereas in developed countries endoscopy is frequently used without major clinical gain. There is a high demand for a simple and non-invasive test for selecting the individuals at increased risk that should undergo the endoscopic examination. Here, we studied the feasibility of a nanomaterial-based breath test for identifying GC among patients with gastric complaints.

Methods:

Alveolar exhaled breath samples from 130 patients with gastric complaints (37 GC/32 ulcers / 61 less severe conditions) that underwent endoscopy/biopsy were analyzed using nanomaterial-based sensors. Predictive models were built employing discriminant factor analysis (DFA) pattern recognition, and their stability against possible confounding factors (alcohol/tobacco consumption; Helicobacter pylori) was tested. Classification success was determined (i) using leave-one-out cross-validation and (ii) by randomly blinding 25% of the samples as a validation set. Complementary chemical analysis of the breath samples was performed using gas chromatography coupled with mass spectrometry.

Results:

Three DFA models were developed that achieved excellent discrimination between the subpopulations: (i) GC vs benign gastric conditions, among all the patients (89% sensitivity; 90% specificity); (ii) early stage GC (I and II) vs late stage (III and IV), among GC patients (89% sensitivity; 94% specificity); and (iii) ulcer vs less severe, among benign conditions (84% sensitivity; 87% specificity). The models were insensitive against the tested confounding factors. Chemical analysis found that five volatile organic compounds (2-propenenitrile, 2-butoxy-ethanol, furfural, 6-methyl-5-hepten-2-one and isoprene) were significantly elevated in patients with GC and/or peptic ulcer, as compared with less severe gastric conditions. The concentrations both in the room air and in the breath samples were in the single p.p.b._v range, except in the case of isoprene.

Conclusion:

The preliminary results of this pilot study could open a new and promising avenue to diagnose GC and distinguish it from other gastric diseases. It should be noted that the applied methods are complementary and the potential marker compounds identified by gas-chromatography/mass spectrometry are not necessarily responsible for the differences in the sensor responses. Although this pilot study does not allow drawing far-reaching conclusions, the encouraging preliminary results presented here have initiated a large multicentre clinical trial to confirm the observed patterns for GC and benign gastric conditions.

Condom use, intervention service utilization and HIV knowledge among female sex workers in China: results of three consecutive cross-sectional surveys in Shandong Province with historically low HIV prevalence

Heterosexual transmission of HIV through contact with female sex workers (FSWs) is a growing concern for the HIV/AIDS epidemic in China. Using consecutive cross-sectional surveys, we examined the prevalence of HIV and sexually transmitted infections (STIs), risk behaviours, HIV knowledge and the utilization of intervention services among FSWs in Shandong Province. Of 3460 participants, half reported ever having STI-related symptoms, 57.8% had ≥7 clients in the last week, half reported inconsistent use of condoms with clients and 11.2% reported ever using illicit drugs. Consistent use of condoms with clients was associated with higher education, being 20-24 years of age, being recruited from hotels, having ever received free condoms and was inversely associated with STI-related symptoms. HIV-related knowledge was associated with higher education, ever testing for HIV and inversely associated with self-reported STI-related symptoms. The low rates of condom use, high number and frequent turnover of clients, high prevalence of self-reported STIs and drug use highlight the urgency for more effective intervention in these FSWs.

Solid pseudopapillary tumour of the pancreas in children: clinical and computed tomography manifestation

PURPOSE

The purpose of our study was to retrospectively assess imaging features of computed tomography (CT) and clinical characteristics of children with solid pseudopapillary tumours (SPTs) of the pancreas in comparison with those of SPTs in adults.

MATERIALS AND METHODS

CT images and clinical data of 86 patients with histopathologically proven SPTs were reviewed. Eighteen patients were classified as children (≤18 years old), and 68 were classified as adults (>18 years old) according to age at diagnosis. Statistical analysis was performed using the χ (2) test and the Student's t test.

