WorldWideScience

Sample records for human imprinted 11p15

  1. Disruption of Imprinted Genes at Chromosome Region 11p15.5 in Paediatric Rhabdomyosarcoma

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    John Anderson

    1999-10-01

    Full Text Available Rhabdomyosarcomas are characterized by loss of heterozygosity (LOH at chromosome region 11pl5.5, a region known to contain several imprinted genes including insulin-like growth factor 2 (IGF2, H19, p57KIP2. We analyzed 48 primary tumour samples and found distinct genetic changes at 11p15.5 in alveolar and embryonal histological subtypes. LOH was a feature of embryonal tumours, but at a lower frequency than previous studies. Loss of imprinting (LOI of the IGF2 gene was detected in 6 of 13 informative cases, all harbouring PAX3—FKHR or PAX7—FKHR fusion genes characteristic of alveolar histology. In contrast, H19 imprinting was maintained in 14 of 15 informative cases and the case with H19 LOI had maintenance of the IGF2 imprint indicating separate mechanisms controlling imprinting of IGF2 and H19. The adult promoter of IGF2, P1, was used in 5 of 14 tumours and its expression was unrelated to IGF2 imprinting status implying a further mechanism of altered IGF2 regulation. The putative tumour suppressor gene p57KIP2 was expressed in 15 of 29 tumours and expression was unrelated to allele status. Moreover, in tumours with p57KIP2 expression, there was no evidence for inactivating mutations, suggesting that p57KIP2 is not a tumour suppressor in rhabdomyosarcoma.

  2. EMQN best practice guidelines for the molecular genetic testing and reporting of chromosome 11p15 imprinting disorders

    DEFF Research Database (Denmark)

    Eggermann, Katja; Bliek, Jet; Brioude, Frédéric

    2016-01-01

    Molecular genetic testing for the 11p15-associated imprinting disorders Silver-Russell and Beckwith-Wiedemann syndrome (SRS, BWS) is challenging because of the molecular heterogeneity and complexity of the affected imprinted regions. With the growing knowledge on the molecular basis of these diso......Molecular genetic testing for the 11p15-associated imprinting disorders Silver-Russell and Beckwith-Wiedemann syndrome (SRS, BWS) is challenging because of the molecular heterogeneity and complexity of the affected imprinted regions. With the growing knowledge on the molecular basis...

  3. Frequency and timing of loss of imprinting at 11p13 and 11p15 in Wilms' tumor development.

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    Brown, Keith W; Power, Frances; Moore, Beth; Charles, Adrian K; Malik, Karim T A

    2008-07-01

    Epigenetic changes occur frequently in Wilms' tumor (WT), especially loss of imprinting (LOI) of IGF2/H19 at 11p15. Our previous results have identified imprinted transcripts (WT1-AS and AWT1) from the WT1 locus at 11p13 and showed LOI of these in some WTs. In this article, we set out to test the relationship between LOI at 11p13 and 11p15 and their timing in WT progression relative to other genetic changes. We found a higher level (83%) of 11p13 LOI in WT than of 11p15 LOI (71%). There was no correlation between methylation levels at the 11p13 and 11p15 differentially methylated regions or between allelic expression of WT1-AS/AWT1 and IGF2. Interestingly, retention of normal imprinting at 11p13 was associated with a small group of relatively late-onset, high-stage WTs. An examination of genetic and epigenetic alterations in nephrogenic rests, which are premalignant WT precursors, showed that LOI at both 11p13 and 11p15 occurred before either 16q loss of heterozygosity (LOH) or 7p LOH. This suggests that these LOH events are very unlikely to be a cause of LOI but that LOH may act by potentiating the effects of overexpression of IGF2 and/or WT1-AS/AWT1 that result from LOI.

  4. Loss of imprinting and loss of heterozygosity on 11p15.5 in head and neck squamous cell carcinomas

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    Rainho, C A; Kowalski, L P; Rogatto, S R

    2001-01-01

    BACKGROUND: IGF2 and H19 are reciprocal imprinted genes with paternal and maternal monoallelic expression, respectively. This is interesting, because IGF2 is known as a growth factor, and H19 encodes a RNA with putative tumor suppressor action. Furthermore, IGF2 and H19 are linked genes located...... involved in head and neck carcinogenesis. Furthermore, our data showed that genetic and epigenetic changes at 11p15.5 could lead to abnormal expression of imprinted genes in HNSCC....

  5. Placental hydroxymethylation vs methylation at the imprinting control region 2 on chromosome 11p15.5

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    H.R. Magalhaes

    2013-11-01

    Full Text Available In addition to methylated cytosines (5-mCs, hydroxymethylcytosines (5-hmCs are present in CpG dinucleotide-enriched regions and some transcription regulator binding sites. Unlike methylation, hydroxymethylation does not result in silencing of gene expression, and the most commonly used methods to study methylation, such as techniques based on restriction enzymatic digestion and/or bisulfite modification, are unable to distinguish between them. Genomic imprinting is a process of gene regulation where only one member of an allelic pair is expressed depending on the parental origin. Chromosome 11p15.5 has an imprinting control region (ICR2 that includes a differentially methylated region (KvDMR1 that guarantees parent-specific gene expression. The objective of the present study was to determine the presence of 5-hmC at the KvDMR1 in human placentas. We analyzed 16 third-trimester normal human placentas (chorionic villi. We compared two different methods based on real-time PCR after enzymatic digestion. The first method distinguished methylation from hydroxymethylation, while the other method did not. Unlike other methylation studies, subtle variations of methylation in ICRs could represent a drastic deregulation of the expression of imprinted genes, leading to important phenotypic consequences, and the presence of hydroxymethylation could interfere with the results of many studies. We observed agreement between the results of both methods, indicating the absence of hydroxymethylation at the KvDMR1 in third-trimester placentas. To the best of our knowledge, this is the first study describing the investigation of hydroxymethylation in human placenta using a genomic imprinting model.

  6. Placental hydroxymethylation vs methylation at the imprinting control region 2 on chromosome 11p15.5.

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    Magalhães, H R; Leite, S B P; Paz, C C P de; Duarte, G; Ramos, E S

    2013-10-22

    In addition to methylated cytosines (5-mCs), hydroxymethylcytosines (5-hmCs) are present in CpG dinucleotide-enriched regions and some transcription regulator binding sites. Unlike methylation, hydroxymethylation does not result in silencing of gene expression, and the most commonly used methods to study methylation, such as techniques based on restriction enzymatic digestion and/or bisulfite modification, are unable to distinguish between them. Genomic imprinting is a process of gene regulation where only one member of an allelic pair is expressed depending on the parental origin. Chromosome 11p15.5 has an imprinting control region (ICR2) that includes a differentially methylated region (KvDMR1) that guarantees parent-specific gene expression. The objective of the present study was to determine the presence of 5-hmC at the KvDMR1 in human placentas. We analyzed 16 third-trimester normal human placentas (chorionic villi). We compared two different methods based on real-time PCR after enzymatic digestion. The first method distinguished methylation from hydroxymethylation, while the other method did not. Unlike other methylation studies, subtle variations of methylation in ICRs could represent a drastic deregulation of the expression of imprinted genes, leading to important phenotypic consequences, and the presence of hydroxymethylation could interfere with the results of many studies. We observed agreement between the results of both methods, indicating the absence of hydroxymethylation at the KvDMR1 in third-trimester placentas. To the best of our knowledge, this is the first study describing the investigation of hydroxymethylation in human placenta using a genomic imprinting model.

  7. EMQN best practice guidelines for the molecular genetic testing and reporting of chromosome 11p15 imprinting disorders: Silver–Russell and Beckwith–Wiedemann syndrome

    Science.gov (United States)

    Eggermann, Katja; Bliek, Jet; Brioude, Frédéric; Algar, Elizabeth; Buiting, Karin; Russo, Silvia; Tümer, Zeynep; Monk, David; Moore, Gudrun; Antoniadi, Thalia; Macdonald, Fiona; Netchine, Irène; Lombardi, Paolo; Soellner, Lukas; Begemann, Matthias; Prawitt, Dirk; Maher, Eamonn R; Mannens, Marcel; Riccio, Andrea; Weksberg, Rosanna; Lapunzina, Pablo; Grønskov, Karen; Mackay, Deborah JG; Eggermann, Thomas

    2016-01-01

    Molecular genetic testing for the 11p15-associated imprinting disorders Silver–Russell and Beckwith–Wiedemann syndrome (SRS, BWS) is challenging because of the molecular heterogeneity and complexity of the affected imprinted regions. With the growing knowledge on the molecular basis of these disorders and the demand for molecular testing, it turned out that there is an urgent need for a standardized molecular diagnostic testing and reporting strategy. Based on the results from the first external pilot quality assessment schemes organized by the European Molecular Quality Network (EMQN) in 2014 and in context with activities of the European Network of Imprinting Disorders (EUCID.net) towards a consensus in diagnostics and management of SRS and BWS, best practice guidelines have now been developed. Members of institutions working in the field of SRS and BWS diagnostics were invited to comment, and in the light of their feedback amendments were made. The final document was ratified in the course of an EMQN best practice guideline meeting and is in accordance with the general SRS and BWS consensus guidelines, which are in preparation. These guidelines are based on the knowledge acquired from peer-reviewed and published data, as well as observations of the authors in their practice. However, these guidelines can only provide a snapshot of current knowledge at the time of manuscript submission and readers are advised to keep up with the literature. PMID:27165005

  8. EMQN best practice guidelines for the molecular genetic testing and reporting of chromosome 11p15 imprinting disorders: Silver-Russell and Beckwith-Wiedemann syndrome.

    Science.gov (United States)

    Eggermann, Katja; Bliek, Jet; Brioude, Frédéric; Algar, Elizabeth; Buiting, Karin; Russo, Silvia; Tümer, Zeynep; Monk, David; Moore, Gudrun; Antoniadi, Thalia; Macdonald, Fiona; Netchine, Irène; Lombardi, Paolo; Soellner, Lukas; Begemann, Matthias; Prawitt, Dirk; Maher, Eamonn R; Mannens, Marcel; Riccio, Andrea; Weksberg, Rosanna; Lapunzina, Pablo; Grønskov, Karen; Mackay, Deborah Jg; Eggermann, Thomas

    2016-10-01

    Molecular genetic testing for the 11p15-associated imprinting disorders Silver-Russell and Beckwith-Wiedemann syndrome (SRS, BWS) is challenging because of the molecular heterogeneity and complexity of the affected imprinted regions. With the growing knowledge on the molecular basis of these disorders and the demand for molecular testing, it turned out that there is an urgent need for a standardized molecular diagnostic testing and reporting strategy. Based on the results from the first external pilot quality assessment schemes organized by the European Molecular Quality Network (EMQN) in 2014 and in context with activities of the European Network of Imprinting Disorders (EUCID.net) towards a consensus in diagnostics and management of SRS and BWS, best practice guidelines have now been developed. Members of institutions working in the field of SRS and BWS diagnostics were invited to comment, and in the light of their feedback amendments were made. The final document was ratified in the course of an EMQN best practice guideline meeting and is in accordance with the general SRS and BWS consensus guidelines, which are in preparation. These guidelines are based on the knowledge acquired from peer-reviewed and published data, as well as observations of the authors in their practice. However, these guidelines can only provide a snapshot of current knowledge at the time of manuscript submission and readers are advised to keep up with the literature.

  9. Gene expression profile of neuronal progenitor cells derived from hESCs: activation of chromosome 11p15.5 and comparison to human dopaminergic neurons.

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    William J Freed

    Full Text Available BACKGROUND: We initiated differentiation of human embryonic stem cells (hESCs into dopamine neurons, obtained a purified population of neuronal precursor cells by cell sorting, and determined patterns of gene transcription. METHODOLOGY: Dopaminergic differentiation of hESCs was initiated by culturing hESCs with a feeder layer of PA6 cells. Differentiating cells were then sorted to obtain a pure population of PSA-NCAM-expressing neuronal precursors, which were then analyzed for gene expression using Massive Parallel Signature Sequencing (MPSS. Individual genes as well as regions of the genome which were activated were determined. PRINCIPAL FINDINGS: A number of genes known to be involved in the specification of dopaminergic neurons, including MSX1, CDKN1C, Pitx1 and Pitx2, as well as several novel genes not previously associated with dopaminergic differentiation, were expressed. Notably, we found that a specific region of the genome located on chromosome 11p15.5 was highly activated. This region contains several genes which have previously been associated with the function of dopaminergic neurons, including the gene for tyrosine hydroxylase (TH, the rate-limiting enzyme in catecholamine biosynthesis, IGF2, and CDKN1C, which cooperates with Nurr1 in directing the differentiation of dopaminergic neurons. Other genes in this region not previously recognized as being involved in the functions of dopaminergic neurons were also activated, including H19, TSSC4, and HBG2. IGF2 and CDKN1C were also found to be highly expressed in mature human TH-positive dopamine neurons isolated from human brain samples by laser capture. CONCLUSIONS: The present data suggest that the H19-IGF2 imprinting region on chromosome 11p15.5 is involved in the process through which undifferentiated cells are specified to become neuronal precursors and/or dopaminergic neurons.

  10. Genomic imbalance in the centromeric 11p15 imprinting center in three families: Further evidence of a role for IC2 as a cause of Russell-Silver syndrome.

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    Cytrynbaum, Cheryl; Chong, Karen; Hannig, Vickie; Choufani, Sanaa; Shuman, Cheryl; Steele, Leslie; Morgan, Thomas; Scherer, Stephen W; Stavropoulos, Dimitri J; Basran, Raveen K; Weksberg, Rosanna

    2016-10-01

    Russell-Silver syndrome is a heterogeneous disorder characterized by intrauterine growth retardation, postnatal growth deficiency, characteristic facial appearance, and other variable features. Genetic and epigenetic alterations are identified in about 60% of individuals with Russell-Silver syndrome. Most frequently, Russell-Silver syndrome is caused by altered gene expression on chromosome 11p15 due to loss of methylation at the telomeric imprinting center. To date there have been a handful of isolated clinical reports implicating the centromeric imprinting center 2 in the etiology of Russell-Silver syndrome. Here we report three new families with genomic imbalances, involving imprinting center 2 resulting in gain of methylation at this center and a Russell-Silver syndrome phenotype, including two families with a maternally inherited microduplication and the first pediatric patient with a paternally derived microdeletion. The findings in our families provide additional evidence of a role for imprinting center 2 in the etiology of Russell-Silver syndrome and suggest that imprinting center 2 imprinting abnormalities may be a more common cause of Russell-Silver syndrome than previously recognized. Furthermore, our findings together with previous clinical reports of genomic imbalances involving imprinting center 2 serve to underscore the complexity of the epigenetic regulation of the 11p15 region making it challenging to predict phenotype on the basis of genotype alone. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  11. Excess functional copy of allele at chromosomal region 11p15 may cause Wiedemann-Beckwith (EMG) syndrome

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    Kubota, T.; Saitoh, S.; Jinno, Y.; Niikawa, N.; Matsumoto, T. [Nagasaki Univ. School of Medicine (Japan); Narahara, K. [Okayama Univ. School of Medicine, Okayama (Japan); Fukushima, Y. [Saitama Children`s Hospital, Iwatsuki (Japan)

    1994-02-15

    Wiedemann-Beckwith syndrome (WBS) is a genetic disorder with overgrowth and predisposition to Wilms` tumor. The putative locus of the gene responsible for this syndrome is assigned to chromosome region 11p15.5, and genomic imprinting in this region has been proposed: the paternally derived gene(s) at 11p15.5 is selectively expressed, while the maternally transmitted gene(s) is inactive. The authors examined 18 patients for the parental origin of their 11p15 regions. DNA polymorphism analyses using 6 loci on chromosome 11 showed that 2 patients with duplications of 11p15 regions from their respective fathers and one from the mother, indicating the transmission of an excessive paternal gene at 11p15 to each patient. The result, together with the previous findings in karyotypically normal or abnormal patients and in overgrowth mouse experiments, are consistent with imprinting hypothesis that overexpression of paternally derived gene(s) at 11p15.5, probably the human insulin-like growth factor II (IFG-II) gene, may cause the phenotype. Total constitutional uniparental paternal disomy (UPD) or segmental UPD for the 6 loci examined of chromosome 11 was not observed in our 12 sporadic patients. In order to explain completely the inheritance of this syndrome in patients with various chromosomal constitutions, the authors propose an alternative imprinting mechanism involving the other locus that may be paternally imprinted and may suppress the expression of this gene. 28 refs., 3 figs., 1 tab.

  12. Complex tissue-specific epigenotypes in Russell-Silver Syndrome associated with 11p15 ICR1 hypomethylation.

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    Azzi, Salah; Blaise, Annick; Steunou, Virginie; Harbison, Madeleine D; Salem, Jennifer; Brioude, Frédéric; Rossignol, Sylvie; Habib, Walid Abi; Thibaud, Nathalie; Neves, Cristina Das; Jule, Marilyne Le; Brachet, Cécile; Heinrichs, Claudine; Bouc, Yves Le; Netchine, Irène

    2014-10-01

    Russell-Silver Syndrome (RSS) is a prenatal and postnatal growth retardation syndrome caused mainly by 11p15 ICR1 hypomethylation. Clinical presentation is heterogeneous in RSS patients with 11p15 ICR1 hypomethylation. We previously identified a subset of RSS patients with 11p15 ICR1 and multilocus hypomethylation. Here, we examine the relationships between IGF2 expression, 11p15 ICR1 methylation, and multilocus imprinting defects in various cell types from 39 RSS patients with 11p15 ICR1 hypomethylation in leukocyte DNA. 11p15 ICR1 hypomethylation was more pronounced in leukocytes than in buccal mucosa cells. Skin fibroblast IGF2 expression was correlated with the degree of ICR1 hypomethylation. Different tissue-specific multilocus methylation defects coexisted in 38% of cases, with some loci hypomethylated and others hypermethylated within the same cell type in some cases. Our new results suggest that tissue-specific epigenotypes may lead to clinical heterogeneity in RSS.

  13. Fibroadenoma in Beckwith-Wiedemann syndrome with paternal uniparental disomy of chromosome 11p15.5.

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    Takama, Yuichi; Kubota, Akio; Nakayama, Masahiro; Higashimoto, Ken; Jozaki, Kosuke; Soejima, Hidenobu

    2014-12-01

    Herein is described a case of breast fibroadenomas in a 16-year-old girl with Beckwith-Wiedemann syndrome (BWS) and uniparental disomy (UPD) of chromosome 11p15.5. She was clinically diagnosed with BWS and direct closure was performed for an omphalocele at birth. Subtotal and 90% pancreatectomy were performed for nesidioblastosis at the ages 2 months and 8 years, respectively. Bilateral multiple breast fibroadenomas were noted at the age of 16 and 17 years. In this case, paternal UPD of chromosome 11p15.5 was identified on microsatellite marker analysis. The relevant imprinted chromosomal region in BWS is 11p15.5, and UPD of chromosome 11p15 is a risk factor for BWS-associated tumorigenicity. Chromosome 11p15.5 consists of imprinting domains of IGF2, the expression of which is associated with the tumorigenesis of various breast cancers. This case suggests that fibroadenomas occurred in association with BWS.

  14. Human imprinted chromosomal regions are historical hot-spots of recombination.

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    Ionel Sandovici

    2006-07-01

    Full Text Available Human recombination rates vary along the chromosomes as well as between the two sexes. There is growing evidence that epigenetic factors may have an important influence on recombination rates, as well as on crossover position. Using both public database analysis and wet-bench approaches, we revisited the relationship between increased rates of meiotic recombination and genome imprinting. We constructed metric linkage disequilibrium (LD maps for all human chromosomal regions known to contain one or more imprinted genes. We show that imprinted regions contain significantly more LD units (LDU and have significantly more haplotype blocks of smaller sizes than flanking nonimprinted regions. There is also an excess of hot-spots of recombination at imprinted regions, and this is likely to do with the presence of imprinted genes, per se. These findings indicate that imprinted chromosomal regions are historical "hot-spots" of recombination. We also demonstrate, by direct segregation analysis at the 11p15.5 imprinted region, that there is remarkable agreement between sites of meiotic recombination and steps in LD maps. Although the increase in LDU/Megabase at imprinted regions is not associated with any significant enrichment for any particular sequence class, major sequence determinants of recombination rates seem to differ between imprinted and control regions. Interestingly, fine-mapping of recombination events within the most male meiosis-specific recombination hot-spot of Chromosome 11p15.5 indicates that many events may occur within or directly adjacent to regions that are differentially methylated in somatic cells. Taken together, these findings support the involvement of a combination of specific DNA sequences and epigenetic factors as major determinants of hot-spots of recombination at imprinted chromosomal regions.

  15. Toward the gene(s) for Wiedemann-Beckwith syndrome and associated tumors in two different regions of 11p15

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    Henry, J.; Chehenase, V.; Boulevin, C. [INSERM, Paris (France)] [and others

    1994-09-01

    Wiedemann-Beckwith syndrome (WBS) is a malformation syndrome associated with predisposition to different types of tumors (WT, ADCC). Cytogenetic and familial studies mapped the WBS locus to 11p15.5. Genomic imprinting has been implicated in the expression of the syndrome. Using 11p15 specific markers we have determined the parental origin of both chromosomes 11 in sporadic WBS cases. Probands in 5 out of 26 informative families (25%) displayed uniparental disomy (UPD) corresponding to a paternal isodisomy for region 11p15.5. Mosaic phenotypes reflect the timing of their origin and the fate of cells involved as well as the cell-specific pattern of imprinting. Somatic mosaicism for UPD may thus explain the incomplete forms of WBS, the association of hemihypertrophy in sporadic WBS and even some cases of isolated hemihypertrophy. Moreover, the risk (60%) of developing a tumor seems higher for patients with paternal 11p UPD than for WBS patients in general (7.5%). Two different genomic libraries specific for region 11p15.5 were constructed and screened to isolate and characterize the gene(s) responsible for WBS and/or tumor progression. The characterization and and the localization of these cDNAs are in progress. 5 CA repeats genetically mapped in 11p15 were used to isolate YACs (CEPH). These CA repeats are now physically mapped using a panel of hybrids specific for the 11p15 region, and the contigs of YACs mapping in the regions of interest will be used to isolate coding sequences.

  16. Paternal uniparental isodisomy of chromosome 11p15.5 within the pancreas causes isolated hyperinsulinaemic hypoglycaemia

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    Sarah E Flanagan

    2011-11-01

    Full Text Available BackgroundLoss of function mutations in the genes encoding the pancreatic β-cell ATP-sensitive potassium (KATP channel are identified in approximately 80% of patients with diazoxide-unresponsive hyperinsulinaemic-hypoglycaemia (HH. For a small number of patients HH can occur as part of a multisystem disease such as Beckwith-Wiedemann syndrome (BWS. In approximately 20% of patients, BWS results from chromosome 11 paternal uniparental disomy (UPD, which causes dysregulation of imprinted growth regulation genes at 11p15.5. There is a considerable range in the clinical features and phenotypic severity associated with BWS which is likely to be due to somatic mosaicism. The cause of HH in these patients is not known.Research Design and methodsWe undertook microsatellite analysis of 12 markers spanning chromosome 11p in two patients with severe HH and diffuse disease requiring a pancreatectomy. In both patients mutations in the KATP channel genes had not been identified. ResultsWe identified segmental paternal UPD in DNA extracted from pancreatic tissue in both patients. UPD was not observed in DNA extracted from the patient’s leukocytes or buccal samples. In both cases the UPD encompassed the differentially methylated region at chromosome 11p15.5. Despite this neither patient had any further features of BWS.ConclusionsPaternal UPD of the chromosome 11p15.5 differentially methylated region limited to the pancreatic tissue may represent a novel cause of isolated diazoxide unresponsive HH. Loss of heterozygosity studies should therefore be considered in all patients with severe HH who have undergone pancreatic surgery when KATP channel mutation(s have not been identified.

  17. Multiple genetic loci within 11p15 defined by Beckwith-Wiedemann syndrome rearrangement breakpoints and subchromosomal transferable fragments.

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    Hoovers, J M; Kalikin, L M; Johnson, L A; Alders, M; Redeker, B; Law, D J; Bliek, J; Steenman, M; Benedict, M; Wiegant, J

    1995-01-01

    Beckwith-Wiedemann syndrome (BWS) involves fetal overgrowth and predisposition to a wide variety of embryonal tumors of childhood. We have previously found that BWS is genetically linked to 11p15 and that this same band shows loss of heterozygosity in the types of tumors to which children with BWS are susceptible. However, 11p15 contains > 20 megabases, and therefore, the BWS and tumor suppressor genes could be distinct. To determine the precise physical relationship between these loci, we isolated yeast artificial chromosomes, and cosmid libraries from them, within the region of loss of heterozygosity in embryonal tumors. Five germ-line balanced chromosomal rearrangement breakpoint sites from BWS patients, as well as a balanced chromosomal translocation breakpoint from a rhabdoid tumor, were isolated within a 295- to 320-kb cluster defined by a complete cosmid contig crossing these breakpoints. This breakpoint cluster terminated approximately 100 kb centromeric to the imprinted gene IGF2 and 100 kb telomeric to p57KIP2, an inhibitor of cyclin-dependent kinases, and was located within subchromosomal transferable fragments that suppressed the growth of embryonal tumor cells in genetic complementation experiments. We have identified 11 transcribed sequences in this BWS/tumor suppressor coincident region, one of which corresponded to p57KIP2. However, three additional BWS breakpoints were > 4 megabases centromeric to the other five breakpoints and were excluded from the tumor suppressor region defined by subchromosomal transferable fragments. Thus, multiple genetic loci define BWS and tumor suppression on 11p15. Images Fig. 1 Fig. 3 PMID:8618920

  18. Congenital hyperinsulinism in an infant with paternal uniparental disomy on chromosome 11p15: few clinical features suggestive of Beckwith-Wiedemann syndrome.

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    Adachi, Hiroyuki; Takahashi, Ikuko; Higashimoto, Ken; Tsuchida, Satoko; Noguchi, Atsuko; Tamura, Hiroaki; Arai, Hirokazu; Ito, Tomoo; Masue, Michiya; Nishibori, Hironori; Takahashi, Tsutomu; Soejima, Hidenobu

    2013-01-01

    Beckwith-Wiedemann syndrome (BWS) is the most common congenital overgrowth syndrome involving tumor predisposition. BWS is caused by various epigenetic or genetic alterations that disrupt the imprinted genes on chromosome 11p15.5 and the clinical findings of BWS are highly variable. Hyperinsulinemic hypoglycemia is reported in about half of all babies with BWS. We identified an infant with diazoxide-unresponsive congenital hyperinsulinism (HI) without any apparent clinical features suggestive of BWS, but diagnosed BWS by molecular testing. The patient developed severe hyperinsulinemic hypoglycemia within a few hours after birth, with macrosomia and mild hydronephrosis. We excluded mutations in the K(ATP) channel genes on chromosome 11p15.1, but found a rare homozygous single nucleotide polymorphism (SNP) of ABCC8. Parental SNP pattern suggested paternal uniparetal disomy in this region. By microsatellite marker analysis on chromosome 11p15, we could diagnose BWS due to the mosaic of paternal uniparental disomy. Our case suggests that some HI of unknown genetic etiology could involve undiagnosed BWS with no apparent clinical features, which might be diagnosed only by molecular testing.

  19. Foster parenting, human imprinting and conventional handling ...

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    p2492989

    3 School of Animal Biology, Faculty of Natural Agricultural Science, ... reared by foster parents were heavier than human-imprinted chicks, while early .... Moreover, the research was designed as a preliminary study to explore potential benefits.

  20. A variant of Freeman-Sheldon syndrome maps to 11p15.5-pter

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    Krakowiak, P.A.; O`Quinn, J.R.; Watkins, W.S. [Univ. of Utah Health Sciences Center, Salt Lake City, UT (United States)] [and others

    1997-02-01

    Distal arthrogryposis type 1 (DA1) and Freeman-Sheldon syndrome (FSS) are the two most common known causes of inherited multiple congenital contractures. We recently have characterized a new disorder (DA213) with a phenotype intermediate between DA1 and FSS. We report the mapping of a gene that causes DA213 to chromosome 11p15.5-pter. Linkage analysis in a single kindred generated a positive LOD score of 5.31 at {theta} = 0 with the marker D11S922, and recombinants localize the gene to an {approximately}3.5-6.5-cM region between the marker TH and the telomere. Analysis of additional families improves the LOD score to 6.45 at {theta} = 0 and suggests linkage homogeneity for DA213. 24 refs., 4 figs., 2 tabs.

  1. Germline mutation in NLRP2 (NALP2 in a familial imprinting disorder (Beckwith-Wiedemann Syndrome.

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    Esther Meyer

    2009-03-01

    Full Text Available Beckwith-Wiedemann syndrome (BWS is a fetal overgrowth and human imprinting disorder resulting from the deregulation of a number of genes, including IGF2 and CDKN1C, in the imprinted gene cluster on chromosome 11p15.5. Most cases are sporadic and result from epimutations at either of the two 11p15.5 imprinting centres (IC1 and IC2. However, rare familial cases may be associated with germline 11p15.5 deletions causing abnormal imprinting in cis. We report a family with BWS and an IC2 epimutation in which affected siblings had inherited different parental 11p15.5 alleles excluding an in cis mechanism. Using a positional-candidate gene approach, we found that the mother was homozygous for a frameshift mutation in exon 6 of NLRP2. While germline mutations in NLRP7 have previously been associated with familial hydatidiform mole, this is the first description of NLRP2 mutation in human disease and the first report of a trans mechanism for disordered imprinting in BWS. These observations are consistent with the hypothesis that NLRP2 has a previously unrecognised role in establishing or maintaining genomic imprinting in humans.

  2. Imprinted anomalies in fetal and childhood growth disorders: the model of Russell-Silver and Beckwith-Wiedemann syndromes.

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    Netchine, Irène; Rossignol, Sylvie; Azzi, Salah; Brioude, Fréderic; Le Bouc, Yves

    2012-01-01

    Fetal growth is a complex process. Its restriction is associated with morbidity and long term metabolic consequences. Imprinted genes have a critical role in mammalian fetal growth. The human chromosome 11p15 encompasses two imprinted domains regulated by their own differentially methylated region (DMR), also called Imprinted Control Region (ICR1 at the H19/IGF-2 domain, paternally methylated), and ICR2 at the KCNQ1/CDKN1C domain (maternally methylated). Loss of imprinting at these two domains is implicated in two growth disorders clinically opposite. A loss of DNA methylation (LOM) at ICR1 is identified in over 50% of patients with Russell-Silver syndrome (RSS), characterized by intrauterine and postnatal growth retardation, spared cranial growth, frequent body asymmetry and severe feeding difficulties. Inversely, a gain of methylation at ICR1 is found in 10% of patients with Beckwith-Wiedemann syndrome (BWS), an overgrowth syndrome with an enhanced childhood tumor risk. We have identified over 150 RSS patients with 11p15 LOM allowing long-term follow-up studies and proposal of clinical guidelines. We also found that ∼10% of RSS patients and ∼25% of BWS patients have multilocus LOM at imprinted regions other than ICR1 or ICR2 11p15, respectively. Recent studies have identified cis-acting regulatory elements and trans-acting factors involved in the regulation of 11p15 imprinting, establishing new potential mechanisms of RSS and BWS.

  3. Human imprinted retrogenes exhibit non-canonical imprint chromatin signatures and reside in non-imprinted host genes

    Science.gov (United States)

    Monk, David; Arnaud, Philippe; Frost, Jennifer M.; Wood, Andrew J.; Cowley, Michael; Martin-Trujillo, Alejandro; Guillaumet-Adkins, Amy; Iglesias Platas, Isabel; Camprubi, Cristina; Bourc’his, Deborah; Feil, Robert; Moore, Gudrun E.; Oakey, Rebecca J.

    2011-01-01

    Imprinted retrotransposed genes share a common genomic organization including a promoter-associated differentially methylated region (DMR) and a position within the intron of a multi-exonic ‘host’ gene. In the mouse, at least one transcript of the host gene is also subject to genomic imprinting. Human retrogene orthologues are imprinted and we reveal that human host genes are not imprinted. This coincides with genomic rearrangements that occurred during primate evolution, which increase the separation between the retrogene DMRs and the host genes. To address the mechanisms governing imprinted retrogene expression, histone modifications were assayed at the DMRs. For the mouse retrogenes, the active mark H3K4me2 was associated with the unmethylated paternal allele, while the methylated maternal allele was enriched in repressive marks including H3K9me3 and H4K20me3. Two human retrogenes showed monoallelic enrichment of active, but not of repressive marks suggesting a partial uncoupling of the relationship between DNA methylation and repressive histone methylation, possibly due to the smaller size and lower CpG density of these DMRs. Finally, we show that the genes immediately flanking the host genes in mouse and human are biallelically expressed in a range of tissues, suggesting that these loci are distinct from large imprinted clusters. PMID:21300645

  4. Sexual imprinting in human mate choice.

    Science.gov (United States)

    Bereczkei, Tamas; Gyuris, Petra; Weisfeld, Glenn E

    2004-06-07

    Animal and human studies have shown that individuals choose mates partly on the basis of similarity, a tendency referred to as homogamy. Several authors have suggested that a specific innate recognition mechanism, phenotypic matching, allows the organism to detect similar others by their resemblance to itself. However, several objections have been raised to this theory on both empirical and theoretical grounds. Here, we report that homogamy in humans is attained partly by sexual imprinting on the opposite-sex parent during childhood. We hypothesized that children fashion a mental model of their opposite-sex parent's phenotype that is used as a template for acquiring mates. To disentangle the effects of phenotypic matching and sexual imprinting, adopted daughters and their rearing families were examined. Judges found significant resemblance on facial traits between daughter's husband and her adoptive father. Furthermore, this effect may be modified by the quality of the father-daughter relationship during childhood. Daughters who received more emotional support from their adoptive father were more likely to choose mates similar to the father than those whose father provided a less positive emotional atmosphere.

  5. Genomic imprinting and human psychology: cognition, behavior and pathology.

    Science.gov (United States)

    Goos, Lisa M; Ragsdale, Gillian

    2008-01-01

    Imprinted genes expressed in the brain are numerous and it has become clear that they play an important role in nervous system development and function. The significant influence of genomic imprinting during development sets the stage for structural and physiological variations affecting psychological function and behaviour, as well as other physiological systems mediating health and well-being. However, our understanding of the role of imprinted genes in behaviour lags far behind our understanding of their roles in perinatal growth and development. Knowledge of genomic imprinting remains limited among behavioral scientists and clinicians and research regarding the influence of imprinted genes on normal cognitive processes and the most common forms of neuropathology has been limited to date. In this chapter, we will explore how knowledge of genomic imprinting can be used to inform our study of normal human cognitive and behavioral processes as well as their disruption. Behavioural analyses of rare imprinted disorders, such as Prader-Willi and Angelman syndromes, provide insight regarding the phenotypic impact of imprinted genes in the brain, and can be used to guide the study of normal behaviour as well as more common but etiologically complex disorders such as ADHD and autism. Furthermore, hypotheses regarding the evolutionary development of imprinted genes can be used to derive predictions about their role in normal behavioural variation, such as that observed in food-related and social interactions.

  6. Imprinting and flexibility in human face cognition

    Science.gov (United States)

    Marcinkowska, Urszula M.; Terraube, Julien; Kaminski, Gwenaël

    2016-01-01

    Faces are an important cue to multiple physiological and psychological traits. Human preferences for exaggerated sex typicality (masculinity or femininity) in faces depend on multiple factors and show high inter-subject variability. To gain a deeper understanding of the mechanisms underlying facial femininity preferences in men, we tested the interactive effect of family structure (birth order, sibling sex-ratio and number of siblings) and parenthood status on these preferences. Based on a group of 1304 heterosexual men, we have found that preference for feminine faces was not only influenced by sibling age and sex, but also that fatherhood modulated this preference. Men with sisters had a weaker preference for femininity than men with brothers, highlighting a possible effect of a negative imprinting-like mechanism. What is more, fatherhood increased strongly the preference for facial femininity. Finally, for fathers with younger sisters only, the more the age difference increased between them, the more femininity preference increased. Overall our findings bring new insight into how early-acquired experience at the individual level may determine face preference in adulthood, and what is more, how these preferences are flexible and potentially dependent on parenthood status in adult men. PMID:27680495

  7. Human imprinting disorders: Principles, practice, problems and progress.

    Science.gov (United States)

    Mackay, Deborah J G; Temple, I Karen

    2017-11-01

    Epigenetic regulation orchestrates gene expression with exquisite precision, over a huge dynamic range and across developmental space and time, permitting genomically-homogeneous humans to develop and adapt to their surroundings. Every generation, these epigenetic marks are re-set twice: in the germline, to enable differentiation of sperm and eggs, and at fertilisation, to create the totipotent zygote that then begins growth and differentiation into a new human. A small group of genes evades the second, zygotic wave of epigenetic reprogramming, and these genes retain an epigenetic 'imprint' of the parent from whom they were inherited. Imprinted genes are (as a general rule) expressed from one parental allele only. Some imprinted genes are critical regulators of growth and development, and thus disruption of their normal monoallelic expression causes congenital imprinting disorders, with clinical features impacting growth, development, behaviour and metabolism. Imprinting disorders as a group have characteristics that challenge diagnosis and management, including clinical and molecular heterogeneity, overlapping clinical features, somatic mosaicism, and multi-locus involvement. New insights into the biology and epigenomics of the early embryo offers new clues about the origin and importance of imprinting disorders. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. Rearrangements at the 11p15 locus and overexpression of insulin-like growth factor-II gene in sporadic adrenocortical tumors

    Energy Technology Data Exchange (ETDEWEB)

    Gicquel, C.; Schneid, H.; Le Bouc, Y. [Hopital Trousseau, Paris (France); Bertagna, X.; Francillard-Leblond, M.; Luton, J.P.; Girard, F. [Hopital Cochin, Paris (France)

    1994-06-01

    Little is known about the pathophysiology of sporadic adrenocortical tumors in adults. Because loss of heterozygosity at the 11p15 locus has been described in childhood tumors, particularly in adrenocortical tumors associated with the Beckwith-Wiedemann syndrome, and because insulin-like growth factor-II (IGF-II) is a crucial regulator of fetal adrenal growth, the authors looked for structural analysis at the 11p15 locus and IGF-II gene expression in 23 sporadic adrenocortical adult tumors: 6 carcinomas (5 with Cushing`s syndrome and 1 nonsecreting) and 17 benign adenomas (13 with Cushing`s syndrome, 1 pure androgen secreting, and 3 nonsecreting). Twenty-one patients were informative at the 11p15 locus, and six (four carcinomas and two adenomas) of them (28.5%) exhibited 11p15 structural abnormalities in tumor DNA (five, a uniparental disomy and one, a mosaicism). In a single case that could be further studied, a paternal isodisomy was observed. Very high IGF-II mRNA contents were detected in seven tumors (30%; 5 of the 6 carcinomas and 2 of the 17 adenomas). They were particularly found in tumors with uniparental disomy at the 11p15 locus. Overall, a strong correlation existed between IGF-II mRNA contents and DNA demethylation at the IGF-II locus. These data show that genetic alterations involving the 11p15 locus were highly frequent in malignant tumors, but found only in rare adenomas. These results in combination with evidence for overexpression of IGF-II from the 11p15.5 locus suggest that abnormalities in structure and/or expression of the IGF-II gene play a role as a late event of a multistep process of tumorigenesis. 58 refs., 6 figs., 4 tabs.

  9. Preparation of protein imprinted materials by hierarchical imprinting techniques and application in selective depletion of albumin from human serum

    Science.gov (United States)

    Liu, Jinxiang; Deng, Qiliang; Tao, Dingyin; Yang, Kaiguang; Zhang, Lihua; Liang, Zhen; Zhang, Yukui

    2014-06-01

    Hierarchical imprinting was developed to prepare the protein imprinted materials, as the artificial antibody, for the selective depletion of HSA from the human serum proteome. Porcine serum albumin (PSA) was employed as the dummy template for the fabrication of the recognition sites. To demonstrate the advantages of the hierarchical imprinting, molecularly imprinted polymers prepared by hierarchical imprinting technique (h-MIPs) were compared with those obtained by bulk imprinting (b-MIPs), in terms of the binding capacity, adsorption kinetics, selectivity and synthesis reproducibility. The binding capacity of h-MIPs could reach 12 mg g-1. And saturation binding could be reached in less than 20 min for the h-MIPs. In the protein mixture, h-MIPs exhibit excellent selectivity for PSA, with imprinting factors as about 3.6, much higher than those for non-template proteins. For the proteomic application, the identified protein group number in serum treated by h-MIPs was increased to 422, which is 21% higher than that obtained from the original serum, meanwhile the identified protein group number for the Albumin Removal kit was only 376. The results demonstrate that protein imprinted polymers prepared by hierarchical imprinting technique, might become the artificial antibodies for the selective depletion of high abundance proteins in proteome study.

  10. Clinical relevance of loss of 11p15 in primary and metastatic breast cancer: association with loss of PRKCDBP expression in brain metastases.

    Directory of Open Access Journals (Sweden)

    Harriet Wikman

    Full Text Available The occurrence of brain metastases among breast cancer patients is currently rising with approximately 20-25% incidence rates, underlining the importance of the identification of new therapeutic and prognostic markers. We have previously screened for new markers for brain metastasis by array CGH. We found that loss of 11p15 is common among these patients. In this study, we investigated the clinical significance of loss of 11p15 in primary breast cancer (BC and breast cancer brain metastases (BCBM. 11p15 aberration patterns were assessed by allelic imbalance (AI analysis in primary BC (n = 78, BCBM (n = 21 and metastases from other distant sites (n = 6 using six different markers. AI at 11p15 was significantly associated with BCBM (p = 0.002. Interestingly, a subgroup of primary BC with a later relapse to the brain had almost equally high AI rates as the BCBM cases. In primary BC, AI was statistically significantly associated with high grade, negative hormone receptor status, and triple-negative (TNBC tumors. Gene expression profiling identified PRKCDBP in the 11p15 region to be significantly downregulated in both BCBM and primary BC with brain relapse compared to primary tumors without relapse or bone metastasis (fdr<0.05. qRT-PCR confirmed these results and methylation was shown to be a common way to silence this gene. In conclusion, we found loss at 11p15 to be a marker for TNBC primary tumors and BCBM and PRKCDBP to be a potential target gene in this locus.

  11. imprints

    Directory of Open Access Journals (Sweden)

    Mindi Rhoades

    2016-07-01

    Full Text Available This set of poems emerges from the flashpoint at the intersection of art, text, translation, and meaning-making. Several result directly from a class field trip with art educator Terry Barrett’s to the Columbus Museum of Art. We wrote during prolonged interactions with particular pieces. Others result from reflecting on making and remembering. The title of this collection, “imprint,” operates on multiple levels. There is the imprint of the text itself, the prints of the photos, the fictional prints and printmaking referenced, the mental images burned into memory, the lasting impression. There is something magical about trying to translate evanescent ideas, unformed understandings, and ephemeral moments into something more, something lasting, something to keep. These poems represent an attempt to capture something fleeting and slippery also in words. They are an attempt to pause, to contemplate in slower cadence, to ponder the surfeit of signs. They are an attempt to notice, to echo, to share and spark connections. They are an assemblage of images told in fractured pieces, bundled together, and shared.

  12. Genomic imprinting and the evolutionary psychology of human kinship.

    Science.gov (United States)

    Haig, David

    2011-06-28

    Genomic imprinting is predicted to influence behaviors that affect individuals to whom an actor has different degrees of matrilineal and patrilineal kinship (asymmetric kin). Effects of imprinted genes are not predicted in interactions with nonrelatives or with individuals who are equally related to the actor's maternally and paternally derived genes (unless a gene also has pleiotropic effects on fitness of asymmetric kin). Long-term mating bonds are common in most human populations, but dissolution of marriage has always affected a significant proportion of mated pairs. Children born in a new union are asymmetric kin of children born in a previous union. Therefore, the innate dispositions of children toward parents and sibs are expected to be sensitive to cues of marital stability, and these dispositions may be subject to effects of imprinted genes.

  13. A novel familial 11p15.4 microduplication associated with intellectual disability, dysmorphic features, and obesity with involvement of the ZNF214 gene.

    Science.gov (United States)

    Sofos, Elvera; Pescosolido, Matthew F; Quintos, Jose B; Abuelo, Dianne; Gunn, Shelly; Hovanes, Karine; Morrow, Eric M; Shur, Natasha

    2012-01-01

    We evaluated a patient with mild intellectual disability, obesity, overgrowth, and dysmorphic features. Array comparative genomic hybridization (aCGH) analysis showed a single copy number increase of a BAC clone in the 11p15.4 region. Oligonucleotide aCGH refined the duplication to approximately 2.29  megabases (Mb) in size. Testing the parents revealed that the father, who had learning disabilities and overgrowth, also had the 11p15.4 duplication, and the mother had a normal microarray. In addition, the patient's brother and grandmother all share clinical features with the proband and tested positive for the duplication. The duplicated region (Chr11:6,934,067-9,220,605) encompasses 29 genes, including the ZNF214 gene, which has been postulated to play a role in Beckwith-Wiedemann syndrome [Alders et al., 2000]. This three-generation pedigree outlines features of a novel microduplication syndrome.

  14. Human imprinting anomalies in fetal and childhood growth disorders: clinical implications and molecular mechanisms.

    Science.gov (United States)

    Azzi, Salah; Brioude, Fréderic; Le Bouc, Yves; Netchine, Irène

    2014-01-01

    Genomic imprinting is among the most important epigenetic mechanisms whereby expression of a subset of genes is restricted to a single parental allele. Loss of imprinting (LOI) through hypo or hyper methylation is involved in various human syndromes. These LOI occur early during development and usually impair growth. Some imprinting syndromes are the consequences of genetic anomalies, such as uniparental disomies (UPD) or copy number variations (deletion or duplications) involving the imprinted domains; others are due to LOI at the imprinting control regions (ICR) regulating each domain. Imprinting disorders are phenotypically heterogeneous, although some share various common clinical features such that diagnosis may be difficult. Multilocus imprinting defects associated with several syndromes have been increasingly reported in recent years, although there are no obvious clinical differences between monolocus and multilocus LOI patients. Subsequently, some rare mutations of transacting factors have been identified in patients with multilocus imprinting defects but they do not explain the majority of the cases; this therefore implies that other factors are involved. By contrast, no mutation of a transacting factor has yet been identified in monolocus LOI. The effect of the environment on the regulation of imprinting is clearly illustrated by studies of assisted reproductive technology (ART). The regulation of imprinting is complex and involves a huge range of genetic and environmental factors; the identification of these factors will undoubtedly help to elucidate the regulation of imprinting and contribute to the understanding of imprinting disorders. This would be beneficial for diagnostics, clinical follow up and the development of treatment guidelines.

  15. The landscape of genomic imprinting across diverse adult human tissues

    Science.gov (United States)

    Baran, Yael; Subramaniam, Meena; Biton, Anne; Tukiainen, Taru; Tsang, Emily K.; Rivas, Manuel A.; Pirinen, Matti; Gutierrez-Arcelus, Maria; Smith, Kevin S.; Kukurba, Kim R.; Zhang, Rui; Eng, Celeste; Torgerson, Dara G.; Urbanek, Cydney; Li, Jin Billy; Rodriguez-Santana, Jose R.; Burchard, Esteban G.; Seibold, Max A.; MacArthur, Daniel G.; Montgomery, Stephen B.; Zaitlen, Noah A.; Lappalainen, Tuuli

    2015-01-01

    Genomic imprinting is an important regulatory mechanism that silences one of the parental copies of a gene. To systematically characterize this phenomenon, we analyze tissue specificity of imprinting from allelic expression data in 1582 primary tissue samples from 178 individuals from the Genotype-Tissue Expression (GTEx) project. We characterize imprinting in 42 genes, including both novel and previously identified genes. Tissue specificity of imprinting is widespread, and gender-specific effects are revealed in a small number of genes in muscle with stronger imprinting in males. IGF2 shows maternal expression in the brain instead of the canonical paternal expression elsewhere. Imprinting appears to have only a subtle impact on tissue-specific expression levels, with genes lacking a systematic expression difference between tissues with imprinted and biallelic expression. In summary, our systematic characterization of imprinting in adult tissues highlights variation in imprinting between genes, individuals, and tissues. PMID:25953952

  16. Short interspersed transposable elements (SINEs) are excluded from imprinted regions in the human genome.

    Science.gov (United States)

    Greally, John M

    2002-01-08

    To test whether regions undergoing genomic imprinting have unique genomic characteristics, imprinted and nonimprinted human loci were compared for nucleotide and retroelement composition. Maternally and paternally expressed subgroups of imprinted genes were found to differ in terms of guanine and cytosine, CpG, and retroelement content, indicating a segregation into distinct genomic compartments. Imprinted regions have been normally permissive to L1 long interspersed transposable element retroposition during mammalian evolution but universally and significantly lack short interspersed transposable elements (SINEs). The primate-specific Alu SINEs, as well as the more ancient mammalian-wide interspersed repeat SINEs, are found at significantly low densities in imprinted regions. The latter paleogenomic signature indicates that the sequence characteristics of currently imprinted regions existed before the mammalian radiation. Transitions from imprinted to nonimprinted genomic regions in cis are characterized by a sharp inflection in SINE content, demonstrating that this genomic characteristic can help predict the presence and extent of regions undergoing imprinting. During primate evolution, SINE accumulation in imprinted regions occurred at a decreased rate compared with control loci. The constraint on SINE accumulation in imprinted regions may be mediated by an active selection process. This selection could be because of SINEs attracting and spreading methylation, as has been found at other loci. Methylation-induced silencing could lead to deleterious consequences at imprinted loci, where inactivation of one allele is already established, and expression is often essential for embryonic growth and survival.

  17. The utility of quantitative methylation assays at imprinted genes for the diagnosis of fetal and placental disorders.

    Science.gov (United States)

    Bourque, D K; Peñaherrera, M S; Yuen, R K C; Van Allen, M I; McFadden, D E; Robinson, W P

    2011-02-01

    An imbalance of imprinted gene expression within 11p15.5 is observed in Beckwith-Wiedemann syndrome (BWS), as well as in a variety of placental abnormalities including complete hydatidiform mole (CHM), placental mesenchymal dysplasia (PMD) and triploidy. To facilitate the diagnosis of epigenetic errors and chromosomal imbalance of 11p15.5, we validated a pyrosequencing assay to measure methylation at KvDMR1 using blood samples from 13 BWS cases, 8 of which showed reduced methylation as compared to control blood. An imbalance between maternal and paternal genomes as is found in triploidy, CHM or PMD was also associated with altered KvDMR1 methylation. A reciprocal pattern of methylation was obtained in the triploid cases by assaying the proximal 11p15.5 ICR associated with H19. To distinguish chromosome 11 specific alterations from whole genome imbalance, other imprinted differentially methylated regions (DMRs) can be utilized. Thus, pyrosequencing assays for DMRs associated with SGCE, SNRPN, and MEST were also compared for their utility in diagnosing parental imbalance in placental samples. While each of these assays could successfully distinguish parental origin of triploidy, SGCE showed the clearest separation between groups. The combined use of a chromosome 11p15.5 assay (e.g. KvDMR1 or H19-ICR) and non-chromosome 11 assay (e.g. SGCE) provides a potentially valuable diagnostic tool in the rapid screening of methylation errors in placental disorders. These results also show the maintenance of imprinting status at these loci in the human placenta, even in the presence of abnormal pathology.

  18. GABA{sub A} receptor beta 3 subunit gene is possibly paternally imprinted in humans

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-02-15

    As the gene for GABA{sub A} receptor beta 3 subunit (GABRB3) is encompassed by a small molecular deletion in chromosome 15q11-q13, which is the critical region for Angelman syndrome(AS), the GABRB3 gene could be a candidate gene for AS. The abnormal phenotype of AS is manifested only when the deletion is inherited from the mother, not from the father. Therefore, a candidate gene for AS should be paternally imprinted. Although it was reported that the GABRB3 gene was expressed equally from either the maternal or paternal chromosome in mouse brain (i.e., not imprinted), it is well known that imprinting shows tissue specificity, and it remains to be determined if all genes imprinted in the mouse are also imprinted in humans. 4 refs., 1 fig.

  19. Loss of fragile histidine triad and amplification of 1p36.22 and 11p15.5 in primary gastric adenocarcinomas

    Institute of Scientific and Technical Information of China (English)

    Yuan-Yuan Liu; Hai-Ying Chen; Man-Li Zhang; Dan Tian; Shibo Li; Ji-Yun Lee

    2012-01-01

    AIM:To investigate the genomic copy number alterations that may harbor key driver genes in gastric tumorigenesis.METHODS:Using high-resolution array comparative genomic hybridization (CGH),we investigated the genomic alterations of 20 advanced primary gastric adenocarcinomas (seventeen tubular and three mucinous)of Chinese patients from the Jilin province.Ten matching adjacent normal regions from the same patients were also studied.RESULTS:The most frequent imbalances detected in these cancer samples were gains of 3q26.31-q27.2,5p,8q,11p,18p,19q and 20q and losses of 3p,4p,18q and 21q.The use of high-resolution array CGH increased the resolution and sensitivity of the observed genomic changes and identified focal genetic imbalances,which included 54 gains and 16 losses that were smaller than 1 Mb in size.The most interesting focal imbalances were the intergenic loss/homozygous deletion of the fragile histidine triad gene and the amplicons 11q13,18q11.2 and 19q12,as well as the novel amplicons 1p36.22 and 11p15.5.CONCLUSION:These regions,especially the focal amplicons,may harbor key driver genes that will serve as biomarkers for either the diagnosis or the prognosis of gastric cancer,and therefore,a large-scale investigation is recommended.

  20. IDENTIFICATION OF HUMAN MURR1, THE HOMOLOGUE OF MOUSE IMPRINTED Murr1 GENE

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhongming; Wang Youdong; Hitomi Yatsuki; Keiichiro Joh; Tsuyoshi Iwasaka; Tsunehiro Mukai

    2006-01-01

    Objective To identify the mRNA sequence, genetic construction, imprinting status, and expression profile of human MURR1 gene, the homologue of mouse imprinted Murr1 gene. Methods The MURR1 mRNA sequence was identified by colony hybridization screening of human cDNA library and the 5'-RACE analyses; Absence of U2AF1-RS1 gene within MURR1 was confirmed by Southern Blotting; Expression profile of MURR1 was examined by Northern Blotting; The imprinting status of MURR1 were revealed by SNP investigation and RT-PCR followed by sequencings and RFLP analyses. Results The full-length mRNA sequence of MURR1 spans 711 bp, transcribed from 3 exons, encodes predicted MURR1 protein of 190 amino acids. The gene was expressed in all the 12 kinds of human adult tissues and 6 kinds of fetal tissues. It showed biallelic expression in all 32 investigated samples including 6 kinds of human fetal tissues and 8 adult brains. Unlike mouse imprinted U2af1-rs1 gene existing in the intron of Murr1, the human U2AF1-RS1 gene was not located in the MURR1 locus. Conclusion Human MURR1 gene is not imprinted and the non-imprinting is possible due to the absence of human homologue of mouse U2af1-rs1 within MURR1 locus.

  1. Identification of the Imprinted KLF14 Transcription Factor Undergoing Human-Specific Accelerated Evolution

    OpenAIRE

    Layla Parker-Katiraee; Carson, Andrew R.; Takahiro Yamada; Philippe Arnaud; Robert Feil; Abu-Amero, Sayeda N.; Moore, Gudrun E; Masahiro Kaneda; Perry, George H.; Stone, Anne C.; Charles Lee; Makiko Meguro-Horike; Hiroyuki Sasaki; Keiko Kobayashi; Kazuhiko Nakabayashi

    2007-01-01

    Imprinted genes are expressed in a parent-of-origin manner and are located in clusters throughout the genome. Aberrations in the expression of imprinted genes on human Chromosome 7 have been suggested to play a role in the etiologies of Russell-Silver Syndrome and autism. We describe the imprinting of KLF14, an intronless member of the Krüppel-like family of transcription factors located at Chromosome 7q32. We show that it has monoallelic maternal expression in all embryonic and extra-embryon...

  2. Identification of the imprinted KLF14 transcription factor undergoing human-specific accelerated evolution

    OpenAIRE

    Parker-Katiraee, L.; Carson, A.R.; Yamada, T; Meguro-Horike, M.; Nakabayashi, K.; Scherer, S.W.; Arnaud, P.; Feil, R; Abu-Amero, S. N.; Moore, G.E.; Kaneda, M.; Sasaki, H.; Perry, G. H.; Stone, A C; Lee, C

    2007-01-01

    Imprinted genes are expressed in a parent-of-origin manner and are located in clusters throughout the genome. Aberrations in the expression of imprinted genes on human Chromosome 7 have been suggested to play a role in the etiologies of Russell-Silver Syndrome and autism. We describe the imprinting of KLF14, an intronless member of the Krüppel-like family of transcription factors located at Chromosome 7q32. We show that it has monoallelic maternal expression in all embryonic and extra-embryon...

  3. Preconcentration of indapamide from human urine using molecularly imprinted solid-phase extraction.

    Science.gov (United States)

    Yılmaz, Hüma; Basan, Hasan

    2015-09-01

    A simple, sensitive, and selective molecularly imprinted solid-phase extraction and spectrophotometric method has been developed for the clean-up and preconcentration of indapamide from human urine. Molecularly imprinted polymers were prepared by a non-covalent imprinting approach using indapamide as a template molecule, 2-(trifluoromethyl) acrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, N,N-azobisisobutyronitrile as a thermal initiator and acetonitrile as a porogenic solvent. A non-imprinted polymer was also prepared in the same way, but in the absence of template. Molecularly imprinted polymer and non-imprinted polymer sorbents were dry-packed into solid-phase extraction cartridges. Eluates from cartridges were analyzed using a spectrophotometer for the determination of indapamide by referring to the calibration curve in the range 0.14-1.50 μg/mL. Preconcentration factor, limit of detection, and limit of quantification were 16.30, 0.025 μg/mL, and 0.075 μg/mL, respectively. A relatively high imprinting factor (9.3) was also achieved and recovery values for the indapamide spiked into human urine were in the range of 80.1-81.2%. In addition, relatively low within-day (0.17-0.42%) and between-day (1.1-1.4%) precision values were obtained as well. The proposed molecularly imprinted solid-phase extraction and spectrophotometric method was successfully applied to selective extraction, preconcentration, and determination of indapamide from human urine samples.

  4. Variable allelic expression of imprinted genes in human pluripotent stem cells during differentiation into specialized cell types in vitro.

    Science.gov (United States)

    Park, Sang-Wook; Kim, Jihoon; Park, Jong-Lyul; Ko, Ji-Yun; Im, Ilkyun; Do, Hyo-Sang; Kim, Hyemin; Tran, Ngoc-Tung; Lee, Sang-Hun; Kim, Yong Sung; Cho, Yee Sook; Lee, Dong Ryul; Han, Yong-Mahn

    2014-04-01

    Genomic imprinting is an epigenetic phenomenon by which a subset of genes is asymmetrically expressed in a parent-of-origin manner. However, little is known regarding the epigenetic behaviors of imprinted genes during human development. Here, we show dynamic epigenetic changes in imprinted genes in hESCs during in vitro differentiation into specialized cell types. Out of 9 imprinted genes with single nucleotide polymorphisms, mono-allelic expression for three imprinted genes (H19, KCNQ1OT1, and IPW), and bi- or partial-allelic expression for three imprinted genes (OSBPL5, PPP1R9A, and RTL1) were stably retained in H9-hESCs throughout differentiation, representing imprinting stability. Three imprinted genes (KCNK9, ATP10A, and SLC22A3) showed a loss and a gain of imprinting in a lineage-specific manner during differentiation. Changes in allelic expression of imprinted genes were observed in another hESC line during in vitro differentiation. These findings indicate that the allelic expression of imprinted genes may be vulnerable in a lineage-specific manner in human pluripotent stem cells during differentiation.

