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The objective of this study was to search for polymorphisms in the ovine prion-related protein (testis-specific) gene ( PRNT). Sampling included 567 sheep from eight Portuguese breeds. The PRNT gene-coding region was analyzed by single-strand conformation polymorphism and sequencing, allowing the identification of the first ovine PRNT polymorphisms, in codons 6, 38, 43 and 48: c.17C>T (p.Ser6Phe, which disrupts a consensus arginine-X-X-serine/threonine motif); c.112G>C (p.Gly38>Arg); c.129T>C and c.144A>G (synonymous) respectively. Polymorphisms in codons 6, 38 and 48 occur simultaneously in 50.6% of the animals, 38.8% presenting as heterozygous. To study the distribution of the polymorphism in codon 43, a restriction fragment length polymorphism analysis was performed. Polymorphic variant c.129C, identified in 89.8% of the animals with 32.8% presented as heterozygous, was considered the wild genotype in Portuguese sheep. Eight different haplotypes which have comparable distribution in all breeds were identified for the PRNT gene. In conclusion, the PRNT coding region is highly polymorphic in sheep, unlike the prion protein 2 dublet gene ( PRND), in which we previously found only one synonymous substitution (c.78G>A), in codon 26. The absence or reduced number of PRND heterozygotes (c.78G>A) was significantly associated with three PRNT haplotypes ( 17C-112G-129T-144A,17 CT-112 GC-129 CT-144 AG and 17T-112C-129C-144G), and the only three animals found homozygous at c.78A had the 17C-112G-129C-144A PRNT haplotype. These results constitute evidence of an association between polymorphic variation in PRND and PRNT genes, as has already been observed for PRND and prion protein gene ( PRNP). [ABSTRACT FROM AUTHOR]

Persons with severe mental disorders have higher chances of presenting oral health problems than persons in the general population. Mental disorders are considered public-health problems worldwide. Interpreting statements on oral health made by medical students receiving instruction in psychiatry is essential to provide elements for reflection on their difficulties, barriers or limited knowledge in managing their patients' oral health. Based on the presupposition that doctors provide their patients with no instruction or support concerning oral complaints, because these do not symbolize the same challenges as those emerging from severe mental disorders. The aim of this study was to interpret symbolic meanings of statements expressed by medical residents in psychiatry at a specialized university outpatient clinic, about their patients' oral health. Qualitative research using the Qualitative-Clinical method was conducted, adopting the theoretical reference of medical psychology. Data were analyzed by the Clinical-Qualitative Content method and the Seven-Step technique. Based on 06 interviews analyzed, the following categories emerged: "What do I do? Psychiatrists' dilemmas about not understanding their role in patients' oral health; and "Dentists do not participate in Balint' so-called "collusion in anonymity". It was concluded that among others, the paradigm consisted of a sociological composition, therefore it was stronger than personal decisions that might eventually oppose the barriers to interdisciplinary work posed by the institutional model, which were intertwined with paradigmatic barriers. Thus, specialist training should include a dental perspective, so that oral examinations would always be included in the physical examinations, from an interdisciplinary perspective of the integrity of health-care., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Guerra et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: To enhance and extend the knowledge about the global historical and phylogenetic relationships between Merino and Merino-derived breeds, 19 populations were genotyped with the OvineSNP50 BeadChip specifically for this study, while an additional 23 populations from the publicly available genotypes were retrieved. Three complementary statistical tests, Rsb (extended haplotype homozygosity between-populations), XP-EHH (cross-population extended haplotype homozygosity), and runs of homozygosity (ROH) islands were applied to identify genomic variants with potential impact on the adaptability of Merino genetic type in two contrasting climate zones., Results: The results indicate that a large part of the Merino's genetic relatedness and admixture patterns are explained by their genetic background and/or geographic origin, followed by local admixture. Multi-dimensional scaling, Neighbor-Net, Admixture, and TREEMIX analyses consistently provided evidence of the role of Australian, Rambouillet and German strains in the extensive gene introgression into the other Merino and Merino-derived breeds. The close relationship between Iberian Merinos and other South-western European breeds is consistent with the Iberian origin of the Merino genetic type, with traces from previous contributions of other Mediterranean stocks. Using Rsb and XP-EHH approaches, signatures of selection were detected spanning four genomic regions located on Ovis aries chromosomes (OAR) 1, 6 and 16, whereas two genomic regions on OAR6, that partially overlapped with the previous ones, were highlighted by ROH islands. Overall, the three approaches identified 106 candidate genes putatively under selection. Among them, genes related to immune response were identified via the gene interaction network. In addition, several candidate genes were found, such as LEKR1, LCORL, GHR, RBPJ, BMPR1B, PPARGC1A, and PRKAA1, related to morphological, growth and reproductive traits, adaptive thermogenesis, and hypoxia responses., Conclusions: To the best of our knowledge, this is the first comprehensive dataset that includes most of the Merino and Merino-derived sheep breeds raised in different regions of the world. The results provide an in-depth picture of the genetic makeup of the current Merino and Merino-derived breeds, highlighting the possible selection pressures associated with the combined effect of anthropic and environmental factors. The study underlines the importance of Merino genetic types as invaluable resources of possible adaptive diversity in the context of the occurring climate changes., (© 2023. The Author(s).)