RESULTS

Eighteen patients (15 girls and three boys) were children, with an average age of 15.1 years at operation. Abdominal pain or discomfort was the most common manifestation in children (66.7%). Mean tumour size in children was significantly larger than in adults (9.1 vs. 5.7 cm; p=0.001). Except for tumour size, no significant statistical difference was observed in clinical factors or imaging features between SPTs in children and adults.

CONCLUSIONS

Ours is the largest single-centre study to demonstrate the features of pancreatic SPT in children. SPT diagnosis should always be considered when a large pancreatic mass with typical imaging is found in a child, especially in adolescent girls.

Recombinant adenovirus Ad-RUNrf2 reduces paraquat-induced A549 injury

OBJECTIVE

An RU486-inducible recombinant adenovirus-Nrf2 construct (Ad-RUNrf2) was constructed and expressed in H460 cells to determine whether Nrf2 gene expression can be regulated and to observe the effect of the adenovirus Ad-RUNrf2 on inflammatory cytokines, oxidative stress and apoptotic factors that mediate paraquat (PQ)-induced A549 cell injury.

METHODS

The Nrf2 gene within the RU486 (mifepristone)-inducible system was introduced into an adenovirus vector. A549 cells were transfected with Ad-RUNrf2, and Nrf2 expression was detected using Western blotting and real time-polymerase chain reaction (RT-PCR). RT-PCR, Western blots and enzyme-linked immunosorbent assay were used for observing the effect of RU486-induced Nrf2 expression on the inflammatory cytokines (interleukin-6 (IL-6), IL-10 and tumor necrosis factor-α (TNF-α)), oxidative stress factors (catalase (CAT) and malondialdehyde (MDA)) and apoptosis factors (caspase-3, caspase-9 and cytochrome C) that mediated PQ-induced A549 cell injury.

RESULTS

After infection of H460 cells by Ad-RUNrf2, RT-PCR and Western blot analyses showed that Nrf2 expression increased with additional RU486 doses. IL-6 and TNF-α protein and gene expression levels were significantly reduced, and IL-10 protein levels were significantly increased. Although IL-10 expression increased, it remained significantly lower than that of noninduced adenovirus infection and the simple virus exposure group. RU486 induced a significant reduction in MDA expression and increased CAT protein levels. Caspase-9 and caspase-3 protein and gene expression levels decreased in the RU486 induction group (p < 0.05). Cytochrome C protein levels were not significantly reduced, but its gene expression was significantly decreased (p < 0.05).

CONCLUSION

Ad-RUNrf2 adenovirus was successfully constructed and can be stably expressed and regulated in cells. Ad-RUNrf2 can reduce PQ-induced inflammation, oxidative stress and apoptosis in A549 cells.

Identification and characterization of pig embryo microRNAs by Solexa sequencing

MicroRNAs (miRNAs) are a class of small, non-coding RNAs of approximately 22 nucleotides in length that regulate gene expression by binding to the 3'-untranslated regions of target mRNAs. It is now clear that miRNAs are involved in many biological processes, including proliferation, differentiation and regulation of gene expression during early embryonic development. The miRBase 16.0 (2010) shows that there are 175, 673, 408 and 1048 annotated miRNAs for Caenorhabditis elegans, Mus musculus, Rattus norvegicus and Homo sapiens, respectively. However, there are only 211 miRNAs described for Sus scrofa. In particular, the full set of miRNAs and their expression patterns are still poorly understood in the embryo. Therefore, we combined Solexa sequencing with computational techniques to analyse the sequences and relative expression levels of S. scrofa miRNAs at embryonic day 33 (E33). Of the distinct miRNAs identified, 76 previously known miRNAs and 194 candidate miRNAs were identified in head, and 77 known miRNAs and 130 predicted candidate miRNAs were identified in organ region. Furthermore, we performed additional investigation for identifying the potential target mRNAs using PicTar and TargetScan. Concurrent function analysis suggested that highly expressed miRNAs are mostly involved in the development of nerves, cerebrum, muscle and organs. Our results provide useful information for the investigation into embryonic miRNAs of pig and provide a valuable resource for investigators interested in the regulation of embryonic development in pigs and other animals.

