25 research outputs found
Longitudinal assessment of PCBs and chlorinated pesticides in pregnant women from Western Canada
BACKGROUND: Maternal exposures to organochlorines prior to pregnancy are considered a risk to neonatal welfare, specifically in relation to neurocognitive functions. There is growing interest in the evaluation of maternal blood testing as a marker for fetal exposure as well as the variable geographic distribution of these priority chemicals. METHODS: Three hundred and twenty-three women in the second trimester of pregnancy entered the study at a prenatal clinic providing genetic counselling information. Subjects who had an indication for genetic amniocentesis based on late maternal age were eligible to participate. Two hundred and thirty-eight completed an environmental questionnaire. A sample of amniotic fluid was taken for karyotype analysis in 323 women and blood samples during pregnancy (209), at birth (105) and from the umbilical cord (97) and breast milk (47) were also collected. These samples were tested for 29 PCB congeners and organochlorine pesticides. RESULTS: The concentrations of PCB 153 in these media were relatively low in relation to other studies. ÎŁ PCBs measurements in samples taken during the second trimester of pregnancy, at birth and in the umbilical cord were strongly correlated. Specific measurements of PCB 153 and PCB 180 among those subjects with completed sampling of blood samples from mothers and cord samples were significantly correlated. The concentrations of PCBs and pesticides did not differ in relation to prior spontaneous abortion history. There were no organochlorines present in the amniotic fluid at the current level of quantification. CONCLUSION: Pregnant women from the Western Canada region of Calgary, Alberta are exposed to relatively low concentrations of organochlorines. Measurement of maternal blood during the second trimester of pregnancy can reliably estimate the fetal exposure to PCBs. This estimate is reliable for Group 2 and 3 PCBs as well as PCB 153 and PCB 180. The amniotic fluid does not contain measurable concentrations of pesticides and PCBs under the conditions of the levels of quantification
Perineural invasion in pancreatic cancer: proteomic analysis and in vitro modelling.
Perineural invasion (PNI) is a common and characteristic feature of pancreatic ductal adenocarcinoma (PDAC) that is associated with poor prognosis, tumor recurrence, and generation of pain. However, the molecular alterations in cancer cells and nerves within PNI have not previously been comprehensively analysed. Here, we describe our proteomic analysis of the molecular changes underlying neuro-epithelial interactions in PNI using liquid chromatography-mass spectrometry (LC-MS/MS) in microdissected PNI and non-PNI cancer, as well as invaded and non-invaded nerves from formalin-fixed, paraffin-embedded PDAC tissues. In addition, an in vitro model of PNI was developed using a co-culture system comprising PDAC cell lines and PC12 cells as the neuronal element. The overall proteomic profiles of PNI and non-PNI cancer appeared largely similar. In contrast, upon invasion by cancer cells, nerves demonstrated widespread plasticity with a pattern consistent with neuronal injury. The upregulation of SCG2 (secretogranin II) and neurosecretory protein VGF (non-acronymic) in invaded nerves in PDAC tissues was further validated using immunohistochemistry. The tested PDAC cell lines were found to be able to induce neuronal plasticity in PC12 cells in our in vitro established co-culture model. Changes in expression levels of VGF, as well as of two additional proteins previously reported to be overexpressed in PNI, Nestin and Neuromodulin (GAP43), closely recapitulated our proteomic findings in PDAC tissues. Furthermore, induction of VGF, while not necessary for PC12 survival, mediated neurite extension induced by PDAC cell lines. In summary, here we report the proteomic alterations underlying PNI in PDAC and confirm that PDAC cells are able to induce neuronal plasticity. In addition, we describe a novel, simple, and easily adaptable co-culture model for in vitro study of neuro-epithelial interactions
Spatially-coordinated airborne data and complementary products for aerosol, gas, cloud, and meteorological studies: The NASA ACTIVATE dataset
The NASA Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) produced a unique dataset for research into aerosol-cloud-meteorology interactions. An HU-25 Falcon and King Air conducted systematic and spatially coordinated flights over the northwest Atlantic Ocean. This paper describes the ACTIVATE flight strategy, instrument and complementary dataset products, data access and usage details, and data application notes
The Absence of the Vomer in the First and Early Second Trimester of Pregnancy - A New Marker of Trisomy 21 and Trisomy 13
PURPOSE: The aim of this study was to measure the two frontomaxillo-facial (FMF) angles: the FMF-vomer (FMF-v) and the FMF-palate (FMF-p), and to visualize the vomer in the 1 (st) and early 2 (nd) trimester, in order to ascertain whether they can be used as markers for trisomy 21 and trisomy 13. MATERIALS AND METHODS: A 2D ultrasound scan was performed in the 340 normal and 12 abnormal pregnancies, using the linear, convex and endovaginal probes. RESULTS: We visualized the FMF angles within 1 to 5 minutes in 253 (72 %) of cases by using the linear probe. FMF-v angle was significantly smaller that the FMF-p angle (79.8° vs. 89.7°, 71.5° vs. 84.5° for the two trimesters, respectively), and that the value of both angles decreased in the second trimester. There was not one single case of trisomy in which vomer could be identified in the 1 (st) and early 2 (nd) trimester. The FMF-p angle failed to present difference between normal cases and the ones with trisomy (89.5°). There was not one single case of trisomy (21 or 13) in which vomer or FMF-v could be identified in the first or early second trimester. The diagnostic accuracy of vomer as a marker for trisomy was 0.985. CONCLUSION: If the vomer cannot be visualized in the 1 (st) and early 2 (nd) trimester, it is important to check the karyotype, and it is not necessary to measure the FMF-p angle. The high resolution probe (L 12 - 5 Mhz) enables easier assessment of the vomer
Molecular characteristics of early-onset pancreatic ductal adenocarcinoma.