Animal welfare is critical to buffer stress in captive animals and to ensure the reliability of data from studies. The most usual environmental enrichment technique (EE) for social non-human primates is the social enrichment. However, some experimental protocols require keeping individuals isolated, thus demanding other types of EE. We tested in six adult Callithrix jacchus females, single housed for experimental purpose, the stress buffering efficacy of a structural enrichment protocol (SEP) and SEP in combination with a foraging enrichment (FSEP) using  fecal cortisol and behaviors to infer stress levels. Both types of EE improved welfare in different ways, while cortisol levels decreased with both EE as compared to the baseline, autogrooming, and piloerection increased after FSEP probably due to the new foods. Therefore, these findings support alternative practices of EE when social animals are living in isolation and reinforce the positive role of structural and food enrichment for decreasing stress markers. It also encourages studies on welfare with females, since its use as an animal model has increased.

Assuming the multidimensionality of health literacy, new complex and comprehensive approaches are more adequate to specific disease contexts, such as cancer. Assessing cancer literacy levels is a priority, since it entails potential serious implications for disease outcomes and patient's quality of life. This article reports on the translation and cultural adaptation of the Cancer Health Literacy Test to measure cancer literacy in Portuguese cancer patients. A multidisciplinary team of experts ensured the translation and cultural adaptation of the CHLT-30. A pre-test was conducted in two stages to evaluate the Portuguese version (CHLT-30 PT) in a sample of cancer patients (n = 71). Descriptive statistics were used to characterize the sample. Reliability (test-retest and internal consistency) and construct validity of CHLT-30 PT were assessed. The results obtained show a good internal consistency of the tool, respectively (Cronbach's alpha = 0.86 in the test and 0.80 in the retest). Patients' raw score mean in both test (23.96) and retest (25.97) and the distribution of scores categories are not statistically different. A suggestive association between higher education level and better total score was found compared to the results reported in CHLT-30-DKspa. The results obtained in the pre-test are favorable, and the instrument is now suitable for the next steps of the validation process. A Portuguese version of this tool will allow outlining patients' cancer literacy along the cancer care continuum, enabling the identification and implementation of adequate socio-educational strategies with highly positive impacts on health outcomes.

Competing Interests: The authors declare no conflicts of interest.