Isolation of fertility-related genes of multiple-allele-inherited male sterility in Brassica rapa ssp pekinensis by cDNA-AFLP

To better understand the molecular mechanisms of multiple-allele-inherited male sterility in Chinese cabbage (Brassica rapa ssp pekinensis), differentially expressed genes in fertile and sterile plants must be isolated. We used cDNA-AFLP analysis to isolate differentially expressed genes in fertile and sterile buds of the two-type line, AB01. Sixteen high-quality sequences were generated, 11 of which were up-regulated in fertile buds, and five of which were up-regulated in sterile buds. Based on BLAST screening and functional annotation, these genes have homology with genes encoding known flower- or bud-specific proteins, metabolism-related proteins and cell-structure proteins. In addition, the full-length cDNA sequences of the actin gene were cloned from the cabbage plants by RACE and used as an internal standard for semi-quantitative reverse transcription-PCR. Expression of three flower- or bud-specific differentially expressed transcript-derived fragments in fertile and sterile buds was examined using RT-PCR; the expression patterns of these genes were similar to the patterns observed in the cDNA-AFLP analysis.

Rectal cancer: 3D dynamic contrast-enhanced MRI; correlation with microvascular density and clinicopathological features

PURPOSE

The primary aim of this prospective study was to evaluate the relationship between three-dimensional dynamic contrast-enhanced magnetic resonance (3D-DCE-MR) imaging parameters and clinicopathological features of rectal cancer and assess their potential as new radiological prognostic predictors.

MATERIALS AND METHODS

Three-dimensional DCE-MR was performed on 26 cases of pathologically proved rectal adenocarcinoma 1 week prior to operation. Data were analysed to calculate transfer constant (Ktrans), leakage space (Ve) and rate constant (Kep) of both tumour and normal rectal wall. Microvessel density (MVD) was evaluated by immunohistochemical staining of surgical specimens. All findings were analysed prospectively and correlated with tumour/node/metastasis (TNM) staging, Dukes staging, histological grading, presence of lymph node metastasis, serosal involvement and MVD.

RESULTS

Mean Ktrans, Ve and Kep for tumours were as follows: Ktrans 7.123±3.850/min, Ve 14.2±3.0%, Kep 49.446±20.404/min, revealing the significant difference between the tumour and normal rectal wall (p=0.001). There was a significant difference for Ktrans not only between patients with and without lymphatic involvement (p=0.000), but also among Dukes staging (p=0.04) and pTNM staging (p=0.03). Kep showed moderate correlation with TNM stages (r=0.479, p=0.02). Ve and MVD revealed no significant correlation with the clinicopathological findings described above (p>0.05).

CONCLUSION

Owing to the moderate and strong relationship between Ktrans and clinicopathological elements, Ktrans might be the prognostic indicator of rectal cancer. Threedimensional DCE high-resolution MR imaging provides a competing opportunity to assess contrast kinetics.

Local adaptation for body color in Drosophila americana

Pigmentation is one of the most variable traits within and between Drosophila species. Much of this diversity appears to be adaptive, with environmental factors often invoked as selective forces. Here, we describe the geographic structure of pigmentation in Drosophila americana and evaluate the hypothesis that it is a locally adapted trait. Body pigmentation was quantified using digital images and spectrometry in up to 10 flies from each of 93 isofemale lines collected from 17 locations across the United States and found to correlate most strongly with longitude. Sequence variation at putatively neutral loci showed no evidence of population structure and was inconsistent with an isolation-by-distance model, suggesting that the pigmentation cline exists despite extensive gene flow throughout the species range, and is most likely the product of natural selection. In all other Drosophila species examined to date, dark pigmentation is associated with arid habitats; however, in D. americana, the darkest flies were collected from the most humid regions. To investigate this relationship further, we examined desiccation resistance attributable to an allele that darkens pigmentation in D. americana. We found no significant effect of pigmentation on desiccation resistance in this experiment, suggesting that pigmentation and desiccation resistance are not unequivocally linked in all Drosophila species.