  5. Human Oocyte-Derived Methylation Differences Persist in the Placenta Revealing Widespread Transient Imprinting.

    Directory of Open Access Journals (Sweden)

    Marta Sanchez-Delgado

    2016-11-01

    Full Text Available Thousands of regions in gametes have opposing methylation profiles that are largely resolved during the post-fertilization epigenetic reprogramming. However some specific sequences associated with imprinted loci survive this demethylation process. Here we present the data describing the fate of germline-derived methylation in humans. With the exception of a few known paternally methylated germline differentially methylated regions (DMRs associated with known imprinted domains, we demonstrate that sperm-derived methylation is reprogrammed by the blastocyst stage of development. In contrast a large number of oocyte-derived methylation differences survive to the blastocyst stage and uniquely persist as transiently methylated DMRs only in the placenta. Furthermore, we demonstrate that this phenomenon is exclusive to primates, since no placenta-specific maternal methylation was observed in mouse. Utilizing single cell RNA-seq datasets from human preimplantation embryos we show that following embryonic genome activation the maternally methylated transient DMRs can orchestrate imprinted expression. However despite showing widespread imprinted expression of genes in placenta, allele-specific transcriptional profiling revealed that not all placenta-specific DMRs coordinate imprinted expression and that this maternal methylation may be absent in a minority of samples, suggestive of polymorphic imprinted methylation.

  6. Human Oocyte-Derived Methylation Differences Persist in the Placenta Revealing Widespread Transient Imprinting

    Science.gov (United States)

    Court, Franck; Martin-Trujillo, Alex; Tayama, Chiharu; Kondova, Ivanela; Bontrop, Ronald; Poo-Llanillo, Maria Eugenia; Nakabayashi, Kazuhiko; Simón, Carlos; Monk, David

    2016-01-01

    Thousands of regions in gametes have opposing methylation profiles that are largely resolved during the post-fertilization epigenetic reprogramming. However some specific sequences associated with imprinted loci survive this demethylation process. Here we present the data describing the fate of germline-derived methylation in humans. With the exception of a few known paternally methylated germline differentially methylated regions (DMRs) associated with known imprinted domains, we demonstrate that sperm-derived methylation is reprogrammed by the blastocyst stage of development. In contrast a large number of oocyte-derived methylation differences survive to the blastocyst stage and uniquely persist as transiently methylated DMRs only in the placenta. Furthermore, we demonstrate that this phenomenon is exclusive to primates, since no placenta-specific maternal methylation was observed in mouse. Utilizing single cell RNA-seq datasets from human preimplantation embryos we show that following embryonic genome activation the maternally methylated transient DMRs can orchestrate imprinted expression. However despite showing widespread imprinted expression of genes in placenta, allele-specific transcriptional profiling revealed that not all placenta-specific DMRs coordinate imprinted expression and that this maternal methylation may be absent in a minority of samples, suggestive of polymorphic imprinted methylation. PMID:27835649

  7. THE MEANING OF GENOMIC IMPRINTING IN HUMAN GENETIC AND DEFECTOLOGY

    Directory of Open Access Journals (Sweden)

    Anastas LAKOSKI

    2000-12-01

    Full Text Available Several genetic phenomena do not appear to conform the Mendel's low in the sense that they are not inherited in simple way through the generations. Such exceptions to Mendel's laws include new mutations, changes in chromosomes, expanded triplet sequences, and genomic imprinting. Many genetic diseases involve spontaneous mutations that are not inherited from generation to generation. Changes in chromosomes include nondisjunction, which is the most important cause of mental retardation, the trisomy of Dowen syndrome. Expanded triplet repeats are responsible for the next important cause of mental retardation, fragile X, and for Huntington's disease. Genomic imprinting occurs when the expression of a gene depends on whether it is inherited from the mother or from the father. In this paper the phenomenon of genomic imprinting is explained on the occurrence of Angelman and Prader-Willi syndromes. It's essential for the counselor to be able during the genetic counseling to recognize this phenomenon and to make a proper decision.

  8. Is Imprinting an Appropriate Model for Human Infant Attachment?

    Science.gov (United States)

    Reed, G. L.; Leiderman, P. H.

    1983-01-01

    Results of animal imprinting studies were generalized to attempt prediction of development of attachment in 28 polymatrically reared Kenyan Gusii infants, ages 6 to 30 months. While results provide evidence against a sensitive phase for attachment, an association was found between age of attachment and developmental level/caregiving history.…

  9. Molecular recognition based iron removal from human plasma with imprinted membranes.

    Science.gov (United States)

    Yavuz, H; Andaç, M; Uzun, L; Say, R; Denizli, A

    2006-09-01

    The aim of this study is to prepare ion-imprinted poly(2-hydroxyethyl methacrylate) (HEMA) based membranes which can be used for the selective removal of Fe3+ ions from Fe3+-overdosed human plasma. N-methacryloyl-(L)-glutamic acid (MAGA) was chosen as the ion-complexing monomer. In the first step, Fe3+ was complexed with MAGA and then, the Fe3+-imprinted poly(HEMA-MAGA) membranes were prepared by UV-initiated photo-polymerization of HEMA and MAGA-Fe3+ complex in the presence of an initiator (benzoyl peroxide). After that, the template (i.e., Fe3+ ions) was removed by using 0.1 M EDTA solution at room temperature. The specific surface area of the Fe3+-imprinted poly(HEMA-MAGA) membranes was found to be 49.2 m2/g and the swelling ratio was 92%. According to the elemental analysis results, the polymeric membranes contained 145.7 micromol MAGA/g polymer. The maximum adsorption capacity was 164.2 micromol Fe3+/g membrane. The relative selectivity coefficients of ion-imprinted membranes for Fe3+/Zn2+ and Fe3+/Cr3+ were 12.6 and 62.5 times greater than the non-imprinted matrix, respectively. The Fe3+-imprinted poly(HEMA-MAGA) membranes could be used many times without decreasing their Fe3+ adsorption capacities significantly.

  10. A statistical design for testing transgenerational genomic imprinting in natural human populations.

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    Yao Li

    Full Text Available Genomic imprinting is a phenomenon in which the same allele is expressed differently, depending on its parental origin. Such a phenomenon, also called the parent-of-origin effect, has been recognized to play a pivotal role in embryological development and pathogenesis in many species. Here we propose a statistical design for detecting imprinted loci that control quantitative traits based on a random set of three-generation families from a natural population in humans. This design provides a pathway for characterizing the effects of imprinted genes on a complex trait or disease at different generations and testing transgenerational changes of imprinted effects. The design is integrated with population and cytogenetic principles of gene segregation and transmission from a previous generation to next. The implementation of the EM algorithm within the design framework leads to the estimation of genetic parameters that define imprinted effects. A simulation study is used to investigate the statistical properties of the model and validate its utilization. This new design, coupled with increasingly used genome-wide association studies, should have an immediate implication for studying the genetic architecture of complex traits in humans.

  11. A statistical design for testing transgenerational genomic imprinting in natural human populations.

    Science.gov (United States)

    Li, Yao; Guo, Yunqian; Wang, Jianxin; Hou, Wei; Chang, Myron N; Liao, Duanping; Wu, Rongling

    2011-02-25

    Genomic imprinting is a phenomenon in which the same allele is expressed differently, depending on its parental origin. Such a phenomenon, also called the parent-of-origin effect, has been recognized to play a pivotal role in embryological development and pathogenesis in many species. Here we propose a statistical design for detecting imprinted loci that control quantitative traits based on a random set of three-generation families from a natural population in humans. This design provides a pathway for characterizing the effects of imprinted genes on a complex trait or disease at different generations and testing transgenerational changes of imprinted effects. The design is integrated with population and cytogenetic principles of gene segregation and transmission from a previous generation to next. The implementation of the EM algorithm within the design framework leads to the estimation of genetic parameters that define imprinted effects. A simulation study is used to investigate the statistical properties of the model and validate its utilization. This new design, coupled with increasingly used genome-wide association studies, should have an immediate implication for studying the genetic architecture of complex traits in humans.

  12. THE MEANING OF GENOMIC IMPRINTING IN HUMAN GENETIC AND DEFECTOLOGY

    OpenAIRE

    Anastas LAKOSKI

    2000-01-01

    Several genetic phenomena do not appear to conform the Mendel's low in the sense that they are not inherited in simple way through the generations. Such exceptions to Mendel's laws include new mutations, changes in chromosomes, expanded triplet sequences, and genomic imprinting. Many genetic diseases involve spontaneous mutations that are not inherited from generation to generation. Changes in chromosomes include nondisjunction, which is the most important cause of mental retardation, the tri...

  13. Establishment of a Conditionally Immortalized Wilms Tumor Cell Line with a Homozygous WT1 Deletion within a Heterozygous 11p13 Deletion and UPD Limited to 11p15.

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    Artur Brandt

    Full Text Available We describe a stromal predominant Wilms tumor with focal anaplasia and a complex, tumor specific chromosome 11 aberration: a homozygous deletion of the entire WT1 gene within a heterozygous 11p13 deletion and an additional region of uniparental disomy (UPD limited to 11p15.5-p15.2 including the IGF2 gene. The tumor carried a heterozygous p.T41A mutation in CTNNB1. Cells established from the tumor carried the same chromosome 11 aberration, but a different, homozygous p.S45Δ CTNNB1 mutation. Uniparental disomy (UPD 3p21.3pter lead to the homozygous CTNNB1 mutation. The tumor cell line was immortalized using the catalytic subunit of human telomerase (hTERT in conjunction with a novel thermolabile mutant (U19dl89-97tsA58 of SV40 large T antigen (LT. This cell line is cytogenetically stable and can be grown indefinitely representing a valuable tool to study the effect of a complete lack of WT1 in tumor cells. The origin/fate of Wilms tumors with WT1 mutations is currently poorly defined. Here we studied the expression of several genes expressed in early kidney development, e.g. FOXD1, PAX3, SIX1, OSR1, OSR2 and MEIS1 and show that these are expressed at similar levels in the parental and the immortalized Wilms10 cells. In addition the limited potential for muscle/ osteogenic/ adipogenic differentiation similar to all other WT1 mutant cell lines is also observed in the Wilms10 tumor cell line and this is retained in the immortalized cells. In summary these Wilms10 cells are a valuable model system for functional studies of WT1 mutant cells.

  14. Large-Scale Analysis of Loss of Imprinting in Human Pluripotent Stem Cells

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    Shiran Bar

    2017-05-01

    Full Text Available The parent-specific monoallelic expression of imprinted genes is controlled by DNA methylation marks that are established differentially in the germline. Perturbation of these marks leads to loss of imprinting (LOI, which is associated with developmental disorders and malignancy and may also obstruct applications of human pluripotent stem cells (hPSCs. Previous studies of LOI in hPSCs were performed on relatively small numbers of cell lines, often leading to conflicting conclusions regarding imprinting stability. Here, we chart the landscape of LOI in hPSCs by applying a large-scale analysis of allele-specific RNA-seq data from more than 270 hPSC samples. We show that reprogrammed hPSCs acquire higher levels of LOI compared with embryonic stem cells and that LOI can pre-exist in their somatic cells of origin. Furthermore, different imprinted genes vary with respect to LOI incidence, surprisingly revealing that those controlled paternally are more prone to disruption. Our findings emphasize the importance of inspecting the imprinting status of hPSCs.

  15. Cellular functions of genetically imprinted genes in human and mouse as annotated in the gene ontology.

    Science.gov (United States)

    Hamed, Mohamed; Ismael, Siba; Paulsen, Martina; Helms, Volkhard

    2012-01-01

    By analyzing the cellular functions of genetically imprinted genes as annotated in the Gene Ontology for human and mouse, we found that imprinted genes are often involved in developmental, transport and regulatory processes. In the human, paternally expressed genes are enriched in GO terms related to the development of organs and of anatomical structures. In the mouse, maternally expressed genes regulate cation transport as well as G-protein signaling processes. Furthermore, we investigated if imprinted genes are regulated by common transcription factors. We identified 25 TF families that showed an enrichment of binding sites in the set of imprinted genes in human and 40 TF families in mouse. In general, maternally and paternally expressed genes are not regulated by different transcription factors. The genes Nnat, Klf14, Blcap, Gnas and Ube3a contribute most to the enrichment of TF families. In the mouse, genes that are maternally expressed in placenta are enriched for AP1 binding sites. In the human, we found that these genes possessed binding sites for both, AP1 and SP1.

  16. High-throughput analysis of candidate imprinted genes and allele-specific gene expression in the human term placenta

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    Clark Taane G

    2010-04-01

    Full Text Available Abstract Background Imprinted genes show expression from one parental allele only and are important for development and behaviour. This extreme mode of allelic imbalance has been described for approximately 56 human genes. Imprinting status is often disrupted in cancer and dysmorphic syndromes. More subtle variation of gene expression, that is not parent-of-origin specific, termed 'allele-specific gene expression' (ASE is more common and may give rise to milder phenotypic differences. Using two allele-specific high-throughput technologies alongside bioinformatics predictions, normal term human placenta was screened to find new imprinted genes and to ascertain the extent of ASE in this tissue. Results Twenty-three family trios of placental cDNA, placental genomic DNA (gDNA and gDNA from both parents were tested for 130 candidate genes with the Sequenom MassArray system. Six genes were found differentially expressed but none imprinted. The Illumina ASE BeadArray platform was then used to test 1536 SNPs in 932 genes. The array was enriched for the human orthologues of 124 mouse candidate genes from bioinformatics predictions and 10 human candidate imprinted genes from EST database mining. After quality control pruning, a total of 261 informative SNPs (214 genes remained for analysis. Imprinting with maternal expression was demonstrated for the lymphocyte imprinted gene ZNF331 in human placenta. Two potential differentially methylated regions (DMRs were found in the vicinity of ZNF331. None of the bioinformatically predicted candidates tested showed imprinting except for a skewed allelic expression in a parent-specific manner observed for PHACTR2, a neighbour of the imprinted PLAGL1 gene. ASE was detected for two or more individuals in 39 candidate genes (18%. Conclusions Both Sequenom and Illumina assays were sensitive enough to study imprinting and strong allelic bias. Previous bioinformatics approaches were not predictive of new imprinted genes

  17. [Epigenetics, genomic imprinting and developmental disorders].

    Science.gov (United States)

    Le Bouc, Yves; Rossignol, Sylvie; Azzi, Salah; Brioude, Frédéric; Cabrol, Sylvie; Gicquel, Christine; Netchine, Irène

    2010-02-01

    Epigenetic phenomena play a key role in regulating gene expression. One of the most widely studied epigenetic modification is DNA methylation at cytosine residues of CpG dinucleotides in gene promoters, transposons and imprinting control regions (ICR). Genomic imprinting refers to epigenetic marking of genes that results in monoallelic expression depending on the parental origin. Several genes encoding key hormones involved in embryonic and fetal growth are imprinted. There are two critical periods of epigenetic reprogramming: gametogenesis and early preimplantation development. Major reprogramming takes place in primordial germ cells, in which parental imprints are erased and totipotency is restored. Imprint marks are then re-established during spermatogenesis or oogenesis, depending on gender. Upon fertilization, genome-wide demethylation is followed by a wave of de novo methylation, both processes being resisted by imprinted loci. Disruption of imprinting can cause growth defects such as the Beckwith-Wiedemann overgrowth syndrome (BWS) and the Russell-Silver (RSS) intrauterine and postnatal growth retardation syndrome. These growth disorders are caused by abnormal DNA methylation in the 11p15 imprinted region encompassing many imprinted genes, such as IGF2. BWS has been linked to loss of methylation (LOM) in the centromeric ICR2/KCNQIOT1 region of the maternal allele, or gain of methylation in the telomeric ICR1/IGF2/H19 region of the maternal allele. This latter epigenetic defect is associated with an increased risk of tumors such as nephroblastoma. LOM in the telomeric ICR1 region of the paternal allele has been detected in RSS. Early embryogenesis is a critical period of epigenetic regulation, and is sensitive to environmental factors. Individuals conceived with the help of assisted reproductive technology (ART) are over-represented among BWS patients, suggesting that ART may favor altered imprinting at the imprinted centromeric 11p15 locus (LOM in the

  18. Early embryonic failure: Expression and imprinted status of candidate genes on human chromosome 21

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, L.S.; Bennett, P.R.; Moore, G.E. [Queen Charlotte`s and Chelsea Hospital, London (United Kingdom)

    1994-09-01

    Two cases of maternal uniparental (hetero)disomy for human chromosome 21 (mUPD21) have been identified in a systematic search for UPD in 23 cases of early embryonic failure (EEF). Bi-parental origin of the other chromosome pairs was confirmed using specific VNTR probes or dinucleotide repeat analysis. Both maternally and paternally derived isochromosomes 21q have previously been identified in two individuals with normal phenotypes. Full UPD21 has a different mechanism of origin than uniparental isochromosome 21q and its effect on imprinted genes and phenotypic outcome will therefore not necessarily be the same. EEF associated with mUPD21 suggests that developmentally important genes on HSA 21 may be imprinted such that they are only expressed from either the maternally or paternally derived alleles. We have searched for monoallelic expression of candidate genes on HSA 21 in human pregnancy (CBS, IFNAR, COL6A1) using intragenic DNA polymorphisms. These genes were chosen either because their murine homologues lie in imprinted regions or because they are potentially important in embryogenesis. Once imprinted candidate genes have been identified, their methylation status and expression in normal, early embryonic failure and uniparental disomy 21 pregnancies will be studied. At the same time, a larger number of cases of EEF are being examined to further investigate the incidence of UPD21 in this group.

  19. 乳腺浸润性导管癌染色体8p22、11p15、17p13区杂合性缺失的研究%Invasive ductal carcinoma of the breast is prevalence of loss of heterozygosity at 8p22,11p15 and 17p13

    Institute of Scientific and Technical Information of China (English)

    李志刚; 周晓军; 孔庆兖; 易龙; 孟奎

    2004-01-01

    目的:观察乳腺浸润性导管癌中8p22、11p15、17p13三个染色体区的杂合性缺失(LOH)及其与临床病理参数之间的关系. 方法:从石蜡包埋的存档标本中选取34例肿瘤组织和其对应的自身正常对照组织,用PCR方法扩增位于此三个染色体区域的三个微卫星位点D8S136、D11S988、TP53,扩增产物用6%聚丙稀酰胺凝胶电泳,银染显色后进行LOH的判定.用免疫组化方法观察ER、PR、P53和c-erBb-2在乳腺癌中的表达情况. 结果:34例乳腺癌中有12例(35.29%)D8S136位点发生LOH, D11S988和TP53两个位点分别发现5例(14.71%)LOH.D11S988和TP53两个位点的LOH与临床病理参数之间无明显相关性,而D8S136发生LOH的肿瘤平均直径明显高于LOH阴性的肿瘤(P=0.0049). 结论:染色体8p22区域有较高的LOH发生率,位于此区域的肿瘤抑制基因的失活可能与乳腺癌的迅速生长有关.

  20. Identification of the imprinted KLF14 transcription factor undergoing human-specific accelerated evolution.

    Science.gov (United States)

    Parker-Katiraee, Layla; Carson, Andrew R; Yamada, Takahiro; Arnaud, Philippe; Feil, Robert; Abu-Amero, Sayeda N; Moore, Gudrun E; Kaneda, Masahiro; Perry, George H; Stone, Anne C; Lee, Charles; Meguro-Horike, Makiko; Sasaki, Hiroyuki; Kobayashi, Keiko; Nakabayashi, Kazuhiko; Scherer, Stephen W

    2007-05-04

    Imprinted genes are expressed in a parent-of-origin manner and are located in clusters throughout the genome. Aberrations in the expression of imprinted genes on human Chromosome 7 have been suggested to play a role in the etiologies of Russell-Silver Syndrome and autism. We describe the imprinting of KLF14, an intronless member of the Krüppel-like family of transcription factors located at Chromosome 7q32. We show that it has monoallelic maternal expression in all embryonic and extra-embryonic tissues studied, in both human and mouse. We examine epigenetic modifications in the KLF14 CpG island in both species and find this region to be hypomethylated. In addition, we perform chromatin immunoprecipitation and find that the murine Klf14 CpG island lacks allele-specific histone modifications. Despite the absence of these defining features, our analysis of Klf14 in offspring from DNA methyltransferase 3a conditional knockout mice reveals that the gene's expression is dependent upon a maternally methylated region. Due to the intronless nature of Klf14 and its homology to Klf16, we suggest that the gene is an ancient retrotransposed copy of Klf16. By sequence analysis of numerous species, we place the timing of this event after the divergence of Marsupialia, yet prior to the divergence of the Xenarthra superclade. We identify a large number of sequence variants in KLF14 and, using several measures of diversity, we determine that there is greater variability in the human lineage with a significantly increased number of nonsynonymous changes, suggesting human-specific accelerated evolution. Thus, KLF14 may be the first example of an imprinted transcript undergoing accelerated evolution in the human lineage.

  1. Identification of the imprinted KLF14 transcription factor undergoing human-specific accelerated evolution.

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    Layla Parker-Katiraee

    2007-05-01

    Full Text Available Imprinted genes are expressed in a parent-of-origin manner and are located in clusters throughout the genome. Aberrations in the expression of imprinted genes on human Chromosome 7 have been suggested to play a role in the etiologies of Russell-Silver Syndrome and autism. We describe the imprinting of KLF14, an intronless member of the Krüppel-like family of transcription factors located at Chromosome 7q32. We show that it has monoallelic maternal expression in all embryonic and extra-embryonic tissues studied, in both human and mouse. We examine epigenetic modifications in the KLF14 CpG island in both species and find this region to be hypomethylated. In addition, we perform chromatin immunoprecipitation and find that the murine Klf14 CpG island lacks allele-specific histone modifications. Despite the absence of these defining features, our analysis of Klf14 in offspring from DNA methyltransferase 3a conditional knockout mice reveals that the gene's expression is dependent upon a maternally methylated region. Due to the intronless nature of Klf14 and its homology to Klf16, we suggest that the gene is an ancient retrotransposed copy of Klf16. By sequence analysis of numerous species, we place the timing of this event after the divergence of Marsupialia, yet prior to the divergence of the Xenarthra superclade. We identify a large number of sequence variants in KLF14 and, using several measures of diversity, we determine that there is greater variability in the human lineage with a significantly increased number of nonsynonymous changes, suggesting human-specific accelerated evolution. Thus, KLF14 may be the first example of an imprinted transcript undergoing accelerated evolution in the human lineage.

  2. A New Molecularly Imprinted Polymer for Solid-phase Extraction of Cotinine from Human Urine

    Institute of Scientific and Technical Information of China (English)

    Jun YANG; Xiao Lan ZHU; Ji Bao CAI; Qing De SU; Yun GAO; Liang ZHANG

    2005-01-01

    A molecularly imprinted polymer (MIP), prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction (SPE) of cotinine from biological samples has been investigated. The results show that cotinine can be quantitatively retained and eluted from the polymer. Experiments with human urine samples indicate that clean target analyte is obtained for HPLC with UV detection using the protocol.

  3. Genome-wide association study identifies two novel regions at 11p15.5-p13 and 1p31 with major impact on acute-phase serum amyloid A.

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    Carola Marzi

    2010-11-01

    Full Text Available Elevated levels of acute-phase serum amyloid A (A-SAA cause amyloidosis and are a risk factor for atherosclerosis and its clinical complications, type 2 diabetes, as well as various malignancies. To investigate the genetic basis of A-SAA levels, we conducted the first genome-wide association study on baseline A-SAA concentrations in three population-based studies (KORA, TwinsUK, Sorbs and one prospective case cohort study (LURIC, including a total of 4,212 participants of European descent, and identified two novel genetic susceptibility regions at 11p15.5-p13 and 1p31. The region at 11p15.5-p13 (rs4150642; p = 3.20×10(-111 contains serum amyloid A1 (SAA1 and the adjacent general transcription factor 2 H1 (GTF2H1, Hermansky-Pudlak Syndrome 5 (HPS5, lactate dehydrogenase A (LDHA, and lactate dehydrogenase C (LDHC. This region explains 10.84% of the total variation of A-SAA levels in our data, which makes up 18.37% of the total estimated heritability. The second region encloses the leptin receptor (LEPR gene at 1p31 (rs12753193; p = 1.22×10(-11 and has been found to be associated with CRP and fibrinogen in previous studies. Our findings demonstrate a key role of the 11p15.5-p13 region in the regulation of baseline A-SAA levels and provide confirmative evidence of the importance of the 1p31 region for inflammatory processes and the close interplay between A-SAA, leptin, and other acute-phase proteins.

  4. Human homogamy in facial characteristics: does a sexual-imprinting-like mechanism play a role?

    Science.gov (United States)

    Nojo, Saori; Tamura, Satoshi; Ihara, Yasuo

    2012-09-01

    Human homogamy may be caused in part by individuals' preference for phenotypic similarities. Two types of preference can result in homogamy: individuals may prefer someone who is similar to themselves (self-referent phenotype matching) or to their parents (a sexual-imprinting-like mechanism). In order to examine these possibilities, we compare faces of couples and their family members in two ways. First, "perceived" similarity between a pair of faces is quantified as similarity ratings given to the pair. Second, "physical" similarity between two groups of faces is evaluated on the basis of correlations in principal component scores generated from facial measurements. Our results demonstrate a tendency to homogamy in facial characteristics and suggest that the tendency is due primarily to self-referent phenotype matching. Nevertheless, the presence of a sexual-imprinting-like effect is also partially indicated: whether individuals are involved in facial homogamy may be affected by their relationship with their parents during childhood.

  5. Sexual imprinting on facial traits of opposite-sex parents in humans.

    Science.gov (United States)

    Marcinkowska, Urszula M; Rantala, Markus J

    2012-09-05

    Positive sexual imprinting is a process by which individuals use the phenotype of their opposite-sex parent as a template for acquiring mates. Recent studies in humans have concluded that an imprinting-like mechanism influences human mate choice in facial traits. However, some of the previous studies have had methodological problems or flaws which might have invalidated or led to an overgeneralization of the original interpretation of their results. In this study, 70 heterosexual adults were used to test if their partners resembled facially their opposite-sex parent as the sexual imprinting hypothesis predicts. Judges assessed the subjective facial similarity between each participant's partner and their parent. We found that there was no perceived facial similarity between women's partners and their fathers. However, men tended to pair more often with women that were perceived as resembling the men's own mothers. In contrast to previous studies, the quality of the relationship between participants and their parents did not predict the level of facial resemblance between the participant's spouse and their parent.

  6. Quantitative analysis of DNA methylation at all human imprinted regions reveals preservation of epigenetic stability in adult somatic tissue

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    Woodfine Kathryn

    2011-01-01

    Full Text Available Abstract Background Genes subject to genomic imprinting are mono-allelically expressed in a parent-of-origin dependent manner. Each imprinted locus has at least one differentially methylated region (DMR which has allele specific DNA methylation and contributes to imprinted gene expression. Once DMRs are established, they are potentially able to withstand normal genome reprogramming events that occur during cell differentiation and germ-line DMRs are stably maintained throughout development. These DMRs, in addition to being either maternally or paternally methylated, have differences in whether methylation was acquired in the germ-line or post fertilization and are present in a variety of genomic locations with different Cytosine-phosphate guanine (CpG densities and CTCF binding capacities. We therefore examined the stability of maintenance of DNA methylation imprints and determined the normal baseline DNA methylation levels in several adult tissues for all imprinted genes. In order to do this, we first developed and validated 50 highly specific, quantitative DNA methylation pyrosequencing assays for the known DMRs associated with human imprinted genes. Results Remarkable stability of the DNA methylation imprint was observed in all germ-line DMRs and paternally methylated somatic DMRs (which maintained average methylation levels of between 35% - 65% in all somatic tissues, independent of gene expression. Maternally methylated somatic DMRs were found to have more variation with tissue specific methylation patterns. Most DMRs, however, showed some intra-individual variability for DNA methylation levels in peripheral blood, suggesting that more than one DMR needs to be examined in order to get an overall impression of the epigenetic stability in a tissue. The plasticity of DNA methylation at imprinted genes was examined in a panel of normal and cancer cell lines. All cell lines showed changes in DNA methylation, especially at the paternal germ

  7. The genome of a Mongolian individual reveals the genetic imprints of Mongolians on modern human populations.

    Science.gov (United States)

    Bai, Haihua; Guo, Xiaosen; Zhang, Dong; Narisu, Narisu; Bu, Junjie; Jirimutu, Jirimutu; Liang, Fan; Zhao, Xiang; Xing, Yanping; Wang, Dingzhu; Li, Tongda; Zhang, Yanru; Guan, Baozhu; Yang, Xukui; Yang, Zili; Shuangshan, Shuangshan; Su, Zhe; Wu, Huiguang; Li, Wenjing; Chen, Ming; Zhu, Shilin; Bayinnamula, Bayinnamula; Chang, Yuqi; Gao, Ying; Lan, Tianming; Suyalatu, Suyalatu; Huang, Hui; Su, Yan; Chen, Yujie; Li, Wenqi; Yang, Xu; Feng, Qiang; Wang, Jian; Yang, Huanming; Wang, Jun; Wu, Qizhu; Yin, Ye; Zhou, Huanmin

    2014-11-05

    Mongolians have played a significant role in modern human evolution, especially after the rise of Genghis Khan (1162[?]-1227). Although the social cultural impacts of Genghis Khan and the Mongolian population have been well documented, explorations of their genome structure and genetic imprints on other human populations have been lacking. We here present the genome of a Mongolian male individual. The genome was de novo assembled using a total of 130.8-fold genomic data produced from massively parallel whole-genome sequencing. We identified high-confidence variation sets, including 3.7 million single nucleotide polymorphisms (SNPs) and 756,234 short insertions and deletions. Functional SNP analysis predicted that the individual has a pathogenic risk for carnitine deficiency. We located the patrilineal inheritance of the Mongolian genome to the lineage D3a through Y haplogroup analysis and inferred that the individual has a common patrilineal ancestor with Tibeto-Burman populations and is likely to be the progeny of the earliest settlers in East Asia. We finally investigated the genetic imprints of Mongolians on other human populations using different approaches. We found varying degrees of gene flows between Mongolians and populations living in Europe, South/Central Asia, and the Indian subcontinent. The analyses demonstrate that the genetic impacts of Mongolians likely resulted from the expansion of the Mongolian Empire in the 13th century. The genome will be of great help in further explorations of modern human evolution and genetic causes of diseases/traits specific to Mongolians.

  8. Differentially methylated regions of imprinted genes in prenatal, perinatal and postnatal human tissues.

    Directory of Open Access Journals (Sweden)

    Susan K Murphy

    Full Text Available Epigenetic plasticity in relation to in utero exposures may mechanistically explain observed differences in the likelihood of developing common complex diseases including hypertension, diabetes and cardiovascular disease through the cumulative effects of subtle alterations in gene expression. Imprinted genes are essential mediators of growth and development and are characterized by differentially methylated regulatory regions (DMRs that carry parental allele-specific methylation profiles. This theoretical 50% level of methylation provides a baseline from which endogenously- or exogenously-induced deviations in methylation can be detected. We quantified DNA methylation at imprinted gene DMRs in a large panel of human conceptal tissues, in matched buccal cell specimens collected at birth and at one year of age, and in the major cell fractions of umbilical cord blood to assess the stability of methylation at these regions. DNA methylation was measured using validated pyrosequencing assays at seven DMRs regulating the IGF2/H19, DLK1/MEG3, MEST, NNAT and SGCE/PEG10 imprinted domains. DMR methylation did not significantly differ for the H19, MEST and SGCE/PEG10 DMRs across all conceptal tissues analyzed (ANOVA p>0.10. Methylation differences at several DMRs were observed in tissues from brain (IGF2 and MEG3-IG DMRs, liver (IGF2 and MEG3 DMRs and placenta (both DLK1/MEG3 DMRs and NNAT DMR. In most infants, methylation profiles in buccal cells at birth and at one year of age were comparable, as was methylation in the major cell fractions of umbilical cord blood. Several infants showed temporal deviations in methylation at multiple DMRs. Similarity of inter-individual and intra-individual methylation at some, but not all of the DMRs analyzed supports the possibility that methylation of these regions can serve as useful biosensors of exposure.

  9. Changes in expression of imprinted genes following treatment of human cancer cell lines with non-mutagenic or mutagenic carcinogens.

    Science.gov (United States)

    Shibui, Takeo; Higo, Yukari; Tsutsui, Takeo W; Uchida, Minoru; Oshimura, Mitsuo; Barrett, J Carl; Tsutsui, Takeki

    2008-08-01

    It remains possible that chemicals that act by mutagenic mechanisms as well as chemicals that do not induce gene mutations may affect epigenetic gene expression. To test the possibility, we investigated the ability of both types of chemicals to alter the expression of five imprinted genes, PEG3, SNRPN, NDN, ZAC and H19, using two human colon cancer cell lines and a human breast cancer cell line. The expression of imprinted genes was changed by some non-mutagenic and mutagenic carcinogens independent of their mutagenic activity. The genes most commonly exhibiting the changes in expression were SNRPN and PEG3. Alterations of the expression of NDN and ZAC were also observed in some conditions. Methylation-specific PCR and chromatin immunoprecipitation assays suggest the possibility that changes in the expression of SNRPN may be associated with DNA hypomethylation and histone acetylation of the promoters and euchromatinization of the heterochromatic domains of the promoters. Changes in expression of the imprinted genes, PEG3 and NDN, were also observed in cells immortalized by treatment of normal human fibroblasts with 4-nitroquinoline 1-oxide or aflatoxin B1. We previously demonstrated that expression of the cancer-related gene, INK4a, in these immortal cells was lost via epigenetic mechanisms. The results prove that, in cancer cells, some mutagenic or non-mutagenic carcinogens can epigenetically influence the transcription levels of imprinted genes and also suggest the possibility that some chemical carcinogens may have epigenetic carcinogenic effects in human cells.

  10. Synthesis, recognition and evaluation of molecularly imprinted polymer nanoparticle using miniemulsion polymerization for controlled release and analysis of risperidone in human plasma samples

    Energy Technology Data Exchange (ETDEWEB)

    Asadi, Ebadullah; Azodi-Deilami, Saman; Abdouss, Majid [Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Kordestani, Davood [Razi University, Kermanshah (Iran, Islamic Republic of); Rahimi, Alireza [Research Institute of Petroleum Industry (RIPI), Tehran (Iran, Islamic Republic of); Asadi, Somayeh [Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of)

    2014-06-15

    We prepared high selective imprinted nanoparticle polymers by a miniemulsion polymerization technique, using risperidone as the template, MAA as the functional monomers, and TRIM as the cross-linker in acetonitrile as solvent. The morphology of the nanoparticles determined by scanning electron microscopy (SEM) images and drug release, binding properties and dynamic light scattering (DLS) of molecularly imprinted polymers (MIPs) were studied. Controlled release of risperidone from nanoparticles was investigated through in 1% wt sodium dodecyl sulfate aqueous solution and by measuring the absorbance by HPLC-UV. The results showed that the imprinted nanoparticles exhibited a higher binding level and slower release rate than non-imprinted nanoparticles, which contributed to interaction of risperidone with imprinted cavities within nanoparticles. Furthermore, the results from HPLC showed good precision (5% for 50.0 µg L{sup -1}) and recoveries (between 86-91) using MIP from human plasma samples.

  11. Methylation and Transcripts Expression at the Imprinted GNAS Locus in Human Embryonic and Induced Pluripotent Stem Cells and Their Derivatives

    Directory of Open Access Journals (Sweden)

    Virginie Grybek

    2014-09-01

    Full Text Available Data from the literature indicate that genomic imprint marks are disturbed in human pluripotent stem cells (PSCs. GNAS is an imprinted locus that produces one biallelic (Gsα and four monoallelic (NESP55, GNAS-AS1, XLsα, and A/B transcripts due to differential methylation of their promoters (DMR. To document imprinting at the GNAS locus in PSCs, we studied GNAS locus DMR methylation and transcript (NESP55, XLsα, and A/B expression in human embryonic stem cells (hESCs and human induced pluripotent stem cells (hiPSCs derived from two human fibroblasts and their progenies. Results showed that (1 methylation at the GNAS locus DMRs is DMR and cell line specific, (2 changes in allelic transcript expression can be independent of a change in allele-specific DNA methylation, and (3 interestingly, methylation at A/B DMR is correlated with A/B transcript expression. These results indicate that these models are valuable to study the mechanisms controlling GNAS methylation, factors involved in transcript expression, and possibly mechanisms involved in the pathophysiology of pseudohypoparathyroidism type 1B.

  12. Quantitation of drugs via molecularly imprinted polymer solid phase extraction and electrospray ionization mass spectrometry: benzodiazepines in human plasma

    OpenAIRE

    2011-01-01

    The association of solid phase extraction with molecularly imprinted polymers (MIP) and electrospray ionization mass spectrometry (ESI-MS) is applied to the direct extraction and quantitation of benzodiazepines in human plasma. The target analytes are sequestered by MIP and directly analyzed by ESI-MS. Due to the MIP highly selective extraction, ionic suppression during ESI is minimized; hence no separation is necessary prior to ESI-MS, which greatly increases analytical speed. Benzodiazepine...

  13. Variation in human mate choice: simultaneously investigating heritability, parental influence, sexual imprinting, and assortative mating.

    Science.gov (United States)

    Zietsch, Brendan P; Verweij, Karin J H; Heath, Andrew C; Martin, Nicholas G

    2011-05-01

    Human mate choice is central to individuals' lives and to the evolution of the species, but the basis of variation in mate choice is not well understood. Here we looked at a large community-based sample of twins and their partners and parents ([Formula: see text] individuals) to test for genetic and family environmental influences on mate choice, while controlling for and not controlling for the effects of assortative mating. Key traits were analyzed, including height, body mass index, age, education, income, personality, social attitudes, and religiosity. This revealed near-zero genetic influences on male and female mate choice over all traits and no significant genetic influences on mate choice for any specific trait. A significant family environmental influence was found for the age and income of females' mate choices, possibly reflecting parental influence over mating decisions. We also tested for evidence of sexual imprinting, where individuals acquire mate-choice criteria during development by using their opposite-sex parent as the template of a desirable mate; there was no such effect for any trait. The main discernible pattern of mate choice was assortative mating; we found that partner similarity was due to initial choice rather than convergence and also at least in part to phenotypic matching.

  14. Well-defined nanostructured surface-imprinted polymers for highly selective magnetic separation of fluoroquinolones in human urine.

    Science.gov (United States)

    He, Yonghuan; Huang, Yanyan; Jin, Yulong; Liu, Xiangjun; Liu, Guoquan; Zhao, Rui

    2014-06-25

    The construction of molecularly imprinted polymers on magnetic nanoparticles gives access to smart materials with dual functions of target recognition and magnetic separation. In this study, the superparamagnetic surface-molecularly imprinted nanoparticles were prepared via surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization using ofloxacin (OFX) as template for the separation of fluoroquinolones (FQs). Benefiting from the living/controlled nature of RAFT reaction, distinct core-shell structure was successfully constructed. The highly uniform nanoscale MIP layer was homogeneously grafted on the surface of RAFT agent TTCA modified Fe3O4@SiO2 nanoparticles, which favors the fast mass transfer and rapid binding kinetics. The target binding assays demonstrate the desirable adsorption capacity and imprinting efficiency of Fe3O4@MIP. High selectivity of Fe3O4@MIP toward FQs (ofloxacin, pefloxacin, enrofloxacin, norfloxacin, and gatifloxacin) was exhibited by competitive binding assay. The Fe3O4@MIP nanoparticles were successfully applied for the direct enrichment of five FQs from human urine. The spiked human urine samples were determined and the recoveries ranging from 83.1 to 103.1% were obtained with RSD of 0.8-8.2% (n = 3). This work provides a versatile approach for the fabrication of well-defined MIP on nanomaterials for the analysis of complicated biosystems.

  15. Global Ecological Human Imprint, Sustainable Development and Environment: Assessment and Impacts

    Directory of Open Access Journals (Sweden)

    Safwat H. Shakir Hanna

    2014-10-01

    Full Text Available Ecological Human Imprint (EHI, sustainability, and environment form three points of thetriangle of technology development. These three points when integrated are the key tounderstanding how to improve global sustainability. The present research focuses onassessment and impacts of global issues of sustainability of human activities. This researchuses modeling of these points and predicts the impacts of human activities on our globalEarth and its natural resources and in consequence, the economic and social impacts.Further, the model uses assessments to develop suggestions about how to conserve ourglobal environment and natural resources for future generations. The model is constructedon data collected and analyzed using published data from USA Agencies: United NationAgencies and other public published data from different countries in the world. Stella™software is used in the development of the model to make the prediction for the next 100years.The results of research applying the model are presented in three scenarios. Thesescenarios are formed applying (1 relaxed, (2 moderate, and (3 very conservativeassumptions. In addition to these scenarios, predictions are developed according to thereal-time data availability. According to the model, it is very important to maintain thetrend of more efficient use of natural resources. Additionally, the more widespreadeducation is very important to combat high demands for on natural resources and toconserve existing resources for continuation of global ecosystems and to supply life onEarth with the goods and services needed. Further, it is important to maintain the globalthe regenerative biological capacities (i.e. renewable resources of Earth, while conserving(and developing new sources of non-renewable resources. Finally, the model shows thatthe nations should close the gaps between population growth and the economicdevelopment.Key Words: Ecology, natural resources, world population, sustainable

  16. Gene structure, DNA methylation, and imprinted expression of the human SNRPN gene

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, C.C.; Jong, T.C.; Filbrandt, M.M. [Univ. of Florida College of Medicine, Gainesville, FL (United States)] [and others

    1996-02-01

    The human SNRPN (small nuclear ribonucleoprotein polypeptide N) gene is one of a gene family that encode proteins involved in pre-mRNA splicing and maps to the smallest deletion region involved in the Prader-Willi syndrome (PWS) within chromosome 15q11-q13. Paternal only expression of SNRPN has previously been demonstrated by use of cell lines from PWS patients (maternal allele only) and Angelman syndrome (AS) patients (paternal allele only). We have characterized two previously unidentified 5{prime} exons of the SNRPN gene and demonstrate that exons -1 and 0 are included in the full-length transcript. This gene is expressed in a wide range of somatic tissues and at high, approximately equal levels in all regions of the brain. Both the first exon of SNRPN (exon -1) and the putative transcription start site are embedded within a CpG island. This CpG island is extensively methylated on the repressed maternal allele and is unmethylated on the expressed paternal allele, in a wide range of fetal and adult somatic cells. This provides a quick and highly reliable diagnostic assay for PWS and AS, which is based on DNA-methylation analysis that has been tested on >100 patients in a variety of tissues. Conversely, several CpG sites {approximately}22 kb downstream of the transcription start site in intron 5 are preferentially methylated on the expressed paternal allele in somatic tissues and male germ cells, whereas these same sites are unmethylated in fetal oocytes. These findings are consistent with a key role for DNA methylation in the imprinted inheritance and subsequent gene expression of the human SNRPN gene. 59 refs., 9 figs., 1 tab.

  17. Synthesis and characterization of core–shell magnetic molecularly imprinted polymer nanoparticles for selective extraction of tizanidine in human plasma

    Indian Academy of Sciences (India)

    GOLALEH SHEYKHAGHAEI; MOAYAD HOSSAINI SADR; SALAH KHANAHMADZADEH

    2016-06-01

    In this study, simple, effective and general processes were used for the synthesis of a new nanomolecularly imprinted polymers (MIPs) layer on magnetic Fe3O4 nanoparticles (NPs) with uniform core–shell structure by combining surface imprinting and nanotechniques. The first step for the synthesis of magnetic NPs was co-precipitation of Fe$^{2+}$ and Fe$^{3+}$ in an ammonia solution. Then, an SiO$_2$ shell was coated on the magnetic core with the Stöber method. Subsequently, the C$=$C groups were grafted onto the silica-modified Fe$_3$O$_4$ surface by 3-(trimethoxysilyl) propyl methacrylate. Finally, MIPs films were formed on the surface of Fe$_3$O$_4$@SiO$_2$ by the copolymerization of C$=$C end groups with methacrylic acid (functional monomer), ethylene glycol dimethacrylate (crosslinker),2,2-azobisisobutyronitrile (initiator) and tizanidine (template molecule). The products were characterized using techniques that included Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), UV spectrophotometry, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Measurement of tizanidine through use of the core–shell magnetic molecularly imprinted polymers nanoparticles (MMIPs-NPs) in human plasma samples compared to the paracetamol showed that the synthesized nanosized MMIP for tizanidine has acted selectively.

  18. Water-compatible molecularly imprinted polymer as a sorbent for the selective extraction and purification of adefovir from human serum and urine.

    Science.gov (United States)

    Pourfarzib, Mojgan; Dinarvand, Rasoul; Akbari-Adergani, Behrouz; Mehramizi, Ali; Rastegar, Hossein; Shekarchi, Maryam

    2015-05-01

    A molecularly imprinted polymer has been synthesized to specifically extract adefovir, an antiviral drug, from serum and urine by dispersive solid-phase extraction before high-performance liquid chromatography with UV analysis. The imprinted polymers were prepared by bulk polymerization by a noncovalent imprinting method that involved the use of adefovir (template molecule) and functional monomer (methacrylic acid) complex prior to polymerization, ethylene glycol dimethacrylate as cross-linker, and chloroform as porogen. Molecular recognition properties, binding capacity, and selectivity of the molecularly imprinted polymers were evaluated and the results show that the obtained polymers have high specific retention and enrichment for adefovir in aqueous medium. The new imprinted polymer was utilized as a molecular sorbent for the separation of adefovir from human serum and urine. The serum and urine extraction of adefovir by the molecularly imprinted polymer followed by high-performance liquid chromatography showed a linear calibration curve in the range of 20-100 μg/L with excellent precisions (2.5 and 2.8% for 50 μg/L), respectively. The limit of detection and limit of quantization were determined in serum (7.62 and 15.1 μg/L), and urine (5.45 and 16 μg/L). The recoveries for serum and urine samples were found to be 88.2-93.5 and 84.3-90.2%, respectively.

  19. Molecular Imprint of Exposure to Naturally Occurring Genetic Variants of Human Cytomegalovirus on the T cell Repertoire

    Science.gov (United States)

    Smith, Corey; Gras, Stephanie; Brennan, Rebekah M.; Bird, Nicola L.; Valkenburg, Sophie A.; Twist, Kelly-Anne; Burrows, Jacqueline M.; Miles, John J.; Chambers, Daniel; Bell, Scott; Campbell, Scott; Kedzierska, Katherine; Burrows, Scott R.; Rossjohn, Jamie; Khanna, Rajiv

    2014-02-01

    Exposure to naturally occurring variants of herpesviruses in clinical settings can have a dramatic impact on anti-viral immunity. Here we have evaluated the molecular imprint of variant peptide-MHC complexes on the T-cell repertoire during human cytomegalovirus (CMV) infection and demonstrate that primary co-infection with genetic variants of CMV was coincident with development of strain-specific T-cell immunity followed by emergence of cross-reactive virus-specific T-cells. Cross-reactive CMV-specific T cells exhibited a highly conserved public T cell repertoire, while T cells directed towards specific genetic variants displayed oligoclonal repertoires, unique to each individual. T cell recognition foot-print and pMHC-I structural analyses revealed that the cross-reactive T cells accommodate alterations in the pMHC complex with a broader foot-print focussing on the core of the peptide epitope. These findings provide novel molecular insight into how infection with naturally occurring genetic variants of persistent human herpesviruses imprints on the evolution of the anti-viral T-cell repertoire.

  20. Removal of probable human carcinogenic polycyclic aromatic hydrocarbons from contaminated water using molecularly imprinted polymer.

    Science.gov (United States)

    Krupadam, Reddithota J; Khan, Muntazir S; Wate, Satish R

    2010-02-01

    A molecularly imprinted polymer (MIP) adsorbent for carcinogenic polycyclic aromatic hydrocarbons (PAHs) was prepared using a non-covalent templating technique. MIP particles sized from 2 to 5 microm were synthesized in acetonitrile by using six PAHs mix as a template, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. When compared with the non-imprinted polymer (NIP), the MIP showed an excellent affinity towards PAHs in aqueous solution with binding capacity (B(max)) of 687 microg g(-1)MIP, imprinting effect of 6, and a dissociation constant of 24 microM. The MIP exhibited significant binding affinity towards PAHs even in the presence of environmental parameters such as dissolved organic matter (COD) and total dissolved inorganic solids (TDS), suggesting that this material may be appropriate for removal of carcinogenic PAHs. The feasibility of removing PAHs from water by the MIP demonstrated using groundwater spiked with PAHs. In addition, the MIP reusability without any deterioration in performance was demonstrated at least ten repeated cycles.

  1. Imprinting disorders

    DEFF Research Database (Denmark)

    Eggermann, Thomas; Perez de Nanclares, Guiomar; Maher, Eamonn R

    2015-01-01

    Congenital imprinting disorders (IDs) are characterised by molecular changes affecting imprinted chromosomal regions and genes, i.e. genes that are expressed in a parent-of-origin specific manner. Recent years have seen a great expansion in the range of alterations in regulation, dosage or DNA...... impacts upon growth, development and metabolism. Thus, detailed and systematic analysis of IDs can not only identify unifying principles of molecular epigenetics in health and disease, but also support personalisation of diagnosis and management for individual patients and families....

  2. The amino-terminal structure of human fragile X mental retardation protein obtained using precipitant-immobilized imprinted polymers

    Science.gov (United States)

    Hu, Yufeng; Chen, Zhenhang; Fu, Yanjun; He, Qingzhong; Jiang, Lun; Zheng, Jiangge; Gao, Yina; Mei, Pinchao; Chen, Zhongzhou; Ren, Xueqin

    2015-03-01

    Flexibility is an intrinsic property of proteins and essential for their biological functions. However, because of structural flexibility, obtaining high-quality crystals of proteins with heterogeneous conformations remain challenging. Here, we show a novel approach to immobilize traditional precipitants onto molecularly imprinted polymers (MIPs) to facilitate protein crystallization, especially for flexible proteins. By applying this method, high-quality crystals of the flexible N-terminus of human fragile X mental retardation protein are obtained, whose absence causes the most common inherited mental retardation. A novel KH domain and an intermolecular disulfide bond are discovered, and several types of dimers are found in solution, thus providing insights into the function of this protein. Furthermore, the precipitant-immobilized MIPs (piMIPs) successfully facilitate flexible protein crystal formation for five model proteins with increased diffraction resolution. This highlights the potential of piMIPs for the crystallization of flexible proteins.

  3. Stability of XIST repression in relation to genomic imprinting following global genome demethylation in a human cell line

    OpenAIRE

    E.S.S. de Araújo; Vasques, L.R.; Stabellini,R.; A.C.V. Krepischi; Pereira, L.V.

    2014-01-01

    DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting thatXIST repression is due to a more stable epigenetic mar...

  4. Imprinting of IGF2 P0 transcript and novel alternatively spliced INS-IGF2 isoforms show differences between mouse and human.

    Science.gov (United States)

    Monk, D; Sanches, R; Arnaud, P; Apostolidou, S; Hills, F A; Abu-Amero, S; Murrell, A; Friess, H; Reik, W; Stanier, P; Constância, M; Moore, G E

    2006-04-15

    Genomic imprinting is limited to a subset of genes that play critical roles in fetal growth, development and behaviour. One of the most studied imprinted genes encodes insulin-like growth factor 2, and aberrant imprinting and DNA methylation of this gene is associated with the growth disorders Beckwith-Wiedemann and Silver-Russell syndromes and many human cancers. Specific isoforms of this gene have been shown to be essential for normal placental function, as mice carrying paternal null alleles for the Igf2-P0 transcript are growth restricted at birth. We report here the identification of three novel human transcripts from the IGF2 locus. One is equivalent to the mouse Igf2-P0 transcript, whereas the two others (INSIGF long and short) originate from the upstream INS gene that alternatively splices to downstream IGF2 exons. In order to elucidate the molecular mechanisms involved in the complex imprinting of these novel IGF2 transcripts, both the allele-specific expression and methylation for all the IGF2 promoters including P0 and the INSIGF transcripts were analysed in human tissues. Similar to the mouse, the human IGF2-P0 transcript is paternally expressed; however, its expression is not limited to placenta. This expression correlates with tissue-specific promoter methylation on the maternal allele. The two novel INSIGF transcripts reported here use the INS promoter and show highly restricted tissue expression profiles including the pancreas. As previously reported for INS in the yolk sac, we demonstrate complex, tissue-specific imprinting of these transcripts. The finding of additional transcripts within this locus will have important implications for IGF2 regulation in both cancer and metabolism.

  5. Paternal uniparental disomy 11p15.5 in the pancreatic nodule of an infant with Costello syndrome: Shared mechanism for hyperinsulinemic hypoglycemia in neonates with Costello and Beckwith-Wiedemann syndrome and somatic loss of heterozygosity in Costello syndrome driving clonal expansion.

    Science.gov (United States)

    Gripp, Karen W; Robbins, Katherine M; Sheffield, Brandon S; Lee, Anna F; Patel, Millan S; Yip, Stephen; Doyle, Daniel; Stabley, Deborah; Sol-Church, Katia

    2016-03-01

    Costello syndrome (CS) entails a cancer predisposition and is caused by activating HRAS mutations, typically arising de novo in the paternal germline. Hypoglycemia is common in CS neonates. A previously reported individual with the rare HRAS p.Gln22Lys had hyperinsulinemic hypoglycemia. Autopsy showed a discrete pancreatic nodule. The morphologic and immunohistochemistry findings, including loss of p57(Kip2) protein, were identical to a focal lesion of congenital hyperinsulinism, however, no KCNJ11 or ABCC8 mutation was identified and germline derived DNA showed no alternation of the maternal or paternal 11p15 alleles. Here we report paternal uniparental disomy (pUPD) within the lesion, similar to the pUPD11p15.5 in Beckwith-Wiedemann syndrome (BWS). The similar extent of the pUPD suggests a similar mechanism driving hyperinsulinemia in both conditions. After coincidental somatic LOH and pUPD, the growth promoting effects of the paternally derived HRAS mutation, in combination with the increased function of the adjacent paternally expressed IGF2, may together result in clonal expansion. Although this somatic LOH within pancreatic tissue resulted in hyperinsulinism, similar LOH in mesenchymal cells may drive embryonal rhabdomyosarcoma (ERMS). Interestingly, biallelic IGF2 expression has been linked to rhabdomyosarcoma tumorigenesis and pUPD11 occurred in all 8 ERMS samples from CS individuals. Somatic KRAS and HRAS mutations occur with comparable frequency in isolated malignancies. Yet, the malignancy risk in CS is notably higher than in Noonan syndrome with a KRAS mutation. It is conceivable that HRAS co-localization with IGF2 and the combined effect of pUPD 11p15.5 on both genes contributes to the oncogenic potential.

  6. The IG-DMR and the MEG3-DMR at human chromosome 14q32.2: hierarchical interaction and distinct functional properties as imprinting control centers.

    Science.gov (United States)

    Kagami, Masayo; O'Sullivan, Maureen J; Green, Andrew J; Watabe, Yoshiyuki; Arisaka, Osamu; Masawa, Nobuhide; Matsuoka, Kentarou; Fukami, Maki; Matsubara, Keiko; Kato, Fumiko; Ferguson-Smith, Anne C; Ogata, Tsutomu

    2010-06-17

    Human chromosome 14q32.2 harbors the germline-derived primary DLK1-MEG3 intergenic differentially methylated region (IG-DMR) and the postfertilization-derived secondary MEG3-DMR, together with multiple imprinted genes. Although previous studies in cases with microdeletions and epimutations affecting both DMRs and paternal/maternal uniparental disomy 14-like phenotypes argue for a critical regulatory function of the two DMRs for the 14q32.2 imprinted region, the precise role of the individual DMR remains to be clarified. We studied an infant with upd(14)pat body and placental phenotypes and a heterozygous microdeletion involving the IG-DMR alone (patient 1) and a neonate with upd(14)pat body, but no placental phenotype and a heterozygous microdeletion involving the MEG3-DMR alone (patient 2). The results generated from the analysis of these two patients imply that the IG-DMR and the MEG3-DMR function as imprinting control centers in the placenta and the body, respectively, with a hierarchical interaction for the methylation pattern in the body governed by the IG-DMR. To our knowledge, this is the first study demonstrating an essential long-range imprinting regulatory function for the secondary DMR.

  7. The IG-DMR and the MEG3-DMR at human chromosome 14q32.2: hierarchical interaction and distinct functional properties as imprinting control centers.

    Directory of Open Access Journals (Sweden)

    Masayo Kagami

    2010-06-01

    Full Text Available Human chromosome 14q32.2 harbors the germline-derived primary DLK1-MEG3 intergenic differentially methylated region (IG-DMR and the postfertilization-derived secondary MEG3-DMR, together with multiple imprinted genes. Although previous studies in cases with microdeletions and epimutations affecting both DMRs and paternal/maternal uniparental disomy 14-like phenotypes argue for a critical regulatory function of the two DMRs for the 14q32.2 imprinted region, the precise role of the individual DMR remains to be clarified. We studied an infant with upd(14pat body and placental phenotypes and a heterozygous microdeletion involving the IG-DMR alone (patient 1 and a neonate with upd(14pat body, but no placental phenotype and a heterozygous microdeletion involving the MEG3-DMR alone (patient 2. The results generated from the analysis of these two patients imply that the IG-DMR and the MEG3-DMR function as imprinting control centers in the placenta and the body, respectively, with a hierarchical interaction for the methylation pattern in the body governed by the IG-DMR. To our knowledge, this is the first study demonstrating an essential long-range imprinting regulatory function for the secondary DMR.

  8. Comparable frequencies of coding mutations and loss of imprinting in human pluripotent cells derived by nuclear transfer and defined factors.

    Science.gov (United States)

    Johannesson, Bjarki; Sagi, Ido; Gore, Athurva; Paull, Daniel; Yamada, Mitsutoshi; Golan-Lev, Tamar; Li, Zhe; LeDuc, Charles; Shen, Yufeng; Stern, Samantha; Xu, Nanfang; Ma, Hong; Kang, Eunju; Mitalipov, Shoukhrat; Sauer, Mark V; Zhang, Kun; Benvenisty, Nissim; Egli, Dieter

    2014-11-06

    The recent finding that reprogrammed human pluripotent stem cells can be derived by nuclear transfer into human oocytes as well as by induced expression of defined factors has revitalized the debate on whether one approach might be advantageous over the other. Here we compare the genetic and epigenetic integrity of human nuclear-transfer embryonic stem cell (NT-ESC) lines and isogenic induced pluripotent stem cell (iPSC) lines, derived from the same somatic cell cultures of fetal, neonatal, and adult origin. The two cell types showed similar genome-wide gene expression and DNA methylation profiles. Importantly, NT-ESCs and iPSCs had comparable numbers of de novo coding mutations, but significantly more than parthenogenetic ESCs. As iPSCs, NT-ESCs displayed clone- and gene-specific aberrations in DNA methylation and allele-specific expression of imprinted genes. The occurrence of these genetic and epigenetic defects in both NT-ESCs and iPSCs suggests that they are inherent to reprogramming, regardless of derivation approach.