In this study, we aimed to evaluate the genetic diversity within and among chicken breeds from the northeast region of Brazil (states of Bahia and Piauí) using microsatellite markers. In addition, we assessed the identity and genetic relationships of chickens from Europe, Africa, and South America, as well as their influence on the formation of the Brazilian breeds. A total of 25 microsatellite markers and a panel containing 886 samples from 20 breeds (including the Brazilian chickens) were used in this study. Different statistical parameters were used to estimate the genetic diversity and relationship among the genetic groups studied. Our study indicates that the Brazilian Creole chickens have high genetic variability. The results show that chickens reared in the states of Bahia and Piauí could have originated from different ancestors. The Brazilian breeds studied have an evolutionary relationship with chickens from Portugal, Nigeria, Chile, and Spain. Our results will contribute directly to the conservation and recognition of Brazilian Creole chicken breeds and provide a solid basis for the demonstration of their genetic identity and genetic conservation of American Creole chicken populations.

Cancer prevention should start as early as possible. Young adults would benefit largely from the use of a smartphone app aiming at promoting cancer prevention behaviours. The aims of the study described in this paper are to (1) examine the user participation and engagement with a cancer prevention app in real-life settings and (2) assess changes in the users' cancer prevention behaviours. A cancer prevention smartphone app called Happy was developed and released to the general population. Data from registered app users' (N = 3326) demographics and baseline cancer prevention behaviours was analysed. App engagement was measured and all behaviour data logged through the app was analysed to assess the effectiveness of the app in the promotion of cancer prevention behaviours. User demographics and baseline behaviour assessment show that the app reached its intended target population: young adults that generally do not comply with cancer prevention guidelines. Logged behavioural data showed an increased frequency in several cancer prevention behaviours and a significant increase in the overall putative cancer prevention level (p < 0.001). However, user engagement with the app was limited and might condition the long-term impact of such changes. Happy reached its intended population and seems to be an effective tool to promote cancer prevention. Further research is needed to fully assess its long-term persuasive potential.

Cancer literacy is currently one of the most important dimensions of cancer continuum. Objective assessment of cancer knowledge in populations remains a challenging field to public health entities. Different evaluation tools are currently available; still, some groups remain disregarded due to the absence of validated instruments. Cancer literacy in adolescents and young adults has been clearly overlooked being a subject that requires new tools to be properly studied. To address this topic, we developed a new instrument and field tested it in a classroom environment for internal reliability, construct, and face validity. "Students Knowledge and Perceptions about Cancer questionnaire" was designed in Portuguese language and adapted to the Portuguese context by a multidisciplinary team. The final version of the questionnaire includes 35 items organized in three sections, encompassing knowledge and perceptions about cancer and socio-biographic data. Cancer experts ensured content validity, while tailoring of contents was refined with high school teachers. Test and retest of the instrument showed a good reliability of the scale and construct validity. Also, the clarity of the questionnaire and suitability to proper evaluate cancer knowledge was consistent between test and retest. The Students' Knowledge and Perceptions About Cancer Questionnaire (SKPaC) showed to be a valid tool to assess adolescents' knowledge and perceptions about cancer that can be used in the educational context.