Immunomodulated signaling in macrophages: Studies on activation of Raf-1, MAPK, cPLA(2) and secretion of IL-12

Little is known about the mechanism and signal transduction by LPS-mediated immunomodulation of murine peritoneal macrophages. It is found that the signal molecules of the down-stream of Ras, Raf-1, MAPK p44, and MAPK p42 are phosphorylated, and cPLA(2) is activated with a significant increase of the release of [ H(3) ] AA by macrophages in response to LPS and PMA. Compared with the very recent finding that LPS and PMA trigger the activation and translocation of PKC-alpha and PKC-epsilon, these findings suggest that there is a connection between PKC signaling pathway and the Raf-1/MAPK pathway and that the activation of these main signaling events may be closely related to the secretion of IL-12 during LPS-induced modulation of macrophages.

The C242T CYBA polymorphism as a major determinant of NADPH oxidase activity in patients with cardiovascular disease

Single nucleotide polymorphisms (SNP) in the CYBA gene encoding p22(phox) have been associated with respiratory burst and cardiovascular phenotypes. We previously reported a reduced phagocytic respiratory burst activity in healthy adults with the C242T SNP, but found no correlation between CYBA SNPs and coronary artery disease (CAD) phenotype. Using lymphoblastoid cells, we hypothesized that CYBA SNPs affect enzyme activity in patients with cardiovascular disease (CVD), but would not be associated with angiographic severity of CAD due to confounding by risk factors. We established lymphoblastoid cell lines from patients with CVD and genotyped the study cohort for CYBA SNPs and phenotyped each subject's coronary angiogram for CAD severity. As quantified by electron spin resonance, superoxide production in picomoles per 10(6) resting lymphoblastoid cells per minute for the CC, CT, and TT genotypes of the C242T SNP were 16.2+/-1.4, n=70, 11.9+/-0.7, n=87, and 11.9+/-1.5, n=28, respectively (P=0.002). The -930(A/G) and A640G SNPs did not affect superoxide production (P > 0.2). Expression of p22(phox) was not affected as determined by real-time RT-PCR and Western blot analysis. The C242T CYBA SNP is associated with altered NADPH oxidase activity in lymphoblastoid cells of patients with CVD. By reducing the influence of confounding environmental factors, lymphoblastoid cell lines could serve as a tool to assess direct genotype/phenotype interactions of candidate genes known to affect atherosclerosis.

The value of multidetector-row CT in the preoperative detection of pancreatic insulinomas

PURPOSE

The authors sought to quantitatively analyse enhancement characteristics of pancreatic insulinomas in different phases and determine the value of multidetector-row computed tomography (CT) for detecting insulinomas.

MATERIALS AND METHODS

Forty-six patients with surgically proven insulinomas diagnosed between 2002 and 2007 were retrospectively reviewed. These patients underwent single-phase (group 1) or dual-phase (group 2) helical CT scanning.

RESULTS

Sensitivity for detecting insulinomas in group 2 was superior to that in group 1 (p<0.05).The sensitivity for insulinoma detection in the arterial phase was superior to that in the portal-venous phase (p<0.05). The mean attenuation values of the insulinomas and normal pancreas during the unenhanced arterial and portal-venous phases were, respectively, 40.5+/-8.75 HU (Hounsfield units), 114.48+/-27.30 HU, 112.19+/-19.52 HU and 44.56+/-6.48 HU, 81.16+/-15.22 HU, 90.54+/-13.80 HU, and there was statistical difference between them (p=0.000). The contrast enhancement of insulinomas in the arterial and portal-venous phases was 74.03+/-29.51 HU and 70.90+/-21.93 HU, respectively, and there was no statistical difference between them (p=0.499). The tumour to normal-pancreas attenuation differences in the arterial and portal-venous phases were respectively 33.32+/-20.96 HU and 20.58+/-16.32 HU, respectively, and there was statistical difference between them (p=0.011).