  9. Obesity-related DNA methylation at imprinted genes in human sperm: Results from the TIEGER study.

    Science.gov (United States)

    Soubry, Adelheid; Guo, Lisa; Huang, Zhiqing; Hoyo, Cathrine; Romanus, Stephanie; Price, Thomas; Murphy, Susan K

    2016-01-01

    Epigenetic reprogramming in mammalian gametes resets methylation marks that regulate monoallelic expression of imprinted genes. In males, this involves erasure of the maternal methylation marks and establishment of paternal-specific methylation to appropriately guide normal development. The degree to which exogenous factors influence the fidelity of methylation reprogramming is unknown. We previously found an association between paternal obesity and altered DNA methylation in umbilical cord blood, suggesting that the father's endocrine, nutritional, or lifestyle status could potentiate intergenerational heritable epigenetic abnormalities. In these analyses, we examine the relationship between male overweight/obesity and DNA methylation status of imprinted gene regulatory regions in the gametes. Linear regression models were used to compare sperm DNA methylation percentages, quantified by bisulfite pyrosequencing, at 12 differentially methylated regions (DMRs) from 23 overweight/obese and 44 normal weight men. Our study population included 69 volunteers from The Influence of the Environment on Gametic Epigenetic Reprogramming (TIEGER) study, based in NC, USA. After adjusting for age and fertility patient status, semen from overweight or obese men had significantly lower methylation percentages at the MEG3 (β = -1.99; SE = 0.84; p = 0.02), NDN (β = -1.10; SE = 0.47; p = 0.02), SNRPN (β = -0.65; SE = 0.27; p = 0.02), and SGCE/PEG10 (β = -2.5; SE = 1.01; p = 0.01) DMRs. Our data further suggest a slight increase in DNA methylation at the MEG3-IG DMR (β = +1.22; SE = 0.59; p = 0.04) and H19 DMR (β = +1.37; SE = 0.62; p = 0.03) in sperm of overweight/obese men. Our data support that male overweight/obesity status is traceable in the sperm epigenome. Further research is needed to understand the effect of such changes and the point of origin of DNA methylation differences between lean and

  10. Stability of XIST repression in relation to genomic imprinting following global genome demethylation in a human cell line

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, E.S.S. de [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Centro Internacional de Pesquisa, A.C. Camargo Cancer Center, São Paulo, SP (Brazil); Vasques, L.R. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Stabellini, R.; Krepischi, A.C.V. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil); Centro Internacional de Pesquisa, A.C. Camargo Cancer Center, São Paulo, SP (Brazil); Pereira, L.V. [Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-10-17

    DNA methylation is essential in X chromosome inactivation and genomic imprinting, maintaining repression of XIST in the active X chromosome and monoallelic repression of imprinted genes. Disruption of the DNA methyltransferase genes DNMT1 and DNMT3B in the HCT116 cell line (DKO cells) leads to global DNA hypomethylation and biallelic expression of the imprinted gene IGF2 but does not lead to reactivation of XIST expression, suggesting that XIST repression is due to a more stable epigenetic mark than imprinting. To test this hypothesis, we induced acute hypomethylation in HCT116 cells by 5-aza-2′-deoxycytidine (5-aza-CdR) treatment (HCT116-5-aza-CdR) and compared that to DKO cells, evaluating DNA methylation by microarray and monitoring the expression of XIST and imprinted genes IGF2, H19, and PEG10. Whereas imprinted genes showed biallelic expression in HCT116-5-aza-CdR and DKO cells, the XIST locus was hypomethylated and weakly expressed only under acute hypomethylation conditions, indicating the importance of XIST repression in the active X to cell survival. Given that DNMT3A is the only active DNMT in DKO cells, it may be responsible for ensuring the repression of XIST in those cells. Taken together, our data suggest that XIST repression is more tightly controlled than genomic imprinting and, at least in part, is due to DNMT3A.

  11. Molecularly imprinted polymer cartridges coupled on-line with high performance liquid chromatography for simple and rapid analysis of human insulin in plasma and pharmaceutical formulations.

    Science.gov (United States)

    Moein, Mohammad Mahdi; Javanbakht, Mehran; Akbari-adergani, Behrouz

    2014-04-01

    In this paper, a novel method is described for automated determination of human insulin in biological fluids using principle of sequential injection on a molecularly imprinted solid-phase extraction (MISPE) cartridge as a sample clean-up technique combined with high performance liquid chromatography (HPLC). The water-compatible molecularly imprinted polymers (MIPs) were prepared using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, chloroform as a porogen and insulin as a template molecule. The imprinted polymers were then employed as the solid-phase extraction sorbent for on-line extraction of insulin from human plasma samples. To achieve the best condition, influential parameters on the extraction efficiency were thoroughly investigated. Rapid and simple analysis of the hormone was successfully accomplished through the good selectivity of the prepared sorbent coupled with HPLC. Limits of detection (LOD) and quantification (LOQ) of 0.2 ng mL(-1), 0.7 ng mL(-1), and 0.03 ng mL(-1), 0.1 ng mL(-1) were obtained in plasma and urine respectively. The obtained data exhibited the great recoveries for extraction of insulin from human plasma and pharmaceutical samples, higher than 87%.

  12. Preparation of a pipette tip-based molecularly imprinted solid-phase microextraction monolith by epitope approach and its application for determination of enkephalins in human cerebrospinal fluid.

    Science.gov (United States)

    Li, Hua; Li, Dan

    2015-11-10

    In this study, a novel molecularly imprinted polymer (MIP) monolith for highly selective extraction of enkephalins was synthesized and prepared in a micropipette tip using epitope imprinting technique. The synthesized MIPs were characterized by scanning electron microscope (SEM) and infrared spectroscopy. A molecularly imprinted solid-phase microextraction (MISPME) method was developed for extraction of enkephalins in aqueous solutions. The parameters affecting MISPME were optimized. The results indicated that this MIP monolith exhibited specific recognition capability, high enrichment efficiency and excellent reusability for enkephalins. MALDI-TOF MS analysis demonstrated that this MIP monolith can act as a useful tool for highly selective purification and enrichment of enkephalin, a kind of low abundance protein, from high-abundance proteins in human cerebrospinal fluids (CSF). Employed this MIP monolith as solid-phase microextraction column, quantitative assay of enkephalins in human CSF was developed by HPLC-ultraviolet (UV) detection in this work. The detection limits were 0.05-0.08nM. This MISPME/HPLC-UV method was used to quantify Met-enkephalin and Leu-enkephalin levels in the CSF of patients with cancer pain.

  13. Molecularly imprinted solid-phase extraction for the selective determination of methamphetamine, amphetamine, and methylenedioxyphenylalkylamine designer drugs in human whole blood by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Kumazawa, Takeshi; Hasegawa, Chika; Hara, Kenji; Uchigasaki, Seisaku; Lee, Xiao-Pen; Seno, Hiroshi; Suzuki, Osamu; Sato, Keizo

    2012-03-01

    A novel method is described for the extraction of methamphetamine, amphetamine, and methylenedioxyphenylalkylamine designer drugs, such as 3,4-methylenedioxy-methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxyethylamphetamine, N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine, and 3,4-(methylenedioxyphenyl)-2-butanamine, from human whole blood using molecularly imprinted solid-phase extraction as highly selective sample clean-up technique. Whole blood samples were diluted with 10 mmol/L ammonium acetate (pH 8.6) and applied to a SupelMIP-Amphetamine molecularly imprinted solid-phase extraction cartridge. The cartridge was then washed to eliminate interferences, and the amphetamines of interest were eluted with formic acid/methanol (1:100, v/v). After derivatization with trifluoroacetic anhydride, the analytes were quantified using gas chromatography-mass spectrometry. Recoveries of the seven amphetamines spiked into whole blood were 89.1-102%. The limits of quantification for each compound in 200 μL of whole blood were between 0.25 and 1.0 ng. The maximum intra- and inter-day coefficients of variation were 9.96 and 13.8%, respectively. The results show that methamphetamine, amphetamine, and methylenedioxyphenylalkyl-amine designer drugs can be efficiently extracted from crude biological samples such as whole blood by molecularly imprinted solid-phase extraction with good reproducibility. This extraction method will be useful for the pretreatment of human samples before gas chromatography-mass spectrometry.

  14. Preparation and application of a novel molecularly imprinted solid-phase microextraction monolith for selective enrichment of cholecystokinin neuropeptides in human cerebrospinal fluid.

    Science.gov (United States)

    Ji, Xiang; Li, Dan; Li, Hua

    2015-08-01

    A novel molecularly imprinted polymer (MIP) monolith for highly selective extraction of cholecystokinin (CCK) neuropeptides was prepared in a micropipette tip. The MIPs were synthesized by epitope imprinting technique and the polymerization conditions were investigated and optimized. The synthesized MIPs were characterized by infrared spectroscopy, elemental analyzer and scanning electron microscope. A molecularly imprinted solid-phase microextraction (MI-μ-SPE) method was developed for the extraction of CCK neuropeptides in aqueous solutions. The parameters affecting MI-μ-SPE were optimized. The results indicated that this MIP monolith exhibited specific recognition capability and high enrichment efficiency for CCK neuropeptides. In addition, it showed excellent reusability. This MIP monolith was used for desalting and enrichment of CCK4, CCK5 and CCK8 from human cerebrospinal fluid prior to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis, and the results show that this MIP monolith can be a useful tool for effective purification and highly selective enrichment of multiple homologous CCK neuropeptides in cerebrospinal fluid simultaneously. By employing MI-μ-SPE combined with HPLC-ESI-MS/MS analysis, endogenous CCK4 in human cerebrospinal fluid was quantified.

  15. Molecularly imprinted pipette-tip solid phase extraction for selective determination of fluoroquinolones in human urine using HPLC-DAD.

    Science.gov (United States)

    de Oliveira, Hanna Leijoto; da Silva Anacleto, Sara; da Silva, Anny Talita Maria; Pereira, Arnaldo César; de Souza Borges, Warley; Figueiredo, Eduardo Costa; Borges, Keyller Bastos

    2016-10-15

    A simple method using HPLC-DAD was developed for the determination of fluoroquinolones in human urine including ciprofloxacin (CIPRO), enrofloxacino (ENRO), marbofloxacino (MARBO) and norfloxacin (NOR). In addition, it was studied the extraction of fluoroquinolones in human urine samples using pipette tip-based molecularly imprinted polymers solid phase extraction (PT-MIPs-SPE). With the goal of finding the best procedure for extraction of four fluoroquinolones in human urine, several parameters that are likely to affect the efficiency of extraction during sample preparation, including the washing solvent, type and volume of eluent, amount of material, the volume of the sample, pH and the ionic strength were systematically optimized. Chromatographic separations of fluoroquinolones were hit within 10min using a Synergi(®) C18 (250×4.6mm, 4μm) column and mobile phase consisting of water (10mM of phosphoric acid, the pH adjusted at 3.29 with triethylamine) : acetonitrile (85.7: 14.3, v/v) at a flow rate of 1.5mLmin(-1). Detection was performed at 290nm. The average extraction recoveries/standard deviation relative to ENRO, CIPRO, NOR and MARBO were 96.40±5.51%, 42.47±4.81%, 41.82±7.99% and 87.49±4.70, respectively. The method was liner from 39 to 1260ngmL(-1) for each fluoroquinolone with correlation coefficient of 0.9904, 0.9910, 0.9914 and 0.9919, to ENRO, CIPRO, NOR and MARBO, respectively. The assays of within-day and between-day precision and accuracy for all analytes were studied at three concentration levels and were lower than 15%. The method was successfully employed in a preliminary cumulative urinary excretion study after administration of CIPRO to a healthy volunteer. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Human imprint on archaeological anthroposols: first assessment of combined micromophological, pedological and lipid biomarkers analyses of organic matter

    Science.gov (United States)

    Cammas, Cécilia; Thuy Nguyen Tu, Thanh; Plessis, Marion; Clotuche, Raphaël; Derenne, Sylvie

    2013-04-01

    Archaeological anthroposol matrix contains significant amounts of fine organic matter (OM), which can give archaeological information. Geoarchaeological studies of OM aim to reveal its origin in order to reconstruct past human activities. Such studies are complex because the nature and the abundance of OM is the result of human activities together with natural processes. Also, MO evolves over time, a process that is not well understood. Combination of complementary approaches may give further insights into human imprint on archaeological anthroposols. For example, micromorphology gives data on in situ activities and pedological processes with the result that components of animal and vegetal origin can be identified but not some amorphous / fibrous material and very fine residues (pedo-sedimentary history and OM preservation. Two tanning pits in urban craft areas were selected for sampling, as they are likely to contain large amounts of organic matter of vegetal and animal origin. The pit of Saint-Denis (SDN, 10 km at the north of Paris, calcareous alluvium, 13th cAD) was a reference tanning pit. The pit of Famars (FAM, near the Belgian border, luvisols, Roman period) was hypothesized to be a part of the tanning process. To assess preservation of organic components and molecules in relation with pedo-sedimentary context and their potential as biomarkers of human activities, methodology combined micromorphology, pedological analysis (C, N, LOI, P total, organic and inorganic phosphorus) and lipid analysis by GC/MS, lipids having a high preservation potential and containing biomarkers indicative of OM origin. Micromorphological study showed a high amount and diversity of organic components in the two pits. At the SDN pit, the interpretation of tanning (liming) was supported by the presence of scarce fragments of lime with calcitic hairs pseudomorphoses. Plant remains and bone fragments were identified, but red fibrous and yellow amorphous material were not. At the FAM

  17. Variation in human mate choice: Simultaneously investigating heritability, parental influence, sexual imprinting, and assortative mating

    NARCIS (Netherlands)

    Zietsch, B.P.; Verweij, C.J.H.; Heath, A.C.; Martin, N.G.

    2011-01-01

    Human mate choice is central to individuals' lives and to the evolution of the species, but the basis of variation in mate choice is not well understood. Here we looked at a large community-based sample of twins and their partners and parents (N > 20,000 individuals) to test for genetic and famil

  18. Genomic imprinting and Turner syndrome.

    Science.gov (United States)

    Bondy, Carolyn A; Hougen, Helen Y; Zhou, Jian; Cheng, Clara M

    2012-05-01

    The term 'genomic imprinting' refers to selective repression of transcription from distinct chromosomal regions determined by their maternal or paternal inheritance. There are two potentially important aspects of imprinting that may manifest in individuals with X monosomy, or Turner syndrome (TS). Given that men are monosomic for Xm while women are mosaic for Xm:Xp, genomic imprinting of important X-linked genes should be associated with sexually dimorphic traits, e.g., social skills, regional fat deposition and adult height. Such X-imprinted traits are predicted to differ in Turner groups monosomic for Xm vs. Xp. We review relevant studies of psychosocial attributes, regional fat distribution and height in TS related to parent of origin for the single normal X chromosome. In addition, we review recent evidence that monosomy for the X chromosome per se, regardless of the parental origin, may disrupt the normal distribution of autosomal imprint patterns. This may contribute to a high rate of fetal loss in human monosomy via impaired placentation in the most severe cases, and to loss of paternal contribution to growth in the mildest manifestation.

  19. Humans as Superorganisms: How Microbes, Viruses, Imprinted Genes, and Other Selfish Entities Shape Our Behavior.

    Science.gov (United States)

    Kramer, Peter; Bressan, Paola

    2015-07-01

    Psychologists and psychiatrists tend to be little aware that (a) microbes in our brains and guts are capable of altering our behavior; (b) viral DNA that was incorporated into our DNA millions of years ago is implicated in mental disorders; (c) many of us carry the cells of another human in our brains; and (d) under the regulation of viruslike elements, the paternally inherited and maternally inherited copies of some genes compete for domination in the offspring, on whom they have opposite physical and behavioral effects. This article provides a broad overview, aimed at a wide readership, of the consequences of our coexistence with these selfish entities. The overarching message is that we are not unitary individuals but superorganisms, built out of both human and nonhuman elements; it is their interaction that determines who we are.

  20. Effect of dietary phytoestrogens on human growth regulation: imprinting in health & disease

    Directory of Open Access Journals (Sweden)

    K Griffiths

    2014-01-01

    Full Text Available This group has advocated a return to the notional Palζolithic diet with fruits, vegetables, roots, leaves, seeds, phytochemical antioxidants and proteins, etc. Phytoestrogens, viz. lignans, isoflavonoids and flavonoids are weak oestrogenic constituents of such a diet and may have a considerable impact on human health and disease. The aim of this paper was to conduct a preliminary overview of about 2000 research-led studies from the 1930s to the present time reported in the literature on flavonoids/isoflavonoids/lignans and to assemble evidence for a future strictly formal literature review on the health benefits and risks of flavonoids in a variety of diseases.

  1. Effect of dietary phytoestrogens on human growth regulation: imprinting in health & disease.

    Science.gov (United States)

    Griffiths, K; Wilson, D W; Singh, R B; De Meester, F

    2014-11-01

    This group has advocated a return to the notional Palæolithic diet with fruits, vegetables, roots, leaves, seeds, phytochemical antioxidants and proteins, etc. Phytoestrogens, viz. lignans, isoflavonoids and flavonoids are weak oestrogenic constituents of such a diet and may have a considerable impact on human health and disease. The aim of this paper was to conduct a preliminary overview of about 2000 research-led studies from the 1930s to the present time reported in the literature on flavonoids/isoflavonoids/lignans and to assemble evidence for a future strictly formal literature review on the health benefits and risks of flavonoids in a variety of diseases.

  2. Human leukocyte telomere length is associated with DNA methylation levels in multiple subtelomeric and imprinted loci.

    Science.gov (United States)

    Buxton, Jessica L; Suderman, Matthew; Pappas, Jane J; Borghol, Nada; McArdle, Wendy; Blakemore, Alexandra I F; Hertzman, Clyde; Power, Christine; Szyf, Moshe; Pembrey, Marcus

    2014-05-14

    In humans, leukocyte telomere length (LTL) is positively correlated with lifespan, and shorter LTL is associated with increased risk of age-related disease. In this study we tested for association between telomere length and methylated cytosine levels. Measurements of mean telomere length and DNA methylation at >450,000 CpG sites were obtained for both blood (N = 24) and EBV-transformed cell-line (N = 36) DNA samples from men aged 44-45 years. We identified 65 gene promoters enriched for CpG sites at which methylation levels are associated with leukocyte telomere length, and 36 gene promoters enriched for CpG sites at which methylation levels are associated with telomere length in DNA from EBV-transformed cell-lines. We observed significant enrichment of positively associated methylated CpG sites in subtelomeric loci (within 4 Mb of the telomere) (P telomere length, DNA methylation and gene expression in health and disease.

  3. Health and Disease Imprinted in the Time Variability of the Human Microbiome

    Science.gov (United States)

    Rubio, Teresa; Gracia, César; Peña, Manuel; Latorre, Amparo

    2017-01-01

    ABSTRACT The animal microbiota (including the human microbiota) plays an important role in keeping the physiological status of the host healthy. Research seeks greater insight into whether changes in the composition and function of the microbiota are associated with disease. We analyzed published 16S rRNA and shotgun metagenomic sequencing (SMS) data pertaining to the gut microbiotas of 99 subjects monitored over time. Temporal fluctuations in the microbial composition revealed significant differences due to factors such as dietary changes, antibiotic intake, age, and disease. This article shows that a fluctuation scaling law can describe the temporal changes in the gut microbiota. This law estimates the temporal variability of the microbial population and quantitatively characterizes the path toward disease via a noise-induced phase transition. Estimation of the systemic parameters may be of clinical utility in follow-up studies and have more general applications in fields where it is important to know whether a given community is stable or not. IMPORTANCE The human microbiota correlates closely with the health status of its host. This article analyzes the microbial composition of several subjects under different conditions over time spans that ranged from days to months. Using the Langevin equation as the basis of our mathematical framework to evaluate microbial temporal stability, we proved that stable microbiotas can be distinguished from unstable microbiotas. This initial step will help us to determine how temporal microbiota stability is related to a subject’s health status and to develop a more comprehensive framework that will provide greater insight into this complex system. PMID:28345059

  4. Congenital imprinting disorders

    DEFF Research Database (Denmark)

    Eggermann, Thomas; Netchine, Irène; Temple, I Karen

    2015-01-01

    Imprinting disorders (IDs) are a group of eight rare but probably underdiagnosed congenital diseases affecting growth, development and metabolism. They are caused by similar molecular changes affecting regulation, dosage or the genomic sequence of imprinted genes. Each ID is characterised...... EUCID.net (European network of congenital imprinting disorders) now aims to promote better clinical care and scientific investigation of imprinting disorders by establishing a concerted multidisciplinary alliance of clinicians, researchers, patients and families. By encompassing all IDs and establishing...

  5. Imprinting in plants

    Institute of Scientific and Technical Information of China (English)

    GUTIERREZ-MARCOS Jose

    2009-01-01

    Genomic imprinting leads to the differential expression of parental alleles after fertilization. Imprinting appears to have evolved independently in mammals and flowering plants to regulate the development of nutrient-transfer placental tissues. In addition, the regulation of imprinting in both mammals and flowering plants involves changes in DNA methylation and histone methylation, thus suggesting that the epigenetic signals that regulate imprinting have been co-opted in these distantly related species.

  6. Molecularly imprinted microspheres synthesized by a simple, fast, and universal suspension polymerization for selective extraction of the topical anesthetic benzocaine in human serum and fish tissues.

    Science.gov (United States)

    Sun, Hui; Lai, Jia-Ping; Chen, Fang; Zhu, De-Rong

    2015-02-01

    A simple, fast, and universal suspension polymerization method was used to synthesize the molecularly imprinted microspheres (MIMs) for the topical anesthetic benzocaine (BZC). The desired diameter (10-20 μm) and uniform morphology of the MIMs were obtained easily by changing one or more of the synthesis conditions, including type and amount of surfactant, stirring rate, and ratio of organic to water phase. The MIMs obtained were used as a molecular-imprinting solid-phase-extraction (MISPE) material for extraction of BZC in human serum and fish tissues. The MISPE results revealed that the BZC in these biosamples could be enriched effectively after the MISPE operation. The recoveries of BZC on MIMs cartridges were higher than 90% (n = 3). Finally, an MISPE-HPLC method with UV detection was developed for highly selective extraction and fast detection of trace BZC in human serum and fish tissues. The developed method could also be used for the enrichment and detection of BZC in other complex biosamples.

  7. Molecularly imprinted polymer microspheres prepared by Pickering emulsion polymerization for selective solid-phase extraction of eight bisphenols from human urine samples.

    Science.gov (United States)

    Yang, Jiajia; Li, Yun; Wang, Jincheng; Sun, Xiaoli; Cao, Rong; Sun, Hao; Huang, Chaonan; Chen, Jiping

    2015-05-01

    The bisphenol A (BPA) imprinted polymer microspheres were prepared by simple Pickering emulsion polymerization. Compared to traditional bulk polymerization, both high yields of polymer and good control of particle sizes were achieved. The characterization results of scanning electron microscopy and nitrogen adsorption-desorption measurements showed that the obtained molecularly imprinted polymer microsphere (MIPMS) particles possessed regular spherical shape, narrow diameter distribution (30-60 μm), a specific surface area (S(BET)) of 281.26 m(2) g(-1) and a total pore volume (V(t)) of 0.459 cm(3) g(-1). Good specific adsorption capacity for BPA was obtained in the sorption experiment and good class selectivity for BPA and its seven structural analogs (bisphenol F, bisphenol B, bisphenol E, bisphenol AF, bisphenol S, bisphenol AP and bisphenol Z) was demonstrated by the chromatographic evaluation experiment. The MIPMS as solid-phase extraction (SPE) packing material was then evaluated for extraction and clean-up of these bisphenols (BPs) from human urine samples. An accurate and sensitive analytical method based on the MIPMS-SPE coupled with HPLC-DAD has been successfully established for simultaneous determination of eight BPs from human urine samples with detection limits of 1.2-2.2 ng mL(-1). The recoveries of BPs for urine samples at two spiking levels (100 and 500 ng mL(-1) for each BP) were in the range of 81.3-106.7% with RSD values below 8.3%.

  8. Voltammetric sensor based on carbon paste electrode modified with molecular imprinted polymer for determination of sulfadiazine in milk and human serum.

    Science.gov (United States)

    Sadeghi, Susan; Motaharian, Ali

    2013-12-01

    A new sensitive voltammetric sensor for determination of sulfadiazine is described. The developed sensor is based on carbon paste electrode modified with sulfadiazine imprinted polymer (MIP) as a recognition element. For comparison, a non-imprinted polymer (NIP) modified carbon paste electrode was prepared. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods were performed to study the binding event and electrochemical behavior of sulfadiazine at the modified carbon paste electrodes. The determination of sulfadiazine after its extraction onto the electrode surface was carried out by DPV at 0.92 V vs. Ag/AgCl owing to oxidation of sulfadiazine. Under the optimized operational conditions, the peak current obtained at the MIP modified carbon paste electrode was proportional to the sulfadiazine concentration within the range of 2.0×10(-7)-1.0×10(-4) mol L(-1) with a detection limit and sensitivity of 1.4×10(-7) mol L(-1) and 4.2×10(5) μA L mol(-1), respectively. The reproducibility of the developed sensor in terms of relative standard deviation was 2.6%. The sensor was successfully applied for determination of sulfadiazine in spiked cow milk and human serum samples with recovery values in the range of 96.7-100.9%.

  9. A molecular-imprint nanosensor for ultrasensitive detection of proteins

    Science.gov (United States)

    Cai, Dong; Ren, Lu; Zhao, Huaizhou; Xu, Chenjia; Zhang, Lu; Yu, Ying; Wang, Hengzhi; Lan, Yucheng; Roberts, Mary F.; Chuang, Jeffrey H.; Naughton, Michael J.; Ren, Zhifeng; Chiles, Thomas C.

    2010-08-01

    Molecular imprinting is a technique for preparing polymer scaffolds that function as synthetic receptors. Imprinted polymers that can selectively bind organic compounds have proven useful in sensor development. Although creating synthetic molecular-imprinting polymers that recognize proteins remains challenging, nanodevices and nanomaterials show promise in this area. Here, we show that arrays of carbon-nanotube tips with an imprinted non-conducting polymer coating can recognize proteins with subpicogram per litre sensitivity using electrochemical impedance spectroscopy. We have developed molecular-imprinting sensors specific for human ferritin and human papillomavirus derived E7 protein. The molecular-imprinting-based nanosensor can also discriminate between Ca2+-induced conformational changes in calmodulin. This ultrasensitive, label-free electrochemical detection of proteins offers an alternative to biosensors based on biomolecule recognition.

  10. Genomic Imprinting in Mammals

    Science.gov (United States)

    Barlow, Denise P.

    2014-01-01

    Genomic imprinting affects a subset of genes in mammals and results in a monoallelic, parental-specific expression pattern. Most of these genes are located in clusters that are regulated through the use of insulators or long noncoding RNAs (lncRNAs). To distinguish the parental alleles, imprinted genes are epigenetically marked in gametes at imprinting control elements through the use of DNA methylation at the very least. Imprinted gene expression is subsequently conferred through lncRNAs, histone modifications, insulators, and higher-order chromatin structure. Such imprints are maintained after fertilization through these mechanisms despite extensive reprogramming of the mammalian genome. Genomic imprinting is an excellent model for understanding mammalian epigenetic regulation. PMID:24492710

  11. Molecularly imprinted polymer microspheres prepared by Pickering emulsion polymerization for selective solid-phase extraction of eight bisphenols from human urine samples

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jiajia [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Yun; Wang, Jincheng [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Sun, Xiaoli; Cao, Rong [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Sun, Hao [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); Department of Chemistry, Liaoning University, Shenyang 110000 (China); Huang, Chaonan [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Jiping, E-mail: chenjp@dicp.ac.cn [Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023 (China)

    2015-05-04

    Highlights: • BPA imprinted polymer microspheres were prepared by Pickering emulsion polymerization. • Regular spherical shape and narrow diameter distribution. • Good specific adsorption capacity for BPA. • Good class-selectivity and clean-up efficiency for bisphenols in human urine under SPE mode. • Good recoveries and sensitivity for bisphenols using the MIPMS-SPE coupled with HPLC-DAD method. - Abstract: The bisphenol A (BPA) imprinted polymer microspheres were prepared by simple Pickering emulsion polymerization. Compared to traditional bulk polymerization, both high yields of polymer and good control of particle sizes were achieved. The characterization results of scanning electron microscopy and nitrogen adsorption–desorption measurements showed that the obtained molecularly imprinted polymer microsphere (MIPMS) particles possessed regular spherical shape, narrow diameter distribution (30–60 μm), a specific surface area (S{sub BET}) of 281.26 m{sup 2} g{sup −1} and a total pore volume (V{sub t}) of 0.459 cm{sup 3} g{sup −1}. Good specific adsorption capacity for BPA was obtained in the sorption experiment and good class selectivity for BPA and its seven structural analogs (bisphenol F, bisphenol B, bisphenol E, bisphenol AF, bisphenol S, bisphenol AP and bisphenol Z) was demonstrated by the chromatographic evaluation experiment. The MIPMS as solid-phase extraction (SPE) packing material was then evaluated for extraction and clean-up of these bisphenols (BPs) from human urine samples. An accurate and sensitive analytical method based on the MIPMS-SPE coupled with HPLC-DAD has been successfully established for simultaneous determination of eight BPs from human urine samples with detection limits of 1.2–2.2 ng mL{sup −1}. The recoveries of BPs for urine samples at two spiking levels (100 and 500 ng mL{sup −1} for each BP) were in the range of 81.3–106.7% with RSD values below 8.3%.

  12. Molecularly imprinted polymers for alpha-tocopherol delivery.

    Science.gov (United States)

    Puoci, Francesco; Cirillo, Giuseppe; Curcio, Manuela; Iemma, Francesca; Parisi, Ortensia Ilaria; Castiglione, Mariarosaria; Picci, Nevio

    2008-05-01

    Biomedical applications of antioxidants have increased dramatically since the link between human diseases and oxidative stress was established. This paper focuses on alpha -tocopherol and on the possibility of employing molecularly imprinted polymers as a controlled release device for alpha-tocopherol in gastrointestinal simulating fluids. Polymers were synthesized using methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker. Considerable differences in recognition characteristics between imprinted and non-imprinted polymers, both in organic and in aqueous media, were observed. Imprinted polymers bound much more alpha-tocopherol and showed a controlled/sustained drug release capacity in gastrointestinal simulating fluids.

  13. Molecularly imprinted polymer-sol-gel tablet toward micro-solid phase extraction: I. Determination of methadone in human plasma utilizing liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    El-Beqqali, Aziza; Abdel-Rehim, Mohamed

    2016-09-14

    In the present work molecularly imprinted sol-gel tablet (MIP-Tablet) was prepared. The MIP-sol-gel was prepared as a thin layer on polyethylene material in a tablet form. Methadone-d9 was selected as the template and 3-(propylmethacrylate)-trimethoxysilane was used as precursor. MIP-Tablet was applied for micro-solid phase extraction (μ-SPE). The MIP-Tablet was used for the determination of methadone in human plasma samples utilizing liquid chromatography-tandem mass spectrometry; and each tablet could be used twenty times. The extraction time was 10 min while desorption time was 6 min. Factors affecting the extraction efficiency such as desorption solvents, sample pH, salt addition, extraction time, desorption time and adsorption capacity were investigated. The calibration curves were obtained within the range of 5-5000 ng/mL using methadone in human plasma samples. The coefficients of determination (r(2)) values were ≥0.999 for all runs and the extraction recovery was >80%. The accuracy values for quality control samples varied from +3.6 to +9.7% and the inter-day precision (RSD %) values were ranged from 5.0 to 8.0%. The limit of detection was 1.0 ng/mL and the lower limit of quantification was 5 ng/mL utilizing methadone in human plasma samples.

  14. [Neurobiology of imprinting].

    Science.gov (United States)

    Ohki-Hamazaki, Hiroko

    2012-06-01

    Imprinting is an example of learning and memory acquisition in infancy. In the case of precocial birds, such as geese, ducks, and chickens, the baby birds learn the characteristics of the first moving object that they see within a critical period, and they imprint on it and follow it around. We analyzed the neural basis of this behavior in order to understand the neural mechanism of learning and memory in infancy. Information pertaining to a visual imprinting stimulus is recognized and processed in the visual Wulst, a region that corresponds to the mammalian visual cortex. It is then transmitted to the posterior region of the telencephalon, followed by the core region of the hyperpallium densocellulare (HDCo), periventricular region of the hyperpallium densocellulare (HDPe), and finally, the intermediate medial mesopallium (IMM), a region similar to the mammalian association cortex. Memory is stored in the IMM. After imprint training, plastic changes are observed in the visual Wulst as well as in the neurons of this circuit. HDCo cells, located at the center of this circuit, express N-methyl-D-aspartate (NMDA) receptors containing the NMDA receptor (NR) 2B subunit; the expression of this receptor increased after the imprint training. Inhibition of this receptor in the cells of the HDCo region leads to failure of imprinting and inactivation of this circuit. Thus, NMDA receptors bearing the NR2B subunit play a critical role in plastic changes in this circuit and in induction of imprinting.

  15. Systems biology discoveries using non-human primate pluripotent stem and germ cells: novel gene and genomic imprinting interactions as well as unique expression patterns.

    Science.gov (United States)

    Ben-Yehudah, Ahmi; Easley, Charles A; Hermann, Brian P; Castro, Carlos; Simerly, Calvin; Orwig, Kyle E; Mitalipov, Shoukhrat; Schatten, Gerald

    2010-08-05

    The study of pluripotent stem cells has generated much interest in both biology and medicine. Understanding the fundamentals of biological decisions, including what permits a cell to maintain pluripotency, that is, its ability to self-renew and thereby remain immortal, or to differentiate into multiple types of cells, is of profound importance. For clinical applications, pluripotent cells, including both embryonic stem cells and adult stem cells, have been proposed for cell replacement therapy for a number of human diseases and disorders, including Alzheimer's, Parkinson's, spinal cord injury and diabetes. One challenge in their usage for such therapies is understanding the mechanisms that allow the maintenance of pluripotency and controlling the specific differentiation into required functional target cells. Because of regulatory restrictions and biological feasibilities, there are many crucial investigations that are just impossible to perform using pluripotent stem cells (PSCs) from humans (for example, direct comparisons among panels of inbred embryonic stem cells from prime embryos obtained from pedigreed and fertile donors; genomic analysis of parent versus progeny PSCs and their identical differentiated tissues; intraspecific chimera analyses for pluripotency testing; and so on). However, PSCs from nonhuman primates are being investigated to bridge these knowledge gaps between discoveries in mice and vital information necessary for appropriate clinical evaluations. In this review, we consider the mRNAs and novel genes with unique expression and imprinting patterns that were discovered using systems biology approaches with primate pluripotent stem and germ cells.

  16. Rapid determination of memantine in human plasma by using nanoring carboxyl-functionalized paramagnetic molecularly imprinted polymer d-μ-SPE and UFLC-MS/MS.

    Science.gov (United States)

    Qiu, Hai-Wen; Xia, Lei; Gong, Li-Min; Ruan, Lie-Min; Zhao, Yong-Gang

    2015-06-01

    A novel, simple, and sensitive method based on the use of dispersive micro-solid-phase extraction (d-μ-SPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) for the determination of memantine (ME) was developed and validated over the linearity range 0.05-10.0 µg/L with 100 μL of human plasma using memantine-D6 (ME-D6) as the internal standard. The novel nanoring carboxyl-functionalized paramagnetic molecularly imprinted polymer (NR-CF-Mag-MIP) was synthesized by ultrasound-assisted suspension polymerization, using ME as a template molecule, methacrylic acid as a functional monomer, and divinylbenzene as a cross-linking agent. The NR-CF-Mag-MIP was used as the d-μ-SPE sorbent to extract ME from human plasma samples. The obtained results demonstrated the higher extraction capacity of NR-CF-Mag-MIP with recoveries between 97.6 and 101%. The limits of quantification (LOQs) for ME was 0.015 µg/L. Validation results on linearity, specificity, accuracy, precision, and stability, as well as on application to the analysis of samples taken up to 480 h after oral administration of 20 mg (two 10 mg capsules) of ME in healthy volunteers demonstrated the applicability to bioequivalence studies.

  17. Aberrant genomic imprinting in rhesus monkey embryonic stem cells.

    Science.gov (United States)

    Fujimoto, Akihisa; Mitalipov, Shoukhrat M; Kuo, Hung-Chih; Wolf, Don P

    2006-03-01

    Genomic imprinting involves modification of a gene or a chromosomal region that results in the differential expression of parental alleles. Disruption or inappropriate expression of imprinted genes is associated with several clinically significant syndromes and tumorigenesis in humans. Additionally, abnormal imprinting occurs in mouse embryonic stem cells (ESCs) and in clonally derived animals. Imprinted gene expression patterns in primate ESCs are largely unknown, despite the clinical potential of the latter in the cell-based treatment of human disease. Because of the possible implications of abnormal gene expression to cell or tissue replacement therapies involving ESCs, we examined allele specific expression of four imprinted genes in the rhesus macaque. Genomic and complementary DNA from embryos and ESC lines containing useful single nucleotide polymorphisms were subjected to polymerase chain reaction-based amplification and sequence analysis. In blastocysts, NDN expression was variable indicating abnormal or incomplete imprinting whereas IGF2 and SNRPN were expressed exclusively from the paternal allele and H19 from the maternal allele as expected. In ESCs, both NDN and SNRPN were expressed from the paternal allele while IGF2 and H19 showed loss of imprinting and biallelic expression. In differentiated ESC progeny, these expression patterns were maintained. The implications of aberrant imprinted gene expression to ESC differentiation in vitro and on ESC-derived cell function in vivo after transplantation are unknown.

  18. Molecularly Imprinted Biodegradable Nanoparticles

    Science.gov (United States)

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization.

  19. Molecularly Imprinted Biodegradable Nanoparticles

    Science.gov (United States)

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization. PMID:28071745

  20. Design of a new cartridge for selective solid phase extraction using molecularly imprinted polymers: selective extraction of theophylline from human serum samples.

    Science.gov (United States)

    Khorrami, Afshin Rajabi; Rashidpur, Amene

    2009-11-15

    This paper describes design of a new cartridge for selective solid phase extraction (SPE) using molecularly imprinted polymers (MIPs). The apparatus which is termed solvent extraction-MISPE (SE-MISPE) cartridge, consisted of a modified conventional micro test tube and has been developed to perform simultaneous forward-extraction of analyte from aqueous sample solution to an organic phase and back-extraction to MIP solid phase. In order to evaluate the performance of the proposed method, extraction of theophylline (THP) from human serum sample was investigated. An appropriate amount of THP-imprinted polymer was placed in the bottom of the micro tube and an organic solvent pipetted onto it and left to swell the polymer completely. A polyethylene frit to secure MIP particles was positioned by two Teflon rings such that it was fixed below the level of the organic layer. Then, aqueous sample solution containing THP was layered over the organic phase and the lid was closed. After completion of extraction, the organic and aqueous phases were removed and the adsorbed analyte was desorbed using a polar organic solvent. In order to reach the highest recovery, the experimental parameters such as the type of organic solvent, pH and ionic strength of aqueous phase, organic to aqueous volume ratio, time of extraction, type and amount of desorbent solvent were optimized. Under the experimental conditions, a plot of HPLC peak areas vs. initial concentrations of THP in the concentration interval of 0.5-30 microg ml(-1) showed a good linearity (r=0.9974). The limit of detection (LOD) and limit of quantification (LOQ) based on three and ten times of the noise of HPLC profile were 0.09 and 0.3 microg ml(-1), respectively. The relative standard deviation (RSD) of the proposed method for the extraction and determination of 5 microg THP from 200 microl standard sample solution for 3 replicate measurements was 3.5%. The results showed that by means of the proposed cartridge, THP could

  1. [Preparation of molecularly imprinted polymers using dummy template and the applications in selective solid-phase extraction of seven bisphenols from human urine, bovine serum and beer samples].

    Science.gov (United States)

    Yang, Jiajia; Li, Yun; Wang Jinchengt; Sun, Xiaoli; Chen, Jiping

    2015-05-01

    A molecularly imprinted polymer (MIP) for selective recognition of seven bisphenols (BPs) was prepared using dummy template phenolphthalein (PP) by bulk polymerization. The characterization results of scanning electron microscopy and nitrogen adsorption-desorption measurements showed that the prepared PP-MIP possessed narrow particle diameter distribution (40-60 µm), a specific surface area (S(BET)) of 359.77 m2/g and a total pore volume (Vt) of 0.730 cm3/g. The adsorption capacity for bisphenol A (BPA) of PP-MIP was evaluated by static adsorption experiment. And the Scatchard analysis revealed that the maximum specific adsorption capacity of PP-MIP was 4.661 µmol/g. Good class selectivity for BPA and its six structural analogues of bisphenol B (BPB) , bisphenol E (BPE), bisphenol AF (BPAF), bisphenol S (BPS), bisphenol AP (BPAP) and bisphenol Z (BPZ) was demonstrated by the chromatographic evaluation experiment. The prepared PP-MIP was successfully used as solid-phase extraction (SPE) sorbent for the separation and purification of the seven BPs in human urine, bovine serum and beer samples. Meanwhile, an accurate and sensitive MIP-SPE-HPLC method was established for the determination of the seven BPs in human urine, bovine serum and beer samples. The limits of detection (LODs) for the three samples were in the range of 1.2-2.0 µg/L. The results showed that good linearities were obtained in the range of 0.02-2 mg/L for the seven BPs and the correlation coefficients (r) were higher than 0.999 8. The recoveries of the BPs spiked in blank samples at two spiked levels (100 and 500 µg/L for each BP) were in the range of 90.1%-107.1% with the RSDs ≤ 8.1%. The proposed method is simple and reliable for the rapid detection of the seven BPs in human urine, bovine serum and beer samples.

  2. Genomic imprinting and the social brain.

    Science.gov (United States)

    Isles, Anthony R; Davies, William; Wilkinson, Lawrence S

    2006-12-29

    Genomic imprinting refers to the parent-of-origin-specific epigenetic marking of a number of genes. This epigenetic mark leads to a bias in expression between maternally and paternally inherited imprinted genes, that in some cases results in monoallelic expression from one parental allele. Genomic imprinting is often thought to have evolved as a consequence of the intragenomic conflict between the parental alleles that occurs whenever there is an asymmetry of relatedness. The two main examples of asymmetry of relatedness are when there is partiality of parental investment in offspring (as is the case for placental mammals, where there is also the possibility of extended postnatal care by one parent), and in social groups where there is a sex-biased dispersal. From this evolutionary starting point, it is predicted that, at the behavioural level, imprinted genes will influence what can broadly be termed bonding and social behaviour. We examine the animal and human literature for examples of imprinted genes mediating these behaviours, and divide them into two general classes. Firstly, mother-offspring interactions (suckling, attachment and maternal behaviours) that are predicted to occur when partiality in parental investment in early postnatal offspring occurs; and secondly, adult social interactions, when there is an asymmetry of relatedness in social groups. Finally, we return to the evolutionary theory and examine whether there is a pattern of behavioural functions mediated by imprinted genes emerging from the limited data, and also whether any tangible predictions can be made with regards to the direction of action of genes of maternal or paternal origin.

  3. Paternally transmitted IDDM2 influences diabetes susceptibility despite biallelic expression of the insulin gene in human pancreas.

    Science.gov (United States)

    Bui, M M; Luo, D F; She, J Y; Maclaren, N K; Muir, A; Thomson, G; She, J X

    1996-02-01

    Whereas it is well known that the insulin gene (INS) region at 11p15.5 (IDDM2) confers susceptibility to insulin-dependent diabetes mellitus (IDDM), it is still controversial whether the parental origin of IDDM2 influences IDDM susceptibility. We have analysed the Pst I + 1127 polymorphism in 123 USA multiplex families and detected linkage only in male meioses using the affected sibpair analysis (P = 0.009). Application of the transmission/disequilibrium test (TDT) found significantly increased transmission of the IDDM-associated INS allele from fathers heterozygous for INS to their diabetic offspring (P = 0.00002), but the transmission from heterozygous mothers was not significantly different from random expectation. In non-diabetic families, the transmission from parents heterozygous for INS was not significantly different from random expectation in either paternal or maternal meioses. Maternal imprinting of the INS gene in pancreatic islets was originally considered the most favorable explanation for the observed gender-related difference. However, our study has demonstrated biallelic expression of INS in pancreatic tissues from the human fetuses and thus suggests that INS is probably not imprinted in the pancreatic islets.

  4. Development of a fiber coating based on molecular sol-gel imprinting technology for selective solid-phase micro extraction of caffeine from human serum and determination by gas chromatography/mass spectrometry.

    Science.gov (United States)

    Rajabi Khorrami, Afshin; Rashidpur, Amene

    2012-05-21

    In this work, a molecular sol-gel imprinting approach has been introduced to produce a fiber coating for selective direct immersion solid-phase microextraction (SPME) of caffeine. The polymerization mixture was composed of vinyl trimethoxysilane and methacrylic acid as vinyl sol-gel precursor and functional monomer, respectively. Caffeine was used as template molecule during polymerization process. The prepared fibers could be coupled directly to gas chromatography/mass spectrometry (GC/MS) and used for trace analysis of caffeine in a complex sample such as human serum. The parameters influencing SPME such as time, temperature and stirring speed were optimized. The prepared coating showed good selectivity towards caffeine in the presence of some structurally related compounds. Also, it offered high imprinting capability in comparison to bare fiber and non-imprinted coating. Linear range for caffeine detection was 1-80 μg mL(-1) and the limit of detection was 0.1 μg mL(-1). The intra-day and inter-day precisions of the peak areas for five replicates were 10 and 16%, respectively.

  5. Molecularly Imprinted Membranes

    Directory of Open Access Journals (Sweden)

    Fabrizio Caldera

    2012-07-01

    Full Text Available Although the roots of molecularly imprinted polymers lie in the beginning of 1930s in the past century, they have had an exponential growth only 40–50 years later by the works of Wulff and especially by Mosbach. More recently, it was also proved that molecular imprinted membranes (i.e., polymer thin films that show recognition properties at molecular level of the template molecule are used in their formation. Different procedures and potential application in separation processes and catalysis are reported. The influences of different parameters on the discrimination abilities are also discussed.

  6. A survey of assisted reproductive technology births and imprinting disorders.

    Science.gov (United States)

    Bowdin, Sarah; Allen, Cathy; Kirby, Gail; Brueton, Louise; Afnan, Masoud; Barratt, Christopher; Kirkman-Brown, Jackson; Harrison, Robert; Maher, Eamonn R; Reardon, William

    2007-12-01

    Genomic imprinting is an epigenetic process in which allele-specific gene expression is dependent on the parental inheritance. Although only a minority of human genes are imprinted, those that have been identified to date have been preferentially implicated in prenatal growth and neurodevelopment. Mutations or epimutations in imprinted genes or imprinting control centres are associated with imprinting disorders such as Angelman syndrome (AS) and Beckwith-Wiedemann syndrome (BWS). Recently, an increased frequency of assisted reproductive technology (ART) conceptions has been reported in children with BWS and AS. However, the risk of imprinting disorders in ART children is unknown. We undertook a survey of 2492 children born after ART in the Republic of Ireland and Central England with the aim of detecting cases (both clinically diagnosed and previously unrecognized) of BWS and AS in this cohort. The response rate to an initial questionnaire was 61%, corresponding to data for 1524 children. After evaluation of the questionnaire, 70 children were invited for a detailed clinical assessment, and 47 accepted (response rate of 67%). In this entire cohort, we detected one case of BWS and no cases of AS. We did not find evidence that there exists a significant group of ART children with unrecognized milder forms of AS or BWS. Although previous studies have suggested an increased relative risk of BWS and AS after ART, our findings suggest that the absolute risk of imprinting disorders in children conceived by ART is small (<1%). Precise risk estimates of risk are difficult to define because of the rarity of the conditions and incomplete response rates to the questionnaire and clinical examination invitations. Hence further investigations are indicated to (i) refine the absolute and relative risks of imprinting disorders after ART and (ii) ensure that changes in ART protocols are not associated with increased frequencies of epigenetic changes and imprinting disorders in

  7. Solvent Immersion Imprint Lithography

    Energy Technology Data Exchange (ETDEWEB)

    Vasdekis, Andreas E.; Wilkins, Michael J.; Grate, Jay W.; Kelly, Ryan T.; Konopka, Allan; Xantheas, Sotiris S.; Chang, M. T.

    2014-06-21

    The mechanism of polymer disolution was explored for polymer microsystem prototyping, including microfluidics and optofluidics. Polymer films are immersed in a solvent, imprinted and finally brought into contact with a non-modified surface to permanently bond. The underlying polymer-solvent interactions were experimentally and theoretically investigated, and enabled rapid polymer microsystem prototyping. During imprinting, small molecule integration in the molded surfaces was feasible, a principle applied to oxygen sensing. Polystyrene (PS) was employed for microbiological studies at extreme environmental conditions. The thermophile anaerobe Clostridium Thermocellum was grown in PS pore-scale micromodels, revealing a double mean generation lifetime than under ideal culture conditions. Microsystem prototyping through directed polymer dissolution is simple and accessible, while simultaneous patterning, bonding, and surface/volume functionalization are possible in less than one minute.

  8. Rapid Diagnosis of Imprinting Disorders Involving Copy Number Variation and Uniparental Disomy Using Genome-Wide SNP Microarrays.

    Science.gov (United States)

    Liu, Weiqiang; Zhang, Rui; Wei, Jun; Zhang, Huimin; Yu, Guojiu; Li, Zhihua; Chen, Min; Sun, Xiaofang

    2015-01-01

    Imprinting disorders, such as Beckwith-Wiedemann syndrome (BWS), Prader-Willi syndrome (PWS) and Angelman syndrome (AS), can be detected via methylation analysis, methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA), or other methods. In this study, we applied single nucleotide polymorphism (SNP)-based chromosomal microarray analysis to detect copy number variations (CNVs) and uniparental disomy (UPD) events in patients with suspected imprinting disorders. Of 4 patients, 2 had a 5.25-Mb microdeletion in the 15q11.2q13.2 region, 1 had a 38.4-Mb mosaic UPD in the 11p15.4 region, and 1 had a 60-Mb detectable UPD between regions 14q13.2 and 14q32.13. Although the 14q32.2 region was classified as normal by SNP array for the 14q13 UPD patient, it turned out to be a heterodisomic UPD by short tandem repeat marker analysis. MS-MLPA analysis was performed to validate the variations. In conclusion, SNP-based microarray is an efficient alternative method for quickly and precisely diagnosing PWS, AS, BWS, and other imprinted gene-associated disorders when considering aberrations due to CNVs and most types of UPD.

  9. Short interspersed element (SINE) depletion and long interspersed element (LINE) abundance are not features universally required for imprinting.

    Science.gov (United States)

    Cowley, Michael; de Burca, Anna; McCole, Ruth B; Chahal, Mandeep; Saadat, Ghazal; Oakey, Rebecca J; Schulz, Reiner

    2011-04-20

    Genomic imprinting is a form of gene dosage regulation in which a gene is expressed from only one of the alleles, in a manner dependent on the parent of origin. The mechanisms governing imprinted gene expression have been investigated in detail and have greatly contributed to our understanding of genome regulation in general. Both DNA sequence features, such as CpG islands, and epigenetic features, such as DNA methylation and non-coding RNAs, play important roles in achieving imprinted expression. However, the relative importance of these factors varies depending on the locus in question. Defining the minimal features that are absolutely required for imprinting would help us to understand how imprinting has evolved mechanistically. Imprinted retrogenes are a subset of imprinted loci that are relatively simple in their genomic organisation, being distinct from large imprinting clusters, and have the potential to be used as tools to address this question. Here, we compare the repeat element content of imprinted retrogene loci with non-imprinted controls that have a similar locus organisation. We observe no significant differences that are conserved between mouse and human, suggesting that the paucity of SINEs and relative abundance of LINEs at imprinted loci reported by others is not a sequence feature universally required for imprinting.

  10. Short interspersed element (SINE depletion and long interspersed element (LINE abundance are not features universally required for imprinting.

    Directory of Open Access Journals (Sweden)

    Michael Cowley

    Full Text Available Genomic imprinting is a form of gene dosage regulation in which a gene is expressed from only one of the alleles, in a manner dependent on the parent of origin. The mechanisms governing imprinted gene expression have been investigated in detail and have greatly contributed to our understanding of genome regulation in general. Both DNA sequence features, such as CpG islands, and epigenetic features, such as DNA methylation and non-coding RNAs, play important roles in achieving imprinted expression. However, the relative importance of these factors varies depending on the locus in question. Defining the minimal features that are absolutely required for imprinting would help us to understand how imprinting has evolved mechanistically. Imprinted retrogenes are a subset of imprinted loci that are relatively simple in their genomic organisation, being distinct from large imprinting clusters, and have the potential to be used as tools to address this question. Here, we compare the repeat element content of imprinted retrogene loci with non-imprinted controls that have a similar locus organisation. We observe no significant differences that are conserved between mouse and human, suggesting that the paucity of SINEs and relative abundance of LINEs at imprinted loci reported by others is not a sequence feature universally required for imprinting.

  11. Ultrasound-assisted combined with nano-sized molecularly imprinted polymer for selective extraction and pre-concentration of amitriptyline in human plasma with gas chromatography-flame detection.

    Science.gov (United States)

    Khanahmadzadeh, Salah; Tarigh, Ahmad

    2014-12-01

    A new process was developed for the selective extraction and pre-concentration of amitriptyline (AT) from human plasma using nano-sized molecularly imprinted polymer (MIP) with ultrasound-assisted extraction (UAE). The nano-sized AT imprinted polymer particles were synthesized using suspension polymerization in silicon oil and characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscope (SEM) methods. With the application of optimized values, linearity values in the ranges of 20-200μgmL(-1) and 35-200μgmL(-1) were obtained for AT with the correlation of determination values (r(2)) 0.998 and 0.995 in water and plasma, respectively. The limits of detections (S/N=3) for AT were found to be 0.7 and 1.2μgmL(-1) in water and plasma, respectively. The enrichment factors of AT in water and plasma were 52 and 40, respectively. The inter-day precisions (%) were in the range of 5.8-9.2%. Relative recovery rates ranged from 82.4% to 92.3%. The method was successfully applied to determine AT in the human plasma samples.

  12. Molecularly imprinted solid-phase extraction combined with electrochemical oxidation fluorimetry for the determination of methotrexate in human serum and urine.

    Science.gov (United States)

    Chen, Suming; Zhang, Zhujun

    2008-06-01

    The method of synthesis and evaluation of molecularly imprinted polymers was reported. As a selective solid-phase extraction sorbent, the polymers were coupled with electrochemical fluorimetry detection for the efficient determination of methotrexate in serum and urine. Methotrexate was preconcentrated in the molecularly imprinted solid-phase extraction microcolumn packed with molecularly imprinted polymers, and then eluted. The eluate was detected by fluorescence spectrophotometer after electrochemical oxidation. The conditions of preconcentration, elution, electrochemical oxidation and determination were carefully studied. Under the selected experimental conditions, the calibration graph of the fluorescence intensity versus methotrexate concentration was linear from 4x10(-9) g mL(-1) to 5x10(-7) g mL(-1), and the detection limit was 8.2x10(-10) g mL(-1) (3sigma). The relative standard deviation was 3.92% (n=7) for 1x10(-7) g mL(-1) methotrexate. The experiments showed that the selectivity and sensitivity of fluorimetry could be greatly improved by the proposed method. This method has been successfully applied to the determination of methotrexate. At the same time, the binding characteristics of the polymers to the methotrexate were evaluated by batch and dynamic methods.

  13. Genomic imprinting on the X chromosome: implications for brain and behavioral phenotypes.

    Science.gov (United States)

    Davies, William

    2010-09-01

    Imprinted genes, in contrast to most mammalian genes, are monoallelically expressed in a parent-of-origin dependent manner. The idiosyncratic expression profile associated with imprinted genes arises from the differential epigenetic marking of the alleles in the paternal and maternal germlines. Although small in number, imprinted genes can profoundly influence key developmental and physiological processes, including those in the brain; work in animal models and in humans has shown that such genes can affect behavioral traits and cognition and may confer vulnerability to common mental illnesses. As a consequence of how the X chromosome is inherited, X-linked imprinting may elicit or indeed attenuate sexually dimorphic phenotypes. Thus, studying X-linked imprinting is likely to provide important general information about the evolutionary and mechanistic underpinnings of imprinting, as well as the molecular processes underlying sex-specific neurobiology and sex-biased vulnerability to psychiatric disorders.

  14. Categories with envelopes and imprints

    CERN Document Server

    Akbarov, Sergei

    2011-01-01

    An envelope in a category is a construction generalizing operations of "exterior completion", like completion of a locally convex space. Dually, an imprint generalizes operations of "interior enrichment", like saturation of a locally convex space. We give abstract definition for envelopes and imprints, prove existence of these objects in the categories of stereotype spaces and of stereotype algebras, and give some examples.

  15. Molecularly Imprinted Quartz Crystal Microbalance Sensor (QCM for Bilirubin Detection

    Directory of Open Access Journals (Sweden)

    Çiğdem Çiçek

    2016-11-01

    Full Text Available This study aims the preparation of a QCM sensor for the detection of bilirubin in human plasma. Bilirubin-imprinted poly-(2-hydroxyethyl methacrylate-N-methacryloyl-l-tryptophan methyl ester (PHEMATrp nanofilm (MIP on the gold surface of a QCM chip was synthesized by the molecular imprinting technique. Meanwhile, the non-imprinted PHEMATrp (NIP nanofilm was synthesized by the same experimental technique to examine the imprinting effect. Characterization of MIP and NIP nanofilms on the QCM chip surface was achieved by atomic force microscopy (AFM, ellipsometry, Fourier transform infrared spectrophotometry-attenuated total reflectance (FTIR-ATR and contact angle measurements (CA. The observations indicated that the nanofilm was almost in a monolayer. Thereinafter, the imprinted and the non-imprinted QCM chips were connected to the QCM system to investigate kinetic and affinity properties. In order to examine the selectivity of the MIP-PHEMATrp nanofilm, competitive adsorption of bilirubin with cholesterol and estradiol was performed. Limit of detection (LOD and limit of quantitation (LOQ values were calculated as 0.45 μg/mL and 0.9 μg/mL, respectively.

  16. Angelman syndrome imprinting center encodes a transcriptional promoter.

    Science.gov (United States)

    Lewis, Michael W; Brant, Jason O; Kramer, Joseph M; Moss, James I; Yang, Thomas P; Hansen, Peter J; Williams, R Stan; Resnick, James L

    2015-06-02

    Clusters of imprinted genes are often controlled by an imprinting center that is necessary for allele-specific gene expression and to reprogram parent-of-origin information between generations. An imprinted domain at 15q11-q13 is responsible for both Angelman syndrome (AS) and Prader-Willi syndrome (PWS), two clinically distinct neurodevelopmental disorders. Angelman syndrome arises from the lack of maternal contribution from the locus, whereas Prader-Willi syndrome results from the absence of paternally expressed genes. In some rare cases of PWS and AS, small deletions may lead to incorrect parent-of-origin allele identity. DNA sequences common to these deletions define a bipartite imprinting center for the AS-PWS locus. The PWS-smallest region of deletion overlap (SRO) element of the imprinting center activates expression of genes from the paternal allele. The AS-SRO element generates maternal allele identity by epigenetically inactivating the PWS-SRO in oocytes so that paternal genes are silenced on the future maternal allele. Here we have investigated functional activities of the AS-SRO, the element necessary for maternal allele identity. We find that, in humans, the AS-SRO is an oocyte-specific promoter that generates transcripts that transit the PWS-SRO. Similar upstream promoters were detected in bovine oocytes. This result is consistent with a model in which imprinting centers become DNA methylated and acquire maternal allele identity in oocytes in response to transiting transcription.

  17. Selective solid-phase extraction of naproxen drug from human urine samples using molecularly imprinted polymer-coated magnetic multi-walled carbon nanotubes prior to its spectrofluorometric determination.

    Science.gov (United States)

    Madrakian, Tayyebeh; Ahmadi, Mazaher; Afkhami, Abbas; Soleimani, Mohammad

    2013-08-21

    A drug imprinted polymer based on suspension polymerization on magnetic multi-walled carbon nanotubes (MIPMCNTs) was prepared with a synthesized amidoamine as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, naproxen (NAP) as the template and ammonium persulfate as the initiator. The MIPMCNTs were characterized by TEM, FT-IR and XRD measurements. The prepared magnetic adsorbent can be well dispersed in aqueous media and can be easily separated magnetically from the medium after loading with NAP. All the aspects influencing the adsorption (extraction time, adsorbent dosage and pH) and desorption (desorption time and desorption solvent) of the analyte on the MIPMCNTs have been investigated. The extracted NAP could be easily desorbed with a mixture of methanol/sodium hydroxide aqueous solution and determined spectrofluorometrically at λem = 353 nm (λex = 271 nm). A linear dynamic range was established from 4.0 to 40.0 ng mL⁻¹ of NAP and the limit of detection (LOD) was found to be 2.0 ng mL⁻¹. In addition, the equilibrium adsorption data of NAP by imprinted polymer were analyzed by Langmuir and Freundlich isotherm models. The developed method was utilized for the determination of NAP in human urine samples with satisfactory results.