Background: Estimates predict that more than half of all cancers are due to inadequate lifestyle choices. Smartphones can be successfully used to support the behaviour change needed to prevent cancer., Objective: The purpose of this study was to field-test Happy, a smartphone app designed to promote cancer prevention behaviours, based on tailored-messages., Methods: Thirty-two participants downloaded and used the app for 28 consecutive days (4 weeks). At the end of this period, they all answered an online questionnaire and ten of them were interviewed. Usability, feasibility, message receptivity, and perceived impact of the app were assessed., Results: Compliance with cancer prevention guidelines was lower than expected. Happy was considered simple, intuitive and easy to use. Messages sent by the app were considered easy to understand, providing good advice and meaningful information that catch reader's attention. Participants also considered that Happy might be an effective way to promote cancer prevention. Collected data showed an increased frequency in several cancer prevention related behaviours and an increase in the overall putative cancer prevention level., Conclusions: This study showed the viability of designing and implementing smartphone-based interventions to promote cancer prevention behaviours. The results suggest that Happy is usable and might help users change their behaviour towards healthier choices and thus reduce their personal cancer risk., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background and Aims: As the recent outbreak of microcephaly cases caused by Zika virus has been declared a global health emergency, providing assessment guidelines for multidisciplinary teams providing early developmental screening and stimulation to infants with microcephaly is much needed. Thus, the aim of this manuscript is to provide an overview on what is known about neuroradiological aspects and clinical findings in infants with microcephaly caused by Zika virus and to propose a framework for early evaluation of child development., Methods: The keywords "Zika virus" and "microcephaly" were searched in PubMed database for articles published from incept to May 2017. These texts were reviewed, and the ones addressing neuroradiological and clinical findings in infants were selected. Recommendations for early assessment were made based on the International Classification of Functionality Disability and Health (ICF) model., Outcomes and Results: The database search yielded 599 publications and 36 were selected. The studies detected microcephaly with diffuse brain malformations and calcifications, ventriculomegaly, optic nerve hypoplasia, macular atrophy, cataracts, impaired visual and hearing function, arthrogryposis, spasticity, hyperreflexia, irritability, tremors, and seizures, but very little is known about early development. Early assessments were described based on the ICF domains (Body Function and Structures, Activities and Participation and Contextual factors)., Conclusion and Implications: Studies published showed abnormal brain, optic, neurologic and orthopedic findings, but very little is known about other aspects of functioning in infants with microcephaly caused by Zika virus. The biopsychosocial model based on the ICF paradigm provides an adequate framework to describe the condition of the infant with microcephaly receiving rehabilitative efforts to minimize disability. Efforts towards early identification of developmental delays should be taken within the first six months of life., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: There is initial evidence that the use of volatile anesthetics can reduce the postoperative release of cardiac troponin I, the need for inotropic support, and the number of patients requiring prolonged hospitalization following coronary artery bypass graft (CABG) surgery. Nevertheless, small randomized controlled trials have failed to demonstrate a survival advantage. Thus, whether volatile anesthetics improve the postoperative outcome of cardiac surgical patients remains uncertain. An adequately powered randomized controlled trial appears desirable., Design: Single blinded, international, multicenter randomized controlled trial with 1:1 allocation ratio., Setting: Tertiary and University hospitals., Interventions: Patients (n=10,600) undergoing coronary artery bypass graft will be randomized to receive either volatile anesthetic as part of the anesthetic plan, or total intravenous anesthesia., Measurements and Main Results: The primary end point of the study will be one-year mortality (any cause). Secondary endpoints will be 30-day mortality; 30-day death or non-fatal myocardial infarction (composite endpoint); cardiac mortality at 30day and at one year; incidence of hospital re-admission during the one year follow-up period and duration of intensive care unit, and hospital stay. The sample size is based on the hypothesis that volatile anesthetics will reduce 1-year unadjusted mortality from 3% to 2%, using a two-sided alpha error of 0.05, and a power of 0.9., Conclusions: The trial will determine whether the simple intervention of adding a volatile anesthetic, an intervention that can be implemented by all anesthesiologists, can improve one-year survival in patients undergoing coronary artery bypass graft surgery., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Mucin 1 (MUC1) has been described as the renaissance molecule due to the large set of functions it displays in both normal and neoplastic cells. This membrane-tethered glycoprotein is overexpressed and aberrantly glycosylated in most epithelial cancers, being involved in several processes related with malignant phenotype acquisition. With a highly polymorphic structure, both in the polypeptide and glycan counterparts, MUC1 variability has been associated with susceptibility to several diseases, including cancer. Biochemical features and biological functions have been characterized upon the full-length MUC1 protein, remaining to clarify the real impact on cell dynamics of the plethora of MUC1 isoforms. This review aims to encompass a detailed characterization of MUC1 role in carcinogenesis, highlighting recent findings in cell differentiation and uncovering new evidences of MUC1 isoforms involvement in malignant phenotype., (© 2016 APMIS. Published by John Wiley & Sons Ltd.)