The median age of patients with pancreatic ductal adenocarcinoma (PDAC) at diagnosis is 71 years; however, around 10% present with early-onset pancreatic cancer (EOPC), i.e., before age 50. The molecular mechanisms underlying such an early onset are unknown. We assessed the role of common PDAC drivers (KRAS, TP53, CDKN2A and SMAD4) and determined their mutational status and protein expression in 90 formalin-fixed, paraffin-embedded tissues, including multiple primary and matched metastases, from 37 EOPC patients. KRAS was mutated in 88% of patients; p53 was altered in 94%, and p16 and SMAD4 were lost in 86% and 71% of patients, respectively. Meta-synthesis showed a higher rate of p53 alterations in EOPC than in late-onset PDAC (94% vs. 69%, P = 0.0009) and significantly higher loss of SMAD4 (71% vs. 44%, P = 0.0025). The majority of EOPC patients accumulated aberrations in all four drivers; in addition, high tumour heterogeneity was observed across all tissues. The cumulative effect of an exceptionally high rate of alterations in all common PDAC driver genes combined with high tumour heterogeneity suggests an important mechanism underlying the early onset of PDAC
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Photothermal alternative to device fabrication using atomic precision advanced manufacturing techniques
The attachment of dopant precursor molecules to depassivated areas of hydrogen-terminated silicon templated with a scanning tunneling microscope (STM) has been used to create electronic devices with subnanometer precision, typically for quantum physics experiments. This process, which we call atomic precision advanced manufacturing (APAM), dopes silicon beyond the solid-solubility limit and produces electrical and optical characteristics that may also be useful for microelectronic and plasmonic applications. However, scanned probe lithography lacks the throughput required to develop more sophisticated applications. Here, we demonstrate and characterize an APAM device workflow where scanned probe lithography of the atomic layer resist has been replaced by photolithography. An ultraviolet laser is shown to locally and controllably heat silicon above the temperature required for hydrogen depassivation on a nanosecond timescale, a process resistant to under- and overexposure. STM images indicate a narrow range of energy density where the surface is both depassivated and undamaged. Modeling that accounts for photothermal heating and the subsequent hydrogen desorption kinetics suggests that the silicon surface temperatures reached in our patterning process exceed those required for hydrogen removal in temperature-programmed desorption experiments. A phosphorus-doped van der Pauw structure made by sequentially photodepassivating a predefined area and then exposing it to phosphine is found to have a similar mobility and higher carrier density compared with devices patterned by STM. Lastly, it is also demonstrated that photodepassivation and precursor exposure steps may be performed concomitantly, a potential route to enabling APAM outside of ultrahigh vacuum. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Do green awards and certifications matter? Consumers’ perceptions, green behavioral intentions, and economic implications for the hotel industry: A Sri Lankan perspective
Stool frequency and form and gastrointestinal symptoms differ by day of the menstrual cycle in healthy adult women taking oral contraceptives: a prospective observational study
Specific Physiological Responses in Women with Severe Primary Dysmenorrhea during the Menstrual Cycle
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Consumer Xenocentrism as Determinant of Foreign Product Preference: A System Justification Perspective
Foreign and domestic product purchase behavior largely depends on consumer predispositions. The dominant construct in international marketing literature explaining such behavior has been consumer ethnocentrism, which is conceptually anchored in social identity theory. However, such a perspective overlooks evidence that certain consumers are consistently attracted by the “foreignness” of a product. Drawing from system justification theory, the present investigation conceptualizes and provides an empirical test of the consumer xenocentrism construct that is intended to explain consumer attraction toward foreign products. Using survey data from five complementary studies, the authors develop and validate a new scale (the C-XENSCALE) to measure consumers’ xenocentric tendencies and offer extensive evidence on its ability to explain consumer preferences for foreign products. The authors discuss implications of the findings for theory and managerial practice and identify future research directions