  18. Imprinted functionalized silica sol-gel for solid-phase extraction of triazolamin.

    Science.gov (United States)

    Jin, Guoyou; Zhang, Baofei; Tang, Youwen; Zuo, Xiongjun; Wang, Songcai; Tang, Jingyi

    2011-05-15

    A triazolam-imprinted silica microsphere was prepared by combining a surface molecular-imprinting technique with the sol-gel process. The results illustrate that the triazolam-imprinted silica microspheres provided using γ-aminopropyltriethoxysilane and phenyltrimethoxysilane as monomers exhibited higher selectivity than those provided from γ-aminopropyltriethoxysilane and methyltriethoxysilane. In addition, the optimum affinity occurred when the molar ratio of γ-aminopropyltriethoxysilane, phenyltrimethoxysilane, and the template molecule was 4.2:4.7:0.6. Retention factor (k) and imprinting factor (IF) of triazolam on the imprinted and non-imprinted silica microsphere columns were characterized using high performance liquid chromatography (HPLC) with different mobile phases including methanol, acetonitrile, and water solutions. The molecular selectivity of the imprinted silica microspheres was also evaluated for triazolam and its analogue compounds in various mobile phases. The better results indicated that k and IF of triazolam on the imprinted silica microsphere column were 2.1 and 35, respectively, when using methanol/water (1/1, v/v) as the mobile phase. Finally, the imprinted silica was applied as a sorbent in solid-phase extraction (SPE), to selectively extract triazolam and its metabolite, α-hydroxytriazolam, from human urine samples. The limits of detection (LOD) for triazolam and α-hydroxytriazolam in urine samples were 30 ± 0.21 ng mL(-1) and 33 ± 0.26 ng mL(-1), respectively.

  19. Bisphenol a exposure disrupts genomic imprinting in the mouse.

    Directory of Open Access Journals (Sweden)

    Martha Susiarjo

    2013-04-01

    Full Text Available Exposure to endocrine disruptors is associated with developmental defects. One compound of concern, to which humans are widely exposed, is bisphenol A (BPA. In model organisms, BPA exposure is linked to metabolic disorders, infertility, cancer, and behavior anomalies. Recently, BPA exposure has been linked to DNA methylation changes, indicating that epigenetic mechanisms may be relevant. We investigated effects of exposure on genomic imprinting in the mouse as imprinted genes are regulated by differential DNA methylation and aberrant imprinting disrupts fetal, placental, and postnatal development. Through allele-specific and quantitative real-time PCR analysis, we demonstrated that maternal BPA exposure during late stages of oocyte development and early stages of embryonic development significantly disrupted imprinted gene expression in embryonic day (E 9.5 and 12.5 embryos and placentas. The affected genes included Snrpn, Ube3a, Igf2, Kcnq1ot1, Cdkn1c, and Ascl2; mutations and aberrant regulation of these genes are associated with imprinting disorders in humans. Furthermore, the majority of affected genes were expressed abnormally in the placenta. DNA methylation studies showed that BPA exposure significantly altered the methylation levels of differentially methylated regions (DMRs including the Snrpn imprinting control region (ICR and Igf2 DMR1. Moreover, exposure significantly reduced genome-wide methylation levels in the placenta, but not the embryo. Histological and immunohistochemical examinations revealed that these epigenetic defects were associated with abnormal placental development. In contrast to this early exposure paradigm, exposure outside of the epigenetic reprogramming window did not cause significant imprinting perturbations. Our data suggest that early exposure to common environmental compounds has the potential to disrupt fetal and postnatal health through epigenetic changes in the embryo and abnormal development of the

  20. Genomic imprinting in primate embryos and embryonic stem cells.

    Science.gov (United States)

    Mitalipov, Shoukhrat M

    2006-01-01

    Embryonic stem (ES) cells hold promise for cell and tissue replacement approaches to treating human diseases. However, long-term in vitro culture and manipulations of ES cells may adversely affect their epigenetic integrity including imprinting. Disruption or inappropriate expression of imprinted genes is associated with several clinically significant syndromes and tumorigenesis in humans. We demonstrated aberrant biallelic expression of IGF2 and H19 in several rhesus monkey ES cell lines while SNRPN and NDN were normally imprinted and expressed from the paternal allele. In contrast, expanded blastocyst-stage embryos, from which these ES cells were derived, exhibited normal paternal expression of IGF2 and maternal expression of H19. To test the possibility that aberrant methylation at an imprinting centre (IC) upstream of H19 accounts for the relaxed imprinting of IGF2 and H19, we performed comprehensive methylation analysis by investigating methylation profiles of CpG sites within the IGF2/H19 IC. Our results demonstrate abnormal hypermethylation within the IGF2/H19 IC in all analysed ES cell lines consistent with biallelic expression of these genes. Cellular overproliferation and tumour formation resulting from tissue or cell transplantation are potential problems that must be addressed before clinical trials of ES cell-based therapy are initiated.

  1. Mutations of the Imprinted CDKN1C Gene as a Cause of the Overgrowth Beckwith-Wiedemann Syndrome: Clinical Spectrum and Functional Characterization.

    Science.gov (United States)

    Brioude, Frederic; Netchine, Irène; Praz, Francoise; Le Jule, Marilyne; Calmel, Claire; Lacombe, Didier; Edery, Patrick; Catala, Martin; Odent, Sylvie; Isidor, Bertrand; Lyonnet, Stanislas; Sigaudy, Sabine; Leheup, Bruno; Audebert-Bellanger, Séverine; Burglen, Lydie; Giuliano, Fabienne; Alessandri, Jean-Luc; Cormier-Daire, Valérie; Laffargue, Fanny; Blesson, Sophie; Coupier, Isabelle; Lespinasse, James; Blanchet, Patricia; Boute, Odile; Baumann, Clarisse; Polak, Michel; Doray, Berenice; Verloes, Alain; Viot, Géraldine; Le Bouc, Yves; Rossignol, Sylvie

    2015-09-01

    Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder associating macroglossia, abdominal wall defects, visceromegaly, and a high risk of childhood tumor. Molecular anomalies are mostly epigenetic; however, mutations of CDKN1C are implicated in 8% of cases, including both sporadic and familial forms. We aimed to describe the phenotype of BWS patients with CDKN1C mutations and develop a functional test for CDKN1C mutations. For each propositus, we sequenced the three exons and intron-exon boundaries of CDKN1C in patients presenting a BWS phenotype, including abdominal wall defects, without 11p15 methylation defects. We developed a functional test based on flow cytometry. We identified 37 mutations in 38 pedigrees (50 patients and seven fetuses). Analysis of parental samples when available showed that all mutations tested but one was inherited from the mother. The four missense mutations led to a less severe phenotype (lower frequency of exomphalos) than the other 33 mutations. The following four tumors occurred: one neuroblastoma, one ganglioneuroblastoma, one melanoma, and one acute lymphoid leukemia. Cases of BWS caused by CDKN1C mutations are not rare. CDKN1C sequencing should be performed for BWS patients presenting with abdominal wall defects or cleft palate without 11p15 methylation defects or body asymmetry, or in familial cases of BWS.

  2. Step & flash imprint lithography

    Directory of Open Access Journals (Sweden)

    Douglas J. Resnick

    2005-02-01

    Full Text Available The escalating cost of next generation lithography (NGL is driven in part by the need for complex sources and optics. The cost for a single NGL tool could soon exceed $50 million, a prohibitive amount for many companies. As a result, several research groups are looking at alternative, low-cost methods for printing sub-100 nm features. Many of these methods are limited in their ability to do precise overlay. In 1999, Willson and Sreenivasan developed step and flash imprint lithography (S-FIL™. The use of a quartz template opens up the potential for optical alignment of the wafer and template. This paper reviews several key aspects of the S-FIL process, including template, tool, ultraviolet (UV-curable monomer, and pattern transfer. Two applications are also presented: contact holes and surface acoustic wave (SAW filters.

  3. Molecular imprinting: perspectives and applications.

    Science.gov (United States)

    Chen, Lingxin; Wang, Xiaoyan; Lu, Wenhui; Wu, Xiaqing; Li, Jinhua

    2016-04-21

    Molecular imprinting technology (MIT), often described as a method of making a molecular lock to match a molecular key, is a technique for the creation of molecularly imprinted polymers (MIPs) with tailor-made binding sites complementary to the template molecules in shape, size and functional groups. Owing to their unique features of structure predictability, recognition specificity and application universality, MIPs have found a wide range of applications in various fields. Herein, we propose to comprehensively review the recent advances in molecular imprinting including versatile perspectives and applications, concerning novel preparation technologies and strategies of MIT, and highlight the applications of MIPs. The fundamentals of MIPs involving essential elements, preparation procedures and characterization methods are briefly outlined. Smart MIT for MIPs is especially highlighted including ingenious MIT (surface imprinting, nanoimprinting, etc.), special strategies of MIT (dummy imprinting, segment imprinting, etc.) and stimuli-responsive MIT (single/dual/multi-responsive technology). By virtue of smart MIT, new formatted MIPs gain popularity for versatile applications, including sample pretreatment/chromatographic separation (solid phase extraction, monolithic column chromatography, etc.) and chemical/biological sensing (electrochemical sensing, fluorescence sensing, etc.). Finally, we propose the remaining challenges and future perspectives to accelerate the development of MIT, and to utilize it for further developing versatile MIPs with a wide range of applications (650 references).

  4. Synthesis of magnetic cytosine-imprinted chitosan nanoparticles

    Science.gov (United States)

    Lee, Mei-Hwa; Ahluwalia, Arti; Chen, Jian-Zhou; Shih, Neng-Lang; Lin, Hung-Yin

    2017-02-01

    Molecularly imprinted polymer nanoparticles incorporating magnetic nanoparticles (MNPs) have been investigated for their selective adsorption properties. Here we describe the synthesis and characterization of magnetic cytosine-imprinted chitosan nanoparticles (CIPs) for gene delivery. In particular, CIPs carrying the mammalian expression plasmid of enhanced green fluorescent protein were prepared by the co-precipitation of MNPs, chitosan and a template nucleobase (cytosine). The results show that the selective reabsorption of cytosine to magnetic CIPs was at least double that of non-imprinted polymers and other nucleobases (such as adenine and thymine). The gene carrier CIPs were used for the transfection of human embryonic kidney 293 cells showing dramatic increase their efficiency with that of conventional chitosan nanoparticles. Furthermore, the gene carrier magnetic CIPs also exhibit low toxicity compared to that of commercially available cationic lipids.

  5. Magnetic molecularly imprinted polydopamine nanolayer on multiwalled carbon nanotubes surface for protein capture.

    Science.gov (United States)

    Yin, Yuli; Yan, Liang; Zhang, Zhaohui; Wang, Jing

    2015-11-01

    A novel, facile and low cost process for imprinting protein on the surface of magnetic multiwalled carbon nanotubes (MMWNTs) was developed using human serum albumin (HSA) as the template and dopamine as the functional monomer. The magnetic imprinted polymers were characterized with transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier-transform infrared spectrometry (FT-IR), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA) in detail. The maximum adsorption capacity of the magnetic imprinted polymers toward HSA was 66.23 mg g(-1) and it took 20 min to achieve the adsorption equilibrium. The magnetic imprinted polymers exhibited the specific selective adsorption toward HSA. Coupled with high performance liquid chromatography (HPLC) analysis, the magnetic imprinted polymers were used to solid-phase extract and detect HSA in urine samples successfully with the recoveries of 91.95-97.8%.

  6. MicroRNAs 296 and 298 are imprinted and part of the GNAS/Gnas cluster and miR-296 targets IKBKE and Tmed9

    OpenAIRE

    2012-01-01

    Genomic imprinting is the phenomenon whereby a subset of genes is differentially expressed according to parental origin. Imprinted genes tend to occur in clusters, and microRNAs are associated with the majority of well-defined clusters of imprinted genes. Here the authors show that two microRNAs, miR-296 and miR-298, are part of the imprinted Gnas/GNAS clusters in both mice and humans. Both microRNAs show imprinted expression and are expressed from the paternally derived allele, but not the m...

  7. Recommendations for a nomenclature system for reporting methylation aberrations in imprinted domains

    DEFF Research Database (Denmark)

    Monk, David; Morales, Joannella; den Dunnen, Johan T

    2017-01-01

    by the lack of consistency in reporting sites of methylation evaluated. To avoid confusion surrounding nomenclature, special care is needed to communicate results accurately, especially between scientists and other health care professionals. Within the European Network for Human Congenital Imprinting...

  8. Imprint lithography advances in LED manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Hershey, Robert; Doyle, Gary; Jones, Chris; LaBrake, Dwayne; Miller, Mike [Molecular Imprints Inc., 1807 West Braker Lane, Building C-11, Austin, TX 78758 (United States)

    2007-07-01

    Imprint lithography is a promising cost effect alternative to e-beam and optical lithography for producing photonic crystals and other nano-scale light extraction and beam directing elements for LEDs; however, there are several challenges that must be overcome before imprint lithography can be applied to typical LED substrates. This paper reviews progress made at Molecular Imprints Inc. (MII) in imprinting representative 3{sup ''} GaN on Sapphire substrates including methods for dealing with substrate non-flatness, multi-die imprint, and imprinting on warped and bowed substrates. The results of imprinting over typical GaN on Sapphire topography and common defects such as fall-on particles and EPI defects is presented along with results on GaN wafers optimized for imprint lithography. Whole wafer thin template replication techniques are also discussed. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Ultrasound assisted combined molecularly imprinted polymer for selective extraction of nicotinamide in human urine and milk samples: Spectrophotometric determination and optimization study.

    Science.gov (United States)

    Asfaram, Arash; Ghaedi, Mehrorang; Dashtian, Kheibar

    2017-01-01

    Ultrasound-assisted dispersive solid phase microextraction followed by UV-vis spectrophotometer (UA-DSPME-UV-vis) was designed for extraction and preconcentration of nicotinamide (vitamin B3) by HKUST-1 metal organic framework (MOF) based molecularly imprinted polymer (MIP). This new material was characterized by FTIR and FE-SEM techniques. The preliminary Plackett-Burman design was used for screening and subsequently the central composite design justifies significant terms and possible construction of mathematical equation which give the individual and cooperative contribution of variables like HKUST-1-MOF-NA-MIP mass, sonication time, temperature, eluent volume, pH and vortex time. Accordingly the optimum condition was set as: 2.0mg HKUST-1-MOF-NA-MIP, 200μL eluent and 5.0min sonication time in center points other variables were determined as the best conditions to reach the maximum recovery of the analyte. The UA-DSPME-UV-vis method performances like excellent linearity (LR), limits of detection (LOD), limits of quantification of 10-5000μgL(-1) with R(2) of 0.99, LOD (1.96ngmL(-1)), LOQ (6.53μgL(-1)), respectively show successful and accurate applicability of the present method for monitoring analytes with within- and between-day precision of 0.96-3.38%. The average absolute recoveries of the nicotinamide extracted from the urine, milk and water samples were 95.85-101.27%.

  10. Epigenetic status of H19/IGF2 and SNRPN imprinted genes in aborted and successfully derived embryonic stem cell lines in non-human primates

    Directory of Open Access Journals (Sweden)

    Florence Wianny

    2016-05-01

    Full Text Available The imprinted genes of primate embryonic stem cells (ESCs often show altered DNA methylation. It is unknown whether these alterations emerge while deriving the ESCs. Here we studied the methylation patterns of two differentially methylated regions (DMRs, SNRPN and H19/IGF2 DMRs, during the derivation of monkey ESCs. We show that the SNRPN DMR is characteristically methylated at maternal alleles, whereas the H19/IGF2 DMR is globally highly methylated, with unusual methylation on the maternal alleles. These methylation patterns remain stable from the early stages of ESC derivation to late passages of monkey ESCs and following differentiation. Importantly, the methylation status of H19/IGF2 DMR and the expression levels of IGF2, H19, and DNMT3B mRNAs in early embryo-derived cells were correlated with their capacity to generate genuine ESC lines. Thus, we propose that these markers could be useful to predict the outcomes of establishing an ESC line in primates.

  11. Imprinted genes show unique patterns of sequence conservation

    Directory of Open Access Journals (Sweden)

    Helms Volkhard

    2010-11-01

    Full Text Available Abstract Background Genomic imprinting is an evolutionary conserved mechanism of epigenetic gene regulation in placental mammals that results in silencing of one of the parental alleles. In order to decipher interactions between allele-specific DNA methylation of imprinted genes and evolutionary conservation, we performed a genome-wide comparative investigation of genomic sequences and highly conserved elements of imprinted genes in human and mouse. Results Evolutionarily conserved elements in imprinted regions differ from those associated with autosomal genes in various ways. Whereas for maternally expressed genes strong divergence of protein-encoding sequences is most prominent, paternally expressed genes exhibit substantial conservation of coding and noncoding sequences. Conserved elements in imprinted regions are marked by enrichment of CpG dinucleotides and low (TpG+CpA/(2·CpG ratios indicate reduced CpG deamination. Interestingly, paternally and maternally expressed genes can be distinguished by differences in G+C and CpG contents that might be associated with unusual epigenetic features. Especially noncoding conserved elements of paternally expressed genes are exceptionally G+C and CpG rich. In addition, we confirmed a frequent occurrence of intronic CpG islands and observed a decelerated degeneration of ancient LINE-1 repeats. We also found a moderate enrichment of YY1 and CTCF binding sites in imprinted regions and identified several short sequence motifs in highly conserved elements that might act as additional regulatory elements. Conclusions We discovered several novel conserved DNA features that might be related to allele-specific DNA methylation. Our results hint at reduced CpG deamination rates in imprinted regions, which affects mostly noncoding conserved elements of paternally expressed genes. Pronounced differences between maternally and paternally expressed genes imply specific modes of evolution as a result of differences in

  12. Familiarity interferes with filial imprinting

    NARCIS (Netherlands)

    vanKampen, HS; deVos, GJ

    1996-01-01

    The present study was performed to investigate whether and how pre-exposure to an object affects subsequent filial imprinting to that object. In Experiment 1 junglefowl chicks (Gallus gallus spadiceus) were first exposed to either a red object alone (control group), or a red and a yellow object

  13. Imprinted photonic crystal chemical sensors

    NARCIS (Netherlands)

    Boersma, A.; Burghoorn, M.M.A.; Saalmink, M.

    2011-01-01

    In this paper we present the use of Photonic Crystals as chemical sensors. These 2D nanostructured sensors were prepared by nano-imprint lithography during which a nanostructure is transferred from a nickel template into a responsive polymer, that is be specifically tuned to interact with the chemic

  14. Biological imprinting: Some genetic considerations

    African Journals Online (AJOL)

    Mohammad Saad Zaghloul Salem

    2014-06-21

    Jun 21, 2014 ... Abstract Genetic imprinting represents one of the most puzzling, still unexplained, phenomena in genetics. Changing .... acid defined by the new code comprising the new base), .... advantages constitutes the core concept of evolution. Though .... different mechanisms under independent genetic control. 8.

  15. Familiarity interferes with filial imprinting

    NARCIS (Netherlands)

    vanKampen, HS; deVos, GJ

    1996-01-01

    The present study was performed to investigate whether and how pre-exposure to an object affects subsequent filial imprinting to that object. In Experiment 1 junglefowl chicks (Gallus gallus spadiceus) were first exposed to either a red object alone (control group), or a red and a yellow object simu

  16. The origin of the RB1 imprint.

    Directory of Open Access Journals (Sweden)

    Deniz Kanber

    Full Text Available The human RB1 gene is imprinted due to a differentially methylated CpG island in intron 2. This CpG island is part of PPP1R26P1, a truncated retrocopy of PPP1R26, and serves as a promoter for an alternative RB1 transcript. We show here by in silico analyses that the parental PPP1R26 gene is present in the analysed members of Haplorrhini, which comprise Catarrhini (Old World Monkeys, Small apes, Great Apes and Human, Platyrrhini (New World Monkeys and tarsier, and Strepsirrhini (galago. Interestingly, we detected the retrocopy, PPP1R26P1, in all Anthropoidea (Catarrhini and Platyrrhini that we studied but not in tarsier or galago. Additional retrocopies are present in human and chimpanzee on chromosome 22, but their distinct composition indicates that they are the result of independent retrotransposition events. Chimpanzee and marmoset have further retrocopies on chromosome 8 and chromosome 4, respectively. To examine the origin of the RB1 imprint, we compared the methylation patterns of the parental PPP1R26 gene and its retrocopies in different primates (human, chimpanzee, orangutan, rhesus macaque, marmoset and galago. Methylation analysis by deep bisulfite sequencing showed that PPP1R26 is methylated whereas the retrocopy in RB1 intron 2 is differentially methylated in all primates studied. All other retrocopies are fully methylated, except for the additional retrocopy on marmoset chromosome 4, which is also differentially methylated. Using an informative SNP for the methylation analysis in marmoset, we could show that the differential methylation pattern of the retrocopy on chromosome 4 is allele-specific. We conclude that the epigenetic fate of a PPP1R26 retrocopy after integration depends on the DNA sequence and selective forces at the integration site.

  17. Developmental Stage-Specific Imprinting of IPL in Domestic Pigs (Sus scrofa

    Directory of Open Access Journals (Sweden)

    Shengping Hou

    2010-01-01

    Full Text Available Imprinted in placenta and liver (IPL gene has been identified as an imprinted gene in the mouse and human. Its sequence and imprinting status, however, have not been determined in the domestic pigs. In the present study, a 259 base pair-specific sequence for IPL gene of the domestic pig was obtained and a novel SNP, a T/C transition, was identified in IPL exon 1. The C allele of this polymorphism was found to be the predominant allele in Landrace,Yorkshire, and Duroc. The frequency of CC genotype and C allele are different in Duroc as compared with Yorkshire (P=.038 and P=.005, resp.. Variable imprinting status of this gene was observed in different developmental stages. For example, it is imprinted in 1-dayold newborns (expressed from the maternal allele, but imprinting was lost in 180-day-old adult (expressed from both parental alleles. Real-time PCR analysis showed the porcine IPL gene is expressed in all tested eight organ/tissues. The expression level was significantly higher in spleen, duodenum, lung, and bladder of 180-day-old Lantang adult compared to that in 1-day-old newborns Lantang pigs (P<.05. In conclusion, the imprinting of the porcine IPL gene is developmental stage and tissue specific.

  18. Targeting and Imaging of Cancer Cells via Monosaccharide-Imprinted Fluorescent Nanoparticles

    Science.gov (United States)

    Wang, Shuangshou; Yin, Danyang; Wang, Wenjing; Shen, Xiaojing; Zhu, Jun-Jie; Chen, Hong-Yuan; Liu, Zhen

    2016-03-01

    The recognition of cancer cells is a key for cancer diagnosis and therapy, but the specificity highly relies on the use of biorecognition molecules particularly antibodies. Because biorecognition molecules suffer from some apparent disadvantages, such as hard to prepare and poor storage stability, novel alternatives that can overcome these disadvantages are highly important. Here we present monosaccharide-imprinted fluorescent nanoparticles (NPs) for targeting and imaging of cancer cells. The molecularly imprinted polymer (MIP) probe was fluorescein isothiocyanate (FITC) doped silica NPs with a shell imprinted with sialic acid, fucose or mannose as the template. The monosaccharide-imprinted NPs exhibited high specificity toward the target monosaccharides. As the template monosaccharides used are over-expressed on cancer cells, these monosaccharide-imprinted NPs allowed for specific targeting cancer cells over normal cells. Fluorescence imaging of human hepatoma carcinoma cells (HepG-2) over normal hepatic cells (L-02) and mammary cancer cells (MCF-7) over normal mammary epithelial cells (MCF-10A) by these NPs was demonstrated. As the imprinting approach employed herein is generally applicable and highly efficient, monosaccharide-imprinted NPs can be promising probes for targeting cancer cells.

  19. Molecularly imprinted titania nanoparticles for selective recognition and assay of uric acid

    Science.gov (United States)

    Mujahid, Adnan; Khan, Aimen Idrees; Afzal, Adeel; Hussain, Tajamal; Raza, Muhammad Hamid; Shah, Asma Tufail; uz Zaman, Waheed

    2015-06-01

    Molecularly imprinted titania nanoparticles are su ccessfully synthesized by sol-gel method for the selective recognition of uric acid. Atomic force microscopy is used to study the morphology of uric acid imprinted titania nanoparticles with diameter in the range of 100-150 nm. Scanning electron microscopy images of thick titania layer indicate the formation of fine network of titania nanoparticles with uniform distribution. Molecular imprinting of uric acid as well as its subsequent washing is confirmed by Fourier transformation infrared spectroscopy measurements. Uric acid rebinding studies reveal the recognition capability of imprinted particles in the range of 0.01-0.095 mmol, which is applicable in monitoring normal to elevated levels of uric acid in human blood. The optical shift (signal) of imprinted particles is six times higher in comparison with non-imprinted particles for the same concentration of uric acid. Imprinted titania particles have shown substantially reduced binding affinity toward interfering and structurally related substances, e.g. ascorbic acid and guanine. These results suggest the possible application of titania nanoparticles in uric acid recognition and quantification in blood serum.

  20. Efficient molecularly imprinted polymer as a pipette-tip solid-phase sorbent for determination of carvedilol enantiomers in human urine.

    Science.gov (United States)

    da Silva, Anny Talita Maria; de Oliveira, Hanna Leijoto; Silva, Camilla Fonseca; Fonseca, Matheus Cecílio; Pereira, Thales Fernando Dias; Nascimento, Clebio Soares; de Figueiredo, Eduardo Costa; Borges, Keyller Bastos

    2017-09-01

    In this work, an efficient pipette tip based on molecularly imprinted polymers solid-phase extraction (PT-MIP-SPE) method was developed for carvedilol (CAR) analysis. This compound is available in clinical practice as a racemic mixture, in which (-)-(S)-CAR is a β- and α1-adrenergic antagonist, while (+)-(R)-CAR only acts as an α1-adrenergic antagonist. Enantioseparation of CAR presented satisfactory retention times (5.85 and 14.84min), acceptable theoretical plates (N=2048 and 2018) and good resolution (Rs=9.27). The separation was performed using a Chiralpak(®) IA column (100mm×4.6mm, 3μm), a mixture of methanol:ethanol:water (64:15:21, v/v/v) plus 0.3% diethylamine as mobile phase, temperature of 35°C and flow rate of 1.5mLmin(-1). After density functional theory calculations based on prepolymerization complexes, the best protocol for the MIP synthesis was chosen. Then, some parameters that affect the PT-MIP-SPE technique were investigated. After optimization, the best conditions were 300μL of water as washing solvent, 500μL of acetonitrile:acetic acid (7:3, v/v) as eluting solvent, 20mg of MIP, 500μL of urine sample (pH 12.5) and no addition of NaCl. Recoveries±relative standard deviation (RSD%) for (+)-(R)-CAR and (-)-(S)-CAR were 101.9±4.8% and 104.6±2.1%, respectively. The method was linear over the concentration range from 20 to 1280ngmL(-1) for each enantiomer, with correlation coefficients larger than 0.99 for both enantiomers. The method was applied successfully in a preliminary study of urinary excretion after administration of CAR racemate to a healthy volunteer. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Factors associated with aberrant imprint methylation and oligozoospermia

    Science.gov (United States)

    Kobayashi, Norio; Miyauchi, Naoko; Tatsuta, Nozomi; Kitamura, Akane; Okae, Hiroaki; Hiura, Hitoshi; Sato, Akiko; Utsunomiya, Takafumi; Yaegashi, Nobuo; Nakai, Kunihiko; Arima, Takahiro

    2017-01-01

    Disturbingly, the number of patients with oligozoospermia (low sperm count) has been gradually increasing in industrialized countries. Epigenetic alterations are believed to be involved in this condition. Recent studies have clarified that intrinsic and extrinsic factors can induce epigenetic transgenerational phenotypes through apparent reprogramming of the male germ line. Here we examined DNA methylation levels of 22 human imprinted loci in a total of 221 purified sperm samples from infertile couples and found methylation alterations in 24.8% of the patients. Structural equation model suggested that the cause of imprint methylation errors in sperm might have been environmental factors. More specifically, aberrant methylation and a particular lifestyle (current smoking, excess consumption of carbonated drinks) were associated with severe oligozoospermia, while aging probably affected this pathology indirectly through the accumulation of PCB in the patients. Next we examined the pregnancy outcomes for patients when the sperm had abnormal imprint methylation. The live-birth rate decreased and the miscarriage rate increased with the methylation errors. Our research will be useful for the prevention of methylation errors in sperm from infertile men, and sperm with normal imprint methylation might increase the safety of assisted reproduction technology (ART) by reducing methylation-induced diseases of children conceived via ART. PMID:28186187

  2. Molecular Imprinting of Macromolecules for Sensor Applications.

    Science.gov (United States)

    Saylan, Yeşeren; Yilmaz, Fatma; Özgür, Erdoğan; Derazshamshir, Ali; Yavuz, Handan; Denizli, Adil

    2017-04-19

    Molecular recognition has an important role in numerous living systems. One of the most important molecular recognition methods is molecular imprinting, which allows host compounds to recognize and detect several molecules rapidly, sensitively and selectively. Compared to natural systems, molecular imprinting methods have some important features such as low cost, robustness, high recognition ability and long term durability which allows molecularly imprinted polymers to be used in various biotechnological applications, such as chromatography, drug delivery, nanotechnology, and sensor technology. Sensors are important tools because of their ability to figure out a potentially large number of analytical difficulties in various areas with different macromolecular targets. Proteins, enzymes, nucleic acids, antibodies, viruses and cells are defined as macromolecules that have wide range of functions are very important. Thus, macromolecules detection has gained great attention in concerning the improvement in most of the studies. The applications of macromolecule imprinted sensors will have a spacious exploration according to the low cost, high specificity and stability. In this review, macromolecules for molecularly imprinted sensor applications are structured according to the definition of molecular imprinting methods, developments in macromolecular imprinting methods, macromolecular imprinted sensors, and conclusions and future perspectives. This chapter follows the latter strategies and focuses on the applications of macromolecular imprinted sensors. This allows discussion on how sensor strategy is brought to solve the macromolecules imprinting.

  3. Assignment of casein kinase 2 alpha sequences to two different human chromosomes

    DEFF Research Database (Denmark)

    Boldyreff, B; Klett, C; Göttert, E

    1992-01-01

    Human casein kinase 2 alpha gene (CK-2-alpha) sequences have been localized within the human genome by in situ hybridization and somatic cell hybrid analysis using a CK-2 alpha cDNA as a probe. By in situ hybridization, the CK-2 alpha cDNA could be assigned to two different loci, one on 11p15.1-ter...

  4. Identification of imprinted genes using a novel screening method based on asynchronous DNA replication

    Energy Technology Data Exchange (ETDEWEB)

    Kawame, H.; Hansen, R.S.; Gartler, S.M. [Univ. of Washington, Seattle, WA (United States)

    1994-09-01

    Genomic imprinting refers to the process of epigenetic change that occurs during germ cell development that results in either maternal- or paternal-specific gene expression. Identification of imprinted genes is of primary importance to the understanding of imprinting mechanisms and the role of specific imprinted genes in human disease. Recently, it has been established that chromosomal regions known to contain imprinted genes replicate asynchronously. We propose a novel screening method to identify imprinted genes based on replication asynchrony as a marker for imprinted domains. Dividing human cells were pulse-labeled with BrdU and separated into different fractions of S-phase by flow cytometry. A library of late-replicating inter-Alu sequences should be enriched in gene-associated sequences that replicate early on one chromosome and late on the other homologue. Clones were analyzed for replication timing by hybridization to inter-Alu replication profiles. Candidates for replication asynchrony exhibited broad or biphasic replication timing, and these were analyzed for chromosomal location by hybridizations to inter-Alu products from a hybrid mapping panel. Initial screening of 123 clones resulted in 3 asynchronously-replicating clones that localized to single chromosomes. Chromosome 17 and chromosome 19 candidates might be located in regions thought to be imprinted by synteny with mouse chromosomes. A chromosome 15 clone was further characterized because of its possible localization to the Prader-Willi/Angelman locus. This sequence was localized outside the region deleted in Prader-Willi patients, and was found to be expressed in human cell lines. Replication asynchrony for this sequence appears to be polymorphic because cells derived from some individuals indicated synchronous replication. This appears to be the first example of a polymorphism in replication asynchrony.

  5. DNA methylation patterns of imprinting centers for H19, SNRPN, and KCNQ1OT1 in single-cell clones of human amniotic fluid mesenchymal stem cell

    Directory of Open Access Journals (Sweden)

    Hsiu-Huei Peng

    2012-09-01

    Conclusion: In conclusion, human amniotic fluid mesenchymal stem cells contain a unique epigenetic signature during in vitro cell culture. H19 and KCNQ1OT1 possessed a substantial degree of hypermethylation status, and variable DNA methylation patterns of SNRPN was observed during in vitro cell culture of human amniotic fluid mesenchymal stem cells. Our results urge further understanding of epigenetic status of human amniotic fluid mesenchymal stem cells before it is applied in cell replacement therapy.

  6. Molecularly imprinted polymers as synthetic mimics of bioreceptors. 1. General principles of molecular imprinting

    Directory of Open Access Journals (Sweden)

    Sergeyeva T. A.

    2009-08-01

    Full Text Available The review is devoted to analysis of the publications in the area of synthesis of artificial mimics of biological receptors using the method of molecular imprinting. General principles of molecular imprinting as well as main types of polymers being used in molecular imprinting are described. The special attention is paid to the polymers-biomimics synthesized using the method of non-covalent molecular imprinting.

  7. Molecularly imprinted polymers as synthetic mimics of bioreceptors. 1. General principles of molecular imprinting

    OpenAIRE

    Sergeyeva T. A.

    2009-01-01

    The review is devoted to analysis of the publications in the area of synthesis of artificial mimics of biological receptors using the method of molecular imprinting. General principles of molecular imprinting as well as main types of polymers being used in molecular imprinting are described. The special attention is paid to the polymers-biomimics synthesized using the method of non-covalent molecular imprinting.

  8. Molecular imprinting of protein by coordinate interaction

    Institute of Scientific and Technical Information of China (English)

    Jun Wang; Zhen Dong Hua; Zhi Yong Chen; Yuan Zong Li; Mei Ping Zhao

    2009-01-01

    In this article, a novel strong interaction by forming complex between bovine serum albumin (BSA) and copper ion was utilized for the preparation of molecular imprinted hydrogel in aqueous solution. Results show that the inclusion of copper ion in preparation can bridge the template BSA and functional monomers together and improve the imprinting effect compared to the polymer made without copper ion added. High selectivity factor and large adsorption capacity are also observed for the obtained BSA-imprinted hydrogel.

  9. Computational Insights on Sulfonamide Imprinted Polymers

    OpenAIRE

    Chartchalerm Isarankura-Na-Ayudhya; Chanin Nantasenamat; Prasit Buraparuangsang; Theeraphon Piacham; Leif Bülow; Lei Ye; Virapong Prachayasittikul

    2008-01-01

    Molecular imprinting is one of the most efficient methods for preparing synthetic receptors that possess user defined recognition properties. Despite general success of non-covalent imprinting for a large variety of templates, some groups of compounds remain difficult to tackle due to their structural complexity. In this study we investigate preparation of molecularly imprinted polymers that can bind sulfonamide compounds, which represent important drug candidates. Compared to the biological ...

  10. Imprinting and recalling cortical ensembles.

    Science.gov (United States)

    Carrillo-Reid, Luis; Yang, Weijian; Bando, Yuki; Peterka, Darcy S; Yuste, Rafael

    2016-08-12

    Neuronal ensembles are coactive groups of neurons that may represent building blocks of cortical circuits. These ensembles could be formed by Hebbian plasticity, whereby synapses between coactive neurons are strengthened. Here we report that repetitive activation with two-photon optogenetics of neuronal populations from ensembles in the visual cortex of awake mice builds neuronal ensembles that recur spontaneously after being imprinted and do not disrupt preexisting ones. Moreover, imprinted ensembles can be recalled by single- cell stimulation and remain coactive on consecutive days. Our results demonstrate the persistent reconfiguration of cortical circuits by two-photon optogenetics into neuronal ensembles that can perform pattern completion. Copyright © 2016, American Association for the Advancement of Science.

  11. Molecularly imprinted polymers: synthesis and characterisation.

    Science.gov (United States)

    Cormack, Peter A G; Elorza, Amaia Zurutuza

    2004-05-01

    This short review aims to present, in clear English, a summary of the principal synthetic considerations pertaining to good practice in the polymerisation aspects of molecular imprinting, and is primarily aimed at researchers familiar with molecular imprinting methods but with little or no prior experience in polymer synthesis. It is our hope that this will facilitate researchers to plan their own syntheses of molecular imprints in a more logical and structured fashion, and to begin to appreciate the limitations of the present synthetic approaches in this molecularly complex area, as well as the scope for rationally designing improved imprinted materials in the future.

  12. A model for family-based case–control studies of genetic imprinting and epistasis

    Science.gov (United States)

    Li, Xin; Sui, Yihan; Liu, Tian; Wang, Jianxin; Li, Yongci; Lin, Zhenwu; Hegarty, John; Koltun, Walter A.; Wang, Zuoheng

    2014-01-01

    Genetic imprinting, or called the parent-of-origin effect, has been recognized to play an important role in the formation and pathogenesis of human diseases. Although the epigenetic mechanisms that establish genetic imprinting have been a focus of many genetic studies, our knowledge about the number of imprinting genes and their chromosomal locations and interactions with other genes is still scarce, limiting precise inference of the genetic architecture of complex diseases. In this article, we present a statistical model for testing and estimating the effects of genetic imprinting on complex diseases using a commonly used case–control design with family structure. For each subject sampled from a case and control population, we not only genotype its own single nucleotide polymorphisms (SNPs) but also collect its parents’ genotypes. By tracing the transmission pattern of SNP alleles from parental to offspring generation, the model allows the characterization of genetic imprinting effects based on Pearson tests of a 2 × 2 contingency table. The model is expanded to test the interactions between imprinting effects and additive, dominant and epistatic effects in a complex web of genetic interactions. Statistical properties of the model are investigated, and its practical usefulness is validated by a real data analysis. The model will provide a useful tool for genome-wide association studies aimed to elucidate the picture of genetic control over complex human diseases. PMID:23887693

  13. Development of a monkey model for the study of primate genomic imprinting.

    Science.gov (United States)

    Fujimoto, A; Mitalipov, S M; Clepper, L L; Wolf, D P

    2005-06-01

    An understanding of the role of imprinted genes in primate development requires the identification of suitable genetic markers that allow analysis of allele-specific expression and methylation status. Four genes, NDN (Necdin), H19, SNRPN and IGF2, known to be imprinted in mice and humans, were selected for study in rhesus monkeys along with two imprinting centres (ICs) associated with the regulation of H19/IGF2, NDN and SNRPN. GAPD was employed as a non-imprinted control gene. Primers designed to amplify polymorphic regions in these genes and ICs were based on human sequences. Genomic DNA was isolated from peripheral blood leukocytes of 93 rhesus macaques of Indian or Chinese-origin. Sequence analysis of amplicons resulted in the identification of 32 unique SNPs. Country-of-origin related differences in SNP distributions were evident. Since disruptions in imprinted gene expression and associated developmental abnormalities may result from in vitro embryo manipulation, we also examined imprinting in NDN, H19, SNRPN and IGF2 in rhesus monkey infants produced by natural mating or by ICSI. Muscle biopsies followed by RT-PCR and sequence analysis were performed in four heterozygous animals produced by natural mating and all four genes were expressed monoallelically supporting the conclusion that these genes are normally imprinted in monkeys. In the case of ICSI, five informative infants were selected based on parental analysis. Allele-specific studies indicated that the expected uniparental expression patterns were retained in animals produced from manipulated embryos. Moreover, methylation analysis revealed that CpG islands within H19/IGF2 and SNURF/SNRPN ICs were differentially methylated. The approach described here will allow examination of imprinting in the embryos and embryonic stem cells of the monkey.

  14. Preparation of boronate-functionalized molecularly imprinted monolithic column with polydopamine coating for glycoprotein recognition and enrichment.

    Science.gov (United States)

    Lin, Zian; Wang, Juan; Tan, Xiaoqing; Sun, Lixiang; Yu, Ruifang; Yang, Huanghao; Chen, Guonan

    2013-12-06

    A novel imprinting strategy using reversible covalent complexation of glycoprotein was described for creating glycoprotein-specific recognition cavities on boronate-functionalized monolithic column. Based on it, a molecularly imprinted monolithic column was prepared by self-polymerization of dopamine (DA) on the surface of 4-vinylphenylboronic acid (VPBA)-based polymeric skeletons after reversible immobilization of horseradish peroxidase (HRP). Due to the combination of boronate affinity and surface imprinting of DA, the stable and accessible recognition sites in the as-prepared imprinted monolith could be obtained after the removal of the template, which facilitated the rebinding of the template and provided good reproducibility and lifetime of use. The recognition behaviors of proteins on the bare VPBA-based, HRP-imprinted and nonimprinted monolithic columns were evaluated in detail and the results showed that the HRP-imprinted monolith exhibited higher recognition ability toward the template than another two monolithic columns. Not only nonglycoproteins but also glycoproteins can be well separated with the HRP-imprinted monolith. In addition, the feasibility of the HRP-imprinted monolith, adopted as an in-tube solid phase microextraction (in-tube SPME), was further assessed by selective extraction and enrichment of HRP from human serum. The good results demonstrated its potential in glycoproteome analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Preparation of quercetin imprinted core-shell organosilicate microspheres using surface imprinting technique

    Institute of Scientific and Technical Information of China (English)

    Peng Yang; Wen Dan Hou; Hong Deng Qiu; Xia Liu; Sheng Xiang Jiang

    2012-01-01

    In this work,the quercetin imprinted core-shell microspheres were prepared using silica surface imprinting technique.A simple sol-gel procedure was used for the synthesis of the imprinted materials with 3-aminopropyltriethoxysilane as functional monomer and tetraethyl orthosilicate as crosslinker.The SEM images indicated that the MIPs shell was successfully grafted onto the silica surface.The characteristics of the molecularly imprinted polymers such as capacity,selectivity and absorption dynamic were investigated by rebinding experiments.The results showed that the prepared MIPs had good imprinting effect and adsorption amount of quercetin.

  16. FILIAL IMPRINTING AND ASSOCIATIVE LEARNING - SIMILAR MECHANISMS

    NARCIS (Netherlands)

    van Kampen, Hendrik

    1993-01-01

    This paper reviews a series of experiments designed to investigate whether features characteristic for associative learning are also true of filial imprinting. Phenomena resembling blocking and overshadowing in associative learning may occur during imprinting on two different objects, but it is

  17. Imprinting disorders after assisted reproductive technologies

    DEFF Research Database (Denmark)

    Lidegaard, Øjvind; Pinborg, Anja; Andersen, Anders Nyboe

    2006-01-01

    To assess the evidence of an increased risk of imprinting diseases in children born after use of assisted reproductive technologies.......To assess the evidence of an increased risk of imprinting diseases in children born after use of assisted reproductive technologies....

  18. FILIAL IMPRINTING AND ASSOCIATIVE LEARNING - SIMILAR MECHANISMS

    NARCIS (Netherlands)

    van Kampen, Hendrik

    1993-01-01

    This paper reviews a series of experiments designed to investigate whether features characteristic for associative learning are also true of filial imprinting. Phenomena resembling blocking and overshadowing in associative learning may occur during imprinting on two different objects, but it is unli

  19. The Haglund imprint on the patella.

    Science.gov (United States)

    Graf, J; Bernd, L; Simank, H G; Niethard, F U

    1993-12-01

    Seven hundred and five radiographs of the knee were examined and 17.6% showed a so-called Haglund imprint on the patella. The incidence was the same in patients with chondromalacia and in a control group. There was no statistical difference regarding age, sex and body weight. Haglund's imprint is a variation from the normal and is of no diagnostic value.

  20. Divergence of imprinted genes during mammalian evolution

    Directory of Open Access Journals (Sweden)

    Helms Volkhard

    2010-04-01

    Full Text Available Abstract Background In contrast to the majority of mammalian genes, imprinted genes are monoallelically expressed with the choice of the active allele depending on its parental origin. Due to their special inheritance patterns, maternally and paternally expressed genes might be under different evolutionary pressure. Here, we aimed at assessing the evolutionary history of imprinted genes. Results In this study, we investigated the conservation of imprinted genes in vertebrate genomes and their exposition to natural selection. In a genome-wide comparison, orthologs of imprinted genes show a stronger divergence on cDNA and protein level in mammals. This pattern is most pronounced for maternally expressed genes in rodents in comparison to their non-rodent orthologs. The divergence is not attributable to increased mutation of CpG positions. It is contrasted by strong conservation of paternally expressed genes in mouse and rat. Interestingly, we found that the early divergence of imprinted genes was accompanied by an unusually strict conservation of their paralogs. Conclusions The apparent degeneration of maternally expressed genes may reflect a relaxation of selective pressure due to counteracting effects on maternal and embryonic fitness. Functional redundancy provided by the presence of highly conserved (non-imprinted paralogs may have facilitated the divergence. Moreover, intensification of imprinting in modern rodents seems to have shifted the evolutionary fate of imprinted genes towards strong purifying selection.

  1. Molecularly Imprinted Materials: Towards the Next Generation

    Science.gov (United States)

    2002-04-05

    prepare molecularly imprinted microgels [13]. By adjusting monomer concentration and solvent composition, the cross-linking polymerization produced...mainly intramolecularly cross-linked microgels . The model system utilized covalent bonds between a sugar derivative and a boronic acid monomer in the...imprinting and rebinding reactions. Although binding selectivity of the obtained polymers was only modest, the obtainable nanometer-sized microgels were

  2. Molecularly Imprinted Nanomaterials for Sensor Applications

    Directory of Open Access Journals (Sweden)

    Muhammad Irshad

    2013-11-01

    Full Text Available Molecular imprinting is a well-established technology to mimic antibody-antigen interaction in a synthetic platform. Molecularly imprinted polymers and nanomaterials usually possess outstanding recognition capabilities. Imprinted nanostructured materials are characterized by their small sizes, large reactive surface area and, most importantly, with rapid and specific analysis of analytes due to the formation of template driven recognition cavities within the matrix. The excellent recognition and selectivity offered by this class of materials towards a target analyte have found applications in many areas, such as separation science, analysis of organic pollutants in water, environmental analysis of trace gases, chemical or biological sensors, biochemical assays, fabricating artificial receptors, nanotechnology, etc. We present here a concise overview and recent developments in nanostructured imprinted materials with respect to various sensor systems, e.g., electrochemical, optical and mass sensitive, etc. Finally, in light of recent studies, we conclude the article with future perspectives and foreseen applications of imprinted nanomaterials in chemical sensors.

  3. Astrobiological Molecularly Imprinted Polymer Sensors

    Science.gov (United States)

    Izenberg, N. R.; Murray, G. M.; van Houten, K. A.; Hofstra, A. A.

    2005-12-01

    Development of Molecularly Imprinted Polymer (MIP) sensors for astrobiology is intended to provide a new class of microlaboratory sensors compatible with other life or biomarker detection. Molecular imprinting is a process for making selective binding sites in synthetic polymers. The process may be approached by designing the recognition site or by simply choosing monomers that may have favorable interactions with the imprinting molecule. We are working to apply this methodology to astrobiology for development of a reliable, low cost, low mass, low power consumption sensor technology for quantitative in-situ analysis of biochemistry, biomarkers, and other indicators of astrobiological importance. Specific goals of the project are: 1) To develop a general methodology and specific methods for MIP-based sensor construction. The overall methodology will guide procedures for design and testing of any desired sensor. Specific methods will be applied to key families and specific species of astrobiological interest, i.e., alkanes (and Polycyclic aromatic hydrocarbons - PAHs), amino acids, steroids, and hopanes; 2) To construct and characterize the general family and specific species sensors. We will test for accuracy, precision, interferences, and limitations of the sensor against blanks, standards, and known terrestrial biological environment samples. Additional testing will determine sturdiness and longevity of sensors after exposure to transit conditions (launch and space environment), and at potential target environments (pressure, temperature, pH, etc.); and 3) To construct and demonstrate the combination of multiple sensors into a viable prototype instrument, and roadmap the expansion of potential instrument capabilities and exploration of the ultimate environmental limitations of the technology, and the necessary changes and additions to create a mission-ready instrument. Initial work has resulted successful detection of aqueous alanine (D and L) with simple MIP

  4. Dual effects of superovulation: loss of maternal and paternal imprinted methylation in a dose-dependent manner.

    Science.gov (United States)

    Market-Velker, Brenna A; Zhang, Liyue; Magri, Lauren S; Bonvissuto, Anne C; Mann, Mellissa R W

    2010-01-01

    Superovulation or ovarian stimulation is currently an indispensable assisted reproductive technology (ART) for human subfertility/infertility treatment. Recently, increased frequencies of imprinting disorders have been correlated with ARTs. Significantly, for Angelman and Beckwith-Wiedemann Syndromes, patients have been identified where ovarian stimulation was the only procedure used by the couple undergoing ART. In many cases, increased risk of genomic imprinting disorders has been attributed to superovulation in combination with inherent subfertility. To distinguish between these contributing factors, carefully controlled experiments are required on spontaneously ovulated, in vivo-fertilized oocytes and their induced-ovulated counterparts, thereby minimizing effects of in vitro manipulations. To this end, effects of superovulation on genomic imprinting were evaluated in a mouse model, where subfertility is not a confounding issue. This work represents the first comprehensive examination of the overall effects of superovulation on imprinted DNA methylation for four imprinted genes in individual blastocyst stage embryos. We demonstrate that superovulation perturbed genomic imprinting of both maternally and paternally expressed genes; loss of Snrpn, Peg3 and Kcnq1ot1 and gain of H19 imprinted methylation were observed. This perturbation was dose-dependent, with aberrant imprinted methylation more frequent at the high hormone dosage. Superovulation is thought to primarily affect oocyte development; thus, effects were expected to be limited to maternal alleles. Our study revealed that maternal as well as paternal H19 methylation was perturbed by superovulation. We postulate that superovulation has dual effects during oogenesis, disrupting acquisition of imprints in growing oocytes, as well as maternal-effect gene products subsequently required for imprint maintenance during pre-implantation development.

  5. Visualizing allele-specific expression in single cells reveals epigenetic mosaicism in an H19 loss-of-imprinting mutant.

    Science.gov (United States)

    Ginart, Paul; Kalish, Jennifer M; Jiang, Connie L; Yu, Alice C; Bartolomei, Marisa S; Raj, Arjun

    2016-03-01

    Imprinting is a classic mammalian epigenetic phenomenon that results in expression from a single parental allele. Imprinting defects can lead to inappropriate expression from the normally silenced allele, but it remains unclear whether every cell in a mutant organism follows the population average, which would have profound implications for human imprinting disorders. Here, we apply a new fluorescence in situ hybridization method that measures allele-specific expression in single cells to address this question in mutants exhibiting aberrant H19/Igf2 (insulin-like growth factor 2) imprinting. We show that mutant primary embryonic mouse fibroblasts are comprised of two subpopulations: one expressing both H19 alleles and another expressing only the maternal copy. Only in the latter cell population is Igf2 expression detected. Furthermore, the two subpopulations are stable in that cells do not interconvert between the two expression patterns. Combined small input methylation analysis and transcriptional imaging revealed that these two mutant subpopulations exhibit distinct methylation patterns at their imprinting control regions. Consistently, pharmacological inhibition of DNA methylation reduced the proportion of monoallelic cells. Importantly, we observed that the same two subpopulations are also present in vivo within murine cardiac tissue. Our results establish that imprinting disorders can display striking single-cell heterogeneity in their molecular phenotypes and suggest that such heterogeneity may underlie epigenetic mosaicism in human imprinting disorders.

  6. Dissecting genomic imprinting and genetic conflict from a game theory prospective. Comment on: ;Epigenetic game theory: How to compute the epigenetic control of maternal-to-zygotic transition; by Qian Wang et al.

    Science.gov (United States)

    Cui, Yuehua; Yang, Haitao

    2017-03-01

    Epigenetics typically refers to changes in the structure of a chromosome that affect gene activity and expression. Genomic imprinting is a special type of epigenetic phenomenon in which the expression of an allele depends on its parental origin. When an allele inherited from the mother (or father) is imprinted (i.e., silent), it is termed as maternal (or paternal) imprinting. Imprinting is often resulted from DNA methylation and tends to cluster together in the genome [1]. It has been shown to play a key role in many genetic disorders in humans [2]. Imprinting is heritable and undergoes a reprogramming process in gametes before and after fertilization [1]. Sometimes the reprogramming process is not reversible, leading to the loss of imprinting [3]. Although efforts have been made to experimentally or computationally infer imprinting genes, the underlying molecular mechanism that leads to unbalanced allelic expression is still largely unknown.

  7. Imprints of Natural Phenomena and Human Activity Observed During 10 Years of ELF Magnetic Measurements at the Hylaty Geophysical Station in Poland

    Science.gov (United States)

    Nieckarz, Zenon

    2016-12-01

    Current human activity produces strong electromagnetic pollution. The power spectrum in the extremely low frequency (ELF, 3-3000 Hz) range is mainly polluted by anthropogenic narrow spectral lines at 16.66, 50, and 60 Hz and their harmonics. Meanwhile, signatures connected with natural phenomena appearing in the Earth's atmosphere, ionosphere and magnetosphere are also observed in the same frequency range. This paper presents the amplitude behaviour of the anthropogenic lines in the years 2005-2014 based on the 10 years of activity of the Hylaty station situated in southeast Poland. The analysis includes, i.a., an assessment of the correctness of the choice of the Bieszczady mountains as a location for the installation of an ELF station for long-term geophysical and climatological studies.

  8. Neural basis of imprinting behavior in chicks.

    Science.gov (United States)

    Nakamori, Tomoharu; Maekawa, Fumihiko; Sato, Katsushige; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

    2013-01-01

    Newly hatched chicks memorize the characteristics of the first moving object they encounter, and subsequently show a preference for it. This "imprinting" behavior is an example of infant learning and is elicited by visual and/or auditory cues. Visual information of imprinting stimuli in chicks is first processed in the visual Wulst (VW), a telencephalic area corresponding to the mammalian visual cortex, congregates in the core region of the hyperpallium densocellulare (HDCo) cells, and transmitted to the intermediate medial mesopallium (IMM), a region similar to the mammalian association cortex. The imprinting memory is stored in the IMM, and activities of IMM neurons are altered by imprinting. Imprinting also induces functional and structural plastic changes of neurons in the circuit that links the VW and the IMM. Of these neurons, the activity of the HDCo cells is strongly influenced by imprinting. Expression and modulation of NR2B subunit-containing N-methyl-D-aspartate (NMDA) receptors in the HDCo cells are crucial for plastic changes in this circuit as well as the process of visual imprinting. Thus, elucidation of cellular and molecular mechanisms underlying the plastic changes that occurred in the HDCo cells may provide useful knowledge about infant learning. © 2012 The Authors Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

  9. Molecular imprinting of bulk, microporous silica

    Science.gov (United States)

    Katz, Alexander; Davis, Mark E.

    2000-01-01

    Molecular imprinting aims to create solid materials containing chemical functionalities that are spatially organized by covalent or non-covalent interactions with imprint (or template) molecules during the synthesis process. Subsequent removal of the imprint molecules leaves behind designed sites for the recognition of small molecules, making the material ideally suited for applications such as separations, chemical sensing and catalysis. Until now, the molecular imprinting of bulk polymers and polymer and silica surfaces has been reported, but the extension of these methods to a wider range of materials remains problematic. For example, the formation of substrate-specific cavities within bulk silica, while conceptually straightforward, has been difficult to accomplish experimentally. Here we describe the imprinting of bulk amorphous silicas with single aromatic rings carrying up to three 3-aminopropyltriethoxysilane side groups; this generates and occupies microporosity and attaches functional organic groups to the pore walls in a controlled fashion. The triethoxysilane part of the molecules' side groups is incorporated into the silica framework during sol-gel synthesis, and subsequent removal of the aromatic core creates a cavity with spatially organized aminopropyl groups covalently anchored to the pore walls. We find that the imprinted silicas act as shape-selective base catalysts. Our strategy can be extended to imprint other functional groups, which should give access to a wide range of functionalized materials.

  10. Automated visual inspection of imprinted pharmaceutical tablets

    Science.gov (United States)

    Bukovec, Marko; Špiclin, Žiga; Pernuš, Franjo; Likar, Boštjan

    2007-09-01

    This paper is on automated visual inspection of tablets that may, in contrast to manual tablet sorting, provide objective and reproducible tablet quality assurance. Visual inspection of the ever-increasing numbers of produced imprinted tablets, regulatory enforced for unambiguous identification of active ingredients and dosage strength of each tablet, is especially demanding. The problem becomes more tractable by incorporating some a priori knowledge of the imprint shape and/or appearance. For this purpose, we consider two alternative automated tablet defect detection methods. The geometrical method, incorporating geometrical a priori knowledge of the imprint shape, enables specific inspection of the imprinted and non-imprinted tablet surface, while the statistical method exploits statistical a priori knowledge of tablet surface appearance, derived from a training image database. The two methods were evaluated on a large tablet image database, consisting of 3445 images of four types of imprinted tablets, with and without typical production defects. A 'gold standard' for testing the performances of the two inspection methods was established by manually classifying the tablets into good and five defective classes. The results, obtained by ROC (receiver operating characteristics) analysis, indicate that the statistical method yields better defect detection sensitivity and specificity than the geometrical method. Both presented image analysis methods are quite general and promising tools for automated visual inspection of imprinted pharmaceutical tablets.

  11. Modulation of imprinted gene expression following superovulation.

    Science.gov (United States)

    Fortier, Amanda L; McGraw, Serge; Lopes, Flavia L; Niles, Kirsten M; Landry, Mylène; Trasler, Jacquetta M

    2014-05-05

    Although assisted reproductive technologies increase the risk of low birth weight and genomic imprinting disorders, the precise underlying causes remain unclear. Using a mouse model, we previously showed that superovulation alters the expression of imprinted genes in the placenta at 9.5days (E9.5) of gestation. Here, we investigate whether effects of superovulation on genomic imprinting persisted at later stages of development and assess the surviving fetuses for growth and morphological abnormalities. Superovulation, followed by embryo transfer at E3.5, as compared to spontaneous ovulation (controls), resulted in embryos of normal size and weight at 14.5 and 18.5days of gestation. The normal monoallelic expression of the imprinted genes H19, Snrpn and Kcnq1ot1 was unaffected in either the placentae or the embryos from the superovulated females at E14.5 or E18.5. However, for the paternally expressed imprinted gene Igf2, superovulation generated placentae with reduced production of the mature protein at E9.5 and significantly more variable mRNA levels at E14.5. We propose that superovulation results in the ovulation of abnormal oocytes with altered expression of imprinted genes, but that the coregulated genes of the imprinted gene network result in modulated expression. Copyright © 2014. Published by Elsevier Ireland Ltd.

  12. [Imprinting genes and it's expression in Arabidopsis].