CONCLUSIONS

Dual-phase CT has a promising sensitivity in detecting pancreatic insulinomas. The acquisition of images in the arterial phase is more helpful for detecting insulinomas.

The role of magnetoelastic strain on orbital control and transport properties in an LaTiO(3)-CoFe(2)O(4) heterostructure

Epitaxial heterostructures of CoFe(2)O(4)/LaTiO(3)/LaAlO(3) have been successfully prepared by using the pulsed laser deposition technique. The magnetoresistance (MR) of the samples is negative and linear with field at H≥2 T, exhibiting no dependence on field directions. Nevertheless, when H<2 T, the MR is negative in a field parallel to the sample plane, but positive in that along the film normal. This novel observed anisotropic MR is explained in terms of the magnetic anisotropy in the ferrimagnetic layer, as well as the magnetoelastic coupling between the two. In fields of different directions, the top CoFe(2)O(4) layer contracts or expands in the sample plane due to the significant magnetostriction effect, changing its resistance accordingly and exerting compressive or tensile strains on the bottom LaTiO(3) layer. Apparently the orbital status and the one-electron bandwidth in the LaTiO(3) layer are altered, which leads to a change in resistance.

Analysis of expressed sequence tags from Uromyces appendiculatus hyphae and haustoria and their comparison to sequences from other rust fungi

Hyphae, 2 to 8 days postinoculation (dpi), and haustoria, 5 dpi, were isolated from Uromyces appendiculatus infected bean leaves (Phaseolus vulgaris cv. Pinto 111) and a separate cDNA library prepared for each fungal preparation. Approximately 10,000 hyphae and 2,700 haustoria clones were sequenced from both the 5' and 3' ends. Assembly of all of the fungal sequences yielded 3,359 contigs and 927 singletons. The U. appendiculatus sequences were compared with sequence data for other rust fungi, Phakopsora pachyrhizi, Uromyces fabae, and Puccinia graminis. The U. appendiculatus haustoria library included a large number of genes with unknown cellular function; however, summation of sequences of known cellular function suggested that haustoria at 5 dpi had fewer transcripts linked to protein synthesis in favor of energy metabolism and nutrient uptake. In addition, open reading frames in the U. appendiculatus data set with an N-terminal signal peptide were identified and compared with other proteins putatively secreted from rust fungi. In this regard, a small family of putatively secreted RTP1-like proteins was identified in U. appendiculatus and P. graminis.

Selective targeting of pigmented retinal pigment epithelial (RPE) cells by a single pulsed laser irradiation: an in vitro study

This work describes the selective targeting of pigmented retinal pigment epithelial (RPE) cells by a single pulsed laser irradiation. We observed: (1) single pulsed laser irradiation caused cellular damages on pigmented, and not on non-pigmented RPE cells at laser radiant exposure up to 2550 mJ/cm(2); (2) in the mixture of pigmented and non-pigmented RPE cells, single pulsed laser-induced damage was confined to pigmented RPE cells. This study demonstrates that the pigmented RPE cells can be selectively damaged, using a single pulsed laser irradiation, without thermal coagulation to adjacent non-pigmented RPE cells.

Proximal magnetometry in thin films using betaNMR

Low energy ion implantation of hyperpolarized radioactive magnetic resonance probes allows the NMR study of thin film heterostructures by enabling depth-resolved measurements on a nanometer lengthscale. By stopping the probe ions in a layer adjacent to a layer of interest, it is possible to study magnetic fields proximally. Here we show that, in the simplest case of a uniformly magnetized layer, this yields an unperturbed in situ frequency reference. We also discuss demagnetization contributions to measured shifts for this case. With a simple illustrative calculation, we show how a nonuniformly magnetized layer causes a strongly depth-dependent line broadening in an adjacent layer. We then give some experimental examples of resonance line broadening in heterostructures.