Objectives: This study sought to explore the views and experiences of healthy young adults concerning the fundamental features of a cancer prevention smartphone app that seeks behaviour change., Methods: Three focus groups were conducted with 16 healthy young adults that explored prior experiences, points of view and opinions about currently available health-related smartphone apps. Then, an online questionnaire was designed and applied to a larger sample of healthy young adults. Focus group and online questionnaire data were analysed and confronted., Results: Study results identified behaviour tracking, goal setting, tailored information and use of reminders as the most desired features in a cancer prevention app. Participants highlighted the importance of privacy and were reluctant to share personal health information with other users. The results also point out important dimensions to be considered for long-term use of health promotion apps related with usability and perceived usefulness. Participants didn't consider gamification features as important dimensions for long-term use of apps., Conclusions: This study allowed the definition of a guideline set for the development of a cancer prevention app., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Despite the fact that the biological function of cluster of differentiation (CD)133 remains unclear, this glycoprotein is currently used in the identification and isolation of tumor-initiating cells from certain malignant tumors, including pancreatic cancer. In the present study, the involvement of mucin 1 (MUC1) in the signaling pathways of a highly tumorigenic CD133+ cellular subpopulation sorted from the pancreatic cancer cell line HPAF-II was evaluated. The expression of MUC1-cytoplasmic domain (MUC1-CD) and oncogenic signaling transducers (epidermal growth factor receptor, protein kinase C delta, glycogen synthase kinase 3 beta and growth factor receptor-bound protein 2), as well as the association between MUC1 and β-catenin, were characterized in HPAF-II CD133+ and CD133low cell subpopulations and in tumor xenografts generated from these cells. Compared with HPAF CD133 low cells, HPAF-II CD133+ cancer cells exhibited increased tumorigenic potential in immunocompromised mice, which was associated with overexpression of MUC1 and with the accordingly altered expression profile of MUC1-associated signaling partners. Additionally, MUC1-CD/β-catenin interactions were increased both in the HPAF-II CD133+ cell subpopulation and derived tumor xenografts compared with HPAF CD133 low cells. These results suggest that, in comparison with HPAF CD133 low cells, CD133+ cells exhibit higher expression of MUC1, which contributes to their tumorigenic phenotype through increased interaction between MUC1-CD and β-catenin, which in turn modulates oncogenic signaling cascades.

Objectives: Gold nanoparticles have become promising vectors for cancer diagnosis and treatment. The present study investigates the effect of bortezomib (BTZ), a proteasome inhibitor, conjugated with pegylated gold nanoparticles (PEGAuNPs) in pancreatic and lung cancer cells., Methods: Synthesized gold nanoparticles (PEGAuNPs) were conjugated with bortezomib antitumor drug. We investigated the cytotoxicity induced by BTZ conjugated with functionalized gold nanoparticles in vitro, in the human pancreatic (S2-013) and lung (A549) cancer cell lines., Results: We found an efficient of conjugation of BTZ with PEGAuNPs. In vitro assays showed that after 72 h' incubation with PEGAuNPs-BTZ cancer cells revealed alterations in morphology; also for S2-013 and A549 cancer cells, the IC50 value of free BTZ is respectively 1.5 and 4.3 times higher than the IC50 value of PEGAuNPs-BTZ. Furthermore, for TERT-HPNE, the IC50 value is around 63 times lower for free BTZ than the conjugated nanovehicle. Cell growth inhibition results showed a remarkable enhancement in the effect of BTZ when conjugated with AuNPs., Conclusions: Our findings showed that conjugation with PEGAuNPs enhance the BTZ growth-inhibition effect on human cancer cells (S2-013 and A549) and decreases its toxicity against normal cells (TERT-HPNE).