    Science.gov (United States)

    Zhang, Hong-Yu; Xu, Pei-Zhou; Yang, Hua; Wu, Xian-Jun

    2010-07-01

    Genomic imprinting refers to the phenomenon that the expression of a gene copy depends on its parent of origin. The Arabidopsis imprinted FIS (Fertilisation-independent seed) genes, mea, fis2, and fie, play essential roles in the repression of central cell and the regulation of early endosperm development. fis mutants display two phenotypes: autonomous diploid endosperm development when fertilization is absent and un-cellularised endosperm formation when fertilization occurs. The FIS Polycomb protein complex including the above three FIS proteins catalyzes histone H3 K27 tri-methylation on target loci. DME (DEMETER), a DNA glycosylase, and AtMET1 (Methyltransferase1), a DNA methyltransferase, are involved in the regulation of imprinted expression of both mea and fis2. This review summarizes the studies on the Arabidopsis imprinted FIS genes and other related genes. Recent works have shown that the insertion of transposons may affect nearby gene expression, which may be the main driving force behind the evolution of genomic imprinting. This summary covers the achievements on Arabidopsis imprinted genes will provide important information for studies on genomic imprinting in the important crops such as rice and maize.

  13. Imprinting in Plants and Its Underlying Mechanisms

    Institute of Scientific and Technical Information of China (English)

    Hongyu Zhang; Abed Chaudhury; Xianjun Wu

    2013-01-01

    Genomic imprinting (or imprinting) refers to an epigenetic phenomenon by which the allelic expression of a gene depends on the parent of origin.It has evolved independently in placental mammals and flowering plants.In plants,imprinting is mainly found in endosperm.Recent genome-wide surveys in Arabidopsis,rice,and maize identified hundreds of imprinted genes in endosperm.Since these genes are of diverse functions,endosperm development is regulated at different regulatory levels.The imprinted expression of only a few genes is conserved between Arabidopsis and monocots,suggesting that imprinting evolved quickly during speciation.In Arabidopsis,DEMETER (DME) mediates hypomethylation in the maternal genome at numerous loci (mainly transposons and repeats) in the central cell and results in many differentially methylated regions between parental genomes in the endosperm,and subsequent imprinted expression of some genes.In addition,histone modification mediated by Polycomb group (PcG) proteins is also involved in regulating imprinting.DMEinduced hypomethylated alleles in the central cell are considered to produce small interfering RNAs (siRNAs) which are imported to the egg to reinforce DNA methylation.In parallel,the activity of DME in the vegetative cell of the male gametophyte demethylates many regions which overlap with the demethylated regions in the central cell.siRNAs from the demethylated regions are hypothesized to be also transferred into sperm to reinforce DNA methylation.Imprinting is partly the result of genome-wide epigenetic reprogramming in the central cell and vegetative cell and evolved under different selective pressures.

  14. Microcontact imprinted surface plasmon resonance sensor for myoglobin detection

    Energy Technology Data Exchange (ETDEWEB)

    Osman, Bilgen [Uludag University, Department of Chemistry, Bursa (Turkey); Uzun, Lokman [Hacettepe University, Department of Chemistry, Ankara (Turkey); Beşirli, Necati [Uludag University, Department of Chemistry, Bursa (Turkey); Denizli, Adil, E-mail: denizli@hacettepe.edu.tr [Hacettepe University, Department of Chemistry, Ankara (Turkey)

    2013-10-15

    In this study, we prepared surface plasmon resonance (SPR) sensor using the molecular imprinting technique for myoglobin detection in human serum. For this purpose, we synthesized myoglobin imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan methyl ester) [poly(HEMA-MATrp)] nanofilm on the surface of SPR sensor. We also synthesized non-imprinted poly(HEMA-MATrp) nanofilm without myoglobin for the control experiments. The SPR sensor was characterized with contact angle measurements, atomic force microscopy, X-ray photoelectron spectroscopy, and ellipsometry. We investigated the effectiveness of the sensor using the SPR system. We evaluated the ability of SPR sensor to sense myoglobin with myoglobin solutions (pH 7.4, phosphate buffer) in different concentration range and in the serum taken from a patient with acute myocardial infarction. We found that the Langmuir adsorption model was the most suitable for the sensor system. The detection limit was 87.6 ng/mL. In order to show the selectivity of the SPR sensor, we investigated the competitive detection of myoglobin, lysozyme, cytochrome c and bovine serum albumin. The results showed that the SPR sensor has high selectivity and sensitivity for myoglobin. - Highlights: • Micro-contact imprinted surface plasmon resonance sensor. • Real-time myoglobin detection in the serum taken from a patient with acute myocardial infarction • Reproducible results for consecutive myoglobin solution supplement • LOD and LOQ values of the SPR sensor were determined to be 26.3 and 87.6 ng/mL. • The SPR sensor has potential for myoglobin sensing during acute MI cases.

  15. NUP98/11p15 translocations affect CD34+ cells in myeloid and T lymphoid leukemias.

    Science.gov (United States)

    Crescenzi, Barbara; Nofrini, Valeria; Barba, Gianluca; Matteucci, Caterina; Di Giacomo, Danika; Gorello, Paolo; Beverloo, Berna; Vitale, Antonella; Wlodarska, Iwona; Vandenberghe, Peter; La Starza, Roberta; Mecucci, Cristina

    2015-07-01

    We assessed lineage involvement by NUP98 translocations in myelodysplastic syndromes (MDS), acute myeloid leukaemia (AML), and T-cell acute lymphoblastic leukaemia (T-ALL). Single cell analysis by FICTION (Fluorescence Immunophenotype and Interphase Cytogenetics as a Tool for Investigation of Neoplasms) showed that, despite diverse partners, i.e. NSD1, DDX10, RAP1GDS1, and LNP1, NUP98 translocations always affected a CD34+/CD133+ hematopoietic precursor. Interestingly the abnormal clone included myelomonocytes, erythroid cells, B- and T- lymphocytes in MDS/AML and only CD7+/CD3+ cells in T-ALL. The NUP98-RAP1GDS1 affected different hematopoietic lineages in AML and T-ALL. Additional specific genomic events, were identified, namely FLT3 and CEBPA mutations in MDS/AML, and NOTCH1 mutations and MYB duplication in T-ALL.

  16. Ferroelectric capacitor with reduced imprint

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Jr., Joseph T. (13609 Verbena Pl., NE., Albuquerque, NM 87112); Warren, William L. (7716 Wm. Moyers Ave., NE., Albuquerque, NM 87122); Tuttle, Bruce A. (12808 Lillian Pl., NE., Albuquerque, NM 87122); Dimos, Duane B. (6105 Innsbrook Ct., NE., Albuquerque, NM 87111); Pike, Gordon E. (1609 Cedar Ridge, NE., Albuquerque, NM 87112)

    1997-01-01

    An improved ferroelectric capacitor exhibiting reduced imprint effects in comparison to prior art capacitors. A capacitor according to the present invention includes top and bottom electrodes and a ferroelectric layer sandwiched between the top and bottom electrodes, the ferroelectric layer comprising a perovskite structure of the chemical composition ABO.sub.3 wherein the B-site comprises first and second elements and a dopant element that has an oxidation state greater than +4. The concentration of the dopant is sufficient to reduce shifts in the coercive voltage of the capacitor with time. In the preferred embodiment of the present invention, the ferroelectric element comprises Pb in the A-site, and the first and second elements are Zr and Ti, respectively. The preferred dopant is chosen from the group consisting of Niobium, Tantalum, and Tungsten. In the preferred embodiment of the present invention, the dopant occupies between 1 and 8% of the B-sites.

  17. Tailoring Imprinted Titania Nanoparticles for Purines Recognition

    Directory of Open Access Journals (Sweden)

    Adnan Mujahid

    2015-01-01

    Full Text Available Molecular imprinted titania nanoparticles were developed for selective recognition of purines, for example, guanine and its final oxidation product uric acid. Titania nanoparticles were prepared by hydrolysis of titanium butoxide as precursor in the presence of pattern molecules. The morphology of synthesized nanoparticles is evaluated by SEM images. Recognition characteristics of imprinted titania nanoparticles are studied by exposing them to standard solution of guanine and uric acid, respectively. The resultant change in their concentration is determined by UV/Vis analysis that indicated imprinted titania nanoparticles possess high affinity for print molecules. In both cases, nonimprinted titania is taken as control to observe nonspecific binding interactions. Cross sensitivity studies suggested that imprinted titania is at least five times more selective for binding print molecules than competing analyte thus indicating its potential for bioassay of purines.

  18. Application of molecular imprinted polymer nanoparticles as a selective solid phase extraction for preconcentration and trace determination of 2,4-dichlorophenoxyacetic acid in the human urine and different water samples.

    Science.gov (United States)

    Omidi, Fariborz; Behbahani, Mohammad; Sadeghi Abandansari, Hamid; Sedighi, Alireza; Shahtaheri, Seyed Jamaleddin

    2014-01-01

    A molecular-imprinted polymer nanoparticles (MIP-NP) for the selective preconcentration of 2,4-dichlorophenoxyacetic acid (2,4-D) is described. It was obtained by precipitation polymerization from methacrylic acid (the functional monomer), ethylene glycol dimethacrylate (the cross-linker), 2,2'-azobisisobutyronitrile (the initiator) and 2,4-D (the template molecule) in acetonitrile solution. The MIP-NPs were characterized by thermogravimetric analysis, and by scanning electron microscopy. Imprinted 2,4-D molecules were removed from the polymeric structure using acetic acid in methanol (15:85 v/v %) as the eluting solvent. The sorption and desorption process occur within 10 min and 15 min, respectively. The maximum sorbent capacity of the molecular imprinted polymer is 89.2 mg g(-1). The relative standard deviation and limit of detection for water samples by introduced selective solid phase extraction were 4.2% and 1.25 μg L(-1), and these data for urine samples were 4.7% and 1.80 μg L(-1), respectively. The method was applied to the determination of 2,4-D in the urine and different water samples.

  19. Distributed feedback imprinted electrospun fiber lasers.

    Science.gov (United States)

    Persano, Luana; Camposeo, Andrea; Del Carro, Pompilio; Fasano, Vito; Moffa, Maria; Manco, Rita; D'Agostino, Stefania; Pisignano, Dario

    2014-10-01

    Imprinted, distributed feedback lasers are demonstrated on individual, active electrospun polymer nanofibers. In addition to advantages related to miniaturization, optical confinement and grating nanopatterning lead to a significant threshold reduction compared to conventional thin-film lasers. The possibility of imprinting arbitrary photonic crystal geometries on electrospun lasing nanofibers opens new opportunities for realizing optical circuits and chips. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. MEDEA takes control of its own imprinting.

    Science.gov (United States)

    Arnaud, Philippe; Feil, Robert

    2006-02-10

    Genomic imprinting is an essential epigenetic process that controls the size of seeds in flowering plants. In Arabidopsis, DEMETER activates the maternal copy of the imprinted MEDEA Polycomb gene. In this issue of Cell, Gehring et al. (2006) demonstrate that this activation involves DNA demethylation of MEDEA by DEMETER. Remarkably, they also find that silencing of the paternal MEDEA allele is independent of DNA methylation and is controlled by maternal expression of MEDEA itself.

  1. MOLECULAR IMPRINTED POLYMERS--Novel Polymer Adsorbents

    Institute of Scientific and Technical Information of China (English)

    LI Haitao; XU Mancai; SHI Zuoqing; HE Binglin

    2001-01-01

    Molecular imprinted polymers (MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules. These novel functional polymers have promised potential applications in racemic resolution, sensor, chromatography, adsorptive separation and other fields. This review exhibits the approach for preparing MIPs, the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs. The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.

  2. Molecularly Imprinted Polymers: Present and Future Prospective

    Directory of Open Access Journals (Sweden)

    Giuseppe Vasapollo

    2011-09-01

    Full Text Available Molecular Imprinting Technology (MIT is a technique to design artificial receptors with a predetermined selectivity and specificity for a given analyte, which can be used as ideal materials in various application fields. Molecularly Imprinted Polymers (MIPs, the polymeric matrices obtained using the imprinting technology, are robust molecular recognition elements able to mimic natural recognition entities, such as antibodies and biological receptors, useful to separate and analyze complicated samples such as biological fluids and environmental samples. The scope of this review is to provide a general overview on MIPs field discussing first general aspects in MIP preparation and then dealing with various application aspects. This review aims to outline the molecularly imprinted process and present a summary of principal application fields of molecularly imprinted polymers, focusing on chemical sensing, separation science, drug delivery and catalysis. Some significant aspects about preparation and application of the molecular imprinting polymers with examples taken from the recent literature will be discussed. Theoretical and experimental parameters for MIPs design in terms of the interaction between template and polymer functionalities will be considered and synthesis methods for the improvement of MIP recognition properties will also be presented.

  3. Facile preparation of glycoprotein-imprinted 96-well microplates for enzyme-linked immunosorbent assay by boronate affinity-based oriented surface imprinting.

    Science.gov (United States)

    Bi, Xiaodong; Liu, Zhen

    2014-01-01

    Molecularly imprinted polymers (MIPs), as inexpensive and stable substitutes of antibodies, have shown great promise in immunoassays. Glycoproteins are of significant diagnostic value. To facilitate the application of MIPs in clinical diagnostics, a general and facile imprinting method toward glycoproteins oriented for an enzyme-linked immunosorbent assay (ELISA) in the form of a 96-well microplate is essential but has not been fully explored yet. In this study, a new method called boronate affinity-based oriented surface imprinting was proposed for facile preparation of glycoprotein-imprinted microplates. A template glycoprotein was first immobilized by a boronic acid-modified microplate through boronate affinity binding, and then, a thin layer of polyaniline was formed to cover the microplate surface via in-water self-copolymerization. After the template was removed by an acidic solution, 3D cavities that can rebind the template were fabricated on the microplate surface. Using horseradish peroxidase (HRP) as a model target, the effects of imprinting conditions as well as the properties and performance of the prepared MIPs were investigated. α-Fetoprotein (AFP)-imprinted microplate was then prepared, and thereby, a MIP-based ELISA method was established. The prepared MIPs exhibited several highly favorable features, including excellent specificity, widely applicable binding pH, superb tolerance for interference, high binding strength, fast equilibrium kinetics, and reusability. The MIP-based ELISA method was finally applied to the analysis of AFP in human serum. The result was in good agreement with that by radioimmunoassay, showing a promising prospect of the proposed method in clinical diagnostics.

  4. Molecular Imprinting Techniques Used for the Preparation of Biosensors

    Directory of Open Access Journals (Sweden)

    Gizem Ertürk

    2017-02-01

    Full Text Available Molecular imprinting is the technology of creating artificial recognition sites in polymeric matrices which are complementary to the template in their size, shape and spatial arrangement of the functional groups. Molecularly imprinted polymers (MIPs and their incorporation with various transducer platforms are among the most promising approaches for detection of several analytes. There are a variety of molecular imprinting techniques used for the preparation of biomimetic sensors including bulk imprinting, surface imprinting (soft lithography, template immobilization, grafting, emulsion polymerization and epitope imprinting. This chapter presents an overview of all of these techniques with examples from particular publications.

  5. IMPRINTING IN AN ALTRICIAL BIRD: THE BLOND RING DOVE (STREPTOPELIA RISORIA).

    Science.gov (United States)

    KLINGHAMMER, E; HESS, E H

    1964-10-09

    Newborn ring doves were taken away from their parents when they were from 4 to 14 days old. They were then either raised by hand in complete visual isolation from other members of their species or placed in a community cage after weaning. They were tested as adults in a free-choice situation between human beings and ring doves. An optimum period for imprinting was found when they were about 7 to 9 days old. The controls showed that subsequent experiences during the life span of a bird also have an effect on the choice of a mate, and, in this species, imprinting can be said to be reversible.

  6. Determination of donepezil in serum samples using molecularly imprinted polymer nanoparticles followed by high-performance liquid chromatography with ultraviolet detection.

    Science.gov (United States)

    Khansari, Mehdi Rajabnia; Bikloo, Shahrzad; Shahreza, Sara

    2016-03-01

    A molecularly imprinted polymer designed for the selective extraction of donepezil from serum samples was synthesized using a noncovalent molecular imprinting approach. The molecularly imprinted polymer was evaluated chromatographically and then its affinity for donepezil was confirmed by solid-phase extraction. The optimal conditions for solid-phase extraction were provided by cartridge conditioning using acidified water purified from a Milli-Q system, sample loading under basic aqueous conditions, clean-up using acetonitrile, and elution with methanol/tetrahydrofuran. Desirable molecular recognition properties of the molecularly imprinted polymer led to good donepezil recoveries (90-102%). The data indicated that the imprinted polymer has a perfect selectivity and affinity for donepezil and could be used for selective extraction and analysis of donepezil in human serum.

  7. Evolution and function of genomic imprinting in plants.

    Science.gov (United States)

    Rodrigues, Jessica A; Zilberman, Daniel

    2015-12-15

    Genomic imprinting, an inherently epigenetic phenomenon defined by parent of origin-dependent gene expression, is observed in mammals and flowering plants. Genome-scale surveys of imprinted expression and the underlying differential epigenetic marks have led to the discovery of hundreds of imprinted plant genes and confirmed DNA and histone methylation as key regulators of plant imprinting. However, the biological roles of the vast majority of imprinted plant genes are unknown, and the evolutionary forces shaping plant imprinting remain rather opaque. Here, we review the mechanisms of plant genomic imprinting and discuss theories of imprinting evolution and biological significance in light of recent findings. © 2015 Rodrigues and Zilberman; Published by Cold Spring Harbor Laboratory Press.

  8. Prader-Willi Syndrome: Obesity due to Genomic Imprinting

    National Research Council Canada - National Science Library

    Merlin G. Butler

    2011-01-01

    Prader-Willi syndrome (PWS) is a complex neurodevelopmental disorder due to errors in genomic imprinting with loss of imprinted genes that are paternally expressed from the chromosome 15q11-q13 region. Approximately 70...

  9. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Zhenzhong Guo

    2016-10-01

    Full Text Available The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclusion and future expectations are described herein.

  10. Molecularly imprinted polymers for biomedical and biotechnological applications

    Science.gov (United States)

    Dmitrienko, E. V.; Pyshnaya, I. A.; Martyanov, O. N.; Pyshnyi, D. V.

    2016-05-01

    This survey covers main advances in the preparation and application of molecularly imprinted polymers which are capable of specific recognition of biologically active compounds. The principles underlying the production of highly efficient and template-specific molecularly imprinted polymers are discussed. The focus is on the imprinting of highly structured macromolecular and supramolecular templates. The existing and potential applications of molecularly imprinted polymers in various fields of chemistry and molecular biology are considered. The bibliography includes 261 references.

  11. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    OpenAIRE

    Zhenzhong Guo; Anca Florea; Mengjuan Jiang; Yong Mei; Weiying Zhang; Aidong Zhang; Robert Săndulescu; Nicole Jaffrezic-Renault

    2016-01-01

    The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF) for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclu...

  12. Computational Insights on Sulfonamide Imprinted Polymers

    Directory of Open Access Journals (Sweden)

    Chartchalerm Isarankura-Na-Ayudhya

    2008-12-01

    Full Text Available Molecular imprinting is one of the most efficient methods for preparing synthetic receptors that possess user defined recognition properties. Despite general success of non-covalent imprinting for a large variety of templates, some groups of compounds remain difficult to tackle due to their structural complexity. In this study we investigate preparation of molecularly imprinted polymers that can bind sulfonamide compounds, which represent important drug candidates. Compared to the biological system that utilizes metal coordinated interaction, the imprinted polymer provided pronounced selectivity when hydrogen bond interaction was employed in an organic solvent. Computer simulation of the interaction between the sulfonamide template and functional monomers pointed out that although methacrylic acid had strong interaction energy with the template, it also possessed high non-specific interaction with the solvent molecules of tetrahydrofuran as well as being prone to self-complexation. On the other hand, 1-vinyl-imidazole was suitable for imprinting sulfonamides as it did not cross-react with the solvent molecules or engage in self-complexation structures.

  13. Computational insights on sulfonamide imprinted polymers.

    Science.gov (United States)

    Isarankura-Na-Ayudhya, Chartchalerm; Nantasenamat, Chanin; Buraparuangsang, Prasit; Piacham, Theeraphon; Ye, Lei; Bülow, Leif; Prachayasittikul, Virapong

    2008-12-10

    Molecular imprinting is one of the most efficient methods for preparing synthetic receptors that possess user defined recognition properties. Despite general success of non-covalent imprinting for a large variety of templates, some groups of compounds remain difficult to tackle due to their structural complexity. In this study we investigate preparation of molecularly imprinted polymers that can bind sulfonamide compounds, which represent important drug candidates. Compared to the biological system that utilizes metal coordinated interaction, the imprinted polymer provided pronounced selectivity when hydrogen bond interaction was employed in an organic solvent. Computer simulation of the interaction between the sulfonamide template and functional monomers pointed out that although methacrylic acid had strong interaction energy with the template, it also possessed high non-specific interaction with the solvent molecules of tetrahydrofuran as well as being prone to self-complexation. On the other hand, 1-vinyl-imidazole was suitable for imprinting sulfonamides as it did not cross-react with the solvent molecules or engage in self-complexation structures.

  14. Dynamic assembly of molecularly imprinted polymer nanoparticles.

    Science.gov (United States)

    Gong, Haiyue; Hajizadeh, Solmaz; Jiang, Lingdong; Ma, Huiting; Ye, Lei

    2017-09-11

    Manipulation of specific binding and recycling of materials are two important aspects for practical applications of molecularly imprinted polymers. In this work, we developed a new approach to control the dynamic assembly of molecularly imprinted nanoparticles by surface functionalization. Molecularly imprinted polymer nanoparticles with a well-controlled core-shell structure were synthesized using precipitation polymerization. The specific binding sites were created in the core during the first step imprinting reaction. In the second polymerization step, epoxide groups were introduced into the particle shell to act asan intermediate linker to immobilize phenylboronic acids, as well as to introduce cis-diol structures on surface. The imprinted polymer nanoparticles modified with boronic acid and cis-diol structures maintained high molecular binding specificity, and the nanoparticles could be induced to form dynamic particle aggregation that responded to pH variation and chemical stimuli. The possibility of modulating molecular binding and nanoparticle assembly in a mutually independent fashion can be exploited in a number of applications where repeated use of precious nanoparticles is needed. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Imprint cytology: A boon in tissue diagnosis

    Directory of Open Access Journals (Sweden)

    Charusheela Rajesh Gore

    2017-01-01

    Full Text Available Background: The technique of imprint cytology has provided great impetus to cytodiagnosis due to its simplicity, cost effectiveness, rapid results. It plays a significant role in the rapid diagnosis of the lesions. Objectives: To analyze the sensitivity and specificity of imprint cytology and thereby to evaluate its diagnostic utility. Materials and Methods: The prospective study was carried out in a tertiary care hospital. It included 105 cases. Both benign and malignant lesions from different organ systems were included in the study. Various techniques like touch imprints scrape cytology and squash preparations were used according to the nature of tissue sample. The cytodiagnosis was correlated with histopathological (HP diagnosis to evaluate the sensitivity and specificity of imprint cytology. Results: Maximum lesions were of central nervous system (25.7% followed by breast, head, and neck. Imprint cytology diagnosis had sensitivity of 95.5% with 100% specificity for detection of benign and malignant lesions. Overall accuracy of detecting type of lesion was 98.1%. Total discordance with HP diagnosis was found in 1.9% of cases. Conclusion: The use of smear technique in intraoperative diagnosis provides a rapid and efficient means of pathological assessment which in experienced hand, is capable of obtaining a high degree of accuracy. Its use is highly recommended routinely.

  16. Epigenetic Mechanisms of Genomic Imprinting: Common Themes in the Regulation of Imprinted Regions in Mammals, Plants, and Insects

    Directory of Open Access Journals (Sweden)

    William A. MacDonald

    2012-01-01

    Full Text Available Genomic imprinting is a form of epigenetic inheritance whereby the regulation of a gene or chromosomal region is dependent on the sex of the transmitting parent. During gametogenesis, imprinted regions of DNA are differentially marked in accordance to the sex of the parent, resulting in parent-specific expression. While mice are the primary research model used to study genomic imprinting, imprinted regions have been described in a broad variety of organisms, including other mammals, plants, and insects. Each of these organisms employs multiple, interrelated, epigenetic mechanisms to maintain parent-specific expression. While imprinted genes and imprint control regions are often species and locus-specific, the same suites of epigenetic mechanisms are often used to achieve imprinted expression. This review examines some examples of the epigenetic mechanisms responsible for genomic imprinting in mammals, plants, and insects.

  17. Metal films with imprinted nanostructures by template stripping

    DEFF Research Database (Denmark)

    Eriksen, René Lynge; Pors, Anders; Dreier, Jes

    We present a novel template stripping procedure for fabricating metal films with imprinted nanostructures. The basic idea is to deposit a gold film onto a nano-structured substrate and subsequently strip the film from the substrate surface thereby revealing imprinted nanostructures in the film...... result is a thin gold film with imprinted nano-cavities....

  18. Transcription is required to establish maternal imprinting at the Prader-Willi syndrome and Angelman syndrome locus.

    Directory of Open Access Journals (Sweden)

    Emily Y Smith

    2011-12-01

    Full Text Available The Prader-Willi syndrome (PWS [MIM 17620] and Angelman syndrome (AS [MIM 105830] locus is controlled by a bipartite imprinting center (IC consisting of the PWS-IC and the AS-IC. The most widely accepted model of IC function proposes that the PWS-IC activates gene expression from the paternal allele, while the AS-IC acts to epigenetically inactivate the PWS-IC on the maternal allele, thus silencing the paternally expressed genes. Gene order and imprinting patterns at the PWS/AS locus are well conserved from human to mouse; however, a murine AS-IC has yet to be identified. We investigated a potential regulatory role for transcription from the Snrpn alternative upstream exons in silencing the maternal allele using a murine transgene containing Snrpn and three upstream exons. This transgene displayed appropriate imprinted expression and epigenetic marks, demonstrating the presence of a functional AS-IC. Transcription of the upstream exons from the endogenous locus correlates with imprint establishment in oocytes, and this upstream exon expression pattern was conserved on the transgene. A transgene bearing targeted deletions of each of the three upstream exons exhibited loss of imprinting upon maternal transmission. These results support a model in which transcription from the Snrpn upstream exons directs the maternal imprint at the PWS-IC.

  19. Developing electrochemical sensor for point-of-care diagnostics of oxidative stress marker using imprinted bimetallic Fe/Pd nanoparticle.

    Science.gov (United States)

    Roy, Ekta; Patra, Santanu; Madhuri, Rashmi; Sharma, Prashant K

    2015-01-01

    A novel electrochemical-sensing platform based on imprinted bimetallic Fe/Pd (BI-Fe/Pd) nanoparticle has been fabricated for point-of-care diagnostics of oxidative stress marker (3-nitrotyrosine) in biological fluids. Herein, BI-Fe/Pd nanoparticles are used as a platform on which 3-nitrotyrosine imprinted cavities are created using acrylamide as monomer and N-N'-methylene bisacrylamide as cross-linker. The performance of the obtained imprinted sensor is investigated by cyclic, differential pulse, and square wave voltammetry in stripping mode. The imprinted sensor exhibits high recognition ability and affinity for 3-nitrotyrosine in comparison with the non-imprinted one. In addition, the proposed sensor is capable of measuring 3-nitrotyrosine in aqueous as well as in human blood serum, plasma, and urine samples within the range of 4.90-867.57 µg L(-1) and 9.90-867.57 µg L(-1) with detection limit of 1.20 µg L(-1) and 3.25 µg L(-1) by square wave and differential pulse stripping voltammetry, respectively. Imprinted BI-Fe/Pd nanoparticle modified sensor shows high affinity and no interference from blood or urine components. Modified sensor was stored for 45 days at room temperature without any detrimental effects to their binding properties. The high affinity of proposed sensor and the lack of requirement for cold chain logistics make them an attractive alternative to the enzyme-linked immunosorbent assay (ELISA) technique. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Parental origin of chromosomes influences crossover activity within the Kcnq1 transcriptionally imprinted domain of Mus musculus

    Directory of Open Access Journals (Sweden)

    Petkov Petko M

    2009-05-01

    Full Text Available Abstract Background Among the three functions of DNA, mammalian replication and transcription can be subject to epigenetic imprinting specified by the parental origin of chromosomes, and although there is suggestive indication that this is also true for meiotic recombination, no definitive evidence has yet been reported. Results We have now obtained such evidence on mouse chromosome 7 by assaying meiotic recombination as it occurs in reciprocal F1 mice. A 166 kb region near the Kcnq1 transcriptionally imprinted domain showed significantly higher recombination activity in the CAST×B6 parental direction (p Slc22a18 showed a definitive parent of origin effect on recombination frequency (p Kcnq1 and neighboring H19-Igf2 imprinted domains with their human counterparts, we found that elevated recombination activity in these domains is a consequence of their chromosomal position relative to the telomere and not an intrinsic characteristic of transcriptionally imprinted domains as has been previously suggested. Conclusion Similar to replication and transcription, we demonstrate that meiotic recombination can be subjected to epigenetic imprinting and hotspot activity can be influenced by the parental origin of chromosomes. Furthermore, transcriptionally imprinted regions exhibiting elevated recombination activity are likely a consequence of their chromosomal location rather than their transcriptional characteristic.

  1. Phase-imprinted multiphoton subradiant states

    Science.gov (United States)

    Jen, H. H.

    2017-08-01

    We propose to generate the multiphoton subradiant states and investigate their fluorescences in an array of two-level atoms. These multiphoton states are created initially from the timed Dicke states. Then we can use either a Zeeman or Stark field gradient pulse to imprint linearly increasing phases on the atoms, and this phase-imprinting process unitarily evolves the system to the multiphoton subradiant states. The fluorescence engages a long-range dipole-dipole interaction which originates from a system-reservoir coupling in the dissipation. We locate some of the subradiant multiphoton states from the eigenmodes and show that an optically thick atomic array is best for the preparation of the state with the most reduced decay rate. This phase-imprinting process enables quantum-state engineering of the multiphoton subradiant states and realizes a potential quantum storage of the photonic qubits in the two-level atoms.

  2. Molecular imprinted polymers as drug delivery vehicles.

    Science.gov (United States)

    Zaidi, Shabi Abbas

    2016-09-01

    This review is aimed to discuss the molecular imprinted polymer (MIP)-based drug delivery systems (DDS). Molecular imprinted polymers have proved to possess the potential and also as a suitable material in several areas over a long period of time. However, only recently it has been employed for pharmaceuticals and biomedical applications, particularly as drug delivery vehicles due to properties including selective recognition generated from imprinting the desired analyte, favorable in harsh experimental conditions, and feedback-controlled recognitive drug release. Hence, this review will discuss their synthesis, the reason they are selected as drug delivery vehicles and for their applications in several drug administration routes (i.e. transdermal, ocular and gastrointestinal or stimuli-reactive routes).

  3. Specific transgenerational imprinting effects of the endocrine disruptor methoxychlor on male gametes.

    Science.gov (United States)

    Stouder, Christelle; Paoloni-Giacobino, Ariane

    2011-02-01

    Endocrine-disrupting chemicals (EDCs), among which methoxychlor (MXC), have been reported to affect the male reproductive system. This study evaluates the possible deleterious effects of MXC on imprinted genes. After administration of the chemical in adult male mice or in pregnant mice we analyzed by pyrosequencing possible methylation defects in two paternally imprinted (H19 and Meg3 (Gtl2)) and three maternally imprinted (Mest (Peg1), Snrpn, and Peg3) genes in the sperm and in the tail, liver, and skeletal muscle DNAs of the adult male mice and of the male offspring. MXC treatment of adult mice decreased the percentages of methylated CpGs of Meg3 and increased those of Mest, Snrpn, and Peg3 in the sperm DNA. MXC treatment of pregnant mice decreased the mean sperm concentrations by 30% and altered the methylation pattern of all the imprinted genes tested in the F1 offspring. In the latter case, MXC effects were transgenerational but disappeared gradually from F1 to F3. MXC did not affect imprinting in the somatic cells, suggesting that it exerts its damaging effects via the process of reprogramming that is unique to gamete development. A systematic analysis at the CpG level showed a heterogeneity in the CpG sensitivity to MXC. This observation suggests that not only DNA methylation but also other epigenetic modifications can explain the transgenerational effects of MXC. The reported effects of EDCs on human male spermatogenesis might be mediated by complex imprinting alterations analogous to those described in this study.

  4. Molecularly imprinted polymers for bioanalytical sample preparation.

    Science.gov (United States)

    Gama, Mariana Roberto; Bottoli, Carla Beatriz Grespan

    2017-02-01

    Molecularly imprinted polymers (MIP) are stable polymers with molecular recognition abilities, provided by the presence of a template during their synthesis, and are excellent materials with high selectivity for sample preparation in bioanalytical methods. This short review discusses aspects of MIP preparation and its applications as a sorbent material in pharmaceutical and biomedical analysis. MIP in different extraction configurations, including classical solid-phase extraction, solid-phase microextraction, magnetic molecularly imprinted solid-phase extraction, microextraction by packed sorbent and solid-phase extraction in pipette tips, are used to illustrate the good performance of this type of sorbent for sample preparation procedures of complex matrices, especially prior to bioanalytical approaches.

  5. MOLECULAR IMPRINTED POLYMERS—Novel Polymer Adsorbents

    Institute of Scientific and Technical Information of China (English)

    LIHaitao; XUMancai; 等

    2001-01-01

    Molecular imprinted polymers(MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules,These novel functional polymers have promised potential applications in racemic resolution,sensor,chromatography,adsorptive separation and other fields.This review exhibits the approach for preparing MIPs,the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs.The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.

  6. Genomic imprinting in development, growth, behavior and stem cells.

    Science.gov (United States)

    Plasschaert, Robert N; Bartolomei, Marisa S

    2014-05-01

    Genes that are subject to genomic imprinting in mammals are preferentially expressed from a single parental allele. This imprinted expression of a small number of genes is crucial for normal development, as these genes often directly regulate fetal growth. Recent work has also demonstrated intricate roles for imprinted genes in the brain, with important consequences on behavior and neuronal function. Finally, new studies have revealed the importance of proper expression of specific imprinted genes in induced pluripotent stem cells and in adult stem cells. As we review here, these findings highlight the complex nature and developmental importance of imprinted genes.

  7. Improvement of DNA recognition through molecular imprinting: hybrid oligomer imprinted polymeric nanoparticles (oligoMIP NPs)

    National Research Council Canada - National Science Library

    Brahmbhatt, H; Poma, A; Pendergraff, H M; Watts, J K; Turner, N W

    2016-01-01

    .... Molecularly imprinted polymers (MIPs) are cost-effective "smart" polymeric materials capable of antibody-like detection, but characterized by superior robustness and the ability to work in extreme environmental...

  8. Genomic imprinting in mammals: emerging themes and established theories.

    Directory of Open Access Journals (Sweden)

    Andrew J Wood

    2006-11-01

    Full Text Available The epigenetic events that occur during the development of the mammalian embryo are essential for correct gene expression and cell-lineage determination. Imprinted genes are expressed from only one parental allele due to differential epigenetic marks that are established during gametogenesis. Several theories have been proposed to explain the role that genomic imprinting has played over the course of mammalian evolution, but at present it is not clear if a single hypothesis can fully account for the diversity of roles that imprinted genes play. In this review, we discuss efforts to define the extent of imprinting in the mouse genome, and suggest that different imprinted loci may have been wrought by distinct evolutionary forces. We focus on a group of small imprinted domains, which consist of paternally expressed genes embedded within introns of multiexonic transcripts, to discuss the evolution of imprinting at these loci.

  9. Thermochemical study of amino acid imprinted polymer films.

    Science.gov (United States)

    Chai, Ziyi; BelBruno, Joseph J

    2015-11-01

    Molecularly imprinted polymers provide an alternative to traditional methods of amino acid analysis. The imprinted polymers are more robust and significantly less expensive than, for example, ELISA analysis. Amino acid imprinted nylon-6 thin films were studied by differential scanning calorimetry and scanning electron microscopy. Endothermic peaks were observed for imprinted films at temperatures higher than that for pure nylon, indicating the formation of a more-ordered, hydrogen bonded polymer. Removal of the amino acid from the imprinted film resulted in reversion to the peak observed for pure nylon-6. Additives, β-cyclodextrin and multiwalled carbon nanotubes, were added to the imprinted polymer solutions as a means to increase the porosity of the films. These studies resulted in alternative morphologies and calorimetric results that provide additional functionalities and applications for imprinted polymers.

  10. Molecular recognition effects in atomistic models of imprinted polymers.

    Science.gov (United States)

    Dourado, Eduardo M A; Herdes, Carmelo; van Tassel, Paul R; Sarkisov, Lev

    2011-01-01

    In this article we present a model for molecularly imprinted polymers, which considers both complexation processes in the pre-polymerization mixture and adsorption in the imprinted structures within a single consistent framework. As a case study we investigate MAA/EGDMA polymers imprinted with pyrazine and pyrimidine. A polymer imprinted with pyrazine shows substantial selectivity towards pyrazine over pyrimidine, thus exhibiting molecular recognition, whereas the pyrimidine imprinted structure shows no preferential adsorption of the template. Binding sites responsible for the molecular recognition of pyrazine involve one MAA molecule and one EGDMA molecule, forming associations with the two functional groups of the pyrazine molecule. Presence of these specific sites in the pyrazine imprinted system and lack of the analogous sites in the pyrimidine imprinted system is directly linked to the complexation processes in the pre-polymerization solution. These processes are quite different for pyrazine and pyrimidine as a result of both enthalpic and entropic effects.

  11. Molecular Recognition Effects in Atomistic Models of Imprinted Polymers

    Directory of Open Access Journals (Sweden)

    Carmelo Herdes

    2011-07-01

    Full Text Available In this article we present a model for molecularly imprinted polymers, which considers both complexation processes in the pre-polymerization mixture and adsorption in the imprinted structures within a single consistent framework. As a case study we investigate MAA/EGDMA polymers imprinted with pyrazine and pyrimidine. A polymer imprinted with pyrazine shows substantial selectivity towards pyrazine over pyrimidine, thus exhibiting molecular recognition, whereas the pyrimidine imprinted structure shows no preferential adsorption of the template. Binding sites responsible for the molecular recognition of pyrazine involve one MAA molecule and one EGDMA molecule, forming associations with the two functional groups of the pyrazine molecule. Presence of these specific sites in the pyrazine imprinted system and lack of the analogous sites in the pyrimidine imprinted system is directly linked to the complexation processes in the pre-polymerization solution. These processes are quite different for pyrazine and pyrimidine as a result of both enthalpic and entropic effects.

  12. The imprinted gene neuronatin is regulated by metabolic status and associated with obesity

    DEFF Research Database (Denmark)

    Vrang, Niels; Meyre, David; Froguel, Phillippe

    2010-01-01

    Using restriction fragment differential display (RFDD) technology, we have identified the imprinted gene neuronatin (Nnat) as a hypothalamic target under the influence of leptin. Nnat mRNA expression is decreased in several key appetite regulatory hypothalamic nuclei in rodents with impaired leptin...... signaling and during fasting conditions. Furthermore, peripheral administration of leptin to ob/ob mice normalizes hypothalamic Nnat expression. Comparative immunohistochemical analysis of human and rat hypothalami demonstrates that NNAT protein is present in anatomically equivalent nuclei, suggesting human...

  13. Imprinting Technology in Electrochemical Biomimetic Sensors

    Directory of Open Access Journals (Sweden)

    Manuela F. Frasco

    2017-03-01

    Full Text Available Biosensors are a promising tool offering the possibility of low cost and fast analytical screening in point-of-care diagnostics and for on-site detection in the field. Most biosensors in routine use ensure their selectivity/specificity by including natural receptors as biorecognition element. These materials are however too expensive and hard to obtain for every biochemical molecule of interest in environmental and clinical practice. Molecularly imprinted polymers have emerged through time as an alternative to natural antibodies in biosensors. In theory, these materials are stable and robust, presenting much higher capacity to resist to harsher conditions of pH, temperature, pressure or organic solvents. In addition, these synthetic materials are much cheaper than their natural counterparts while offering equivalent affinity and sensitivity in the molecular recognition of the target analyte. Imprinting technology and biosensors have met quite recently, relying mostly on electrochemical detection and enabling a direct reading of different analytes, while promoting significant advances in various fields of use. Thus, this review encompasses such developments and describes a general overview for building promising biomimetic materials as biorecognition elements in electrochemical sensors. It includes different molecular imprinting strategies such as the choice of polymer material, imprinting methodology and assembly on the transduction platform. Their interface with the most recent nanostructured supports acting as standard conductive materials within electrochemical biomimetic sensors is pointed out.

  14. Plastic Antibodies: Molecular Recognition with Imprinted Polymers

    Science.gov (United States)

    Rushton, Gregory T.; Furmanski, Brian; Shimizu, Ken D.

    2005-01-01

    Synthetic polymers are prepared and tested in a study for their molecular recognition properties of an adenine derivative, ethyl adenine-9-acetate (EA9A), within two laboratory periods. The procedure introduces undergraduate chemistry students to noncovalent molecular imprinting as well as the analytical techniques for assessing their recognition…

  15. Surface Plasmon Resonance Studies on Molecular Imprinting

    Directory of Open Access Journals (Sweden)

    Baoping Lin

    2002-01-01

    Full Text Available The molecular imprinted polymer (MIP members were fabricated with the print molecule L-phenylalanine ethyl ester. The elution and adsorption procedures were investigated by surface plasmon resonance in situ. The changes of refractive angle during elution procedure suggest that the MIP is prepared on the base of the non-covalent interactions. This MIP member sensor can achieve enantioselective recognition.

  16. Cell shape recognition by colloidal cell imprints

    NARCIS (Netherlands)

    Borovička, Josef; Stoyanov, S.D.; Paunov, V.N.

    2015-01-01

    The results presented in this study are aimed at the theoretical estimate of the interactions between a spherical microbial cell and the colloidal cell imprints in terms of the Derjaguin, Landau, Vervey, and Overbeek (DLVO) surface forces. We adapted the Derjaguin approximation to take into accou

  17. Molecularly imprinted polymers for some reactive dyes.

    Science.gov (United States)

    Okutucu, Burcu; Akkaya, Alper; Pazarlioglu, Nurdan Kasikara

    2010-01-01

    Depending upon their structure, azo- and anthraquinonic dyes are the two major classes and together represent 90% of all organic colorants. Adsorption of dye molecules onto a sorbent can be an effective, low-cost method of color removal. Most of the techniques used for removal of dyes are of high production cost, and the regeneration also makes them uneconomical. There is much interest in the development of cheaper and effective newer materials for use as adsorbents. Molecular imprinting is a new kind of materials that can be alternative adsorbents. In this study, molecularly imprinted polymers of three textile dyes (Cibacron Orange P-4R, Cibacron Red P-4B, Cibacron Black PSG) were prepared. Methacrylic acid was used as a monomer for red and orange dyes and acrylamide was used for black dye. Methanol:acetonitrile was used as a porogen. The selective recognition ability of the molecularly imprinted polymers was studied by an equilibrium-adsorption batch method. The adsorption data are for Cibacron Black PSG 65% and nonimprinted polymer (NIP) 25%; Cibacron Red P-4B 72% and NIP 18%; and Cibacron Orange P-4R 45% and NIP 10%, respectively. Dye-imprinted polymers were used as a solid-phase extraction material for selective adsorption from wastewater of textile factory.

  18. Molecular Imprinting Applications in Forensic Science.

    Science.gov (United States)

    Yılmaz, Erkut; Garipcan, Bora; Patra, Hirak K; Uzun, Lokman

    2017-03-28

    Producing molecular imprinting-based materials has received increasing attention due to recognition selectivity, stability, cast effectiveness, and ease of production in various forms for a wide range of applications. The molecular imprinting technique has a variety of applications in the areas of the food industry, environmental monitoring, and medicine for diverse purposes like sample pretreatment, sensing, and separation/purification. A versatile usage, stability and recognition capabilities also make them perfect candidates for use in forensic sciences. Forensic science is a demanding area and there is a growing interest in molecularly imprinted polymers (MIPs) in this field. In this review, recent molecular imprinting applications in the related areas of forensic sciences are discussed while considering the literature of last two decades. Not only direct forensic applications but also studies of possible forensic value were taken into account like illicit drugs, banned sport drugs, effective toxins and chemical warfare agents in a review of over 100 articles. The literature was classified according to targets, material shapes, production strategies, detection method, and instrumentation. We aimed to summarize the current applications of MIPs in forensic science and put forth a projection of their potential uses as promising alternatives for benchmark competitors.

  19. Imprinting Technology in Electrochemical Biomimetic Sensors.

    Science.gov (United States)

    Frasco, Manuela F; Truta, Liliana A A N A; Sales, M Goreti F; Moreira, Felismina T C

    2017-03-06

    Biosensors are a promising tool offering the possibility of low cost and fast analytical screening in point-of-care diagnostics and for on-site detection in the field. Most biosensors in routine use ensure their selectivity/specificity by including natural receptors as biorecognition element. These materials are however too expensive and hard to obtain for every biochemical molecule of interest in environmental and clinical practice. Molecularly imprinted polymers have emerged through time as an alternative to natural antibodies in biosensors. In theory, these materials are stable and robust, presenting much higher capacity to resist to harsher conditions of pH, temperature, pressure or organic solvents. In addition, these synthetic materials are much cheaper than their natural counterparts while offering equivalent affinity and sensitivity in the molecular recognition of the target analyte. Imprinting technology and biosensors have met quite recently, relying mostly on electrochemical detection and enabling a direct reading of different analytes, while promoting significant advances in various fields of use. Thus, this review encompasses such developments and describes a general overview for building promising biomimetic materials as biorecognition elements in electrochemical sensors. It includes different molecular imprinting strategies such as the choice of polymer material, imprinting methodology and assembly on the transduction platform. Their interface with the most recent nanostructured supports acting as standard conductive materials within electrochemical biomimetic sensors is pointed out.

  20. Genomic Imprinting Is Implicated in the Psychology of Music.

    Science.gov (United States)

    Mehr, Samuel A; Kotler, Jennifer; Howard, Rhea M; Haig, David; Krasnow, Max M

    2017-08-01

    Why do people sing to babies? Human infants are relatively altricial and need their parents' attention to survive. Infant-directed song may constitute a signal of that attention. In Prader-Willi syndrome (PWS), a rare disorder of genomic imprinting, genes from chromosome 15q11-q13 that are typically paternally expressed are unexpressed, which results in exaggeration of traits that reduce offspring's investment demands on the mother. PWS may thus be associated with a distinctive musical phenotype. We report unusual responses to music in people with PWS. Subjects with PWS ( N = 39) moved more during music listening, exhibited greater reductions in heart rate in response to music listening, and displayed a specific deficit in pitch-discrimination ability relative to typically developing adults and children ( N = 589). Paternally expressed genes from 15q11-q13, which are unexpressed in PWS, may thus increase demands for music and enhance perceptual sensitivity to music. These results implicate genomic imprinting in the psychology of music, informing theories of music's evolutionary history.

  1. The evolution of imprinting: chromosomal mapping of orthologues of mammalian imprinted domains in monotreme and marsupial mammals

    Directory of Open Access Journals (Sweden)

    Dunham Ian

    2007-09-01

    Full Text Available Abstract Background The evolution of genomic imprinting, the parental-origin specific expression of genes, is the subject of much debate. There are several theories to account for how the mechanism evolved including the hypothesis that it was driven by the evolution of X-inactivation, or that it arose from an ancestrally imprinted chromosome. Results Here we demonstrate that mammalian orthologues of imprinted genes are dispersed amongst autosomes in both monotreme and marsupial karyotypes. Conclusion These data, along with the similar distribution seen in birds, suggest that imprinted genes were not located on an ancestrally imprinted chromosome or associated with a sex chromosome. Our results suggest imprinting evolution was a stepwise, adaptive process, with each gene/cluster independently becoming imprinted as the need arose.

  2. A Path to Soluble Molecularly Imprinted Polymers

    Directory of Open Access Journals (Sweden)

    Abhilasha Verma

    2011-12-01

    Full Text Available Molecular imprinting is a technique for making a selective binding site for a specific chemical. The technique involves building a polymeric scaffold of molecular complements containing the target molecule. Subsequent removal of the target leaves a cavity with a structural “memory” of the target. Molecularly imprinted polymers (MIPs can be employed as selective adsorbents of specific molecules or molecular functional groups. In addition, sensors for specific molecules can be made using optical transduction through lumiphores residing in the imprinted site. We have found that the use of metal ions as chromophores can improve selectivity due to selective complex formation. The combination of molecular imprinting and spectroscopic selectivity can result in sensors that are highly sensitive and nearly immune to interferences. A weakness of conventional MIPs with regard to processing is the insolubility of crosslinked polymers. Traditional MIPs are prepared either as monoliths and ground into powders or are prepared in situ on a support. This limits the applicability of MIPs by imposing tedious or difficult processes for their inclusion in devices. The size of the particles hinders diffusion and slows response. These weaknesses could be avoided if a means were found to prepare individual macromolecules with crosslinked binding sites with soluble linear polymeric arms. This process has been made possible by controlled free radical polymerization techniques that can form pseudo-living polymers. Modern techniques of controlled free radical polymerization allow the preparation of block copolymers with potentially crosslinkable substituents in specific locations. The inclusion of crosslinkable mers proximate to the binding complex in the core of a star polymer allows the formation of molecularly imprinted macromolecules that are soluble and processable. Due to the much shorter distance for diffusion, the polymers exhibit rapid responses. This paper

  3. On the detection of imprinted quantitative trait loci in experimental crosses of outbred species

    NARCIS (Netherlands)

    Koning, de D.J.; Bovenhuis, H.; Arendonk, van J.A.M.

    2002-01-01

    In this article, the quantitative genetic aspects of imprinted genes and statistical properties of methods to detect imprinted QTL are studied. Different models to detect imprinted QTL and to distinguish between imprinted and Mendelian QTL were compared in a simulation study. Mendelian and imprinted

  4. On the detection of imprinting quantitative trait loci in experimental crosses of outbred species

    NARCIS (Netherlands)

    Koning, de D.J.; Bovenhuis, H.; Arendonk, van J.A.M.

    2002-01-01

    In this article, the quantitative genetic aspects of imprinted genes and statistical properties of methods to detect imprinted QTL are studied. Different models to detect imprinted QTL and to distinguish between imprinted and Mendelian QTL were compared in a simulation study. Mendelian and imprinted

  5. A needle extraction utilizing a molecularly imprinted-sol-gel xerogel for on-line microextraction of the lung cancer biomarker bilirubin from plasma and urine samples.

    Science.gov (United States)

    Moein, Mohammad Mahdi; Jabbar, Dunia; Colmsjö, Anders; Abdel-Rehim, Mohamed

    2014-10-31

    In the present work, a needle trap utilizing a molecularly imprinted sol-gel xerogel was prepared for the on-line microextraction of bilirubin from plasma and urine samples. Each prepared needle could be used for approximately one hundred extractions before it was discarded. Imprinted and non-imprinted sol-gel xerogel were applied for the extraction of bilirubin from plasma and urine samples. The produced molecularly imprinted sol-gel xerogel polymer showed high binding capacity and fast adsorption/desorption kinetics for bilirubin in plasma and urine samples. The adsorption capacity of molecularly imprinted sol-gel xerogel polymer was approximately 60% higher than that of non-imprinted polymer. The effect of the conditioning, washing and elution solvents, pH, extraction time, adsorption capacity and imprinting factor were investigated. The limit of detection and the lower limit of quantification were set to 1.6 and 5nmolL(-1), respectively using plasma or urine samples. The standard calibration curves were obtained within the concentration range of 5-1000nmolL(-1) in both plasma and urine samples. The coefficients of determination values (R(2)) were ≥0.998 for all runs. The extraction recovery was approximately 80% for BR in the human plasma and urine samples.

  6. Molecularly imprinted polydopamine nano-layer on the pore surface of porous particles for protein capture in HPLC column.

    Science.gov (United States)

    Nematollahzadeh, Ali; Shojaei, Akbar; Abdekhodaie, Mohammad J; Sellergren, Börje

    2013-08-15

    Bio-inspired Human Serum Albumin (HSA) imprinted polydopamine nano-layer was produced through oxidative polymerization of dopamine on the pore surface of HSA modified porous silica particles. The coating thickness was controlled by the reaction time and thereby varied within 0-12 nm. The samples were characterized by elemental analysis, FT-IR, DSC, SEM, TEM, TGA, physisorption and thermoporometry. The characterization confirmed the success of evolution and deposition of polydopamine layer on the silica pore surface. Batch rebinding experiment showed that the molecularly imprinted polymer (MIP) with 8.7 nm coating thickness, in comparison with the thinner and thicker coatings, displays the highest uptake of the target protein. The chromatographic evaluation of the materials packed in HPLC columns showed that the HSA imprinted polydopamine offers good mechanical stability and retains practically all the target protein from an HSA solution or human plasma. Affinity of the imprinting column was examined by using Bovine Serum Albumin (BSA) and Immunoglobulin G (IgG) as competitive proteins. The results showed that the template, HSA, was the most adsorbed protein by the imprinted polydopamine layer. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  7. Potentiometric Sensors Based on Surface Molecular Imprinting: Detection of Cancer Biomarkers and Viruses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Zhang, Z; Jain, V; Yi, J; Mueller, S; Sokolov, J; Liu, Z; Levon, K; Rigas, B; Rafailovich, M

    2010-01-01

    The continuing discovery of cancer biomarkers necessitates improved methods for their detection. Molecular imprinting using artificial materials provides an alternative to the detection of a wide range of substances. We applied surface molecular imprinting using self-assembled monolayers to design sensing elements for the detection of cancer biomarkers and other proteins. These elements consist of a gold-coated silicon chip onto which hydroxyl-terminated alkanethiol molecules and template biomolecule are co-adsorbed, where the thiol molecules are chemically bound to the metal substrate and self-assembled into highly ordered monolayers, the biomolecules can be removed, creating the foot-print cavities in the monolayer matrix for this kind of template molecules. Re-adsorption of the biomolecules to the sensing chip changes its potential, which can be measured potentiometrically. We applied this method to the detection of carcinoembryonic antigen (CEA) in both solutions of purified CEA and in the culture medium of a CEA-producing human colon cancer cell line. The CEA assay, validated also against a standard immunoassay, was both sensitive (detection range 2.5-250 ng/mL) and specific (no cross-reactivity with hemoglobin; no response by a non-imprinted sensor). Similar results were obtained for human amylase. In addition, we detected virions of poliovirus in a specific manner (no cross-reactivity to adenovirus, no response by a non-imprinted sensor). Our findings demonstrate the application of the principles of molecular imprinting to the development of a new method for the detection of protein cancer biomarkers and to protein-based macromolecular structures such as the capsid of a virion. This approach has the potential of generating a general assay methodology that could be highly sensitive, specific, simple and likely inexpensive.

  8. Theoretical analysis of a high performance protein imprint on a nanosensor

    Directory of Open Access Journals (Sweden)

    Jianfa Chen

    2016-03-01

    Full Text Available The structural details and flexibilities of protein impose significant challenges to develop protein imprint, especially for the selection of functional monomer. Using NAMD, AutoDock 4 and AutoDock Vina, we investigated the formation of a high performance protein imprint on a nanosensor that detected human papillomavirus (HPV biomarker protein E7 with high sensitivity. According to molecular dynamics, the phenolic oligomers were shown to assemble with the E7 protein and form a complex at specific targeting areas on the protein. Docking analysis efficiently screened chemical compounds by evaluating the binding affinity. A new parameter, i.e., average binding energy (ΔG/contact, was used together with binding energy (ΔG to screen compounds. The screening went through 189 compounds and identified a subpopulation of 22 compounds showing unique characteristics of binding, and could potentially be used to develop the specific and robust imprint. Accordingly, the study implicated a novel approach to screen functional compounds for rational design of the protein imprint.

  9. Epigenetic alteration of imprinted genes during neural differentiation of germline-derived pluripotent stem cells.

    Science.gov (United States)

    Lee, Hye Jeong; Choi, Na Young; Lee, Seung-Won; Ko, Kisung; Hwang, Tae Sook; Han, Dong Wook; Lim, Jisun; Schöler, Hans R; Ko, Kinarm

    2016-03-01

    Spermatogonial stem cells (SSCs), which are unipotent stem cells in the testes that give rise to sperm, can be converted into germline-derived pluripotent stem (gPS) by self-induction. The androgenetic imprinting pattern of SSCs is maintained even after their reprogramming into gPS cells. In this study, we used an in vitro neural differentiation model to investigate whether the imprinting patterns are maintained or altered during differentiation. The androgenetic patterns of H19, Snrpn, and Mest were maintained even after differentiation of gPS cells into NSCs (gPS-NSCs), whereas the fully unmethylated status of Ndn in SSCs was altered to somatic patterns in gPS cells and gPS-NSCs. Thus, our study demonstrates epigenetic alteration of genomic imprinting during the induction of pluripotency in SSCs and neural differentiation, suggesting that gPS-NSCs can be a useful model to study the roles of imprinted genes in brain development and human neurodevelopmental disorders.

  10. [Exploration of research approaches of Chinese medicine's pharmacology based on "imprinting templates" (medical element) of supramolecules].

    Science.gov (United States)

    He, Fu-yuan; He, Hong; Deng, Kai-wen; Zhou, Yi-qun; Shi, Ji-lian; Liu, Wen-long; Yang, Yan-tao; Tang, Yu

    2015-11-01

    The paper, based on the previous publication as special impact of Chinese medicine theories on supramolcular chemistry, aims to analyze the natural origination for the Chinese medicine and to explain the special impact of "Qi chromatography" reaction on "imprinting templates" in supramolcular host of human being with Chinese medicine, in order to reveal the CM's properties of "medical element" with "imprinting templates" autonomisation generally took place in natural supramolecules, and also to discover that the CM's pharmacology are satisfied with its own approaches different form western pharmacology. It was decided, for CM's pharmacology guided by CM's theories, to "Qi chromatography" relations between the CM's ingredient groups and the meridian zang-fu viscera. The supramolcular chemistry played an all-through role in procession of making macro-regularities and special presentation on behavior of "Qi chromatography" impulse owning to the matching action of all kinds of ingredients on the meridian zang-fu viscera with similar "imprinting templates". The CM's pharmacology were guided by CM's theories, owing to its interpretation of supramolecular chemistry. The pharmacology was achieved to construct up completely on base of classical chemical single molecular bonds whereas the CM's pharmacology be configured to big building by way of "imprinting templates" as multi-weak bonds among "supramolecular society". CM's pharmacology was supramolcular pharmacology dealt with "molecular society" on the base of western pharmacology, and employed to double research approaches both math-physical quantitative representation on macroscope and qualitative analyses in microscope.

  11. NMDA receptor antagonists extend the sensitive period for imprinting.

    Science.gov (United States)

    Parsons, C H; Rogers, L J

    2000-03-01

    Filial imprinting in the domestic chick occurs during a sensitive period of development. The exact timing of this period can vary according to the methods used to measure imprinting. Using our imprinting paradigm, we have shown that normal, dark-reared chicks lose the ability to imprint after the second day post-hatching. Further, we reported that chicks treated 10 h after hatching with a mixture of the noncompetitive NMDA receptor antagonist ketamine (55 mg/kg) and the alpha(2)-adrenergic receptor agonist xylazine (6 mg/kg) were able to imprint on day 8 after hatching, whereas controls treated with saline did not imprint. We now show that the effect of the ketamine-xylazine mixture can be mimicked by treating chicks with ketamine alone or with another noncompetitive NMDA receptor antagonist, MK-801 (5 mg/kg). Treating chicks with a single dose of ketamine (55 mg/kg) or with a single dose of xylazine (6 mg/kg) failed to produce the effect on the sensitive period. However, prolonging the action of ketamine by treating chicks with two doses of ketamine (at 10 and 12 h after hatching) did allow imprinting on day 8. In contrast, prolonging the action of xylazine had no effect on the sensitive period for imprinting. Chicks treated with MK-801 were also able to imprint on day 8. Thus, we have evidence that the NMDA receptor system is involved in the mechanisms that control the sensitive period for imprinting.

  12. A comparison of covalent and non-covalent imprinting strategies for the synthesis of stigmasterol imprinted polymers.

    Science.gov (United States)

    Hashim, Shima N N S; Boysen, Reinhard I; Schwarz, Lachlan J; Danylec, Basil; Hearn, Milton T W

    2014-09-12

    Non-covalent and covalent imprinting strategies have been investigated for the synthesis of stigmasterol imprinted polymers. The synthesized molecularly imprinted polymers (MIPs) were then evaluated for their recognition and selectivity towards stigmasterol via static and dynamic batch-binding assays and their performance measured against control non-imprinted polymers (NIPs). MIPs prepared using the conventional non-covalent imprinting method displayed little to no binding affinity for stigmasterol under various conditions. In contrast, the application of a covalent imprinting approach using the novel post-synthetically cleavable monomer-template composite stigmasteryl-3-O-methacrylate resulted in the fabrication of a MIP that successfully recognized stigmasterol in both organic and partially aqueous environments. The affinity and selectivity of the covalently prepared MIP was enhanced when undertaken in a partially aqueous environment consisting of an acetonitrile/water (9:1, v/v) solvent mixture. These features have been exploited in a molecularly imprinted solid-phase extraction (MISPE) format, wherein the preferential retention of stigmasterol (with an imprint factor of 12) was demonstrated with 99% recovery in comparison to cholesterol (imprint factor of 6) and ergosterol (imprint factor of 4) while in the presence of several closely related steryl analogues.

  13. [Spectroscopic Study of Salbutamol Molecularly Imprinted Polymers].

    Science.gov (United States)

    Ren, Hui-peng; Guan, Yu-yu; Dai, Rong-hua; Liu, Guo-yan; Chai, Chun-yan

    2016-02-01

    In order to solve the problem of on-site rapid detection of salbutamol residues in feed and animal products, and develop a new method of fast detection of salbutamol on the basis of the molecular imprinting technology, this article uses the salbutamol (SAL) working as template molecule, methacrylic acid (MAA) working as functional monomer. On this basis, a new type of core-shell type salbutamol molecularly imprinted polymers were prepared with colloidal gold particles as triggering core. Superficial characteristics of the MIPs and the related compounds were investigated by ultraviolet (UV) spectra and infrared (IR) spectra, Raman spectra, Scanning electron microscopy (SEM) respectively. The results indicated that a stable hydrogen bonding complex has been formed between the carboxyl groups of SAL and MA with a matching ratio of 1:1. The complex can be easily eluted by the reagent containing hydrogen bonding. The chemical binding constant K reaches -0.245 x 10⁶ L² · mol⁻². The possible binding sites of the hydrogen bonding was formed between the hydrogen atoms of -COOH in MA and the oxygen atoms of C==O in SAL. IR and Raman spectrum showed that, compared with MA, a significant red shift of -OH absorption peak was manifested in MIPs, which proved that SAL as template molecule occurred a specific bond between MA. Red shift of stretching vibration absorption peak of C==O was also detected in the un-eluted MIPs and obvious energy loss happened, which demonstrated a possible binding sites is SAL intramolecular of C==O atom of oxygen. If the hydrogen atoms of -COOH in MA wanted to generate hydrogen bond. However, the shapes of absorption peak of other functional groups including C==C, C==O, and -OH were very similar both in MIPs and NIPs. Specific cavities were formed after the template molecules in MIPs were removed. It was proved by the adsorption experiment that the specific sites in these cavities highly match with the chemical and space structure of SAL

  14. Characterization of molecularly imprinted polymer nanoparticles by photon correlation spectroscopy.

    Science.gov (United States)

    Malm, Björn; Yoshimatsu, Keiichi; Ye, Lei; Krozer, Anatol

    2014-12-01

    We follow template-binding induced aggregation of nanoparticles enantioselectively imprinted against (S)-propranolol, and the non-imprinted ones, using photon correlation spectroscopy (dynamic light scattering). The method requires no separation steps. We have characterized binding of (R,S)-propranolol to the imprinted polymers and determined the degree of non-specificity by comparing the specific binding with the results obtained using non-imprinted nanoparticles. Using (S)-propranolol as a template for binding to (S)-imprinted nanoparticle, and (R)-propranolol as a non-specific control, we have determined range of concentrations where chiral recognition can be observed. By studying aggregation induced by three analytes related to propranolol, atenolol, betaxolol, and 1-amino-3-(naphthalen-1-yloxy)propan-2-ol, we were able to determine which parts of the template are involved in the specific binding, discuss several details of specific adsorption, and the structure of the imprinted site.

  15. [Werkgartner's muzzle imprint mark--a literature study].

    Science.gov (United States)

    Geserick, Gunther; Vendura, Klaus; Wirth, Ingo

    2009-01-01

    Since Werkgartner described and correctly interpreted the muzzle imprint mark around the gunshot entrance wound in 1922, this finding has been generally accepted as a sign of a contact shot. In further studies, it could finally be clarified that the muzzle imprint mark is caused by the expansive power of the powder gases with pressure on and abrasion of the skin at the muzzle (weapon imprint). Its shape depends on the firearm, the ammunition and the anatomical conditions, but does not require a bullet. Examinations under a magnifying glass microscope and histological investigations can complete the macroscopic findings. Occasionally, the muzzle imprint mark requires a certain "drying period" in order to become clearly visible. In rare cases, muzzle imprint marks also form on textiles perforated by the projectile. Characteristically shaped muzzled imprint marks can provide clues to the type of the firearm and its position at the time of discharge.

  16. A new accurate pill recognition system using imprint information

    Science.gov (United States)

    Chen, Zhiyuan; Kamata, Sei-ichiro

    2013-12-01

    Great achievements in modern medicine benefit human beings. Also, it has brought about an explosive growth of pharmaceuticals that current in the market. In daily life, pharmaceuticals sometimes confuse people when they are found unlabeled. In this paper, we propose an automatic pill recognition technique to solve this problem. It functions mainly based on the imprint feature of the pills, which is extracted by proposed MSWT (modified stroke width transform) and described by WSC (weighted shape context). Experiments show that our proposed pill recognition method can reach an accurate rate up to 92.03% within top 5 ranks when trying to classify more than 10 thousand query pill images into around 2000 categories.

  17. Expression and imprinting of DIO3 and DIO3OS genes in Holstein cattle

    Indian Academy of Sciences (India)

    WENZHI YANG; DONGJIE LI; GUANNAN WANG; XIHONG WU; MINGYUE ZHANG; CUI ZHANG; YALI CUI; SHIJIE LI

    2017-06-01

    DIO3 and DIO3OS are two imprinted genes identified in mouse and humans. The DIO3 gene, which encodes for the type 3 deiodinase, is preferentially expressed from the paternal allele, while the DIO3OS transcript is transcribed inopposite orientation to DIO3, multiple noncoding and alternatively splicing isoforms from maternal allele. In this study, the five splice variants of DIO3OS were identified in Holstein cattle and had complex, tissue-specific expression patterns observed in eight tissues, including heart, liver, spleen, lung, kidney, muscle, fat and brain. In the G+C rich region, upstream from the cattle DIO3 gene, there were three small conserved regions and some promoter elements similar to those observed in mouse and humans. An allele-specific expression analysis-based SNP method revealed that DIO3 and DIO3OS genes exhibited monoallelic expression in the eight tissues, indicating that DIO3 and DIO3OS are imprinted in cattle.

  18. Computational simulation and preparation of fluorescent magnetic molecularly imprinted silica nanospheres for ciprofloxacin or norfloxacin sensing.

    Science.gov (United States)

    Gao, Bo; He, Xin-Ping; Jiang, Yang; Wei, Jia-Tong; Suo, Hui; Zhao, Chun

    2014-12-01

    A magnetic molecularly imprinted fluorescent sensor for the sensitive and convenient determination of ciprofloxacin or norfloxacin in human urine was synthesized and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, ultraviolet/visible spectroscopy, and fluorescence spectroscopy. Both cadmium telluride quantum dots and ferroferric oxide nanoparticles are introduced into the polymer for the rapid separation and detection of the target molecules. The synthesized molecularly imprinted polymers were applied to detect ciprofloxacin or its structural analog norfloxacin in human urine with the detection limit 130 ng/mL. A computational study was developed to evaluate the template-monomer geometry and interaction energy in the polymerization mixture to determine the reaction molar ratio of the template and monomer molecules. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Preparation of imprinted monolithic column under molecular crowding conditions

    Institute of Scientific and Technical Information of China (English)

    Xiao Xia Li; Xin Liu; Li Hong Bai; Hong Quan Duan; Yan Ping Huang; Zhao Sheng Liu

    2011-01-01

    Molecular crowding is a new concept to obtain molecularly imprinted polymers (MIPs) with greater capacity and selectivity. In this work, molecular crowding agent was firstly applied to the preparation of MIPs monolithic column. A new polymerization system based on molecular crowding surrounding was developed to prepare enrofloxacin-imprinted monolith, which was composed of polystyrene and tetrahydrofuran. The result showed that the monolithic MIPs under molecular crowding conditions presented good molecular recognition for enrofloxacin with an imprinting factor of 3.03.

  20. The evolutionary foundation of genomic imprinting in lower vertebrates

    Institute of Scientific and Technical Information of China (English)

    XIE BingHua; ZHANG Lei; ZHENG Kang; LUO Chen

    2009-01-01

    In mammals,genomic imprinting confers developmental asymmetry and complementation on the a-rental genomes and makes both parental genomes essential for complete development.Genomic im-printing is,therefore,the first regulatory step of genome-wide gene expression of embryogeneais and thought to be the epigenetic foundation of bisexual reproduction.However,how the genomic imprint-ing is originated,established and maintained during vertebrate evolution remains unknown.Because no endogenous imprinting gene has been identified in non-mammalian vertebrates,genomic imprinting is thought to be a unique evolutionary event of mammals.Here,in order to study the evolutionary origin of genomic imprinting in vertebrates,we examined whether parent-specific methylation occurred in the teleost homologue of mammalian imprinting gene during gametogenesis.Bisulfate sequencing analy-sis showed that,as mammalian Igf2 CpG island,goldfish Igf2 CpG island was a parental differentially methylated region (DMR) that was hypermethylated in sperm but unmethylated in eggs.Unlike mam-malian imprinting gene DMR,however,the parent-specific methylation pattern of goldfish Igf2 DMR was not maintained during embryogenesis,suggesting that the parent-specific methylation of goldfish Igf2 DMR might be a primitive genomic imprinting in the early period of vertebrate evolution.These results indicate that the evolutionary foundation of genomic imprinting exists in lower vertebrates and ge-nomic imprinting should not be considered as a unique evolutionary event of mammals.

  1. Development of a Molecularly Imprinted Biomimetic Electrode

    Directory of Open Access Journals (Sweden)

    Evangelyn C. Alocilja

    2007-08-01

    Full Text Available The technique of molecular imprinting produces artificial receptor sites in apolymer that can be used in a biomimetic sensor. This research extends previous studies ofa molecularly imprinted polymer (MIP biomimetic sensor for the small drug theophylline.The presence of theophylline in the biomimetic sensor was monitored by analyzing thepeak currents from cyclic voltammetry experiments. The functional working range of theMIP modified electrode was 2 - 4 mM theophylline. The concentration of theophyllinethat resulted in the best signal was 3 mM. The MIP sensor showed no response to thestructurally related molecule caffeine, and therefore was selective to the target analytetheophylline. This research will provide the foundation for future studies that will result indurable biomimetic sensors that can offer a viable alternative to current sensors.

  2. Gastric mucormycosis: Diagnosis by imprint cytology.

    Science.gov (United States)

    Tathe, Shilpa P; Dani, Aarti A; Chawhan, Sanjay M; Meshram, Saroj A; Randale, Archana A; Raut, Waman K

    2016-10-01

    The fungi in the order of Mucorales commonly target diabetics and other immunocompromised hosts, producing fatal respiratory and or CNS infections. Gastrointestinal mucormycosis is uncommon and seldom diagnosed in living patients due to nonspecific clinical manifestations. We report a case of gastric mucormycosis in an immmunocompetent male patient, diagnosed by imprint cytology-a rare site and a rare setting. To the best of our knowledge, this is only the second report of gastric mucormycosis being diagnosed on cytology. As the disease is rapidly progressive and often fatal, early diagnosis is critical to the patient survival. Imprint cytology or brush cytology is extremely useful for the rapid diagnosis of gastric mucormycosis as these organisms are morphologically distinct. Familiarity with the cytomorphology of these organisms assists in the correct diagnosis of this disease. Diagn. Cytopathol. 2016;44:820-822. © 2016 Wiley Periodicals, Inc.

  3. Bolt Cutter Blade's Imprint in Toolmarks Examination.

    Science.gov (United States)

    Volkov, Nikolai; Finkelstein, Nir; Novoselsky, Yehuda; Tsach, Tsadok

    2015-11-01

    Bolt cutters are known as cutting tools which are used for cutting hard objects and materials, such as padlocks and bars. Bolt cutter blades leave their imprint on the cut objects. When receiving a cut object from a crime scene, forensic toolmarks examiners can determine whether the suspected cutting tool was used in a specific crime or not based on class characteristic marks and individual marks that the bolt cutter blades leave on the cut object. The paper presents preliminary results of a study on ten bolt cutters and suggests a quick preliminary examination-the comparison between the blade thickness and the width of the imprint left by the tool on the cut object. Based on the comparison result, if there is not a match, the examiner can eliminate the feasibility of the use of the suspected cutting tool in a specific crime. This examination simplifies and accelerates the comparison procedure.

  4. Imprinting localized plasmons for enhanced solar cells.

    Science.gov (United States)

    Dunbar, Ricky B; Pfadler, Thomas; Lal, Niraj N; Baumberg, Jeremy J; Schmidt-Mende, Lukas

    2012-09-28

    Imprinted silver nanovoid arrays are investigated via angle-resolved reflectometry to demonstrate their suitability for plasmonic light trapping. Both wavelength- and subwavelength-scale nanovoids are imprinted into standard solar cell architectures to achieve nanostructured metallic electrodes which provide enhanced absorption for improving solar cell performance. The technique is versatile, low-cost and scalable and can be applied to a wide range of organic semiconductors. Absorption features which are independent of incident polarization and weakly dependent on incident angle reveal localized plasmonic modes at the structured interface. Metallic nanostructure-PCPDTBT:PCBM samples demonstrate absorption enhancements of up to 40%. The structured interface provides light trapping, which boosts absorption at wavelengths where the semiconductors absorb poorly.

  5. Imprinting: seeing food and eating it.

    Science.gov (United States)

    Healy, Susan D

    2006-07-11

    A recent study has found that although, ordinarily, cuttlefish hatchlings prefer shrimp-like prey, when visually exposed to crabs in the first hours of day one, they later prefer crabs to shrimps. As the development of this preference occurs during a short sensitive phase, does not depend on food ingestion and is long lasting, it fulfils all the criteria for imprinting, a phenomenon more usually associated with vertebrates and social learning.

  6. Nanoscale molecularly imprinted polymers and method thereof

    Science.gov (United States)

    Hart, Bradley R.; Talley, Chad E.

    2008-06-10

    Nanoscale molecularly imprinted polymers (MIP) having polymer features wherein the size, shape and position are predetermined can be fabricated using an xy piezo stage mounted on an inverted microscope and a laser. Using an AMF controller, a solution containing polymer precursors and a photo initiator are positioned on the xy piezo and hit with a laser beam. The thickness of the polymeric features can be varied from a few nanometers to over a micron.

  7. Ligand Replacement Approach to Raman-Responded Molecularly Imprinted Monolayer for Rapid Determination of Penicilloic Acid in Penicillin.

    Science.gov (United States)

    Zhang, Liying; Jin, Yang; Huang, Xiaoyan; Zhou, Yujie; Du, Shuhu; Zhang, Zhongping

    2015-12-01

    Penicilloic acid (PA) is a degraded byproduct of penicillin and often causes fatal allergies to humans, but its rapid detection in penicillin drugs remains a challenge due to its similarity to the mother structure of penicillin. Here, we reported a ligand-replaced molecularly imprinted monolayer strategy on a surface-enhanced Raman scattering (SERS) substrate for the specific recognition and rapid detection of Raman-inactive PA in penicillin. The bis(phenylenediamine)-Cu(2+)-PA complex was first synthesized and stabilized onto the surface of silver nanoparticle film that was fabricated by a bromide ion-added silver mirror reaction. A molecularly imprinted monolayer was formed by the further modification of alkanethiol around the stabilized complex on the Ag film substrate, and the imprinted recognition site was then created by the replacement of the complex template with Raman-active probe molecule p-aminothiophenol. When PA rebound into the imprinted site in the alkanethiol monolayer, the SERS signal of p-aminothiophenol exhibited remarkable enhancement with a detection limit of 0.10 nM. The imprinted monolayer can efficiently exclude the interference of penicillin and thus provides a selective determination of 0.10‰ (w/w) PA in penicillin, which is about 1 order of magnitude lower than the prescribed residual amount of 1.0‰. The strategy reported here is simple, rapid and inexpensive compared to the traditional chromatography-based methods.

  8. Synthesis of a Molecularly Imprinted Polymer for Dioxin

    OpenAIRE

    Magda Brattoli; Vito Sgobba; Giuseppe Ciccarella; Rosaria Anna Picca; Cosimino Malitesta

    2006-01-01

    A molecularly imprinted polymer for recognising selectively 2,3,7,8-tetrachlorodibenzodioxin (TCDD) was made by a new non-covalent method employing a“dummy†template. The proposed way represents a simplification of a synthetic schemeproposed by Lübke et al.[1] for covalent imprinting. Comparison of extraction yields of thenovel polymer, a non imprinted polymer and an imprinting polymer, prepared by theoriginal procedure demonstrates the binding capacity of the proposed polymer, wh...

  9. [Biological decontamination of the imprints obtained from different dental materials].

    Science.gov (United States)

    Brekhlichuk, P P; Petrov, V O; Bati, V V; Levchuk, O B; Boĭko, N V

    2013-01-01

    Microbiological contamination of the imprints made of alginate ("Ypeen") and silicone material ("Speedex") with and without the correction supplement has been investigated. Streptococcus and Staphylococcus have been estimated to be the most survivable species on the imprint surface, however their concentration differ depending on the type of imprints' material. The strains resistant to antibiotics dominated among all the isolated microorganisms. Bacterial preparations based on Bacillus - Biosporin and Subalin and some extracts of edible plants, fruits and berries can be used in dentistry for the decontamination of imprints obtained by the use of different materials.

  10. Synthesis of a Molecularly Imprinted Polymer for Dioxin

    Directory of Open Access Journals (Sweden)

    Magda Brattoli

    2006-08-01

    Full Text Available A molecularly imprinted polymer for recognising selectively 2,3,7,8-tetrachlorodibenzodioxin (TCDD was made by a new non-covalent method employing a“dummy” template. The proposed way represents a simplification of a synthetic schemeproposed by Lübke et al.[1] for covalent imprinting. Comparison of extraction yields of thenovel polymer, a non imprinted polymer and an imprinting polymer, prepared by theoriginal procedure demonstrates the binding capacity of the proposed polymer, which is inprinciple applicable to solid phase extraction (SPE of dioxin.

  11. Phospholipid imprinted polymers as selective endotoxin scavengers

    Science.gov (United States)

    Sulc, Robert; Szekely, Gyorgy; Shinde, Sudhirkumar; Wierzbicka, Celina; Vilela, Filipe; Bauer, David; Sellergren, Börje

    2017-03-01

    Herein we explore phospholipid imprinting as a means to design receptors for complex glycolipids comprising the toxic lipopolysaccharide endotoxin. A series of polymerizable bis-imidazolium and urea hosts were evaluated as cationic and neutral hosts for phosphates and phosphonates, the latter used as mimics of the phospholipid head groups. The bis-imidazolium hosts interacted with the guests in a cooperative manner leading to the presence of tight and well defined 1:2 ternary complexes. Optimized monomer combinations were subsequently used for imprinting of phosphatidic acid as an endotoxin dummy template. Presence of the aforementioned ternary complexes during polymerization resulted in imprinting of lipid dimers - the latter believed to crudely mimic the endotoxin Lipid A motif. The polymers were characterized with respect to template rebinding, binding affinity, capacity and common structural properties, leading to the identification of polymers which were thereafter subjected to an industrially validated endotoxin removal test. Two of the polymers were capable of removing endotoxin down to levels well below the accepted threshold (0.005 EU/mg API) in pharmaceutical production.

  12. Phospholipid imprinted polymers as selective endotoxin scavengers

    Science.gov (United States)

    Sulc, Robert; Szekely, Gyorgy; Shinde, Sudhirkumar; Wierzbicka, Celina; Vilela, Filipe; Bauer, David; Sellergren, Börje

    2017-01-01

    Herein we explore phospholipid imprinting as a means to design receptors for complex glycolipids comprising the toxic lipopolysaccharide endotoxin. A series of polymerizable bis-imidazolium and urea hosts were evaluated as cationic and neutral hosts for phosphates and phosphonates, the latter used as mimics of the phospholipid head groups. The bis-imidazolium hosts interacted with the guests in a cooperative manner leading to the presence of tight and well defined 1:2 ternary complexes. Optimized monomer combinations were subsequently used for imprinting of phosphatidic acid as an endotoxin dummy template. Presence of the aforementioned ternary complexes during polymerization resulted in imprinting of lipid dimers – the latter believed to crudely mimic the endotoxin Lipid A motif. The polymers were characterized with respect to template rebinding, binding affinity, capacity and common structural properties, leading to the identification of polymers which were thereafter subjected to an industrially validated endotoxin removal test. Two of the polymers were capable of removing endotoxin down to levels well below the accepted threshold (0.005 EU/mg API) in pharmaceutical production. PMID:28303896

  13. Role of imprint/exfoliative cytology in ulcerated skin neoplasms.

    Science.gov (United States)

    Ramakrishnaiah, Vishnu Prasad Nelamangala; Babu, Ravindra; Pai, Dinker; Verma, Surendra Kumar

    2013-12-01

    Imprint cytology is a method of studying cells by taking an imprint from the cut surface of a wedge biopsy specimen or from the resected margins of a surgical specimen. It is rapid, simple and fairly accurate. Exfoliative cytology is an offshoot from the imprint cytology where in cells obtained from the surface of ulcers, either by scrape or brush, are analyzed for the presence of malignant cells. We undertook this study to see the role of imprint/exfoliative cytology in the diagnosis of ulcerated skin neoplasm and to check the adequacy of resected margins intra-operatively. This was a prospective investigative study conducted from September 2003 to July 2005. All patients presenting to surgical clinic with ulcerated skin and soft tissue tumours were included in the study. A wedge biopsy obtained from the ulcer and imprint smears were taken from the cut surface. Exfoliative cytology was analyzed from the surface smears. Wedge biopsy specimen was sent for histopathological (HPE) examination. The cytology and HPE were analyzed by a separate pathologist. Imprint cytology was also used to check the adequacy of resected margins in case of wide excision. This was compared with final HPE. Total of 107 patients was included in the present study and 474 imprint smears were done, with an average of 4.43 slides per lesion. Out of 59 wide excision samples, 132 imprint smears were prepared for assessing resected margins accounting for an average of 2.24 slides per each excised lesion. On combining imprint cytology with exfoliative cytology the overall sensitivity, specificity and positive predictive value were 90.38 %, 100 % and 90.38 % respectively. Only one out of 59 cases had a positive resected margin which was not picked by imprint cytology. Imprint cytology can be used for rapid and accurate diagnosis of various skin malignancies. It can also be used to check the adequacy of the resected margin intraoperatively.

  14. Synthesis of L-lysine imprinted cryogels for immunoglobulin G adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Çulha, Senem; Armutcu, Canan; Uzun, Lokman; Şenel, Serap, E-mail: senel@hacettepe.edu.tr; Denizli, Adil

    2015-07-01

    L-Lysine imprinted poly(2-hydroxyethyl methacrylate-co-N-methacryloyl-L-aspartic acid) [P(HEMA-co-MAAsp)] cryogels were synthesized and characterized with Fourier transform infrared spectroscopy, scanning electron microscopy, surface area measurements, swelling, and squeezing tests. Specific surface area for imprinted cryogel was 34.2 m{sup 2}/g while the value was 21.3 m{sup 2}/g for non-imprinted cryogel. IgG adsorption from aqueous solution was examined in continuous mode examining the factors effecting adsorption capacity such as pH, concentration, flow rate, temperature, ionic strength, and incubation time. 0.5 M NaCl was used as desorption agent. The IgG adsorption capacity was determined as 55.1 mg/g for 1.0 mg/mL IgG original concentration at 25.0 °C while pH and flow rate were 7.0 and 0.5 mL/min, respectively. When human serum was used as IgG source, the removal of 90.4% of crude IgG was attained for 1/20 diluted plasma sample. The imprinted cryogel was used in ten successive cycles without significant loss in adsorption capacity. The cryogel was determined to be 1.79 times more selective to IgG than albumin and 1.45 times more selective than hemoglobin. The adsorption behavior well suited to Langmuir isotherm and the kinetics followed pseudo-second-order model. Thermodynamic parameters ΔH°, ΔS° and ΔG° for this adsorption process were also calculated. - Highlights: • L-Lysine imprinted cryogels through epitope imprinting approach • Optimization of recognition conditions for template (L-lysine) and target (IgG) biomolecules • Efficient reusability (upto 10 cycles) without any significant change in capacity • A great potential for specific and selective IgG purification • Promising, cost-friendly, specific and selective adsorbent • IgG separation/purification from complex feeding solutions like human serum.

  15. Evolution of genomic imprinting with biparental care: implications for Prader-Willi and Angelman syndromes.

    Directory of Open Access Journals (Sweden)

    Francisco Ubeda

    2008-08-01

    Full Text Available The term "imprinted gene" refers to genes whose expression is conditioned by their parental origin. Among theories to unravel the evolution of genomic imprinting, the kinship theory prevails as the most widely accepted, because it sheds light on many aspects of the biology of imprinted genes. While most assumptions underlying this theory have not escaped scrutiny, one remains overlooked: mothers are the only source of parental investment in mammals. But, is it reasonable to assume that fathers' contribution of resources is negligible? It is not in some key mammalian orders including humans. In this research, I generalize the kinship theory of genomic imprinting beyond maternal contribution only. In addition to deriving new conditions for the evolution of imprinting, I have found that the same gene may show the opposite pattern of expression when the investment of one parent relative to the investment of the other changes; the reversion, interestingly, does not require that fathers contribute more resources than mothers. This exciting outcome underscores the intimate connection between the kinship theory and the social structure of the organism considered. Finally, the insight gained from my model enabled me to explain the clinical phenotype of Prader-Willi syndrome. This syndrome is caused by the paternal inheritance of a deletion of the PWS/AS cluster of imprinted genes in human Chromosome 15. As such, children suffering from this syndrome exhibit a striking biphasic phenotype characterized by poor sucking and reduced weight before weaning but by voracious appetite and obesity after weaning. Interest in providing an evolutionary explanation to such phenotype is 2-fold. On the one hand, the kinship theory has been doubted as being able to explain the symptoms of patients with Prader-Willi. On the other hand, the post-weaning symptoms remain as one of the primary concern of pediatricians treating children with Prader-Willi. In this research, I

  16. Human Systems Integration (HSI) in Acquisition. Management Guide

    Science.gov (United States)

    2009-08-01

    Outputs boxes. Tools: ● CATIA ● HSI Requirements Guide ● IMPRINT Activities for Each Output: 1.0 Collect domain requirements inputs 1.1 Ensure...numbers In the Inputs and Outputs boxes. Technology Development Phase (Inputs) Human Systems Integration Tools: ● IMPRINT ● CATIA ● IPME...Outputs boxes. Technology Development Phase (Outputs) Human Systems Integration Tools: ● IMPRINT ● CATIA ● IPME Activities for Each Output: 1.0

  17. Investigation of imprinting parameters and their recognition nature for quinine-molecularly imprinted polymers

    Science.gov (United States)

    He, Jian-feng; Zhu, Quan-hong; Deng, Qin-ying

    2007-08-01

    A series of molecularly imprinted polymers (MIPs) was prepared using quinine as the template molecules by bulk polymerization. The presence of monomer-template solution complexes in non-covalent MIPs systems has been verified by both fluorescence and UV-vis spectrometric detection. The influence of different synthetic conditions (porogen, functional monomer, cross-linkers, initiation methods, monomer-template ratio, etc.) on recognition properties of the polymers was investigated. Scatchard analysis revealed that two classes of binding sites were formed in the imprinted polymer. The corresponding dissociation constants were estimated to be 45.00 μmol l -1 and 1.42 mmol l -1, respectively, by utilizing a multi-site recognition model. The binding characteristics of the imprinted polymers were explored in various solvents using equilibrium binding experiments. In the organic media, results suggested that polar interactions (hydrogen bonding, ionic interactions, etc.) between acidic monomer/polymer and template molecules were mainly responsible for the recognition, whereas in aqueous media, hydrophobic interactions had a remarkable non-specific contribution to the overall binding. The specificity of MIP was evaluated by rebinding the other structurally similar compounds. The results indicated that the imprinted polymers exhibited an excellent stereo-selectivity toward quinine.

  18. Imprinting diseases and IVF: Danish National IVF cohort study

    DEFF Research Database (Denmark)

    Lidegaard, Ojvind; Pinborg, Anja; Andersen, Anders Nyboe

    2005-01-01

    The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children.......The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children....

  19. Imprinting can cause a maladaptive preference for infectious conspecifics.

    Science.gov (United States)

    Stephenson, Jessica F; Reynolds, Michael

    2016-04-01

    Recognizing and associating with specific individuals, such as conspecifics or kin, brings many benefits. One mechanism underlying such recognition is imprinting: the long-term memory of cues encountered during development. Typically, juveniles imprint on cues of nearby individuals and may later associate with phenotypes matching their 'recognition template'. However, phenotype matching could lead to maladaptive social decisions if, for instance, individuals imprint on the cues of conspecifics infected with directly transmitted diseases. To investigate the role of imprinting in the sensory ecology of disease transmission, we exposed juvenile guppies,Poecilia reticulata, to the cues of healthy conspecifics, or to those experiencing disease caused by the directly transmitted parasite Gyrodactylus turnbulli In a dichotomous choice test, adult 'disease-imprinted' guppies preferred to associate with the chemical cues of G. turnbulli-infected conspecifics, whereas 'healthy-imprinted' guppies preferred to associate with cues of uninfected conspecifics. These responses were only observed when stimulus fish were in late infection, suggesting imprinted fish responded to cues of disease, but not of infection alone. We discuss how maladaptive imprinting may promote disease transmission in natural populations of a social host. © 2016 The Author(s).

  20. A STUDY OF BLOCKING AND OVERSHADOWING IN FILIAL IMPRINTING

    NARCIS (Netherlands)

    VANKAMPEN, HS; DEVOS, GJ

    1995-01-01

    The occurrence of blocking and overshadowing in filial imprinting was investigated in junglefowl chicks (Gallus gallus spadiceus). When subjects were exposed to a novel object in the presence of a familiar one, imprinting on the novel object was impaired in one of two experimental groups (Experiment

  1. A STUDY OF BLOCKING AND OVERSHADOWING IN FILIAL IMPRINTING

    NARCIS (Netherlands)

    VANKAMPEN, HS; DEVOS, GJ

    1995-01-01

    The occurrence of blocking and overshadowing in filial imprinting was investigated in junglefowl chicks (Gallus gallus spadiceus). When subjects were exposed to a novel object in the presence of a familiar one, imprinting on the novel object was impaired in one of two experimental groups (Experiment

  2. Molecularly imprinted nanotubes for enantioselective drug delivery and controlled release.

    Science.gov (United States)

    Yin, Junfa; Cui, Yue; Yang, Gengliang; Wang, Hailin

    2010-11-07

    Molecularly imprinted nanotubes for enantioselective drug delivery and controlled release are fabricated by the combination of template synthesis and ATRP grafting. The release of R-propranolol from the imprinted nanotubes in rats is restricted while the release of pharmacologically active S-enantiomer is greatly promoted.

  3. DNA replication: stalling a fork for imprinting and switching

    DEFF Research Database (Denmark)

    Egel, Richard

    2004-01-01

    Mating-type switching in fission yeast has long been known to be directed by a DNA 'imprint'. This imprint has now been firmly characterized as a protected site-specific and strand-specific nick. New work also links the widely conserved Swi1-Swi3 complex to the protection of stalled replication...

  4. Development of fructosyl valine binding polymers by covalent imprinting.

    Science.gov (United States)

    Rajkumar, Rajagopal; Warsinke, Axel; Möhwald, Helmuth; Scheller, Frieder W; Katterle, Martin

    2007-06-15

    Molecularly imprinted polymers (MIPs) against fructosyl valine (Fru-Val), the N-terminal constituent of hemoglobin A1c beta-chains, were prepared by cross-linking of beta-D-Fru-Val-O-bis(4-vinylphenylboronate) with an excess of ethylene glycol dimethacrylate (EDMA) or trimethylolpropane trimethacrylate (TRIM). Control MIPs were prepared in analogy by cross-linking the corresponding vinylphenylboronate esters of fructose and pinacol. After template extraction batch rebinding studies were performed using different pH values and buffer compositions. The Fru-Val imprinted TRIM cross-linked polymer binds about 1.4 times more Fru-Val than the fructose imprinted polymer and 2.7 times more Fru-Val than pinacol imprinted polymer. The highest imprinting effect was obtained in 100 mM sodium carbonate/10% methanol (pH 11.4). The TRIM cross-linked Fru-Val imprinted polymer showed a better specificity than the EDMA cross-linked polymer. The binding of valine was very low. Thermo gravimetric analysis indicated that the generated Fru-Val imprinted polymer has high thermo stability. No change in binding was observed after incubation of the polymers in buffer at 80 degrees C for 36 h. Since the functional group of the polymers (phenyl boronic acid) targets the sugar part of Fru-Val the imprint technique used should also be applicable for the development of MIPs against other glycated amino acids and peptides.

  5. Imprinting diseases and IVF: Danish National IVF cohort study

    DEFF Research Database (Denmark)

    Lidegaard, Ojvind; Pinborg, Anja; Andersen, Anders Nyboe

    2005-01-01

    The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children.......The aim of this study was to compare the frequency of imprinting diseases in children born after IVF with the incidence in naturally conceived children....

  6. Mycotoxin analysis using imprinted materials technology: Recent developments

    Science.gov (United States)

    Molecular imprinting technology is an attractive, cost effective, and robust alternative to address the limitations of highly selective natural receptors, such as antibodies and aptamers. The field of molecular imprinting has seen a recent surge in growth with several commercially available products...

  7. Characterization of three novel imprinted snoRNAs from mouse Irm gene.

    Science.gov (United States)

    Xiao, Yu; Zhou, Hui; Qu, Liang-Hu

    2006-02-24

    Most, if not all, of snoRNAs in mammals are intron-encoded, implying the expressional and functional relativeness between the snoRNA and their hosts. By computational analysis of an intron database extracted from 65 known mouse imprinted genes, three novel orphan box C/D snoRNAs were identified from Irm gene which is maternally expressed and related to human disorders. The snoRNAs were positively detected and found to express in all the mouse tissues except kidney. The imprinted snoRNAs exhibit stringent structures, but quite variable in locations at their host introns, suggesting their maturation probably through a splicing independent manner. We characterized Irm as a new kind of snoRNA host gene which has no protein-coding capacity and no 5'TOP structure in its mRNA. The newly identified snoRNAs appear mouse-specific, however, their function remains to be elucidated.

  8. Characteristic and Synthetic Approach of Molecularly Imprinted Polymer

    Directory of Open Access Journals (Sweden)

    Kyung Ho Row

    2006-06-01

    Full Text Available Molecularly imprinted polymers (MIP exhibiting high selectivity and affinity tothe predetermined molecule (template are now seeing a fast growing research. However,optimization of the imprinted products is difficult due to the fact that there are manyvariables to consider, some or all of which can potentially impact upon the chemical,morphological and molecular recognition properties of the imprinted materials. This reviewpresent a summary of the principal synthetic considerations pertaining to good practice in thepolymerization aspects of molecular imprinting, and is primarily aimed at researcher familiarwith molecular imprinting methods but with little or no prior experience in polymersynthesis. The synthesis, characteristic, effect of molecular recognition and differentpreparation methods of MIP in recent few years are discussed in this review, unsolvedproblems and possible developments of MIP were also been briefly discussed.

  9. Molecularly imprinted macroporous monolithic materials for protein recognition

    Institute of Scientific and Technical Information of China (English)

    Qi Liang Deng; Yan Li Li; Li Hua Zhang; Yu Kui Zhang

    2011-01-01

    Synthetic materials that can specifically recognize proteins will find wide application in many fields. In this report, bovine serum albumin was chosen as the template protein. Acrylamide and N, N'-methylenebisacrylamide were employed as the functional and cross-linker monomers, respectively. Molecularly imprinted macroporous monolithic materials that can preferentially bind the template protein in an aqueous environment were prepared by combination of molecular imprinting technique and freezing/thawing preparation method. The resulted imprinted macroporous monolithic columns were evaluated by utilizing as stationary phase in high performance liquid chromatography and solid-phase extraction materials. The experimental results indicated that the imprinted macroporous monolithic column exhibited good recognition for template protein, as compared with the control protein (hemoglobin), whereas the non-imprinted polymer (prepared under the same conditions except without addition template protein) had no selective properties.

  10. Small organic molecular imprinted materials: their preparation and application.

    Science.gov (United States)

    Jiang, Xiaoman; Jiang, Na; Zhang, Haixia; Liu, Mancang

    2007-09-01

    Molecular imprinting is a technique for preparing polymeric materials that are capable of recognizing and binding the desired molecular target with a high affinity and selectivity. The materials can be applied to a wide range of target molecules, even those for which no natural binder exists or whose antibodies are difficult to raise. The imprinting of small organic molecules (e.g., pharmaceuticals, pesticides, amino acids, steroids, and sugars) is now almost routine. In this review, we pay special attention to the synthesis and application of molecular imprinted polymer (MIPs) imprinted with small organic molecules, including herbicides, pesticides, and drugs. The advantages, applications, and recent developments in small organic molecular imprinted technology are highlighted.

  11. BACs as tools for the study of genomic imprinting.

    Science.gov (United States)

    Tunster, S J; Van De Pette, M; John, R M

    2011-01-01

    Genomic imprinting in mammals results in the expression of genes from only one parental allele. Imprinting occurs as a consequence of epigenetic marks set down either in the father's or the mother's germ line and affects a very specific category of mammalian gene. A greater understanding of this distinctive phenomenon can be gained from studies using large genomic clones, called bacterial artificial chromosomes (BACs). Here, we review the important applications of BACs to imprinting research, covering physical mapping studies and the use of BACs as transgenes in mice to study gene expression patterns, to identify imprinting centres, and to isolate the consequences of altered gene dosage. We also highlight the significant and unique advantages that rapid BAC engineering brings to genomic imprinting research.

  12. BACs as Tools for the Study of Genomic Imprinting

    Directory of Open Access Journals (Sweden)

    S. J. Tunster

    2011-01-01

    Full Text Available Genomic imprinting in mammals results in the expression of genes from only one parental allele. Imprinting occurs as a consequence of epigenetic marks set down either in the father's or the mother's germ line and affects a very specific category of mammalian gene. A greater understanding of this distinctive phenomenon can be gained from studies using large genomic clones, called bacterial artificial chromosomes (BACs. Here, we review the important applications of BACs to imprinting research, covering physical mapping studies and the use of BACs as transgenes in mice to study gene expression patterns, to identify imprinting centres, and to isolate the consequences of altered gene dosage. We also highlight the significant and unique advantages that rapid BAC engineering brings to genomic imprinting research.

  13. Imprinting of Microorganisms for Biosensor Applications

    Science.gov (United States)

    Idil, Neslihan; Mattiasson, Bo

    2017-01-01

    There is a growing need for selective recognition of microorganisms in complex samples due to the rapidly emerging importance of detecting them in various matrices. Most of the conventional methods used to identify microorganisms are time-consuming, laborious and expensive. In recent years, many efforts have been put forth to develop alternative methods for the detection of microorganisms. These methods include use of various components such as silica nanoparticles, microfluidics, liquid crystals, carbon nanotubes which could be integrated with sensor technology in order to detect microorganisms. In many of these publications antibodies were used as recognition elements by means of specific interactions between the target cell and the binding site of the antibody for the purpose of cell recognition and detection. Even though natural antibodies have high selectivity and sensitivity, they have limited stability and tend to denature in conditions outside the physiological range. Among different approaches, biomimetic materials having superior properties have been used in creating artificial systems. Molecular imprinting is a well suited technique serving the purpose to develop highly selective sensing devices. Molecularly imprinted polymers defined as artificial recognition elements are of growing interest for applications in several sectors of life science involving the investigations on detecting molecules of specific interest. These polymers have attractive properties such as high bio-recognition capability, mechanical and chemical stability, easy preparation and low cost which make them superior over natural recognition reagents. This review summarizes the recent advances in the detection and quantification of microorganisms by emphasizing the molecular imprinting technology and its applications in the development of sensor strategies. PMID:28353629

  14. Functional mapping imprinted quantitative trait loci underlying developmental characteristics

    Directory of Open Access Journals (Sweden)

    Li Gengxin

    2008-03-01

    Full Text Available Abstract Background Genomic imprinting, a phenomenon referring to nonequivalent expression of alleles depending on their parental origins, has been widely observed in nature. It has been shown recently that the epigenetic modification of an imprinted gene can be detected through a genetic mapping approach. Such an approach is developed based on traditional quantitative trait loci (QTL mapping focusing on single trait analysis. Recent studies have shown that most imprinted genes in mammals play an important role in controlling embryonic growth and post-natal development. For a developmental character such as growth, current approach is less efficient in dissecting the dynamic genetic effect of imprinted genes during individual ontology. Results Functional mapping has been emerging as a powerful framework for mapping quantitative trait loci underlying complex traits showing developmental characteristics. To understand the genetic architecture of dynamic imprinted traits, we propose a mapping strategy by integrating the functional mapping approach with genomic imprinting. We demonstrate the approach through mapping imprinted QTL controlling growth trajectories in an inbred F2 population. The statistical behavior of the approach is shown through simulation studies, in which the parameters can be estimated with reasonable precision under different simulation scenarios. The utility of the approach is illustrated through real data analysis in an F2 family derived from LG/J and SM/J mouse stains. Three maternally imprinted QTLs are identified as regulating the growth trajectory of mouse body weight. Conclusion The functional iQTL mapping approach developed here provides a quantitative and testable framework for assessing the interplay between imprinted genes and a developmental process, and will have important implications for elucidating the genetic architecture of imprinted traits.

  15. The Drosophila homolog of the mammalian imprint regulator, CTCF, maintains the maternal genomic imprint in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Rasheva Vanya

    2010-07-01

    Full Text Available Abstract Background CTCF is a versatile zinc finger DNA-binding protein that functions as a highly conserved epigenetic transcriptional regulator. CTCF is known to act as a chromosomal insulator, bind promoter regions, and facilitate long-range chromatin interactions. In mammals, CTCF is active in the regulatory regions of some genes that exhibit genomic imprinting, acting as insulator on only one parental allele to facilitate parent-specific expression. In Drosophila, CTCF acts as a chromatin insulator and is thought to be actively involved in the global organization of the genome. Results To determine whether CTCF regulates imprinting in Drosophila, we generated CTCF mutant alleles and assayed gene expression from the imprinted Dp(1;fLJ9 mini-X chromosome in the presence of reduced CTCF expression. We observed disruption of the maternal imprint when CTCF levels were reduced, but no effect was observed on the paternal imprint. The effect was restricted to maintenance of the imprint and was specific for the Dp(1;fLJ9 mini-X chromosome. Conclusions CTCF in Drosophila functions in maintaining parent-specific expression from an imprinted domain as it does in mammals. We propose that Drosophila CTCF maintains an insulator boundary on the maternal X chromosome, shielding genes from the imprint-induced silencing that occurs on the paternally inherited X chromosome. See commentary: http://www.biomedcentral.com/1741-7007/8/104

  16. Imprint of Galactic dynamics on Earth's climate

    DEFF Research Database (Denmark)

    Svensmark, Henrik

    2006-01-01

    A connection between climate and the Solar system's motion perpendicular to the Galactic plane during the last 200 Myr years is studied. An imprint of galactic dynamics is found in a long-term record of the Earth's climate that is consistent with variations in the Solar system oscillation around ......(arm)/rho(interarm) approximate to 1.5-1.8), and finally, using current knowledge of spiral arm positions, a pattern speed of Omega(P) = 13.6 +/- 1.4 km s(-1) kpc(-1) is determined....

  17. Imprints of Anisotropic Inflation on the CMB

    CERN Document Server

    Watanabe, Masa-aki; Soda, Jiro

    2010-01-01

    We study the imprints of anisotropic inflation on the CMB temperature fluctuations and polarizations. The statistical anisotropy stems not only from the direction dependence of curvature and tensor perturbations, but also from the cross correlation between curvature and tensor perturbations, and the linear polarization of tensor perturbations. We show that off-diagonal $TB$ and $EB$ spectrum as well as on- and off-diagonal $TT, EE, BB, TE$ spectrum are induced from anisotropic inflation. We emphasize that the off-diagonal spectrum induced by the cross correlation could be a characteristic signature of anisotropic inflation.

  18. Molecular mechanisms of memory in imprinting.

    Science.gov (United States)

    Solomonia, Revaz O; McCabe, Brian J

    2015-03-01

    Converging evidence implicates the intermediate and medial mesopallium (IMM) of the domestic chick forebrain in memory for a visual imprinting stimulus. During and after imprinting training, neuronal responsiveness in the IMM to the familiar stimulus exhibits a distinct temporal profile, suggesting several memory phases. We discuss the temporal progression of learning-related biochemical changes in the IMM, relative to the start of this electrophysiological profile. c-fos gene expression increases <15 min after training onset, followed by a learning-related increase in Fos expression, in neurons immunopositive for GABA, taurine and parvalbumin (not calbindin). Approximately simultaneously or shortly after, there are increases in phosphorylation level of glutamate (AMPA) receptor subunits and in releasable neurotransmitter pools of GABA and taurine. Later, the mean area of spine synapse post-synaptic densities, N-methyl-D-aspartate receptor number and phosphorylation level of further synaptic proteins are elevated. After ∼ 15 h, learning-related changes in amounts of several synaptic proteins are observed. The results indicate progression from transient/labile to trophic synaptic modification, culminating in stable recognition memory. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  19. Molecular mechanisms of memory in imprinting

    Science.gov (United States)

    Solomonia, Revaz O.; McCabe, Brian J.

    2015-01-01

    Converging evidence implicates the intermediate and medial mesopallium (IMM) of the domestic chick forebrain in memory for a visual imprinting stimulus. During and after imprinting training, neuronal responsiveness in the IMM to the familiar stimulus exhibits a distinct temporal profile, suggesting several memory phases. We discuss the temporal progression of learning-related biochemical changes in the IMM, relative to the start of this electrophysiological profile. c-fos gene expression increases <15 min after training onset, followed by a learning-related increase in Fos expression, in neurons immunopositive for GABA, taurine and parvalbumin (not calbindin). Approximately simultaneously or shortly after, there are increases in phosphorylation level of glutamate (AMPA) receptor subunits and in releasable neurotransmitter pools of GABA and taurine. Later, the mean area of spine synapse post-synaptic densities, N-methyl-d-aspartate receptor number and phosphorylation level of further synaptic proteins are elevated. After ∼15 h, learning-related changes in amounts of several synaptic proteins are observed. The results indicate progression from transient/labile to trophic synaptic modification, culminating in stable recognition memory. PMID:25280906

  20. Molecularly Imprinted Filtering Adsorbents for Odor Sensing

    Directory of Open Access Journals (Sweden)

    Sho Shinohara

    2016-11-01

    Full Text Available Versatile odor sensors that can discriminate among huge numbers of environmental odorants are desired in many fields, including robotics, environmental monitoring, and food production. However, odor sensors comparable to an animal’s nose have not yet been developed. An animal’s olfactory system recognizes odor clusters with specific molecular properties and uses this combinatorial information in odor discrimination. This suggests that measurement and clustering of odor molecular properties (e.g., polarity, size using an artificial sensor is a promising approach to odor sensing. Here, adsorbents composed of composite materials with molecular recognition properties were developed for odor sensing. The selectivity of the sensor depends on the adsorbent materials, so specific polymeric materials with particular solubility parameters were chosen to adsorb odorants with various properties. The adsorption properties of the adsorbents could be modified by mixing adsorbent materials. Moreover, a novel molecularly imprinted filtering adsorbent (MIFA, composed of an adsorbent substrate covered with a molecularly imprinted polymer (MIP layer, was developed to improve the odor molecular recognition ability. The combination of the adsorbent and MIP layer provided a higher specificity toward target molecules. The MIFA thus provides a useful technique for the design and control of adsorbents with adsorption properties specific to particular odor molecules.

  1. Econazole imprinted textiles with antifungal activity.

    Science.gov (United States)

    Hossain, Mirza Akram; Lalloz, Augustine; Benhaddou, Aicha; Pagniez, Fabrice; Raymond, Martine; Le Pape, Patrice; Simard, Pierre; Théberge, Karine; Leblond, Jeanne

    2016-04-01

    In this work, we propose pharmaceutical textiles imprinted with lipid microparticles of Econazole nitrate (ECN) as a mean to improve patient compliance while maintaining drug activity. Lipid microparticles were prepared and characterized by laser diffraction (3.5±0.1 μm). Using an optimized screen-printing method, microparticles were deposited on textiles, as observed by scanning electron microscopy. The drug content of textiles (97±3 μg/cm(2)) was reproducible and stable up to 4 months storage at 25 °C/65% Relative Humidity. Imprinted textiles exhibited a thermosensitive behavior, as witnessed by a fusion temperature of 34.8 °C, which enabled a larger drug release at 32 °C (temperature of the skin) than at room temperature. In vitro antifungal activity of ECN textiles was compared to commercial 1% (wt/wt) ECN cream Pevaryl®. ECN textiles maintained their antifungal activity against a broad range of Candida species as well as major dermatophyte species. In vivo, ECN textiles also preserved the antifungal efficacy of ECN on cutaneous candidiasis infection in mice. Ex vivo percutaneous absorption studies demonstrated that ECN released from pharmaceutical textiles concentrated more in the upper skin layers, where the fungal infections develop, as compared to dermal absorption of Pevaryl®. Overall, these results showed that this technology is promising to develop pharmaceutical garments textiles for the treatment of superficial fungal infections.

  2. Genomic imprinting: genetic mechanisms and phenotypic consequences in Prader-Willi and Angelman syndromes

    Directory of Open Access Journals (Sweden)

    Cintia Fridman

    2000-12-01

    Full Text Available Chromosomal 15q11-q13 region is of great interest in Human Genetics because many structural rearrangements have been described for it (deletions, duplications and translocations leading to phenotypes resulting in conditions such as the Prader-Willi (PWS and Angelman (AS syndromes which were the first human diseases found to be related to the differential expression of parental alleles (genomic imprinting. Contrary to Mendelian laws where the parental inheritance of genetic information does not influence gene expression, genomic imprinting is characterized by DNA modifications that produce different phenotypes depending on the parental origin of the mutation. Clinical manifestation of PWS appears when the loss of paternally expressed genes occurs and AS results from the loss of a maternally expressed gene. Different genetic mechanisms can lead to PWS or AS, such as deletions, uniparental disomy or imprinting mutation. In AS patients an additional class occurs with mutations on the UBE3A gene. Studies of PWS and AS patients can help us to understand the imprinting process, so that other genomic regions with similar characteristics can be located, and different syndromes can have their genetic mechanisms elucidated.O segmento cromossômico 15q11-q13 é de grande interesse em Genética Humana uma vez que diversos rearranjos estruturais têm sido descritos nessa região (deleções, duplicações e translocações resultando em fenótipos diferentes como os das síndromes de Prader-Willi (PWS e Angelman (AS, que foram as primeiras doenças humanas a serem relacionadas com a expressão diferencial de alelos parentais (imprinting genômico. Contrário às leis de Mendel onde a herança parental da informação genética não influencia a expressão gênica, o imprinting genômico é caracterizado por modificações no DNA que produzem diferentes fenótipos dependendo da origem parental da mutação. A manifestação clínica da PWS aparece quando

  3. Neuronal plasticity and multisensory integration in filial imprinting.

    Science.gov (United States)

    Town, Stephen Michael; McCabe, Brian John

    2011-03-10

    Many organisms sample their environment through multiple sensory systems and the integration of multisensory information enhances learning. However, the mechanisms underlying multisensory memory formation and their similarity to unisensory mechanisms remain unclear. Filial imprinting is one example in which experience is multisensory, and the mechanisms of unisensory neuronal plasticity are well established. We investigated the storage of audiovisual information through experience by comparing the activity of neurons in the intermediate and medial mesopallium of imprinted and naïve domestic chicks (Gallus gallus domesticus) in response to an audiovisual imprinting stimulus and novel object and their auditory and visual components. We find that imprinting enhanced the mean response magnitude of neurons to unisensory but not multisensory stimuli. Furthermore, imprinting enhanced responses to incongruent audiovisual stimuli comprised of mismatched auditory and visual components. Our results suggest that the effects of imprinting on the unisensory and multisensory responsiveness of IMM neurons differ and that IMM neurons may function to detect unexpected deviations from the audiovisual imprinting stimulus.

  4. A model for transgenerational imprinting variation in complex traits.

    Science.gov (United States)

    Wang, Chenguang; Wang, Zhong; Luo, Jiangtao; Li, Qin; Li, Yao; Ahn, Kwangmi; Prows, Daniel R; Wu, Rongling

    2010-07-14

    Despite the fact that genetic imprinting, i.e., differential expression of the same allele due to its different parental origins, plays a pivotal role in controlling complex traits or diseases, the origin, action and transmission mode of imprinted genes have still remained largely unexplored. We present a new strategy for studying these properties of genetic imprinting with a two-stage reciprocal F mating design, initiated with two contrasting inbred lines. This strategy maps quantitative trait loci that are imprinted (i.e., iQTLs) based on their segregation and transmission across different generations. By incorporating the allelic configuration of an iQTL genotype into a mixture model framework, this strategy provides a path to trace the parental origin of alleles from previous generations. The imprinting effects of iQTLs and their interactions with other traditionally defined genetic effects, expressed in different generations, are estimated and tested by implementing the EM algorithm. The strategy was used to map iQTLs responsible for survival time with four reciprocal F populations and test whether and how the detected iQTLs inherit their imprinting effects into the next generation. The new strategy will provide a tool for quantifying the role of imprinting effects in the creation and maintenance of phenotypic diversity and elucidating a comprehensive picture of the genetic architecture of complex traits and diseases.

  5. A model for transgenerational imprinting variation in complex traits.

    Directory of Open Access Journals (Sweden)

    Chenguang Wang

    Full Text Available Despite the fact that genetic imprinting, i.e., differential expression of the same allele due to its different parental origins, plays a pivotal role in controlling complex traits or diseases, the origin, action and transmission mode of imprinted genes have still remained largely unexplored. We present a new strategy for studying these properties of genetic imprinting with a two-stage reciprocal F mating design, initiated with two contrasting inbred lines. This strategy maps quantitative trait loci that are imprinted (i.e., iQTLs based on their segregation and transmission across different generations. By incorporating the allelic configuration of an iQTL genotype into a mixture model framework, this strategy provides a path to trace the parental origin of alleles from previous generations. The imprinting effects of iQTLs and their interactions with other traditionally defined genetic effects, expressed in different generations, are estimated and tested by implementing the EM algorithm. The strategy was used to map iQTLs responsible for survival time with four reciprocal F populations and test whether and how the detected iQTLs inherit their imprinting effects into the next generation. The new strategy will provide a tool for quantifying the role of imprinting effects in the creation and maintenance of phenotypic diversity and elucidating a comprehensive picture of the genetic architecture of complex traits and diseases.

  6. Characterization of the Binding Properties of Molecularly Imprinted Polymers.

    Science.gov (United States)

    Ansell, Richard J

    2015-01-01

    The defining characteristic of the binding sites of any particular molecularly imprinted material is heterogeneity: that is, they are not all identical. Nonetheless, it is useful to study their fundamental binding properties, and to obtain average properties. In particular, it has been instructive to compare the binding properties of imprinted and non-imprinted materials. This chapter begins by considering the origins of this site heterogeneity. Next, the properties of interest of imprinted binding sites are described in brief: affinity, selectivity, and kinetics. The binding/adsorption isotherm, the graph of concentration of analyte bound to a MIP versus concentration of free analyte at equilibrium, over a range of total concentrations, is described in some detail. Following this, the techniques for studying the imprinted sites are described (batch-binding assays, radioligand binding assays, zonal chromatography, frontal chromatography, calorimetry, and others). Thereafter, the parameters that influence affinity, selectivity and kinetics are discussed (solvent, modifiers of organic solvents, pH of aqueous solvents, temperature). Finally, mathematical attempts to fit the adsorption isotherms for imprinted materials, so as to obtain information about the range of binding affinities characterizing the imprinted sites, are summarized.

  7. The evolution of genomic imprinting: theories, predictions and empirical tests.

    Science.gov (United States)

    Patten, M M; Ross, L; Curley, J P; Queller, D C; Bonduriansky, R; Wolf, J B

    2014-08-01

    The epigenetic phenomenon of genomic imprinting has motivated the development of numerous theories for its evolutionary origins and genomic distribution. In this review, we examine the three theories that have best withstood theoretical and empirical scrutiny. These are: Haig and colleagues' kinship theory; Day and Bonduriansky's sexual antagonism theory; and Wolf and Hager's maternal-offspring coadaptation theory. These theories have fundamentally different perspectives on the adaptive significance of imprinting. The kinship theory views imprinting as a mechanism to change gene dosage, with imprinting evolving because of the differential effect that gene dosage has on the fitness of matrilineal and patrilineal relatives. The sexual antagonism and maternal-offspring coadaptation theories view genomic imprinting as a mechanism to modify the resemblance of an individual to its two parents, with imprinting evolving to increase the probability of expressing the fitter of the two alleles at a locus. In an effort to stimulate further empirical work on the topic, we carefully detail the logic and assumptions of all three theories, clarify the specific predictions of each and suggest tests to discriminate between these alternative theories for why particular genes are imprinted.

  8. THE DIAGNOSTIC ACCURACY OF IMPRINT CYTOLOGY IN BREAST LESIONS

    Directory of Open Access Journals (Sweden)

    Shashidhar

    2015-03-01

    Full Text Available BACKGROUND : The imprint cytology is one of the rapid diagnostic tools in the field of diagnostic pathology. This method not only helps us to examine the individual cells but also aids in analyzing the patterns of particular lesion. Differentiating between benign and malignant lesions prior to or during surgery, helps the surgeon to decide on the extent of surgery. AIMS : The present study was conducted to know the accuracy of intraoperative imprint smears and to compare the results with that of histopathological sections in all breast tumors. MATERIALS AND METHOD S : This was a descriptive study on 100 cases of breast lesions comprising of inflammatory, benign & malignant. Results were compared with histopathology. STATISTICAL ANALYSIS USED: Sensitivity, specificity, positive predictive value an d negative predictive value . RESULTS : Out of 100 cases, 50 cases were diagnosed as benign and 50 cases as malignant lesions on imprint smear . Fibroadenoma (26% was the most common benign lesion and invasive ductal carcinoma ( 38% was the most common malig nant lesion. The sensitivity and specificity of imprint cytology were 98% and 96.1% respectively. 96% PPV, 98% NPV and 97% overall diagnostic accuracy was observed for imprint cytology in the present study. CONCLUSIONS: Imprint cytology is a simple, accurate, rapid & cost effective diagnostic tool used intra operatively, where in facilities for frozen sections are not available. KEYWORDS : Imprint; histopathology; benign ; malignant; breast.