Objectives: A drug delivery system based on colloidal pegylated gold nanoparticles (PEGAuNPs) conjugated with the tyrosine kinase inhibitor afatinib was designed and tested for enhancing the drug activity against pancreatic and NSCLC cells., Methods: PEGAuNPs were synthesized and characterized physicochemically. Confocal imaging was performed to evaluate the nanoparticle (NP) internalization in cancer cells. For cell-cycle distribution analysis, conjugated NPs and afatinib alone were incubated with cells and alterations on the cell-cycle profile subsequently analyzed by total DNA staining. Cancer cell survival and growth inhibition following incubation with afatinib and PEGAuNPs-afatinib (concentrations between 0.007 and 0.500 µM afatinib) were evaluated., Results: A higher cellular uptake of PEGAuNPs was observed by cancer cells. Our data suggest an efficient conjugation of PEGAuNPs with the drug, enhancing the afatinib activity in comparison with afatinib alone. In fact, IC50 and GI50 results obtained show that the PEGAuNPs-afatinib conjugate is ca. 5 and 20 times more potent than afatinib alone in S2-013 and A549 cell lines, respectively., Conclusions: Conjugating PEGAuNPs with afatinib is a promising antitumor delivery system for cancer therapy as it improves drug efficacy, allowing a reduction in drug dose used and minimizing possible toxicity-related side effects.

The aim of this study was to develop a drug delivery system based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles for an efficient and targeted action of the proteasome inhibitor bortezomib against pancreatic cancer cells. The PLGA nanoparticles were formulated with a poloxamer, and further surface-modified with transferrin for tumor targeting. The nanoparticles were characterized as polymer carriers of bortezomib, and the cellular uptake and growth inhibitory effects were evaluated in pancreatic cells. Cellular internalization of nanoparticles was observed in normal and cancer cells, but with higher uptake by cancer cells. The sustained release of the loaded bortezomib from PLGA nanoparticles showed cytotoxic effects against pancreatic normal and cancer cells. Noteworthy differential cytotoxicity was attained by transferrin surface-modified PLGA nanoparticles since significant cell growth inhibition by delivered bortezomib was only observed in cancer cells. These findings demonstrate that the ligand transferrin enhanced the targeted delivery of bortezomib-loaded PLGA nanoparticles to pancreatic cancer cells. These in vitro results highlight the transferrin surface-modified PLGA nanoparticles as a promising system for targeted delivery of anticancer drugs., (© 2014 Wiley Periodicals, Inc.)

Cancer is one of the leading causes of death worldwide, and thus represents a priority for national public health programs. Prevention has been assumed as the best strategy to reduce cancer burden, however most cancer prevention programs are implemented by healthcare professionals, which constrain range and educational impacts. We developed an innovative approach for cancer prevention education focused on high-school biology teachers, considered privileged mediators in the socialization processes. A training program, "Cancer, Educate to Prevent" was applied, so that the teachers were able to independently develop and implement prevention campaigns focused on students and school-related communities. The program encompassed different educational modules, ranging from cancer biology to prevention campaigns design. Fifty-four teachers were empowered to develop and implement their own cancer prevention campaigns in a population up to five thousands students. The success of the training program was assessed through quantitative evaluation--questionnaires focused on teachers' cancer knowledge and perceptions, before the intervention (pre-test) and immediately after (post-test). The projects developed and implemented by teachers were also evaluated regarding the intervention design, educational contents and impact on the students' knowledge about cancer. This study presents and discusses the results concerning the training program "Cancer, Educate to Prevent" and clearly shows a significant increase in teacher's cancer literacy (knowledge and perceptions) and teachers' acquired proficiency to develop and deliver cancer prevention campaigns with direct impact on students' knowledge about cancer. This pilot study reinforces the potential of high-school teachers and schools as cancer prevention promoters and opens a new perspective for the development and validation of cancer prevention education strategies, based upon focused interventions in restricted targets (students) through non-health professionals (teachers).