  9. Positive darwinian selection at the imprinted MEDEA locus in plants.

    Science.gov (United States)

    Spillane, Charles; Schmid, Karl J; Laoueillé-Duprat, Sylvia; Pien, Stéphane; Escobar-Restrepo, Juan-Miguel; Baroux, Célia; Gagliardini, Valeria; Page, Damian R; Wolfe, Kenneth H; Grossniklaus, Ueli

    2007-07-19

    In mammals and seed plants, a subset of genes is regulated by genomic imprinting where an allele's activity depends on its parental origin. The parental conflict theory suggests that genomic imprinting evolved after the emergence of an embryo-nourishing tissue (placenta and endosperm), resulting in an intragenomic parental conflict over the allocation of nutrients from mother to offspring. It was predicted that imprinted genes, which arose through antagonistic co-evolution driven by a parental conflict, should be subject to positive darwinian selection. Here we show that the imprinted plant gene MEDEA (MEA), which is essential for seed development, originated during a whole-genome duplication 35 to 85 million years ago. After duplication, MEA underwent positive darwinian selection consistent with neo-functionalization and the parental conflict theory. MEA continues to evolve rapidly in the out-crossing species Arabidopsis lyrata but not in the self-fertilizing species Arabidopsis thaliana, where parental conflicts are reduced. The paralogue of MEA, SWINGER (SWN; also called EZA1), is not imprinted and evolved under strong purifying selection because it probably retained the ancestral function of the common precursor gene. The evolution of MEA suggests a late origin of genomic imprinting within the Brassicaceae, whereas imprinting is thought to have originated early within the mammalian lineage.

  10. Targeted deletion of the Nesp55 DMR defines another Gnas imprinting control region and provides a mouse model of autosomal dominant PHP-Ib.

    Science.gov (United States)

    Fröhlich, Leopold F; Mrakovcic, Maria; Steinborn, Ralf; Chung, Ung-Il; Bastepe, Murat; Jüppner, Harald

    2010-05-18

    Approximately 100 genes undergo genomic imprinting. Mutations in fewer than 10 imprinted genetic loci, including GNAS, are associated with complex human diseases that differ phenotypically based on the parent transmitting the mutation. Besides the ubiquitously expressed Gsalpha, which is of broad biological importance, GNAS gives rise to an antisense transcript and to several Gsalpha variants that are transcribed from the nonmethylated parental allele. We previously identified two almost identical GNAS microdeletions extending from exon NESP55 to antisense (AS) exon 3 (delNESP55/delAS3-4). When inherited maternally, both deletions are associated with erasure of all maternal GNAS methylation imprints and autosomal-dominant pseudohypoparathyroidism type Ib, a disorder characterized by parathyroid hormone-resistant hypocalcemia and hyperphosphatemia. As for other imprinting disorders, the mechanisms resulting in abnormal GNAS methylation are largely unknown, in part because of a paucity of suitable animal models. We now showed in mice that deletion of the region equivalent to delNESP55/delAS3-4 on the paternal allele (DeltaNesp55(p)) leads to healthy animals without Gnas methylation changes. In contrast, mice carrying the deletion on the maternal allele (DeltaNesp55(m)) showed loss of all maternal Gnas methylation imprints, leading in kidney to increased 1A transcription and decreased Gsalpha mRNA levels, and to associated hypocalcemia, hyperphosphatemia, and secondary hyperparathyroidism. Besides representing a murine autosomal-dominant pseudohypoparathyroidism type Ib model and one of only few animal models for imprinted human disorders, our findings suggest that the Nesp55 differentially methylated region is an additional principal imprinting control region, which directs Gnas methylation and thereby affects expression of all maternal Gnas-derived transcripts.

  11. Gene interactions in the evolution of genomic imprinting.

    Science.gov (United States)

    Wolf, J B; Brandvain, Y

    2014-08-01

    Numerous evolutionary theories have been developed to explain the epigenetic phenomenon of genomic imprinting. Here, we explore a subset of theories wherein non-additive genetic interactions can favour imprinting. In the simplest genic interaction--the case of underdominance--imprinting can be favoured to hide effectively low-fitness heterozygous genotypes; however, as there is no asymmetry between maternally and paternally inherited alleles in this model, other means of enforcing monoallelic expression may be more plausible evolutionary outcomes than genomic imprinting. By contrast, more successful interaction models of imprinting rely on an asymmetry between the maternally and paternally inherited alleles at a locus that favours the silencing of one allele as a means of coordinating the expression of high-fitness allelic combinations. For example, with interactions between autosomal loci, imprinting functionally preserves high-fitness genotypes that were favoured by selection in the previous generation. In this scenario, once a focal locus becomes imprinted, selection at interacting loci favours a matching imprint. Uniparental transmission generates similar asymmetries for sex chromosomes and cytoplasmic factors interacting with autosomal loci, with selection favouring the expression of either maternal or paternally derived autosomal alleles depending on the pattern of transmission of the uniparentally inherited factor. In a final class of models, asymmetries arise when genes expressed in offspring interact with genes expressed in one of its parents. Under such a scenario, a locus evolves to have imprinted expression in offspring to coordinate the interaction with its parent's genome. We illustrate these models and explore key links and differences using a unified framework.

  12. Shape recognition of microbial cells by colloidal cell imprints

    Science.gov (United States)

    Borovička, Josef; Stoyanov, Simeon D.; Paunov, Vesselin N.

    2013-08-01

    We have engineered a class of colloids which can recognize the shape and size of targeted microbial cells and selectively bind to their surfaces. These imprinted colloid particles, which we called ``colloid antibodies'', were fabricated by partial fragmentation of silica shells obtained by templating the targeted microbial cells. We successfully demonstrated the shape and size recognition between such colloidal imprints and matching microbial cells. High percentage of binding events of colloidal imprints with the size matching target particles was achieved. We demonstrated selective binding of colloidal imprints to target microbial cells in a binary mixture of cells of different shapes and sizes, which also resulted in high binding selectivity. We explored the role of the electrostatic interactions between the target cells and their colloid imprints by pre-coating both of them with polyelectrolytes. Selective binding occurred predominantly in the case of opposite surface charges of the colloid cell imprint and the targeted cells. The mechanism of the recognition is based on the amplification of the surface adhesion in the case of shape and size match due to the increased contact area between the target cell and the colloidal imprint. We also tested the selective binding for colloid imprints of particles of fixed shape and varying sizes. The concept of cell recognition by colloid imprints could be used for development of colloid antibodies for shape-selective binding of microbes. Such colloid antibodies could be additionally functionalized with surface groups to enhance their binding efficiency to cells of specific shape and deliver a drug payload directly to their surface or allow them to be manipulated using external fields. They could benefit the pharmaceutical industry in developing selective antimicrobial therapies and formulations.

  13. Imprinting, learning and development: from behaviour to brain and back.

    Science.gov (United States)

    Bolhuis, J J; Honey, R C

    1998-07-01

    Neural and behavioural analyses have shown that the formation of filial preferences in young, precocial birds involves at least two separate processes. One process is an emerging predisposition to approach stimuli with the characteristics of the natural mother. The other (learning) process of filial imprinting results in chicks preferentially-approaching a stimulus to which they have been exposed and involves forming links between the components of the exposed stimulus. The neural substrate for the predisposition is different from that underlying imprinting, and different regions of the chick brain are involved in distinct aspects of learning about imprinting stimuli.

  14. Dummy molecularly imprinted mesoporous silica prepared by hybrid imprinting method for solid-phase extraction of bisphenol A.

    Science.gov (United States)

    Yu, Dan; Hu, Xiaolei; Wei, Shoutai; Wang, Qiang; He, Chiyang; Liu, Shaorong

    2015-05-29

    A novel hybrid dummy imprinting strategy was developed to prepare a mesoporous silica for the solid-phase extraction (SPE) of bisphenol A (BPA). A new covalent template-monomer complex (BPAF-Si) was first synthesized with 2,2-bis(4-hydroxyphenyl)hexafluoropropane (BPAF) as the template. The imprinted silica was obtained through the gelation of BPAF-Si with tetraethoxysilane and the subsequent removal of template by thermal cleavage, and then it was characterized by FT-IR spectroscopy, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption isotherms. Results showed that the new silica had micron-level particle size and ordered mesoporous structure. The static binding test verified that the imprinted silica had much higher recognition ability for BPA than the non-imprinted silica. The imprinted silica also showed high extraction efficiencies and high enrichment factor for SPE of BPA. Using the imprinted silica, a SPE-HPLC-UV method was developed and successfully applied for detecting BPA in BPA-spiked tap water and lake water samples with a recovery of 99-105%, a RSD of 2.7-5.0% and a limit of detection (S/N=3) of 0.3ng/mL. The new imprinted silica avoided the interference of the residual template molecules and reduced the non-specific binding sites, and therefore it can be utilized as a good sorbent for SPE of BPA in environmental water samples.

  15. Imprinted ZnO nanostructure-based electrochemical sensing of calcitonin: A clinical marker for medullary thyroid carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Patra, Santanu; Roy, Ekta [Department of Applied Chemistry, Indian School of Mines, Dhanbad, Jharkhand 826 004 (India); Madhuri, Rashmi, E-mail: rshmmadhuri@gmail.com [Department of Applied Chemistry, Indian School of Mines, Dhanbad, Jharkhand 826 004 (India); Sharma, Prashant K. [Functional Nanomaterials Research Laboratory, Department of Applied Physics, Indian School of Mines, Dhanbad, Jharkhand 826 004 (India)

    2015-01-01

    Highlights: • Molecular imprinting-based sensor for medullary thyroid carcinoma marker was developed. • ZnO nanostructure was used as a platform for synthesis of imprinted polymer. • Imprinted polymer was prepared by ARGET–ATRP method. • A novel and biocompatible tyrosine amino acid derivative was used as monomer. • Linear working range is found from 9.99 ng L{sup −1} to 7.919 mg L{sup −1} with LOD 3.09 ng L{sup −1}. - Abstract: The present work describes an exciting method for the selective and sensitive determination of calcitonin in human blood serum samples. Adopting the surface molecular imprinting technique, a calcitonin-imprinted polymer was prepared on the surface of the zinc oxide nanostructure. Firstly, a biocompatible tyrosine derivative as a monomer was grafted onto the surface of zinc oxide nanostructure followed by their polymerization on vinyl functionalized electrode surface by activator regenerated by electron transfer–atom transfer radical polymerization (ARGET–ATRP) technique. Such sensor can predict the small change in the concentration of calcitonin in the human body and it may also consider to be as cost-effective, renewable, disposable, and reliable for clinical studies having no such cross-reactivity and matrix effect from real samples. The morphologies and properties of the proposed sensor were characterized by scanning electron microscopy, cyclic voltammetry, difference pulse voltammetry and chronocoulometry. The linear working range was found to be 9.99 ng L{sup −1} to 7.919 mg L{sup −1} and the detection limit as low as 3.09 ± 0.01 ng L{sup −1} (standard deviation for three replicate measurements) (S/N = 3)

  16. The imprinted SNRPN gene is associated with a polycistronic mRNA and an imprinting control element

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, S.; Nicholls, R.D. [Case Western Reserve Univ., Cleveland, OH (United States); Seip, J. [Pennsylvania State Univ., Hershey, PA (United States)] [and others

    1994-09-01

    The small nuclear ribonucleoprotein-associated protein SmN (SNRPN) gene is located in the Prader-Willi syndrome (PWS) critical region in chromosome 15q11-q13. We have previously shown that it is functionally imprinted in humans, being only expressed from the paternal allele and differentially methylated on parental alleles. Therefore, SNRPN may have a role in PWS, although genetic studies suggest that at least two genes may be necessary for the classical PWS phenotype. We have characterized the SNRPN genomic structure, and shown that it comprises ten exons. Surprisingly, we identified an open reading frame (ORF) in the first three exons, 190-bp 5{prime} to the SmN ORF. Notably, the majority of base substitutions bewteen human and rodents in the upstream ORF occurred in the wobble position of codons, suggesting selection for a protein coding function. This ORF, which we name SNURF (SNRPN upstream reading frame) encodes a putative polypeptide of 71 amino acids. By analogy to prokaryotic operons that encode proteins with related functions, it is possible that SNURF may have a role in pre-mRNA splicing.

  17. Deletions of a differentially methylated CpG island at SNRPN define a putative imprinting control region

    Energy Technology Data Exchange (ETDEWEB)

    Sutcliffe, J.S.,; Nakao, M.; Beaudet, A.L. [Baylor College of Medicine, Houston, TX (United States)] [and others

    1994-09-01

    Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are associated with paternal and maternal deficiencies, respectively, of gene expression within human chromosome 15q11-q13, and are caused by deletion, uniparental disomy, or other mutations. Four transcripts designated PAR-5, PAR-7, PAR-1 and PAR-4 were isolated and localized to a region within 300 kb telomeric to the gene encoding small nuclear ribonucleoprotein-associated polypeptide N (SNRPN). Analysis of the transcripts in cultured fibroblasts and lymphoblasts from deletion patients demonstrated that SNRPN, PAR-5 and PAR-1 are expressed exclusively from the paternal chromosome, defining an imprinted domain that spans at least 200 kb. All three imprinted transcripts were absent in cells from three PWS patients (one pair of sibs and one sporadic case) with small deletions that involve a differentially methylated CpG island containing a previously undescribed 5{prime} untranslated exon ({alpha}) of SNRPN. Methylation of the CpG island is specific for the maternal chromosome consistent with paternal expression of the imprinted domain. One deletion, which is benign when maternally transmitted, extends upstream <30 kb from the CpG island, and is associated with altered methylation centromeric to SNRPN, and loss of transcription telomeric to SNRPN, implying the presence of an imprinting control region around the CpG island containing exon {alpha}.

  18. Synthesis and Characterization of Molecular Imprinting Polymer Microspheres of Cinnamic Acid: Extraction of Cinnamic Acid from Spiked Blood Plasma

    Directory of Open Access Journals (Sweden)

    Alvin Leong Joke Chow

    2016-01-01

    Full Text Available The molecular imprinting technique is used to create the molecularly imprinted polymers (MIPs with higher binding capacity towards the template. In this research precipitation polymerization method with noncovalent approach was used to synthesize imprinted polymer microspheres. The polymerization reaction was conducted in a flask containing acetonitrile as a porogen, cinnamic acid as a template (T, acrylic acid (AA as a monomer, divinylbenzene (DVB as a cross-linker, and azobisisobutyronitrile as an initiator. The polymer particles were characterized by using SEM and FTIR. The rebinding efficiency was conducted by batch binding assay and the results were monitored by using HPLC. The batch binding results suggested MIP1 (T : AA : DVB, 1 : 6 : 20 molar ratio is most suitable composition for the rebinding of cinnamic acid. The highly selective polymer (MIP1 was used for the extraction of cinnamic acid from human plasma. The extraction efficiency of imprinted polymer of cinnamic acid from spiked plasma was above 75%.

  19. Molecularly imprinted polymers: synthetic receptors in bioanalysis.

    Science.gov (United States)

    Tse Sum Bui, Bernadette; Haupt, Karsten

    2010-11-01

    Molecularly imprinted polymers (MIPs) are tailor-made synthetic materials possessing specific cavities designed for a target molecule. Since they recognise their target analyte with affinities and selectivities comparable to those of antibody-antigen, enzyme-substrate and ligand-receptor interactions, they are often referred to as synthetic receptors or plastic antibodies. In this review, we describe the great potential and recent developments of MIPs in affinity separations, with emphasis on their application to the solid-phase extraction (SPE) of analytes from complex matrices. Research efforts made in this field to obtain water-compatible polymers for their applicability in aqueous environments are described. We particularly discuss problems encountered in the use of MIPs in SPE and the attempts carried out to improve their efficiency.

  20. Cell shape recognition by colloidal cell imprints: Energy of the cell-imprint interaction

    Science.gov (United States)

    Borovička, Josef; Stoyanov, Simeon D.; Paunov, Vesselin N.

    2015-09-01

    The results presented in this study are aimed at the theoretical estimate of the interactions between a spherical microbial cell and the colloidal cell imprints in terms of the Derjaguin, Landau, Vervey, and Overbeek (DLVO) surface forces. We adapted the Derjaguin approximation to take into account the geometry factor in the colloidal interaction between a spherical target particle and a hemispherical shell at two different orientations with respect to each other. We took into account only classical DLVO surface forces, i.e., the van der Waals and the electric double layer forces, in the interaction of a spherical target cell and a hemispherical shell as a function of their size ratio, mutual orientation, distance between their surfaces, their respective surface potentials, and the ionic strength of the aqueous solution. We found that the calculated interaction energies are several orders higher when match and recognition between the target cell and the target cell imprint is achieved. Our analysis revealed that the recognition effect of the hemispherical shell towards the target microsphere comes from the greatly increased surface contact area when a full match of their size and shape is produced. When the interaction between the surfaces of the hemishell and the target cell is attractive, the recognition greatly amplifies the attraction and this increases the likelihood of them to bind strongly. However, if the surface interaction between the cell and the imprint is repulsive, the shape and size match makes this interaction even more repulsive and thus decreases the likelihood of binding. These results show that the surface chemistry of the target cells and their colloidal imprints is very important in controlling the outcome of the interaction, while the shape recognition only amplifies the interaction. In the case of nonmonotonous surface-to-surface interaction we discovered some interesting interplay between the effects of shape match and surface chemistry

  1. Synthetic strategies for the generation of molecularly imprinted organic polymers.

    Science.gov (United States)

    Mayes, A G; Whitcombe, M J

    2005-12-06

    Molecular imprinting is a method of inducing molecular recognition properties in synthetic polymers in response to the presence of a template species during formation of the three-dimensional structure of the polymer. The molecularly imprinted polymers (MIPs) prepared in this way have been termed "plastic antibodies" and combine the robustness of the polymer scaffold with binding properties more readily associated with biological receptors. Smart polymers of this type may find applications in drug delivery, controlled release and monitoring of drug and metabolite concentrations. In this review the main synthetic strategies used in the preparation of imprinted organic polymers are described in terms of the chemical principles used in the templating step. These are illustrated with examples taken from the literature and are classified as covalent, semi-covalent, non-covalent, metal-mediated and non-polar. Finally strategies for the selection of monomers, optimisation and modification of the properties of imprinted polymers are reviewed.

  2. Dimensional characterization of biperiodic imprinted structures using optical scatterometry

    KAUST Repository

    Gereige, Issam

    2013-12-01

    In this paper, we report on the characterization of biperiodic imprinted structures using a non-destructive optical technique commonly called scatterometry. The nanostructures consist of periodic arrays of square and circular dots which were imprinted in a thermoplastic polymer by thermal nanoimprint lithography. Optical measurements were performed using spectroscopic ellipsometry in the spectral region of 1.5-4 eV. The geometrical profiles of the imprinted structures were reconstructed using the Rigorous Coupled-Wave Analysis (RCWA) to model the diffraction phenomena by periodic gratings. The technique was also adapted for large scale evaluation of the imprint process. Uniqueness of the solution was examined by analyzing the diffraction of the structure at different experimental conditions, for instance at various angles of incidence. © 2013 Elsevier B.V. All rights reserved.

  3. Changes in Parthenogenetic Imprinting Patterns during Reprogramming by Cell Fusion.

    Directory of Open Access Journals (Sweden)

    Hyun Sik Jang

    Full Text Available Differentiated somatic cells can be reprogrammed into the pluripotent state by cell-cell fusion. In the pluripotent state, reprogrammed cells may then self-renew and differentiate into all three germ layers. Fusion-induced reprogramming also epigenetically modifies the somatic cell genome through DNA demethylation, X chromosome reactivation, and histone modification. In this study, we investigated whether fusion with embryonic stem cells (ESCs also reprograms genomic imprinting patterns in somatic cells. In particular, we examined imprinting changes in parthenogenetic neural stem cells fused with biparental ESCs, as well as in biparental neural stem cells fused with parthenogenetic ESCs. The resulting hybrid cells expressed the pluripotency markers Oct4 and Nanog. In addition, methylation of several imprinted genes except Peg3 was comparable between hybrid cells and ESCs. This finding indicates that reprogramming by cell fusion does not necessarily reverse the status of all imprinted genes to the state of pluripotent fusion partner.

  4. [Evolution of genomic imprinting in mammals: what a zoo!].

    Science.gov (United States)

    Proudhon, Charlotte; Bourc'his, Déborah

    2010-05-01

    Genomic imprinting imposes an obligate mode of biparental reproduction in mammals. This phenomenon results from the monoparental expression of a subset of genes. This specific gene regulation mechanism affects viviparous mammals, especially eutherians, but also marsupials to a lesser extent. Oviparous mammals, or monotremes, do not seem to demonstrate monoparental allele expression. This phylogenic confinement suggests that the evolution of the placenta imposed a selective pressure for the emergence of genomic imprinting. This physiological argument is now complemented by recent genomic evidence facilitated by the sequencing of the platypus genome, a rare modern day case of a monotreme. Analysis of the platypus genome in comparison to eutherian genomes shows a chronological and functional coincidence between the appearance of genomic imprinting and transposable element accumulation. The systematic comparative analyses of genomic sequences in different species is essential for the further understanding of genomic imprinting emergence and divergent evolution along mammalian speciation.

  5. Preparation of hydrophilic molecularly imprinted polymers for tetracycline antibiotics recognition

    Institute of Scientific and Technical Information of China (English)

    Peng Wang; Xiao Fang Fu; Jing Li; Jing Luo; Xiao Ya Zhao; Ming Jun Sun; Yin Zhu Shang; Cheng Ye

    2011-01-01

    Hydrophilic molecularly imprinted polymers (MIPs) were prepared using tetracycline as template, methacrylic acid as monomer and glycidilmethacrylate as pro-hydrophilic co-monomer. Compared with common MIPs, the imprinting effect and adsorption amounts of hydrophilic MIPs for tetracycline (TC) were greatly improved in water media. Furthermore, the electrochemical sensor fabricated by modifying hydrophilic MIPs on glassy carbon electrode was developed for the determination of TC in foodstuff samples.

  6. Recognition Interactions of Metal-complexing Imprinted Polymer

    Institute of Scientific and Technical Information of China (English)

    Ying LIU; Guo Sheng DING; Jun De WANG

    2005-01-01

    Molecularly imprinted polymer, exhibiting considerable enantioselectivity for L-mandelic acid, was prepared using metal coordination-chelation interaction. By evaluating the recognition characteristics in the chromatographic mode, the recognition interactions were proposed: specific and nonspecific metal coordination-chelation interaction and hydrophobic interaction were responsible for substrate binding on metal-complexing imprinted polymer; while the selective recognition only came from specific metal coordination-chelation interaction and specific hydrophobic interaction.

  7. Simultaneous Chiral SeparationUsing a Combinatorial Molecular Imprinting Phase

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Molecular imprinting chiral stationary phase against Cbz-L-Serine (Cbz-L-Ser) and Cbz-L-Alaine (Cbz-L-Ala) were prepared utilizing acrylamide + 2-vinylpyridine as combined basic functional monomers.Cross-selectivity was used to obtain simultaneous chiral separations of Cbz-DL-Ser and Cbz-DL-Ala by connecting two columns packed with Cbz-L-Ser and Cbz-L-Ala imprinted chiral stationary phase, respectively.

  8. Molecularly Imprinted Polymers for 5-Fluorouracil Release in Biological Fluids

    OpenAIRE

    Francesco Puoci; Francesca Iemma; Giuseppe Cirillo; Nevio Picci; Pietro Matricardi; Franco Alhaique

    2007-01-01

    The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs) as a controlled release device for 5-fluorouracil (5-FU) in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs). MIPs were synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic a...

  9. Synthesis of molecular imprinted beta cyclodextrins oligomers in water

    DEFF Research Database (Denmark)

    Yu, Donghong; Nielsen, Anne Louise; Bach, Lone

    2003-01-01

    hydrophobic molecules in aqueous solution, however, with limited selectivity. Templated synthesis of Cyclodextrin polymers was introduced by Komiyama. By use of simple templates, such as cholesterol, polymers with improved selectivity for the template molecules were achieved. In most...... compounds in aqueous solution and, therefore, molecular imprinting of cyclodextrins polymers in aqueous solution is of great interest. In this paper, molecular imprinting of beta cyclodextrins has been performed in water by use of diiodobenzene as template and epichlorohydrin as a crosslinker. Inclusion...

  10. Synthesis of molecular imprinted beta cyclodextrins oligomers in water

    DEFF Research Database (Denmark)

    Yu, Donghong; Nielsen, Anne Louise; Bach, Lone

    2003-01-01

    hydrophobic molecules in aqueous solution, however, with limited selectivity. Templated synthesis of Cyclodextrin polymers was introduced by Komiyama. By use of simple templates, such as cholesterol, polymers with improved selectivity for the template molecules were achieved. In most...... compounds in aqueous solution and, therefore, molecular imprinting of cyclodextrins polymers in aqueous solution is of great interest. In this paper, molecular imprinting of beta cyclodextrins has been performed in water by use of diiodobenzene as template and epichlorohydrin as a crosslinker. Inclusion...

  11. Generation of Five Human Lactoferrin Transgenic Cloned Goats Using Fibroblast Cells and Their Methylation Status of Putative Differential Methylation Regions of IGF2R and H19 Imprinted Genes

    NARCIS (Netherlands)

    Meng, L.; Wan, Y.; Sun, Y.; Zhang, Y.; Wang, Z.; Song, Y.; Wang, F.

    2013-01-01

    Background - Somatic cell nuclear transfer (SCNT) is a promising technique to produce transgenic cloned mammalian, including transgenic goats which may produce Human Lactoferrin (hLF). However, success percentage of SCNT is low, because of gestational and neonatal failure of transgenic embryos.

  12. Design of molecularly imprinted polymers for diphenylamine sensing.

    Science.gov (United States)

    Granado, V L V; Rudnitskaya, A; Oliveira, J A B P; Gomes, M T S R

    2012-05-30

    A series of the polymers imprinted with diphenylamine (DPA) and respective non imprinted polymers were synthesized using precipitation polymerization. Synthesized polymers were characterized by Fourier Transform Infra-Red spectroscopy with Total Attenuated Reflectance (FTIR-ATR), Scanning Electron Microscopy (SEM) and equilibrium batch re-binding experiments. Influence of the synthesis conditions, namely monomer/template ratio and reaction duration, on the polymer binding capacity and selectivity towards aromatic compounds was investigated. Binding behavior of MIP was described using Freundlich isotherm. Significance of the effects of the synthesis conditions on the polymer properties was evaluated using ANOVA. MIPs synthesized at different conditions, which displayed different properties (binding capacity and selectivity), and respective non-imprinted polymers were employed for the fabrication of the potentiometric sensors. While sensors prepared using imprinted polymers had higher sensitivity and selectivity compared to the ones containing non-imprinted polymer, no difference was observed between sensors containing different imprinted polymers. No correspondence between polymers' characteristics obtained in the equilibrium re-binding studies and potentiometric behavior of the sensors based on the same polymers was observed. Therefore, equilibrium re-binding studies cannot be used for predicting sensor behavior.

  13. Sequences sufficient for programming imprinted germline DNA methylation defined.

    Directory of Open Access Journals (Sweden)

    Yoon Jung Park

    Full Text Available Epigenetic marks are fundamental to normal development, but little is known about signals that dictate their placement. Insights have been provided by studies of imprinted loci in mammals, where monoallelic expression is epigenetically controlled. Imprinted expression is regulated by DNA methylation programmed during gametogenesis in a sex-specific manner and maintained after fertilization. At Rasgrf1 in mouse, paternal-specific DNA methylation on a differential methylation domain (DMD requires downstream tandem repeats. The DMD and repeats constitute a binary switch regulating paternal-specific expression. Here, we define sequences sufficient for imprinted methylation using two transgenic mouse lines: One carries the entire Rasgrf1 cluster (RC; the second carries only the DMD and repeats (DR from Rasgrf1. The RC transgene recapitulated all aspects of imprinting seen at the endogenous locus. DR underwent proper DNA methylation establishment in sperm and erasure in oocytes, indicating the DMD and repeats are sufficient to program imprinted DNA methylation in germlines. Both transgenes produce a DMD-spanning pit-RNA, previously shown to be necessary for imprinted DNA methylation at the endogenous locus. We show that when pit-RNA expression is controlled by the repeats, it regulates DNA methylation in cis only and not in trans. Interestingly, pedigree history dictated whether established DR methylation patterns were maintained after fertilization. When DR was paternally transmitted followed by maternal transmission, the unmethylated state that was properly established in the female germlines could not be maintained. This provides a model for transgenerational epigenetic inheritance in mice.

  14. Electropolymerized Molecularly Imprinted Polypyrrole Film for Sensing of Clofibric Acid

    Directory of Open Access Journals (Sweden)

    Bianca Schweiger

    2015-02-01

    Full Text Available Piezoelectric quartz crystals and analogous gold substrates were electrochemically coated with molecularly imprinted polypyrrole films for pulsed amperometric detection (PAD of clofibric acid, a metabolite of clofibrate. Cyclic voltammetry data obtained during polymerization and deposited weight estimations revealed a decrease of the polymerization rate with increasing clofibric acid concentration. XPS measurements indicated that clofibric acid could be removed after imprinting with an aqueous ethanol solution, which was further optimized by using PAD. Zeta potential and contact angle measurements revealed differences between molecularly imprinted (MIP and non-imprinted polymer (NIP layers. Binding experiments with clofibric acid and other substances showed a pronounced selectivity of the MIP for clofibric acid vs. carbamazepine, but the response of MIP and NIP to 2,4-dichlorophenoxyacetic acid was higher than that for clofibric acid. A smooth surface, revealed by AFM measurements, with roughness of 6–8 nm for imprinted and non-imprinted layers, might be a reason for an excessively low density of specific binding sites for clofibric acid. Furthermore, the decreased polymerization rate in the presence of clofibric acid might not result in well-defined polymer structures, which could be the reason for the lower sensitivity.

  15. New molecular imprinted voltammetric sensor for determination of ochratoxin A

    Energy Technology Data Exchange (ETDEWEB)

    Yola, Mehmet Lütfi, E-mail: mehmetyola@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Engineering, Sinop University, Sinop (Turkey); Gupta, Vinod Kumar, E-mail: vinodfcy@iitr.ac.in [Indian Institute of Technology, Department of Chemistry, Roorkee, Roorkee 247667 (India); Department of Applied Chemistry, University of Johannesburg, Johannesburg (South Africa); Atar, Necip [Department of Chemical Engineering, Faculty of Engineering, Pamukkale University, Denizli (Turkey)

    2016-04-01

    In this report, a novel molecular imprinted voltammetric sensor based on silver nanoparticles (AgNPs) involved in a polyoxometalate (H{sub 3}PW{sub 12}O{sub 40}, POM) functionalized reduced graphene oxide (rGO) modified glassy carbon electrode (GCE) was presented for determination of ochrattoxin A (OCH). The developed surfaces were characterized using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) method. OCH imprinted GCE was prepared via electropolymerization process of 100 mM phenol as monomer in the presence of phosphate buffer solution (pH 6.0) containing 25 mM OCH. The linearity range and the detection limit of the method were calculated as 5.0 × 10{sup −11} − 1.5 × 10{sup −9} M and 1.6 × 10{sup −11} M, respectively. The voltammetric sensor was applied to grape juice and wine samples with good selectivity and recovery. The stability of the voltammetric sensor was also reported. - Highlights: • Ochratoxin A-imprinted electrochemical sensor is developed for the sensitive detection of ochratoxin A • The nanomaterial and ochratoxin A-imprinted surfaces were characterized by several methods • Ochratoxin A-imprinted electrochemical sensor is sensitive and selective in analysis of food • Ochratoxin A-imprinted electrochemical sensor is preferred to the other methods.

  16. Autozygosity mapping of a large consanguineous Pakistani family reveals a novel non-syndromic autosomal recessive mental retardation locus on 11p15-tel

    DEFF Research Database (Denmark)

    Rehman, Shoaib ur; Baig, Shahid Mahmood; Eiberg, Hans

    2011-01-01

    Autosomal recessive inherited mental retardation is an extremely heterogeneous disease and accounts for approximately 25% of all non-syndromic mental retardation cases. Autozygosity mapping of a large consanguineous Pakistani family revealed a novel locus for non-syndromic autosomal recessive...

  17. A novel pathway links oxidative stress to loss of insulin growth factor-2 (IGF2 imprinting through NF-κB activation.

    Directory of Open Access Journals (Sweden)

    Bing Yang

    Full Text Available Genomic imprinting is the allele-specific expression of a gene based on parental origin. Loss of imprinting(LOI of Insulin-like Growth Factor 2 (IGF2 during aging is important in tumorigenesis, yet the regulatory mechanisms driving this event are largely unknown. In this study oxidative stress, measured by increased NF-κB activity, induces LOI in both cancerous and noncancerous human prostate cells. Decreased expression of the enhancer-blocking element CCCTC-binding factor(CTCF results in reduced binding of CTCF to the H19-ICR (imprint control region, a major factor in the allelic silencing of IGF2. This ICR then develops increased DNA methylation. Assays identify a recruitment of the canonical pathway proteins NF-κB p65 and p50 to the CTCF promoter associated with the co-repressor HDAC1 explaining gene repression. An IκBα super-repressor blocks oxidative stress-induced activation of NF-κB and IGF2 imprinting is maintained. In vivo experiments using IκBα mutant mice with continuous NF-κB activation demonstrate increased IGF2 LOI further confirming a central role for canonical NF-κB signaling. We conclude CTCF plays a central role in mediating the effects of NF-κB activation that result in altered imprinting both in vitro and in vivo. This novel finding connects inflammation found in aging prostate tissues with the altered epigenetic landscape.

  18. A fluorescent molecularly-imprinted polymer gate with temperature and pH as inputs for detection of alpha-fetoprotein.

    Science.gov (United States)

    Karfa, Paramita; Roy, Ekta; Patra, Santanu; Kumar, Deepak; Madhuri, Rashmi; Sharma, Prashant K

    2016-04-15

    In this work, we have reported a new approach on the use of stimuli-responsive molecularly imprinted polymer (MIP) for trace level sensing of alpha-fetoprotein (AFP), which is a well know cancer biomarker. The stimuli-responsive MIP is composed of three components, a thermo-responsive monomer, a pH responsive component (tyrosine derivative) and a highly fluorescent vinyl silane modified carbon dot. The synthesized AFP-imprinted polymer possesses excellent selectivity towards their template molecule and dual-stimuli responsive behavior. Along with this, the imprinted polymer was also explored as 'OR' logic gate with two stimuli (pH and temperature) as inputs. However, the non-imprinted polymers did not have such 'OR' gate property, which confirms the role of template binding. The imprinted polymer was also used for estimation of AFP in the concentration range of 3.96-80.0 ng mL(-1), with limit of detection (LOD) 0.42 ng mL(-1). The role of proposed sensor was successfully exploited for analysis of AFP in real human blood plasma, serum and urine sample.

  19. A virus resonance light scattering sensor based on mussel-inspired molecularly imprinted polymers for high sensitive and high selective detection of Hepatitis A Virus.

    Science.gov (United States)

    Yang, Bin; Gong, Hang; Chen, Chunyan; Chen, Xiaoming; Cai, Changqun

    2017-01-15

    We described a novel resonance light scattering (RLS) sensor for the specific recognition of trace quantities of Hepatitis A Virus (HAV); the sensor was based on a mussel-inspired hepatitis molecularly imprinted polymer. As a recognition element, polydopamine (PDA)-coated totivirus-imprinted polymer was introduced on the surface of SiO2 nanoparticles (virus-imprinted SiO2@PDA NPs) using an efficient one-step synthesis method. The target virus was selectively captured by the imprinted polymer films, thereby increasing the RLS intensity. A simple fluorescence spectrophotometer was employed to measure the changes in the intensity. The enhanced RLS intensity (∆IRLS) was proportional to the concentration of HAV in the range of 0.04-6.0nmol∙L(-1), with a low limit of detection of 8.6pmol∙L(-1). The selectivity study confirmed that the resultant HAV-imprinted SiO2@PDA NPs possessed high selectivity for HAV. The sensor was successfully applied for the direct detection of additional HAV from a 20,000-fold dilution of human serum. The proposed strategy is simple, eco-friendly, highly selective, and sensitive. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Distinguishing epigenetic marks of developmental and imprinting regulation

    Directory of Open Access Journals (Sweden)

    McEwen Kirsten R

    2010-01-01

    Full Text Available Abstract Background The field of epigenetics is developing rapidly, however we are only beginning to comprehend the complexity of its influence on gene regulation. Using genomic imprinting as a model we examine epigenetic profiles associated with different forms of gene regulation. Imprinting refers to the expression of a gene from only one of the chromosome homologues in a parental-origin-specific manner. This is dependent on heritable germline epigenetic control at a cis-acting imprinting control region that influences local epigenetic states. Epigenetic modifications associated with imprinting regulation can be compared to those associated with the more canonical developmental regulation, important for processes such as differentiation and tissue specificity. Here we test the hypothesis that these two mechanisms are associated with different histone modification enrichment patterns. Results Using high-throughput data extraction with subsequent analysis, we have found that particular histone modifications are more likely to be associated with either imprinting repression or developmental repression of imprinted genes. H3K9me3 and H4K20me3 are together enriched at imprinted genes with differentially methylated promoters and do not show a correlation with developmental regulation. H3K27me3 and H3K4me3, however, are more often associated with developmental regulation. We find that imprinted genes are subject to developmental regulation through bivalency with H3K4me3 and H3K27me3 enrichment on the same allele. Furthermore, a specific tri-mark signature comprising H3K4me3, H3K9me3 and H4K20me3 has been identified at all imprinting control regions. Conclusion A large amount of data is produced from whole-genome expression and epigenetic profiling studies of cellular material. We have shown that such publicly available data can be mined and analysed in order to generate novel findings for categories of genes or regulatory elements. Comparing two

  1. Molecularly Imprinted Polymer (MIP) Film with Improved Surface Area Developed by Using Metal-Organic Framework (MOF) for Sensitive Lipocalin (NGAL) Determination.

    Science.gov (United States)

    Iskierko, Zofia; Sharma, Piyush Sindhu; Prochowicz, Daniel; Fronc, Krzysztof; D'Souza, Francis; Toczydłowska, Diana; Stefaniak, Filip; Noworyta, Krzysztof

    2016-08-10

    Electropolymerizable functional and cross-linking monomers were used to prepare conducting molecularly imprinted polymer film with improved surface area with the help of a sacrificial metal-organic framework (MOF). Subsequent dissolution of the MOF layer resulted in a surface developed MIP film. This surface enlargement increased the analyte accessibility to imprinted molecular cavities. Application of the porous MIP film as a recognition unit of an extended-gate field effect transistor (EG-FET) chemosensor effectively enhanced analytical current signals of determination of recombinant human neutrophil gelatinase-associated lipocalin (NGAL).

  2. Towards the cloning of imprinted genes in the Prader-Willi/Angelman region of chromosome 15q11-q13

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, M.; Sutcliffe, J.S.; Beaudet, A.L. [Baylor College of Medicine, Houston, TX (United States)] [and others

    1994-09-01

    Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are distinct clinical phenotypes resulting from paternal and maternal deficiencies respectively in human chromosome 15q11-q13. The data suggest the presence of oppositely imprinted genes in the region, and the gene for small nuclear ribonucleoprotein-associated polypeptide N (SNRPN) has been identified as a candidate gene for PWS. Previous strategies for positional cloning identified a number of transcripts from the PWS/AS region, and two of them, PAR-5 (D15S226E) and PAR-1 (D15S227E), are paternally expressed in cultured human cells from patients deleted for 15q11-q13 as is SNRPN. Cosmid contig maps have been developed from the following YACs (contained loci in parentheses): 307A12 (D15S13), 457B4 (SNRPN), 132D4 (D15S10), A229A2, and 378A12 (D15S113), to facilitate molecular studies of PWS and AS. Exon trapping has been employed to isolate putative exons from these overlapping cosmids. Two trapped fragments from the D15S113 region and one fragment from the SNRPN region has been isolated. Sequence information is available for all of the fragments. In addition to imprinting analysis in cultured human cells, we have developed a method to detect imprinting in mouse and human using a GC-clamped denaturing gradient gel electrophoresis strategy, in combination with reverse transcription-polymerase chain reaction. The imprinting analyses of putative exons are in progress to investigate their possible candidacy for involvement in PWS or AS phenotypes.

  3. A Procedure for Collecting Mental Workload Data During an Experiment That Is Comparable to IMPRINT Workload Data

    Science.gov (United States)

    2009-11-01

    Resource Theory ( MRT ). According to MRT , human mental resources for handling tasks are limited. When an individual is required to perform multiple...a MRT workload analysis in IMPRINT, analysts begin by building a task-network model to represent the functions and tasks individuals perform as they...feeling in your mind at the time the simulation was paused. 1 2 3 4 5 1 = Nothing to do. Rather boring. 2 = More than enough time for all tasks

  4. Non-coding RNAs and the acquisition of genomic imprinting in mammals

    Institute of Scientific and Technical Information of China (English)

    ZHANG YiJun; QU LiangHu

    2009-01-01

    Genomic imprinting, representing parent-specific expression of alleles at a locus, Is mainly evident in flowering plants and placental mammals. Most imprinted genes, including numerous non-coding RNAs, are located in clusters regulated by imprinting control regions (ICRs). The acquisition and evolution of genomic imprinting is among the most fundamental genetic questions. Discoveries about the transition of mammalian imprinted gene domains from their non-imprinted ancestors, especially recent studies undertaken on the most ancient mammalian clades - the marsupials and monotremes from which model species genomes have recently been sequenced, are of high value. By reviewing and analyzing these studies, a close connection between non-coding RNAs and the acquisition of genomic imprinting in mammals is demonstrated. The evidence comes from two observations accompanied with the ac-quisition of the imprinting: (i) many novel non-coding RNA genes emerged in imprinted regions; (ii) the expressions of some conserved non-coding RNAs have changed dramatically. Furthermore, a system-atical analysis of imprinted snoRNA (small nucleolar RNA) genes from 15 vertebrates suggests that the origination of imprinted snoRNAs occurred after the divergence between eutherians and marsupials, followed by a rapid expansion leading to the fixation of major gene families in the eutherian ancestor prior to the radiation of modern placental mammals. Involved in the regulation of imprinted silencing and mediating the ohromatins epigenetic modification may be the major roles that non-coding RNAs play during the acquisition of genomic imprinting in mammals.

  5. Molecularly imprinted Ru complex catalysts integrated on oxide surfaces.

    Science.gov (United States)

    Muratsugu, Satoshi; Tada, Mizuki

    2013-02-19

    Selective catalysis is critical for the development of green chemical processes, and natural enzymes that possess specialized three-dimensional reaction pockets with catalytically active sites represent the most sophisticated systems for selective catalysis. A reaction space in an enzyme consists of an active metal center, functional groups for molecular recognition (such as amino acids), and a surrounding protein matrix to prepare the reaction pocket. The artificial design of such an integrated catalytic unit in a non-enzymatic system remains challenging. Molecular imprinting of a supported metal complex provides a promising approach for shape-selective catalysis. In this process, an imprinted cavity with a shape matched to a template molecule is created in a polymer matrix with a catalytically active metal site. In this Account, we review our studies on molecularly imprinted metal complex catalysts, focusing on Ru complexes, on oxide surfaces for shape-selective catalysis. Oxide surface-attached transition metal complex catalysts not only improve thermal stability and catalyst dispersion but also provide unique catalytic performance not observed in homogeneous precursors. We designed molecularly imprinted Ru complexes by using surface-attached Ru complexes with template ligands and inorganic/organic surface matrix overlayers to control the chemical environment around the active metal complex catalysts on oxide surfaces. We prepared the designed, molecularly imprinted Ru complexes on SiO(2) surfaces in a step-by-step manner and characterized them with solid-state (SS) NMR, diffuse-reflectance (DR) UV-vis, X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller isotherm (BET), X-ray fluorescence (XRF), and Ru K-edge extended X-ray absorption fine structure (EXAFS). The catalytic performances of these Ru complexes suggest that this process of molecular imprinting facilitates the artificial integration of catalytic functions at surfaces. Further advances such

  6. Parental genome dosage imbalance deregulates imprinting in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Pauline E Jullien

    2010-03-01

    Full Text Available In mammals and in plants, parental genome dosage imbalance deregulates embryo growth and might be involved in reproductive isolation between emerging new species. Increased dosage of maternal genomes represses growth while an increased dosage of paternal genomes has the opposite effect. These observations led to the discovery of imprinted genes, which are expressed by a single parental allele. It was further proposed in the frame of the parental conflict theory that parental genome imbalances are directly mirrored by antagonistic regulations of imprinted genes encoding maternal growth inhibitors and paternal growth enhancers. However these hypotheses were never tested directly. Here, we investigated the effect of parental genome imbalance on the expression of Arabidopsis imprinted genes FERTILIZATION INDEPENDENT SEED2 (FIS2 and FLOWERING WAGENINGEN (FWA controlled by DNA methylation, and MEDEA (MEA and PHERES1 (PHE1 controlled by histone methylation. Genome dosage imbalance deregulated the expression of FIS2 and PHE1 in an antagonistic manner. In addition increased dosage of inactive alleles caused a loss of imprinting of FIS2 and MEA. Although FIS2 controls histone methylation, which represses MEA and PHE1 expression, the changes of PHE1 and MEA expression could not be fully accounted for by the corresponding fluctuations of FIS2 expression. Our results show that parental genome dosage imbalance deregulates imprinting using mechanisms, which are independent from known regulators of imprinting. The complexity of the network of regulations between expressed and silenced alleles of imprinted genes activated in response to parental dosage imbalance does not support simple models derived from the parental conflict hypothesis.

  7. Parental genome dosage imbalance deregulates imprinting in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Pauline E Jullien

    2010-03-01

    Full Text Available In mammals and in plants, parental genome dosage imbalance deregulates embryo growth and might be involved in reproductive isolation between emerging new species. Increased dosage of maternal genomes represses growth while an increased dosage of paternal genomes has the opposite effect. These observations led to the discovery of imprinted genes, which are expressed by a single parental allele. It was further proposed in the frame of the parental conflict theory that parental genome imbalances are directly mirrored by antagonistic regulations of imprinted genes encoding maternal growth inhibitors and paternal growth enhancers. However these hypotheses were never tested directly. Here, we investigated the effect of parental genome imbalance on the expression of Arabidopsis imprinted genes FERTILIZATION INDEPENDENT SEED2 (FIS2 and FLOWERING WAGENINGEN (FWA controlled by DNA methylation, and MEDEA (MEA and PHERES1 (PHE1 controlled by histone methylation. Genome dosage imbalance deregulated the expression of FIS2 and PHE1 in an antagonistic manner. In addition increased dosage of inactive alleles caused a loss of imprinting of FIS2 and MEA. Although FIS2 controls histone methylation, which represses MEA and PHE1 expression, the changes of PHE1 and MEA expression could not be fully accounted for by the corresponding fluctuations of FIS2 expression. Our results show that parental genome dosage imbalance deregulates imprinting using mechanisms, which are independent from known regulators of imprinting. The complexity of the network of regulations between expressed and silenced alleles of imprinted genes activated in response to parental dosage imbalance does not support simple models derived from the parental conflict hypothesis.

  8. Application of molecularly imprinted and non-imprinted polymers for removal of emerging contaminants in water and wastewater treatment: a review.

    Science.gov (United States)

    Murray, Audrey; Ormeci, Banu

    2012-11-01

    Over the past decade, several studies have reported trace levels of endocrine disrupting compounds, pharmaceuticals, and personal care products in surface waters, drinking water, and wastewater effluents. There has also been an increased concern about the ecological and human health impact of these contaminants, and their removal from water and wastewater has become a priority. Traditional treatment processes are limited in their ability to remove emerging contaminants from water, and there is a need for new technologies that are effective and feasible. This paper presents a review on recent research results on molecularly imprinted (MIP) and non-imprinted (NIP) polymers and evaluates their potential as a treatment method for the removal of emerging contaminants from water and wastewater. It also discusses the relative benefits and limitations of using MIP or NIP for water and wastewater treatment. MIP, and in particular NIP, offer promising applications for wastewater treatment, but their toxicity and possible health effects should be carefully studied before they are considered for drinking water treatment. More research is also required to determine how best to incorporate MIP and NIP in treatment plants.

  9. Facialmetric similarities mediate mate choice: sexual imprinting on opposite-sex parents.

    Science.gov (United States)

    Bereczkei, Tamas; Hegedus, Gabor; Hajnal, Gabor

    2009-01-07

    Former studies have suggested that imprinting-like processes influence the shaping of human mate preferences. In this study, we provide more direct evidence for assessing facial resemblance between subjects' partner and subjects' parents. Fourteen facial proportions were measured on 312 adults belonging to 52 families, and the correlations between family members were compared with those of pairs randomly selected from the population. Spouses proved to be assortatively mated in the majority of measured facial proportions. Significant correlations have been found between the young men and their partner's father (but not his mother), especially on facial proportions belonging to the central area of the face. Women also showed resemblance to their partner's mother (but not to their father) in the facial characteristics of their lower face. Replicating our previous studies, facial photographs of participants were also matched by independent judges who ascribed higher resemblance between partners, and subjects and their partners' opposite-sex parents, compared with controls. Our results support the sexual imprinting hypothesis which states that children shape a mental template of their opposite-sex parents and search for a partner who resembles that perceptual schema. The fact that only the facial metrics of opposite-sex parents showed resemblance to the partner's face tends to rule out the role of familiarity in shaping mating preferences. Our findings also reject several other rival hypotheses. The adaptive value of imprinting-related human mating is discussed, and a hypothesis is made of why different facial areas are involved in males' and females' search for resemblance.

  10. Highly Selective Fluorescent Sensing of Proteins Based on a Fluorescent Molecularly Imprinted Nanosensor

    Directory of Open Access Journals (Sweden)

    Shuo Wang

    2013-09-01

    Full Text Available A fluorescent molecularly imprinted nanosensor was obtained by grafting imprinted polymer onto the surface of multi-wall carbon nanotubes and post-imprinting treatment with fluorescein isothiocyanate (FITC. The fluorescence of lysozyme-imprinted polymer (Lys-MIP was quenched more strongly by Lys than that of nonimprinted polymer (NIP, which indicated that the Lys-MIP could recognize Lys. The resulted imprinted material has the ability to selectively sense a target protein, and an imprinting factor of 3.34 was achieved. The Lys-MIP also showed selective detection for Lys among other proteins such as cytochrome C (Cyt C, hemoglobin (HB and bovine serum albumin (BSA due to the imprinted sites in the Lys-MIP. This approach combines the high selectivity of surface molecular imprinting technology and fluorescence, and converts binding events into detectable signals by monitoring fluorescence spectra. Therefore, it will have further applications for Lys sensing.

  11. Spherical molecularly imprinted polymer particles : A promising tool for molecular recognition in capillary electrokinetic separations

    NARCIS (Netherlands)

    de Boer, T; Mol, R; de Zeeuw, RA; de Jong, GJ; Sherrington, DC; Cormack, PAG; Ensing, K

    2002-01-01

    Spherical molecularly imprinted polymer particles obtained via precipitation polymerization, were introduced as a pseudostationary phase in capillary electrophoresis (CE) to study molecular recognition. Analyses were performed via a partial filling technique using (+)-ephedrine-imprinted microsphere

  12. Chemical microsensors with molecularly imprinted sensitive layers

    Science.gov (United States)

    Dickert, Franz L.; Greibl, Wolfgang; Sikorski, Renatus; Tortschanoff, Matthias; Weber, K.; Bulst, W. E.; Fischerauer, G.

    1998-12-01

    The bottleneck in the development of chemical sensors is the design of the coatings for chemical recognition of the analyte. One pronounced method is to tailor supramolecular cavities for different analytes. Polyfunctional linkers or the embedding of these materials in a polymeric matrix can improve stability and response time of the sensor. An even more favorable method to synthesize chemically sensitive layers is realized by molecular imprinting, since a rigid polymer can be generated directly on the transducer of interest and may be included in its production process. The analyte of interest acts as a template during the polymerization process and is evaporated or extracted by suitable solvents. Due to the cavities formed this polymer enriches analyte molecules, which can be detected by mass- sensitive devices such as QMB or SAW resonators or by optical measurements. This procedure allows both the detection of polycyclic aromatic hydrocarbons (PAHs) with fluorescence or mass sensitive devices. If the print PAHs are varied the polymers are tuned to the desired analyte. The enrichment of solvent vapors or other uncolored specimen by the layer can also be followed by the embedding of carbenium ions used as optical labels.

  13. A Zipper-Like On/Off-Switchable Molecularly Imprinted Polymer

    OpenAIRE

    Li, Songjun; Ge, Yi; Piletsky, Sergey A.; Turner, Anthony

    2011-01-01

    A zipper-like on/off-switchable molecularly imprinted polymer is reported. This unique imprinted polymer was composed of template-imprinted polymeric networks that incorporate zipper-like interactions between poly(acrylamide) (PAAm) and poly(2-acrylamide-2-methyl propanesulfonic acid) (PAMPS). This polymer showed marginal recognition ability towards the imprint species under low temperature conditions, due to the interpolymer interaction between PAAm and PAMPS, which inhibited access to the i...

  14. Genomic imprinting is variably lost during reprogramming of mouse iPS cells

    OpenAIRE

    2013-01-01

    Derivation of induced pluripotent stem (iPS) cells is mainly an epigenetic reprogramming process. It is still quite controversial how genomic imprinting is reprogrammed in iPS cells. Thus, we derived multiple iPS clones from genetically identical mouse somatic cells. We found that parentally inherited imprint was variably lost among these iPS clones. Concurrent with the loss of DNA methylation imprint at the corresponding Snrpn and Peg3 imprinted regions, parental origin-specific expression o...

  15. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Directory of Open Access Journals (Sweden)

    Catia Algieri

    2014-07-01

    Full Text Available An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported.

  16. Molecularly Imprinted Polymers for 5-Fluorouracil Release in Biological Fluids

    Directory of Open Access Journals (Sweden)

    Franco Alhaique

    2007-04-01

    Full Text Available The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs as a controlled release device for 5-fluorouracil (5-FU in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs. MIPs were synthesized using methacrylic acid (MAA as functional monomer and ethylene glycol dimethacrylate (EGDMA as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic and aqueous media was evaluated. An in vitro release study was performed both in gastrointestinal and in plasma simulating fluids. The imprinted polymers bound much more 5-Fu than the corresponding non-imprinted ones and showed a controlled/sustained drug release, with MIPs release rate being indeed much more sustained than that obtained from NIPs. These polymers represent a potential valid system for drug delivery and this study indicates that the selective binding characteristic of molecularly imprinted polymers is promising for the preparation of novel controlled release drug dosage form.

  17. Chitosan in Molecularly-Imprinted Polymers: Current and Future Prospects.

    Science.gov (United States)

    Xu, Long; Huang, Yun-An; Zhu, Qiu-Jin; Ye, Chun

    2015-08-07

    Chitosan is widely used in molecular imprinting technology (MIT) as a functional monomer or supporting matrix because of its low cost and high contents of amino and hydroxyl functional groups. The various excellent properties of chitosan, which include nontoxicity, biodegradability, biocompatibility, and attractive physical and mechanical performances, make chitosan a promising alternative to conventional functional monomers. Recently, chitosan molecularly-imprinted polymers have gained considerable attention and showed significant potential in many fields, such as curbing environmental pollution, medicine, protein separation and identification, and chiral-compound separation. These extensive applications are due to the polymers' desired selectivity, physical robustness, and thermal stability, as well as their low cost and easy preparation. Cross-linkers, which fix the functional groups of chitosan around imprinted molecules, play an important role in chitosan molecularly-imprinted polymers. This review summarizes the important cross-linkers of chitosan molecularly-imprinted polymers and illustrates the cross-linking mechanism of chitosan and cross-linkers based on the two glucosamine units. Finally, some significant attempts to further develop the application of chitosan in MIT are proposed.

  18. Molecularly imprinted polymers for 5-fluorouracil release in biological fluids.

    Science.gov (United States)

    Puoci, Francesco; Iemma, Francesca; Cirillo, Giuseppe; Picci, Nevio; Matricardi, Pietro; Alhaiqu, Franco

    2007-04-18

    The aim of this work was to investigate the possibility of employing Molecularly Imprinted Polymers (MIPs) as a controlled release device for 5-fluorouracil (5-FU) in biological fluids, especially gastrointestinal ones, compared to Non Imprinted Polymers (NIPs). MIPs were synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. The capacity of the polymer to recognize and to bind the template selectively in both organic and aqueous media was evaluated. An in vitro release study was performed both in gastrointestinal and in plasma simulating fluids. The imprinted polymers bound much more 5-Fu than the corresponding non-imprinted ones and showed a controlled/sustained drug release, with MIPs release rate being indeed much more sustained than that obtained from NIPs. These polymers represent a potential valid system for drug delivery and this study indicates that the selective binding characteristic of molecularly imprinted polymers is promising for the preparation of novel controlled release drug dosage form.

  19. Creating BHb-imprinted magnetic nanoparticles with multiple binding sites.

    Science.gov (United States)

    Li, Yanxia; Chen, Yiting; Huang, Lu; Lou, BenYong; Chen, Guonan

    2017-01-16

    A kind of protein imprinted over magnetic Fe3O4@Au multifunctional nanoparticles (NPs) with multiple binding sites was synthesized and investigated. Magnetic Fe3O4@Au NPs as carrier materials were modified with 4-mercaptophenylboronic acid (MPBA) and mercaptopropionic acid (MPA) to introduce boronic acids and carboxyl groups. Using Bovine Hemoglobin (BHb) as a template, a polydopamine(PDA)-based molecular imprinted film was fabricated to produce a kind of magnetic molecularly imprinted nanoparticle (MMIP), possessing multiple binding sites with benzene-diol, amino groups, boronic acids and carboxyl groups. The MMIPs exhibited an excellent imprinting effect and adsorption capacity (89.65± 0.38 mg g(-1)) toward the template protein. The results show that the MMIPs reached saturated adsorption at 0.5 mg mL(-1) within 90 min. The synthesized MMIPs are suitable for the removal and enrichment of the template protein in proteomics. The strategy of multiple binding sites paves the way for the preparation of functional nanomaterials in molecular imprinting techniques.

  20. Scalemic and racemic imprinting with a chiral crosslinker.

    Science.gov (United States)

    Hebert, Britney; Meador, Danielle S; Spivak, David A

    2015-08-26

    The development of molecularly imprinted chiral stationary phases has traditionally been limited by the need for a chiral pure template. Paradoxically, availability of a chiral pure template largely defeats the purpose of developing a chiral stationary phase. To solve this paradox, imprinting of scalemic and racemic template mixtures was investigated using both chiral (N-α-bismethacryloyl-L-alanine) and achiral (N,O-bisacrylamide ethanolamine) crosslinkers. Imprinting of scalemic mixtures provided polymers capable of partial separation of Boc-tyrosine enantiomers with virtually the same results when using either the chiral or achiral crosslinker. However, the chiral crosslinker was required for chiral differentiation by the racemic imprinted polymers which were evaluated in both batch rebinding and chromatographic modes. Batch rebinding analysis revealed intersecting binding isotherms for the L- and D-Boc-tyrosine, indicating bias for the D or L enantiomer is concentration dependent. Partial chromatographic separation was achieved by the racemic imprinted polymers providing variable D or L bias in equal probability over multiple replicates of polymer synthesis. Correlation of enantiomer bias with the batch rebinding results and optimization of HPLC parameters are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Electrosynthesis of molecularly imprinted polypyrrole for the antibiotic levofloxacin

    Energy Technology Data Exchange (ETDEWEB)

    Mazzotta, Elisabetta, E-mail: elisabetta.mazzotta@unisalento.it [Laboratorio di Chimica Analitica, Dipartimento di Scienza dei Materiali, Universita del Salento, via Monteroni 73100 Lecce (Italy); Malitesta, Cosimino [Laboratorio di Chimica Analitica, Dipartimento di Scienza dei Materiali, Universita del Salento, via Monteroni 73100 Lecce (Italy); Diaz-Alvarez, Myriam; Martin-Esteban, Antonio [Departamento de Medio Ambiente, INIA, Carretera de A Coruna km 7.5, 28240 Madrid (Spain)

    2012-01-01

    The development of an electrosynthesized imprinted polypyrrole (PPY) film onto a platinum sheet as sorbent phase for a fluoroquinolone antibiotic (levofloxacin) is described. Experimental conditions for the electropolymerization of PPY in the presence of the template were optimized. The molecularly imprinted polymer (MIP) film was characterized by X-Ray Photoelectron Spectroscopy (XPS) to verify the template entrapment in the polymeric matrix. After being subject to washing procedures, MIP was analyzed by XPS and a very satisfactory template removal was estimated being equal to 83%. The effectiveness of washing protocol was assessed also by UV-vis and High Performance Liquid Chromatography (HPLC) analysis of corresponding washing solutions. Rebinding experiments were performed by exposing the imprinted PPY film to levofloxacin solutions, subsequently analyzed by HPLC. The effect of solvent and time of exposure was investigated. The imprinting effect was verified by comparing recognition abilities of both MIP and not imprinted polymer (a polymer prepared in the same conditions but in the absence of the template).