Tumour drug resistance is a major issue in the management of lung cancer patients as almost all lung tumours are either intrinsically resistant or quickly develop acquired resistance to chemotherapeutic drugs. Cancer drug resistance has recently been linked, at least in part, to the existence of cancer stem-like cells (CSLCs), a small sub-population of cells within the tumour that possess stem-like properties. CSLCs are often isolated by fluorescence activated cell sorting (FACS) according to the expression of certain stem-like cell membrane markers. Conflicting results regarding the specificity of particular stem cell surface markers for isolating CSLCs have, however, been recently reported. Therefore, alternative strategies enabling the identification and study of CSLCs should be considered, particularly in tumour types where appropriate stem cell markers are not well established and validated, like in lung cancer. In this article, we review data indicating therapy-selection as a valid approach for putative lung CSLCs enrichment. We believe that this strategy would be determinant for correctly assessing and characterising the sub-populations of CSLCs that are able to survive chemo or radiotherapy regimens and, at the same time, also have the ability to recapitulate and sustain tumour growth. Using therapy-induced enrichment of CSLCs may, therefore, prove to be an extremely useful method for studying CSLCs and provide new clues regarding potential therapeutic targets for their efficient elimination, which will undoubtedly play a decisive role in improving lung cancer patients' survival., (© 2013 UICC.)

Laminae of Adiantum raddianum Presl., a fern belonging to the family Pteridaceae, are characterised by the presence of epidermal fibre-like cells under the vascular bundles. These cells were thought to contain silica bodies, but their thickened walls leave no space for intracellular silica suggesting it may actually be deposited within their walls. Using advanced electron microscopy in conjunction with energy dispersive X-ray microanalysis we showed the presence of silica in the cell walls of the fibre-like idioblasts. However, it was specifically localised to the outer layers of the periclinal wall facing the leaf surface, with the thick secondary wall being devoid of silica. Immunocytochemical experiments were performed to ascertain the respective localisation of silica deposition and glycan polymers. Epitopes characteristic for pectic homogalacturonan and the hemicelluloses xyloglucan and mannan were detected in most epidermal walls, including the silica-rich cell wall layers. The monoclonal antibody, LM6, raised against pectic arabinan, labelled the silica-rich primary wall of the epidermal fibre-like cells and the guard cell walls, which were also shown to contain silica. We hypothesise that the silicified outer wall layers of the epidermal fibre-like cells support the lamina during cell expansion prior to secondary wall formation. This implies that silicification does not impede cell elongation. Although our results suggest that pectic arabinan may be implicated in silica deposition, further detailed analyses are needed to confirm this. The combinatorial approach presented here, which allows correlative screening and in situ localisation of silicon and cell wall polysaccharide distribution, shows great potential for future studies.

Background: Gastric carcinoma is the second leading cause of cancer-associated death worldwide. The high mortality associated with this disease is in part due to limited knowledge about gastric carcinogenesis and a lack of available therapeutic and prevention strategies. MUC1 is a high molecular weight transmembrane mucin protein expressed at the apical surface of most glandular epithelial cells and a major component of the mucus layer above gastric mucosa. Overexpression of MUC1 is found in approximately 95% of human adenocarcinomas, where it is associated with oncogenic activity. The role of MUC1 in gastric cancer progression remains to be clarified., Methodology: We downregulated MUC1 expression in a gastric carcinoma cell line by RNA interference and studied the effects on cellular proliferation (MTT assay), apoptosis (TUNEL assay), migration (migration assay), invasion (invasion assay) and aggregation (aggregation assay). Global gene expression was evaluated by microarray analysis to identify alterations that are regulated by MUC1 expression. In vivo assays were also performed in mice, in order to study the tumorigenicity of cells with and without MUC1 downregulation in MKN45 gastric carcinoma cell line., Results: Downregulation of MUC1 expression increased proliferation and apoptosis as compared to controls, whereas cell-cell aggregation was decreased. No significant differences were found in terms of migration and invasion between the downregulated clones and the controls. Expression of TCN1, KLK6, ADAM29, LGAL4, TSPAN8 and SHPS-1 was found to be significantly different between MUC1 downregulated clones and the control cells. In vivo assays have shown that mice injected with MUC1 downregulated cells develop smaller tumours when compared to mice injected with the control cells., Conclusions: These results indicate that MUC1 downregulation alters the phenotype and tumorigenicity of MKN45 gastric carcinoma cells and also the expression of several molecules that can be involved in tumorigenic events. Therefore, MUC1 should be further studied to better clarify its potential as a novel therapeutic target for gastric cancer.