  2. Polymer Catalysts Imprinted with Metal Ions as Biomimics of Metalloenzymes

    Directory of Open Access Journals (Sweden)

    Joanna Czulak

    2013-01-01

    Full Text Available This work presents the preparation and properties of molecularly imprinted polymers (MIPs with catalytic centers that mimic the active sites of metalloenzymes. The MIP synthesis was based on suspension polymerization of functional monomers (4-vinylpyridine and acrylonitrile with trimethylolpropane trimethacrylate as a crosslinker in the presence of transition metal ions and 4-methoxybenzyl alcohol as a template. Four metal ions have been chosen for imprinting from among the microelements that are the most essential in the native enzymes: Cu2+, Co2+, Mn2+, and Zn2+. To prepare catalysts, the required loading of metal ions was obtained during sorption process. The catalysts imprinted with Cu2+, Co2+, and Zn2+ were successfully used for hydroquinone oxidation in the presence of hydrogen peroxide. The Mn2+-imprinted catalyst showed no activity due to the insufficient metal loading. Cu2+ MIP showed the highest efficiency. In case of Cu- and Co-MIP catalysts, their activity was additionally increased by the use of surface imprinting technique.

  3. Chitosan in Molecularly-Imprinted Polymers: Current and Future Prospects

    Directory of Open Access Journals (Sweden)

    Long Xu

    2015-08-01

    Full Text Available Chitosan is widely used in molecular imprinting technology (MIT as a functional monomer or supporting matrix because of its low cost and high contents of amino and hydroxyl functional groups. The various excellent properties of chitosan, which include nontoxicity, biodegradability, biocompatibility, and attractive physical and mechanical performances, make chitosan a promising alternative to conventional functional monomers. Recently, chitosan molecularly-imprinted polymers have gained considerable attention and showed significant potential in many fields, such as curbing environmental pollution, medicine, protein separation and identification, and chiral-compound separation. These extensive applications are due to the polymers’ desired selectivity, physical robustness, and thermal stability, as well as their low cost and easy preparation. Cross-linkers, which fix the functional groups of chitosan around imprinted molecules, play an important role in chitosan molecularly-imprinted polymers. This review summarizes the important cross-linkers of chitosan molecularly-imprinted polymers and illustrates the cross-linking mechanism of chitosan and cross-linkers based on the two glucosamine units. Finally, some significant attempts to further develop the application of chitosan in MIT are proposed.

  4. Molecularly imprinted polymers as the future drug delivery devices.

    Science.gov (United States)

    Luliński, Piotr

    2013-01-01

    In recent years, the investigations of new drug delivery systems have been directed on the development of some "intelligent" drug delivery devices that are able to directly respond to the patient's individual needs. New drug delivery systems should maximize the efficiency of administrated therapeutic agents and improve the patient's quality of life. Introduction of the new drug delivery devices is an important scientific goal, which could be achieved by combining new technologies and intelligent biomaterials. Molecular imprinting technology has a high potential for the preparation of optimized drug delivery forms. Here, molecularly imprinted polymers (MIPs) are promising new materials for such purposes, but their application in this field is nowadays at a developing stage. In this review, the principles of molecular imprinting and the recognition-release mechanisms of polymeric matrices are discussed. The potential application of molecularly imprinted materials as the future drug delivery systems with various administering routes (transdermal, ocular or oral) are presented, and some future prospects for the imprinted polymers are outlined.

  5. Quantum-dots-encoded-microbeads based molecularly imprinted polymer.

    Science.gov (United States)

    Liu, Yixi; Liu, Le; He, Yonghong; He, Qinghua; Ma, Hui

    2016-03-15

    Quantum dots encoded microbeads have various advantages such as large surface area, superb optical properties and the ability of multiplexing. Molecularly imprinted polymer that can mimic the natural recognition entities has high affinity and selectivity for the specific analyte. Here, the concept of utilizing the quantum dots encoded microbeads as the supporting material and the polydopamine as the functional monomer to form the core-shell molecular imprinted polymer was proposed for the first time. The resulted imprinted polymer can provide various merits: polymerization can complete in aqueous environment; fabrication procedure is facile and universal; the obvious economic advantage; the thickness of the imprinting layer is highly controllable; polydopamine coating can improve the biocompatibility of the quantum dot encoded microbeads. The rabbit IgG binding and flow cytometer experiment result showed the distinct advantages of this strategy: cost-saving, facile and fast preparation procedure. Most importantly, the ability for the multichannel detection, which makes the imprinted polydopamine modified encoded-beads very attractive in protein pre-concentration, recognition, separation and biosensing. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Sexual imprinting: what strategies should we expect to see in nature?

    Science.gov (United States)

    Chaffee, Dalton W; Griffin, Hayes; Gilman, R Tucker

    2013-12-01

    Sexual imprinting occurs when juveniles learn mate preferences by observing the phenotypes of other members of their populations, and it is ubiquitous in nature. Imprinting strategies, that is which individuals and phenotypes are observed and how strong preferences become, vary among species. Imprinting can affect trait evolution and the probability of speciation, and different imprinting strategies are expected to have different effects. However, little is known about how and why different imprinting strategies evolve, or which strategies we should expect to see in nature. We used a mathematical model to study how the evolution of sexual imprinting depends on (1) imprinting costs and (2) the sex-specific fitness effects of the phenotype on which individuals imprint. We found that even small fixed costs prevent the evolution of sexual imprinting, but small relative costs do not. When imprinting does evolve, we identified the conditions under which females should evolve to imprint on their fathers, their mothers, or on other members of their populations. Our results provide testable hypotheses for empirical work and help to explain the conditions under which sexual imprinting might evolve to promote speciation. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  7. 21 CFR 330.3 - Imprinting of solid oral dosage form drug products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Imprinting of solid oral dosage form drug products... AS SAFE AND EFFECTIVE AND NOT MISBRANDED General Provisions § 330.3 Imprinting of solid oral dosage form drug products. A requirement to imprint an identification code on solid oral dosage form drug...

  8. Synthesis of Molecularly Imprinted Polymer Particles by Suspension Polymerization in Silicon Oil

    Institute of Scientific and Technical Information of China (English)

    Xiao Bing WANG; Zhao Hui ZHENG; Xiao Bin DING; Xu CHENG; Xin Hua HU; Yu Xing PENG

    2006-01-01

    Molecularly imprinted polymers using 2,4-dichlorophenoxyacetic acid (2,4-D) as templates were prepared by suspension polymerization in silicon oil. The polymer particles exhibited regular shape in the micro-scale range. The adsorbing experiments indicated that the imprinted polymer particles possessed higher affinity to 2,4-D than the non-imprinted polymer particles.

  9. Methylation status of imprinting centers for H19/IGF2 and SNURF/SNRPN in primate embryonic stem cells.

    Science.gov (United States)

    Mitalipov, Shoukhrat; Clepper, Lisa; Sritanaudomchai, Hathaitip; Fujimoto, Akihisa; Wolf, Don

    2007-03-01

    Embryonic stem cells (ESCs) hold promise for cell and tissue replacement approaches to treating human diseases based on their capacity to differentiate into a wide variety of somatic cells and tissues. However, long-term in vitro culture and manipulations of ESCs may adversely affect their epigenetic integrity, including imprinting. We have recently reported aberrant biallelic expression of IGF2 and H19 in several rhesus monkey ESC lines, whereas SNRPN and NDN were normally imprinted and expressed predominantly from the paternal allele. The dysregulation of IGF2 and H19 that is associated with tumorigenesis in humans may result from improper maintenance of allele-specific methylation patterns at an imprinting center (IC) upstream of H19. To test this possibility, we performed methylation analysis of several monkey ESC lines by genomic bisulfite sequencing. We investigated methylation profiles of CpG islands within the IGF2/H19 IC harboring the CTCF-6 binding site. In addition, the methylation status of the IC within the promoter/exon 1 of SNURF/SNRPN known as the Prader-Willi syndrome IC was examined. Our results demonstrate abnormal hypermethylation within the IGF2/H19 IC in all analyzed ESC lines, whereas the SNURF/SNRPN IC was differentially methylated, consistent with monoallelic expression.

  10. Preparation and recognition performance of cytisine alkaloid-imprinted material prepared using novel surface molecular imprinting technique.

    Science.gov (United States)

    Gao, Baojiao; Niu, Qinyuan; Du, Ruikui

    2010-05-01

    Methacrylic acid was first graft-polymerized on the surfaces of micron-sized silica gel particles in the manner of "grafting from" using 3-methacryloxypropyl trimethoxysilane as an intermedia, obtaining the grafted particle polymethacrylic acid PMAA/SiO(2). By adopting the novel surface-molecular imprinting technique put forward by us, cytisine molecule-imprinted material MIP-PMAA/SiO(2) was prepared with ethylene glycol diglycidyl ether as crosslinking agent. The binding characteristics of MIP-PMAA/SiO(2) towards cytisine was investigated in depth with both batch and column methods and using matrine and oxymatrine as two contrast alkaloids, which with cytisine coexist in sophora alopecuroides and their chemical structure is similar to cytisine to a certain extent. The experimental results show that the surface-imprinted material MIP-PMAA/SiO(2) has excellent binding affinity for cytisine (20.1 g/100 g of binding capacity), and it is more important that MIP-PMAA/SiO(2) has very high recognition selectivity for cytisine in relation to the two contrast alkaloids. The selectivity coefficients of the grafted particles PMAA/SiO(2) (non-imprinted material) for cytosine in relation to matrine and oxymatrine are only 1.03 and 1.06, respectively, displaying no recognition selectivity for cytisine. However, after imprinting, the selectivity coefficient of MIP-PMAA/SiO(2) for cytisine in respect to matrine and oxymatrine are remarkably enhanced to 12.08 and 15.05, respectively.

  11. Modular Polymer Biosensors by Solvent Immersion Imprint Lithography

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Jayven S.; Xantheas, Sotiris S.; Grate, Jay W.; Wietsma, Thomas W.; Gratton, Enrico; Vasdekis, Andreas

    2016-01-01

    We recently demonstrated Solvent Immersion Imprint Lithography (SIIL), a rapid benchtop microsystem prototyping technique, including polymer functionalization, imprinting and bonding. Here, we focus on the realization of planar polymer sensors using SIIL through simple solvent immersion without imprinting. We describe SIIL’s impregnation characteristics, including an inherent mechanism that not only achieves practical doping concentrations, but their unexpected 4-fold enhancement compared to the immersion solution. Subsequently, we developed and characterized optical sensors for detecting molecular O2. To this end, a high dynamic range is reported, including its control through the immersion duration, a manifestation of SIIL’s modularity. Overall, SIIL exhibits the potential of improving the operating characteristics of polymer sensors, while significantly accelerating their prototyping, as it requires a few seconds of processing and no need for substrates or dedicated instrumentation. These are critical for O2 sensing as probed by way of example here, as well as any polymer permeable reactant.

  12. GENE IMPRINTING: ENGRAVING THE PATHOGENESIS OF HERIDETARY DISEASES

    Directory of Open Access Journals (Sweden)

    Sandeep Satapathy

    2014-01-01

    Full Text Available Gene imprinting has conduited the scope of our understanding of phenotypic expression and its corelation with constituent genotype. It is an epigenetic process that involves DNA methylation and histone modulation to attain monoallelic gene expression without altering the genetic sequences. A distinctive model of non-mendelian genetics, imprinting extends the control over expression of traits and selection of the allele that would direct the same, in a manner decided by the parent of origin. The constitutive existence of this imprinting even after gametogenesis, throughout the somatic development extends a clue for its regulatory hold on several heridetary traits. Several heridetary diseases like Cancers, Russell-Silver syndrome, Beckwith-Wiedemann syndrome, Prader-Willi and Angelman Syndromes and Neurodegenration have shown to be a subsequent error in the genomic impriting process. So, understanding these epigenetic regulations can be a therapeutic strategy for disease modelling and especially targeting their patterns of heridetary inheritance.

  13. Measurement of ablative Richtmyer-Meshkov evolution from laser imprint

    Science.gov (United States)

    Martinez, D. A.; Smalyuk, V. A.; Igumenshchev, I. V.; Delorme, B.; Casner, A.; Masse, L.; Park, H.-S.; Remington, B. A.; Olazabal-Loumé, M.

    2017-10-01

    Experiments were performed to investigate the ablative Richtmyer-Meshkov (RM) instability in plastic (CH2) foils. The two-dimensional (2-D) perturbations were created by laser imprinting using a special phase plate with a 2-D single mode, ˜70 μm wavelength sinusoidal intensity pattern on the plastic foil. The growth of imprinted perturbations was measured by face-on, X-ray radiography using Sm and Ta backlighters in 30-μm and 50-μm thick plastic foils, respectively. After the initial imprinting phase, the 2-D perturbations grew due to ablative RM instability before the onset of foil acceleration when they were further amplified by Rayleigh-Taylor instability. Experimental results agree reasonably well with 2-D hydrodynamic simulations and analytic models showing that the modulation growth in areal density is due to ablative RM instability.

  14. Tunable and stable in time ferroelectric imprint through polarization coupling

    Directory of Open Access Journals (Sweden)

    Anirban Ghosh

    2016-06-01

    Full Text Available Here we demonstrate a method to tune a ferroelectric imprint, which is stable in time, based on the coupling between the non-switchable polarization of ZnO and switchable polarization of PbZrxTi(1−xO3. SrRuO3/PbZrxTi(1−xO3/ZnO/SrRuO3 heterostructures were grown with different ZnO thicknesses. It is shown that the coercive voltages and ferroelectric imprint vary linearly with the thickness of ZnO. It is also demonstrated that the ferroelectric imprint remains stable with electric field cycling and electric field stress assisted aging.

  15. Does genomic imprinting play a role in autoimmunity?

    Science.gov (United States)

    Camprubí, Cristina; Monk, David

    2011-01-01

    In the 19th century Gregor Mendel defined the laws of genetic inheritance by crossing different types of peas. From these results arose his principle of equivalence: the gene will have the same behaviour whether it is inherited from the mother or the father. Today, several key exceptions to this principle are known, for example sex-linked traits and genes in the mitochondrial genome, whose inheritance patterns are referred to as 'non mendelian'. A third, important exception in mammals is that of genomic imprinting, where transcripts are expressed in a monoallelic fashion from only the maternal or the paternal chromosome. In this chapter, we discuss how parent-of-origin effects and genomic imprinting may play a role in autoimmunity and speculate how imprinted miRNAs may influence the expression of many target autoimmune associated genes.

  16. A role for chromatin topology in imprinted domain regulation.

    Science.gov (United States)

    MacDonald, William A; Sachani, Saqib S; White, Carlee R; Mann, Mellissa R W

    2016-02-01

    Recently, many advancements in genome-wide chromatin topology and nuclear architecture have unveiled the complex and hidden world of the nucleus, where chromatin is organized into discrete neighbourhoods with coordinated gene expression. This includes the active and inactive X chromosomes. Using X chromosome inactivation as a working model, we utilized publicly available datasets together with a literature review to gain insight into topologically associated domains, lamin-associated domains, nucleolar-associating domains, scaffold/matrix attachment regions, and nucleoporin-associated chromatin and their role in regulating monoallelic expression. Furthermore, we comprehensively review for the first time the role of chromatin topology and nuclear architecture in the regulation of genomic imprinting. We propose that chromatin topology and nuclear architecture are important regulatory mechanisms for directing gene expression within imprinted domains. Furthermore, we predict that dynamic changes in chromatin topology and nuclear architecture play roles in tissue-specific imprint domain regulation during early development and differentiation.

  17. Exploration of hydroxymethylation in Kagami-Ogata syndrome caused by hypermethylation of imprinting control regions.

    Science.gov (United States)

    Matsubara, Keiko; Kagami, Masayo; Nakabayashi, Kazuhiko; Hata, Kenichiro; Fukami, Maki; Ogata, Tsutomu; Yamazawa, Kazuki

    2015-01-01

    5-Hydroxymethylcytosine (5hmC), converted from 5-methylcytosine (5mC) by ten-eleven translocation (Tet) enzymes, has recently drawn attention as the "sixth base" of DNA since it is considered an intermediate of the demethylation pathway. Nonetheless, it remains to be addressed how 5hmC is linked to the development of human imprinting disorders. In this regard, conventional bisulfite (BS) treatment is unable to differentiate 5hmC from 5mC. It is thus hypothesized that BS conversion-derived "hypermethylation" at imprinting control regions (ICRs), which may cause imprinting disorders, would in fact be attributable to excessively increased levels of 5hmC as well as 5mC. To test this hypothesis, we applied the newly developed oxidative BS (oxBS) treatment to detect 5hmC in blood samples from Kagami-Ogata syndrome (KOS14) patients caused by an epimutation (hypermethylation) of two differentially methylated regions (DMRs) functioning as ICRs, namely, IG-DMR and MEG3-DMR. oxBS with pyrosequencing revealed that there were few amounts of 5hmC at the hypermethylated IG-DMR and MEG3-DMR in blood samples from KOS14 patients. oxBS with genome-wide methylation array demonstrated that global levels of 5hmC were very low with similar distribution patterns in blood samples from KOS14 patients and normal controls. We also confirmed the presence of large amounts of 5hmC in the brain sample from a normal control. 5hmC is not a major component in abnormally hypermethylated ICRs or at a global level, at least in blood from KOS14 patients. As the brain sample contained large amounts of 5hmC, the neural tissues of KOS14 patients are promising candidates for analysis in elucidating the role of 5hmC in the neurodevelopmental context.

  18. Ube3a imprinting impairs circadian robustness in Angelman syndrome models.

    Science.gov (United States)

    Shi, Shu-qun; Bichell, Terry Jo; Ihrie, Rebecca A; Johnson, Carl Hirschie

    2015-03-02

    The paternal allele of Ube3a is silenced by imprinting in neurons, and Angelman syndrome (AS) is a disorder arising from a deletion or mutation of the maternal Ube3a allele, which thereby eliminates Ube3a neuronal expression. Sleep disorders such as short sleep duration and increased sleep onset latency are very common in AS. We found a unique link between neuronal imprinting of Ube3a and circadian rhythms in two mouse models of AS, including enfeebled circadian activity behavior and slowed molecular rhythms in ex vivo brain tissues. As a consequence of compromised circadian behavior, metabolic homeostasis is also disrupted in AS mice. Unsilencing the paternal Ube3a allele restores functional circadian periodicity in neurons deficient in maternal Ube3a but does not affect periodicity in peripheral tissues that are not imprinted for uniparental Ube3a expression. The ubiquitin ligase encoded by Ube3a interacts with the central clock components BMAL1 and BMAL2. Moreover, inactivation of Ube3a expression elevates BMAL1 levels in brain regions that control circadian behavior of AS-model mice, indicating an important role for Ube3a in modulating BMAL1 turnover. Ube3a expression constitutes a direct mechanistic connection between symptoms of a human neurological disorder and the central circadian clock mechanism. The lengthened circadian period leads to delayed phase, which could explain the short sleep duration and increased sleep onset latency of AS subjects. Moreover, we report the pharmacological rescue of an AS phenotype, in this case, altered circadian period. These findings reveal potential treatments for sleep disorders in AS patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Fast screening of ketamine in biological samples based on molecularly imprinted photonic hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Liang [Department of Forensic Science, People' s Public Security University of China, Beijing (China); Meng, Pinjia, E-mail: mengpinjia@163.com [Department of Forensic Science, People' s Public Security University of China, Beijing (China); Zhang, Qingqing; Wang, Yanji [Department of Forensic Science, People' s Public Security University of China, Beijing (China)

    2013-04-10

    Graphical abstract: A novel label-free colorimetric chemosensor: with the increase in the concentration of ketamine, the Bragg diffraction peak of MIPHs gradually shifted to the longer wavelength region. Accompanying the peak shift, the color change of MIPHs was also observed obviously: from green to red. Highlights: ► We developed the label-free colorimetric MIPHs for handy and fast screening of ketamine. ► The obvious color change of MIPHs was observed upon ketamine. ► The MIPHs exhibited good sensing abilities in an aqueous environment. ► The sensing mechanisms of the water-compatible MIPHs were investigated. ► The MIPHs were employed to screening ketamine in real biological samples. -- Abstract: A novel label-free colorimetric chemosensor was developed for handy and fast screening of ketamine with high sensitivity and specificity based on molecularly imprinted photonic hydrogels (MIPHs) that combined the colloidal-crystal with molecular imprinting technique. The unique inverse opal arrays with a thin polymer wall in which the imprinted nanocavities of ketamine moleculars distributed allowed high sensitive, quick responsive, specific detection of the target analyte, and good regenerating ability in an aqueous environment. Due to the hierarchical inverse opal structural characteristics, the specific ketamine molecular recognition process can induce obvious swelling of the MIPHs to be directly transferred into visually perceptible optical signal (change in color) which can be detected by the naked eye through Bragg diffractive shifts of ordered macroporous arrays. In order to enhance the recognition ability in aqueous environments, the MIPHs were designed as water-compatible and synthesized in a water–methanol system. The molecular recognition mechanisms were investigated. The proposed MIPHs were successfully employed to screen trace level ketamine in human urine and saliva samples, exhibiting high sensitivity, rapid response, and specificity in the

  20. Paclitaxel molecularly imprinted polymer-PEG-folate nanoparticles for targeting anticancer delivery: Characterization and cellular cytotoxicity.

    Science.gov (United States)

    Esfandyari-Manesh, Mehdi; Darvishi, Behrad; Ishkuh, Fatemeh Azizi; Shahmoradi, Elnaz; Mohammadi, Ali; Javanbakht, Mehran; Dinarvand, Rassoul; Atyabi, Fatemeh

    2016-05-01

    The aim of this work was to synthesize molecularly imprinted polymer-poly ethylene glycol-folic acid (MIP-PEG-FA) nanoparticles for use as a controlled release carrier for targeting delivery of paclitaxel (PTX) to cancer cells. MIP nanoparticles were synthesized by a mini-emulsion polymerization technique and then PEG-FA was conjugated to the surface of nanoparticles. Nanoparticles showed high drug loading and encapsulation efficiency, 15.6 ± 0.8 and 100%, respectively. The imprinting efficiency of MIPs was evaluated by binding experiments in human serum. Good selective binding and recognition were found in MIP nanoparticles. In vitro drug release studies showed that MIP-PEG-FA have a controlled release of PTX, because of the presence of imprinted sites in the polymeric structure, which makes it is suitable for sustained drug delivery. The drug release from polymeric nanoparticles was indeed higher at acidic pH. The molecular structure of MIP-PEG-FA was confirmed by Hydrogen-Nuclear Magnetic Resonance (H NMR), Fourier Transform InfraRed (FT-IR), and Attenuated Total Reflection (ATR) spectroscopy, and their thermal behaviors by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Scanning Electron Microscopy (SEM) and Photon Correlation Spectroscopy (PCS) results showed that nanoparticles have a smooth surface and spherical shape with an average size of 181 nm. MIP-PEG-FA nanoparticles showed a greater amount of intracellular uptake in folate receptor-positive cancer cells (MDA-MB-231 cells) in comparison with the non-folate nanoparticles and free PTX, with half maximal inhibitory concentrations (IC50) of 4.9 ± 0.9, 7.4 ± 0.5 and 32.8 ± 3.8 nM, respectively. These results suggest that MIP-PEG-FA nanoparticles could be a potentially useful drug carrier for targeting drug delivery to cancer cells.

  1. The gene locus encoding iodothyronine deiodinase type 3 (Dio3) is imprinted in the fetus and expresses antisense transcripts.

    Science.gov (United States)

    Hernandez, Arturo; Fiering, Steven; Martinez, Elena; Galton, Valerie Anne; St Germain, Donald

    2002-11-01

    The mouse Dio3 gene codes for the type 3 iodothyronine deiodinase (D3), a conserved selenocysteine-containing enzyme that inactivates thyroid hormones and is highly expressed during early development. The mouse Dio3 gene and its human homolog map to chromosomal regions that are known to contain imprinted genes. We assessed the allelic expression of the Dio3 using a mouse model in which the gene had been inactivated by the introduction of a critical mutation in the selenocysteine codon. We compared Dio3 gene expression in fetuses that were either wild type or heterozygous (+/-Dio3) for the mutation. D3 enzymatic activities in the head, limbs, liver and body of heterozygous fetuses (E14 to E18) that inherited the mutation from the mother were no different from those found in their wild type littermates. However, D3 activities in heterozygous animals that inherited the mutation from the father were only 18 to 28% of the activities of their wild type littermates in these same tissues. No detectable activity was found in fetuses homozygous for the mutation indicating full inactivation of the enzyme. Northern analysis of mRNA from E15 fetuses showed that the Dio3 mRNA transcripts generated from the paternal allele were at least 5 times more abundant than the transcripts originated from the maternal allele. We conclude that the Dio3 gene is subject to genomic imprinting and preferentially expressed from the paternal allele in the mouse fetus. We also identified a gene that is transcribed antisense from the Dio3 locus. The Dio3 gene likely belongs to the same cluster of imprinted genes detected in mouse chromosome 12 and human chromosome 14 and should be considered as a candidate gene that might play a role in the phenotypic abnormalities associated with uniparental disomy of those chromosomes, a condition in which gene expression is altered due to abnormal genomic imprinting.

  2. Restricted access molecularly imprinted polymers obtained by bovine serum albumin and/or hydrophilic monomers' external layers: a comparison related to physical and chemical properties.

    Science.gov (United States)

    Santos, Mariane Gonçalves; Moraes, Gabriel de Oliveira Isac; Nakamura, Maurício Gustavo; dos Santos-Neto, Álvaro José; Figueiredo, Eduardo Costa

    2015-11-21

    Molecularly imprinting polymers (MIPs) can be modified with external layers in order to obtain restricted access molecularly imprinted polymers (RAMIPs) able to exclude macromolecules and retain low weight compounds. These modifications have been frequently achieved using hydrophilic monomers, chemically bound on the MIP surface. Recently, our group proposed a new biocompatible RAMIP based on the formation of a bovine serum albumin coating on the surface of MIP particles. This material has been used to extract drugs directly from untreated human plasma samples, but its physicochemical evaluation has not been carried out yet, mainly in comparison with RAMIPs obtained by hydrophilic monomers. Thus, we proposed in this paper a comparative study involving the surface composition, microscopic aspect, selectivity, binding kinetics, adsorption and macromolecule elimination ability of these different materials. We concluded that the synthesis procedure influences the size and shape of particles and that hydrophilic co-monomer addition as well as coating with BSA do not alter the chemical recognition ability of the material. The difference between imprinted and non-imprinted polymers' adsorption was evident (suggesting that imprinted polymers have a better capacity to bind the template than the non-imprinted ones). The Langmuir model presents the best fit to describe the materials' adsorption profile. The polymer covered with hydrophilic monomers presented the best adsorption for the template in an aqueous medium, probably due to a hydrophilic layer on its surface. We also concluded that an association of the hydrophilic monomers with the bovine serum albumin coating is important to obtain materials with higher capacity of macromolecule exclusion.

  3. Human Systems Integration (HSI) in Acquisition

    Science.gov (United States)

    2009-08-01

    Cost/Risk Drivers The numbers in the Activities boxes correspond to the numbers In the Inputs and Outputs boxes. Tools: ● CATIA ● HSI Requirements...Technology Development Phase (Inputs) Human Systems Integration Tools: ● IMPRINT ● CATIA ● IPME References: ● DODI 5000.02 & DODD 5000.01 ● DAG ● CJCSI...Human Systems Integration Tools: ● IMPRINT ● CATIA ● IPME Activities for Each Output: 1.0 Incorporate domain considerations into baseline

  4. Synthesis and Characterization of Molecularly Imprinted Polymers for Phenoxyacetic Acids

    Directory of Open Access Journals (Sweden)

    Canping Pan

    2008-01-01

    Full Text Available 2-methylphenoxyacetic acid (2-MPA, 2-methyl-4-chlorophenxyacetic acid (MCPA and 4-chlorophenoxyacetic acid (4-CPA were imprinted to investigate the cross-selectivities of molecularly imprinted polymers (MIPs. The result indicates that 2-MPA, which is similar in shape, size and functionality with phenoxyacetic herbicides, are suitable to be used as a suitable template to prepare the MIPs for retaining phenoxyacetic herbicides. To study the ion-pair interactions between template molecules and functional monomer 4-vinylpiridine (4-VP, computational molecular modeling was employed. The data indicate that the cross-selectivities of MIPs for phenoxyacetic acid herbicides depend on the binding energies of complexes.

  5. Quantification and confocal imaging of protein specific molecularly imprinted polymers

    OpenAIRE

    Hawkins, DM; Trache, A; Ellis, EA; Stevenson, D.; Holzenburg, A.; Meininger, GA; Reddy, Subrayal M

    2006-01-01

    We have employed FITC-albumin as the protein template molecule in an aqueous phase molecular imprinted polymer (HydroMIP) strategy. For the first time, the use of a fluorescently labelled template is reported, with subsequent characterisation of the smart material to show that the HydroMIP possess a significant molecular memory in comparison to that of the nonimprinted control polymer (HydroNIP). The imaging of the FITC-albumin imprinted HydroMIP using confocal microscopy is described, with t...

  6. Non-conflict theories for the evolution of genomic imprinting.

    Science.gov (United States)

    Spencer, H G; Clark, A G

    2014-08-01

    Theories focused on kinship and the genetic conflict it induces are widely considered to be the primary explanations for the evolution of genomic imprinting. However, there have appeared many competing ideas that do not involve kinship/conflict. These ideas are often overlooked because kinship/conflict is entrenched in the literature, especially outside evolutionary biology. Here we provide a critical overview of these non-conflict theories, providing an accessible perspective into this literature. We suggest that some of these alternative hypotheses may, in fact, provide tenable explanations of the evolution of imprinting for at least some loci.

  7. Production of abiotic receptors by molecular imprinting of proteins.

    Science.gov (United States)

    Braco, L; Dabulis, K; Klibanov, A M

    1990-01-01

    When a protein is dissolved in a concentrated aqueous solution of a multifunctional organic compound, freeze-dried, and washed with an anhydrous organic solvent to remove the ligand, the resultant "imprinted" protein preparation binds up to 30-fold more of the template compound in anhydrous solvents than the nonimprinted protein in the same solvent (and both proteins in water). These artificial receptors exhibit marked ligand selectivity as well as stability in anhydrous media. This phenomenon of molecular imprinting, demonstrated for several unrelated proteins and ligands, may be helpful in the development of unique bioadsorbents and, potentially, new biocatalysts.

  8. Influence Exogenous Factors on Genomic Imprinting. 1. Effect of Nutrition and Provision of Micronutrients in Mother on Genomic Imprinting Descendants

    Directory of Open Access Journals (Sweden)

    A.Ye. Abaturov

    2016-10-01

    Full Text Available The article analyzes the impact of maternal nutrition during pregnancy on the forming of genomic imprinting in the fetus. It was shown that changes in DNA methylation of imprinted genes, induced by infringement of providing protein and micronutrients, are accompanied by abnormalities of phy­sical development and increased risk of chronic inflammatory diseases, diseases of the cardiovascular system, the metabolic syndrome in the child’s postnatal life. It is emphasized that in order to prevent the development of imprinting-associated di­sease in a child special attention should be paid to the adequate content of protein, folic acid, methionine and group B vitamins in diet of pregnant women while forming their diet.

  9. Early imprinting in wild and game-farm mallards (Anas platyrhynchos): genotype and arousal

    Science.gov (United States)

    Cheng, K.M.; Shoffner, R.N.; Phillips, R.E.; Shapiro, L.J.

    1979-01-01

    Early imprinting was studied under laboratory conditions in five lines of mallards (Anas platyrhynchos) with different degrees of wildness obtained through pedigreed breeding. Data were analyzed by the least squares method. Wild ducklings imprinted better than game-farm (domesticated) ducklings, and heterosis was demonstrated to exist in imprinting traits. Nonadditive genetic variations and genotype-environmental interactions are discussed as possible causes for the heterosis observed. Differences in imprinting between genetic lines are attributed, at least partly, to differences in arousal level during the ducklings' first exposure to the imprinting stimulus.

  10. Enantiomeric Resolution on L-Carnitine Selective Polymers Prepared by Molecular Imprinting

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    L-carnitine selective polymers were prepared by molecular imprinting using methacrylic acid as the functional monomer. The acid function of the monomer is expected to form hydrogen bond and ionic interactions with the amine function of the target molecule L-carnitine. The imprinted polymers were used as stationary phases in high-performance liquid chromatography (HPLC). It was shown that L-carnitine imprinted polymer exhibited a higher affinity to its template molecule, while the non-imprinted polymer had no affinity to the compounds tested. Racemic carnitine hydrochloride was efficiently resolved on the L-carnitine imprinted polymer, and the separation factor is 1.9.

  11. Enantiomeric Resolution on L—Carnitine Selective Polymers Prepared by Molecular Imprinting

    Institute of Scientific and Technical Information of China (English)

    XiaoTaoLI; GuangGuangJIANG; 等

    2002-01-01

    L-carnitine selective polymers were prepared by molecular imprinting using methacrylic acid as the functional monomer. The acid function of the monomer is expected to form hydrogen bond and ionic interactions with the amine function of the target molecule L-carnitine.The imprinted polymers were used as stationary phases in high-performance liquid chromatography (HPLC). It was shown that L-carnitine imprinted polymer exhibited a higher affinity to its template molecule,while the non-imprinted polymer had no affinity to the compounds tested. Racemic carnitine hydrochloride was efficiently resolved on the L-carnitine imprinted polymer, and the separation factor is 1.9.

  12. Paclitaxel molecularly imprinted polymer-PEG-folate nanoparticles for targeting anticancer delivery: Characterization and cellular cytotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Esfandyari-Manesh, Mehdi [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Chemistry, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Darvishi, Behrad [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ishkuh, Fatemeh Azizi [Department of Chemistry, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Shahmoradi, Elnaz [Department of Chemical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Mohammadi, Ali [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Javanbakht, Mehran [Department of Chemistry, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Dinarvand, Rassoul [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Atyabi, Fatemeh, E-mail: atyabifa@tums.ac.ir [Nanotechnology Research Center,Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-05-01

    The aim of this work was to synthesize molecularly imprinted polymer-poly ethylene glycol-folic acid (MIP-PEG-FA) nanoparticles for use as a controlled release carrier for targeting delivery of paclitaxel (PTX) to cancer cells. MIP nanoparticles were synthesized by a mini-emulsion polymerization technique and then PEG-FA was conjugated to the surface of nanoparticles. Nanoparticles showed high drug loading and encapsulation efficiency, 15.6 ± 0.8 and 100%, respectively. The imprinting efficiency of MIPs was evaluated by binding experiments in human serum. Good selective binding and recognition were found in MIP nanoparticles. In vitro drug release studies showed that MIP-PEG-FA have a controlled release of PTX, because of the presence of imprinted sites in the polymeric structure, which makes it is suitable for sustained drug delivery. The drug release from polymeric nanoparticles was indeed higher at acidic pH. The molecular structure of MIP-PEG-FA was confirmed by Hydrogen-Nuclear Magnetic Resonance (H NMR), Fourier Transform InfraRed (FT-IR), and Attenuated Total Reflection (ATR) spectroscopy, and their thermal behaviors by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Scanning Electron Microscopy (SEM) and Photon Correlation Spectroscopy (PCS) results showed that nanoparticles have a smooth surface and spherical shape with an average size of 181 nm. MIP-PEG-FA nanoparticles showed a greater amount of intracellular uptake in folate receptor-positive cancer cells (MDA-MB-231 cells) in comparison with the non-folate nanoparticles and free PTX, with half maximal inhibitory concentrations (IC{sub 50}) of 4.9 ± 0.9, 7.4 ± 0.5 and 32.8 ± 3.8 nM, respectively. These results suggest that MIP-PEG-FA nanoparticles could be a potentially useful drug carrier for targeting drug delivery to cancer cells. - Highlights: • MIP-PEG-FA was synthesized as a controlled release carrier for targeting delivery to cancerous cells. • Nanoparticles

  13. Genomic imprinting is variably lost during reprogramming of mouse iPS cells.

    Science.gov (United States)

    Takikawa, Sachiko; Ray, Chelsea; Wang, Xin; Shamis, Yulia; Wu, Tien-Yuan; Li, Xiajun

    2013-09-01

    Derivation of induced pluripotent stem (iPS) cells is mainly an epigenetic reprogramming process. It is still quite controversial how genomic imprinting is reprogrammed in iPS cells. Thus, we derived multiple iPS clones from genetically identical mouse somatic cells. We found that parentally inherited imprint was variably lost among these iPS clones. Concurrent with the loss of DNA methylation imprint at the corresponding Snrpn and Peg3 imprinted regions, parental origin-specific expression of the Snrpn and Zim1 imprinted genes was also lost in these iPS clones. This loss of parental genomic imprinting in iPS cells was likely caused by the reprogramming process during iPS cell derivation because extended culture of iPS cells did not lead to significant increase in the loss of genomic imprinting. Intriguingly, one to several paternal chromosomes appeared to have acquired de novo methylation at the Snrpn and Zac1 imprinted regions in a high percentage of iPS clones. These results might have some implications for future therapeutic applications of iPS cells. Since DNA methylation imprint can be completely erased in some iPS clones at multiple imprinted regions, iPS cell reprogramming may also be employed to dissect the underlying mechanisms of erasure, reacquisition and maintenance of genomic imprinting in mammals.

  14. Imprinting in plants as a mechanism to generate seed phenotypic diversity

    Directory of Open Access Journals (Sweden)

    A Mark eSettles

    2015-01-01

    Full Text Available Normal plant development requires epigenetic regulation to enforce changes in developmental fate. Genomic imprinting is a type of epigenetic regulation in which identical alleles of genes are expressed in a parent-of-origin dependent manner. Deep sequencing of transcriptomes has identified hundreds of imprinted genes with scarce evidence for the developmental importance of individual imprinted loci. Imprinting is regulated through global DNA demethylation in the central cell prior to fertilization and directed repression of individual loci with the Polycomb Repressive Complex 2 (PRC2. There is significant evidence for transposable elements and repeat sequences near genes acting as cis-elements to determine imprinting status of a gene, implying that imprinted gene expression patterns may evolve randomly and at high frequency. Detailed genetic analysis of a few imprinted loci suggests an imprinted pattern of gene expression is often dispensable for seed development. Few genes show conserved imprinted expression within or between plant species. These data are not fully explained by current models for the evolution of imprinting in plant seeds. We suggest that imprinting may have evolved to provide a mechanism for rapid neofunctionalization of genes during seed development to increase phenotypic diversity of seeds.

  15. Binding characteristics of molecularly imprinted polymers based on fungicides in hydroalcoholic media.

    Science.gov (United States)

    Bitar, Manal; Bou-Maroun, Elias; Lerbret, Adrien; Ouaini, Naim; Cayot, Philippe

    2015-10-01

    An iprodione-imprinted polymer was prepared by copolymerization of methacrylamide and ethylene glycol dimethacrylate using a noncovalent imprinting approach. Methacrylamide was chosen using molecular dynamics simulations. To concentrate iprodione from hydro-alcoholic solutions, batch sorption of iprodione on the imprinted polymer were conducted. The equilibrium time for iprodione sorption is 20 min, and the corresponding kinetic mechanism follows the pseudo-second order indicating a strong interaction between iprodione and the imprinted polymer. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to fit the isotherm of iprodione sorption. The imprinted polymer was found to be more efficient than the nonimprinted polymer for the uptake of iprodione, as revealed by its higher adsorption energy, affinity, and capacity. Finally, a selectivity study was conducted on the imprinted and the nonimprinted polymers to sorb three fungicides. It shows that the imprinted polymer could be used as a preconcentration phase in a multiresidue analysis of fungicides in hydroalcoholic medium.

  16. Embryonic imprinting perturbations do not originate from superovulation-induced defects in DNA methylation acquisition.

    Science.gov (United States)

    Denomme, Michelle M; Zhang, Liyue; Mann, Mellissa R W

    2011-09-01

    To investigate whether superovulation disrupts maternal imprint acquisition in oocytes. Animal model. Academic institute. Spontaneously ovulated and superovulated mice. Low and high hormone dosage treatments were administered to females, and ovulated metaphase II oocytes were collected. Imprinted DNA methylation was analyzed at Snrpn, Kcnq1ot1, Peg3, and H19 in individual oocytes. Examination of 125 individual oocytes derived from females subjected to low and high hormone treatments revealed normal imprinted methylation patterns that were comparable to oocytes derived from spontaneously ovulated females. Maternal imprint acquisition was not affected by superovulation. Given its aberrant effects during preimplantation development, superovulation must instead disrupt maternal-effect gene products that are required after fertilization for imprint maintenance. These results eliminate imprint acquisition per se as the initial stage of imprint loss and point to the importance of analyses on early embryos after procedures involving oocyte manipulation. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  17. Convergent and divergent evolution of genomic imprinting in the marsupial Monodelphis domestica

    Directory of Open Access Journals (Sweden)

    Das Radhika

    2012-08-01

    Full Text Available Abstract Background Genomic imprinting is an epigenetic phenomenon resulting in parent-of-origin specific monoallelic gene expression. It is postulated to have evolved in placental mammals to modulate intrauterine resource allocation to the offspring. In this study, we determined the imprint status of metatherian orthologues of eutherian imprinted genes. Results L3MBTL and HTR2A were shown to be imprinted in Monodelphis domestica (the gray short-tailed opossum. MEST expressed a monoallelic and a biallelic transcript, as in eutherians. In contrast, IMPACT, COPG2, and PLAGL1 were not imprinted in the opossum. Differentially methylated regions (DMRs involved in regulating imprinting in eutherians were not found at any of the new imprinted loci in the opossum. Interestingly, a novel DMR was identified in intron 11 of the imprinted IGF2R gene, but this was not conserved in eutherians. The promoter regions of the imprinted genes in the opossum were enriched for the activating histone modification H3 Lysine 4 dimethylation. Conclusions The phenomenon of genomic imprinting is conserved in Therians, but the marked difference in the number and location of imprinted genes and DMRs between metatherians and eutherians indicates that imprinting is not fully conserved between the two Therian infra-classes. The identification of a novel DMR at a non-conserved location as well as the first demonstration of histone modifications at imprinted loci in the opossum suggest that genomic imprinting may have evolved in a common ancestor of these two Therian infra-classes with subsequent divergence of regulatory mechanisms in the two lineages.

  18. Sexual imprinting on continuous variation: do female zebra finches prefer or avoid unfamiliar sons of their foster parents?

    Science.gov (United States)

    Schielzeth, H; Burger, C; Bolund, E; Forstmeier, W

    2008-09-01

    Sexual imprinting on discrete variation that serves the identification of species, morphs or sexes is well documented. By contrast, sexual imprinting on continuous variation leading to individual differences in mating preferences within a single species, morph and sex has been studied only once (in humans). We measured female preferences in a captive population of wild-type zebra finches. Individual cross-fostering ensured that all subjects grew up with unrelated foster parents and nest mates. Females from two cohorts (N = 113) were given a simultaneous choice between (two or four) unfamiliar males, one of which was a genetic son of their foster parents (SFP). We found no significant overall preference for the SFP (combined effect size d = 0.14 +/- 0.15). Additionally, we tested if foster parent traits could potentially explain between-female variation in preferences. However, neither the effectiveness of cooperation between the parents nor male contribution to parental care affected female preferences for the son of the foster father. We conclude that at least in zebra finches sexual imprinting is not a major source of between-individual variation in mating preferences.

  19. Mammalian-specific genomic functions: Newly acquired traits generated by genomic imprinting and LTR retrotransposon-derived genes in mammals

    Science.gov (United States)

    KANEKO-ISHINO, Tomoko; ISHINO, Fumitoshi

    2015-01-01

    Mammals, including human beings, have evolved a unique viviparous reproductive system and a highly developed central nervous system. How did these unique characteristics emerge in mammalian evolution, and what kinds of changes did occur in the mammalian genomes as evolution proceeded? A key conceptual term in approaching these issues is “mammalian-specific genomic functions”, a concept covering both mammalian-specific epigenetics and genetics. Genomic imprinting and LTR retrotransposon-derived genes are reviewed as the representative, mammalian-specific genomic functions that are essential not only for the current mammalian developmental system, but also mammalian evolution itself. First, the essential roles of genomic imprinting in mammalian development, especially related to viviparous reproduction via placental function, as well as the emergence of genomic imprinting in mammalian evolution, are discussed. Second, we introduce the novel concept of “mammalian-specific traits generated by mammalian-specific genes from LTR retrotransposons”, based on the finding that LTR retrotransposons served as a critical driving force in the mammalian evolution via generating mammalian-specific genes. PMID:26666304

  20. A sensitive fluorescent nanosensor for chloramphenicol based on molecularly imprinted polymer-capped CdTe quantum dots.

    Science.gov (United States)

    Amjadi, Mohammad; Jalili, Roghayeh; Manzoori, Jamshid L

    2016-05-01

    A novel fluorescent nanosensor using molecularly imprinted silica nanospheres embedded CdTe quantum dots (CdTe@SiO2 @MIP) was developed for detection and quantification of chloramphenicol (CAP). The imprinted sensor was prepared by synthesis of molecularly imprinting polymer (MIP) on the hydrophilic CdTe quantum dots via reverse microemulsion method using small amounts of solvents. The resulting CdTe@SiO2 @MIP nanoparticles were characterized by fluorescence, UV-vis absorption and FT-IR spectroscopy and transmission electron microscopy. They preserved 48% of fluorescence quantum yield of the parent quantum dots. CAP remarkably quenched the fluorescence of prepared CdTe@SiO2 @MIP, probably via electron transfer mechanism. Under the optimal conditions, the relative fluorescence intensity of CdTe@SiO2 @MIP decreased with increasing CAP by a Stern-Volmer type equation in the concentration range of 40-500 µg L(-1). The corresponding detection limit was 5.0 µg L(-1). The intra-day and inter-day values for the precision of the proposed method were all <4%. The developed sensor had a good selectivity and was applied to determine CAP in spiked human and bovine serum and milk samples with satisfactory results.

  1. The Interaction Systems Generated by the Teacher's Didactic Imprinting

    Science.gov (United States)

    Peralta, Nadia S.; Roselli, Néstor D.

    2015-01-01

    The current study aimed to identify and analyze the systems of interaction implemented by teachers in university classes, based on their teaching imprints. It focused on the interactions occurred in scholar natural contexts and the construction of knowledge based on said interaction. A form to observe the different behaviors was designed in order…

  2. Imprinting of confining sites for cell cultures on thermoplastic substrates

    Science.gov (United States)

    Cone, C. D.; Fleenor, E. N.

    1969-01-01

    Prevention of test cell migration beyond the field of observation involves confining cells or cultures in microlagoons made in either a layer of grease or a thermoplastic substrate. Thermoplastic films or dishes are easily imprinted with specifically designed patterns of microlagoons.

  3. SEXUAL IMPRINTING AND SONG LEARNING - 2 OF ONE KIND

    NARCIS (Netherlands)

    TENCATE, C; VOS, DR; MANN, N

    1993-01-01

    Imprinting and song learning in birds are usually categorized under the same heading as 'exposure', 'template' or 'programmed' learning. These terms point to several similarities between the processes, but exactly how similar they are and whether the similarity implies a direct causal linkage is not

  4. STIMULUS REPRESENTATION - A SUBPROCESS OF IMPRINTING AND CONDITIONING

    NARCIS (Netherlands)

    HOLLIS, KL; TENCATE, C; BATESON, P

    1991-01-01

    We suggest a way to reconcile imprinting and associative learning that respects the real differences between the two phenomena but helps to recognize underlying commonalities. Rather than treating each type of learning as the manifestation of a unitary mechanism, we approach learning as a combinatio

  5. Molecularly imprinted polymers (MIPs): sensing, an explosive new opportunity?

    Science.gov (United States)

    McCluskey, Adam; Holdsworth, Clovia I; Bowyer, Michael C

    2007-10-21

    Our group is currently developing in-field detection systems alongside the Australian Federal Police Forensic Services utilising molecularly imprinted polymers as the recognition elements. This review looks at MIP synthesis and our perceptions of future directions from an Australian and forensic perspective.

  6. Preparation and Property Recognition of Nimodipine Molecularly Imprinted Polymer

    Institute of Scientific and Technical Information of China (English)

    CHEN Fei-fei

    2015-01-01

    Objective:To explore the application of molecular imprinting technique in the separation and detection of nimodipine. Methods:Methacrylic acid as functional monomer, pentaerythritol triacrylate as cross-linking agent were used to prepare molecularly imprinted polymer (MIP) with the feature of specific recognition performance on imprinting molecule nimodipine under condition of template molecule nimodipine. The preparation conditions, recognition performance of MIP on nimodipine, different proportions of template molecule and functional monomer, the selectivity to other substrate, and the relationship between adsorption quantity (Q) and time were observed. Results: MIP was prepared successfully by nimodipine as template and pentaerythritol triacrylate as cross-linking agent, with the feature of speciifc recognition performance on nimodipine. The static adsorption distribution coefifcient (KD) was 0.2264. The equation of Q and the concentration of substrate of template MIP was y = -0.21x+0.2204. Combining capacity of template molecule at the same concentration enhanced with the increasing proportion of functional monomer. Conclusion:Nimodipine MIP based on molecular imprinting technique may become a new approach to chiral separation for nimodipine.

  7. Molecular imprinted polymers for separation science: a review of reviews.

    Science.gov (United States)

    Cheong, Won Jo; Yang, Song Hee; Ali, Faiz

    2013-02-01

    Molecular imprinted polymer is an artificial receptor made by imprinting molecules of a template in a polymer matrix followed by removing the template molecules via thorough washing to give the permanent template grooves. They show favored affinity to the template molecule compared to other molecules, and this property is the basic driving force for such diverse application of this techniques. Such techniques have been increasingly employed in a wide scope of applications such as chromatography, sample pretreatment, purification, catalysts, sensors, and drug delivery, etc., mostly in bioanalytical areas. A major part of them is related to development of new stationary phases and their application in chromatography and sample pretreatment. Embodiments of molecular imprinted polymer materials have been carried out in a variety of forms such as irregularly ground particles, regular spherical particles, nanoparticles, monoliths in a stainless steel or capillary column, open tubular layers in capillaries, surface attached thin layers, membranes, and composites, etc. There have been numerous review articles on molecular imprinted polymer issues. In this special review, the reviews in recent ca. 10 years will be categorized into several subgroups according to specified topics in separation science, and each review in each subgroup will be introduced in the order of date with brief summaries and comments on new developments and different scopes of prospects. Brief summaries of each categories and conclusive future perspectives are also given.

  8. Preparation and Property Recognition of Nimodipine Molecularly Imprinted Polymer

    Directory of Open Access Journals (Sweden)

    Fei-fei CHEN

    2015-09-01

    Full Text Available Objective: To explore the application of molecular imprinting technique in the separation and detection of nimodipine. Methods: Methacrylic acid as functional monomer, pentaerythritol triacrylate as cross-linking agent were used to prepare molecularly imprinted polymer (MIP with the feature of specific recognition performance on imprinting molecule nimodipine under condition of template molecule nimodipine. The preparation conditions, recognition performance of MIP on nimodipine, different proportions of template molecule and functional monomer, the selectivity to other substrate, and the relationship between adsorption quantity (Q and time were observed. Results: MIP was prepared successfully bynimodipine as template and pentaerythritol triacrylate as cross-linking agent, with the feature of specific recognition performance on nimodipine. The static adsorption distribution coefficient (KD was 0.2264. The equation of Q and the concentration of substrate of template MIP was y = -0.21x+0.2204. Combining capacity of template molecule at the same concentration enhanced with the increasing proportion of functional monomer.Conclusion: Nimodipine MIP based on molecular imprinting technique may become a new approach to chiral separation for nimodipine.

  9. Molecularly imprinted polymers for histamine recognition in aqueous environment.

    Science.gov (United States)

    Trikka, Foteini A; Yoshimatsu, Keiichi; Ye, Lei; Kyriakidis, Dimitrios A

    2012-11-01

    Molecularly imprinted polymers (MIP) for histamine using methacrylic acid were developed and recognition mechanisms were thoroughly characterized for the first time in this study. The binding affinity of imprinted polymer with structurally related compounds was studied in organic and aqueous media, at various conditions. In organic media, MIP was found to bind histamine two and six times more than ranitidine and fluoxetine, respectively, whereas higher selectivity was observed in the case of dimentidene or disodium cromoglycate. The specific binding sites of MIP recognized histamine over L-histidine in aqueous conditions, while higher affinity for histamine compared to ranitidine, disodium cromoglycate, putrescine and to a putrescine analogue was observed. A combination of NMR and UV spectroscopy analyses for investigation of imprinting and recognition properties revealed that strong specific interactions between the functional monomer and histamine in the prepolymerization and in the aqueous solutions were probably responsible for histamine recognition. The preparation of histamine MIPs and elucidation of imprinting and recognition mechanism may serve as useful insight for future application of MIPs.

  10. Prenatal imprinting by environmental toxicants: really an important issue?

    Directory of Open Access Journals (Sweden)

    Karl Ernst v. Mühlendahl

    2015-06-01

    Full Text Available Prenatal imprinting of sexual behaviour and of other traits by environmental toxicants has been one important topic in the ongoing discussions in environmental medicine. This review of the literature shows that, so far, concrete data are sparse and, in part, contradictory.

  11. SEXUAL IMPRINTING IN THE COLLARED DOVE (STREPTOPELIA-DECAOCTO)

    NARCIS (Netherlands)

    TENCATE, C; HILBERS, J; HALL, M

    1992-01-01

    Although the occurrence of sexual imprinting has been demonstrated for doves, it is less well known how strong this effect is and which factors contribute to it. Therefore we examined whether cross-fostering collared doves (Streptopelia decaocto) to white ring doves (Streptopelia risoria) affected l

  12. In Celebration: The National Union Catalog, Pre-1956 Imprints.

    Science.gov (United States)

    Cole, John Y., Ed.

    This document contains the principal papers from a 1981 symposium held to celebrate the completion of the 754-volume National Union Catalog, Pre-1956 Imprints. Papers by both those who use the National Union Catalog (NUC) and those who developed it are included. A brief preface describes the mission of the Center for the Book and the purpose of…

  13. Molecularly Imprinted Polymers and Highly Porous Materials in Sensing Applications

    Science.gov (United States)

    2007-04-01

    microspheres from dilute dispersion polymerization systems (52). MIPs have also been prepared as imprinted membranes by precipitation of linear...and 1200m2/g. Supercritical drying of polysilsesquioxanes results in the formation of aerogels . These very low density materials have been

  14. Imprints of the Quantum World in Classical Mechanics

    OpenAIRE

    de Gosson, Maurice A.; Hiley, Basil

    2010-01-01

    The imprints left by quantum mechanics in classical (Hamiltonian) mechanics are much more numerous than is usually believed. We show Using no physical hypotheses) that the Schroedinger equation for a nonrelativistic system of spinless particles is a classical equation which is equivalent to Hamilton's equations.

  15. Novel imprinting techniques for fabrication of multilevel flexible electronics

    NARCIS (Netherlands)

    Turkenburg, D.H.; Rendering, H.; Hovestad, A.; Stroeks, N.; Maury, P.; Moonen, P.; Huskens, J.; Barbu, I.; Meinders, E.R.

    2011-01-01

    We report a novel method to selectively deposit materials from solution into imprinted micro-capillaries. Dewetting of the solvent just outside the capillaries is balanced to evaporation inside the capillaries. In this way conductive u-wires can be self-assembled and self-aligned on flexible

  16. Shape recognition of microbial cells by colloidal cell imprints

    NARCIS (Netherlands)

    Borovicka, J.; Stoyanov, S.D.; Paunov, V.N.

    2013-01-01

    We have engineered a class of colloids which can recognize the shape and size of targeted microbial cells and selectively bind to their surfaces. These imprinted colloid particles, which we called "colloid antibodies", were fabricated by partial fragmentation of silica shells obtained by templating

  17. Roll-to-roll UV imprint lithography for flexible electronics

    NARCIS (Netherlands)

    Maury, P.; Turkenburg, D.H.; Stroeks, N.; Giesen, P.; Barbu, I.; Meinders, E.R.; Bremen, A. van; Iosad, N.; Werf, R. van der; Onvlee, H.

    2011-01-01

    We propose a roll-to-roll UV imprint lithography tool as a way to pattern flexible PET foil with µm-resolution. As a way to overcome dimensional instability of the foil and its effect on overlay, a self-align approach was investigated, that permits to make several layers in a single lithography step

  18. Extrusion Roller Imprinting with a Variotherm Belt Mold

    Directory of Open Access Journals (Sweden)

    Raymond Frenkel

    2014-12-01

    Full Text Available Although many precision fabrication techniques have demonstrated the ability to produce microstructures and micro-devices with sub 100 nm accuracy, we are yet to see a scalable manufacturing process for large-area production. One promising solution to scalable micro- and nanofabrication is thermal roller imprinting. However, existing investigations on thermal roller imprinting revealed poor pattern transfer fidelity, especially for high aspect ratio features. The standard roller imprinting process suffers from the lack of an effective holding and cooling stage so that the adverse effects from the viscoelastic nature of polymers are not managed. To rectify this problem and further improve the production rate, a new extrusion roller imprinting process with a variotherm belt mold is designed, and its prototype was established at a laboratory scale. The process testing results demonstrate that a 30 μm sawtooth pattern can be faithfully transferred to extruded polyethylene film at take-up speeds higher than 10 m/min. The results are promising in that microfeatures or even nanofeatures may be successfully replicated by a robust and scalable industrial process suitable for large-area, continuous production.

  19. Enzyme activity assay of glycoprotein enzymes based on a boronate affinity molecularly imprinted 96-well microplate.

    Science.gov (United States)

    Bi, Xiaodong; Liu, Zhen

    2014-12-16

    Enzyme activity assay is an important method in clinical diagnostics. However, conventional enzyme activity assay suffers from apparent interference from the sample matrix. Herein, we present a new format of enzyme activity assay that can effectively eliminate the effects of the sample matrix. The key is a 96-well microplate modified with molecularly imprinted polymer (MIP) prepared according to a newly proposed method called boronate affinity-based oriented surface imprinting. Alkaline phosphatase (ALP), a glycoprotein enzyme that has been routinely used as an indicator for several diseases in clinical tests, was taken as a representative target enzyme. The prepared MIP exhibited strong affinity toward the template enzyme (with a dissociation constant of 10(-10) M) as well as superb tolerance for interference. Thus, the enzyme molecules in a complicated sample matrix could be specifically captured and cleaned up for enzyme activity assay, which eliminated the interference from the sample matrix. On the other hand, because the boronate affinity MIP could well retain the enzymatic activity of glycoprotein enzymes, the enzyme captured by the MIP was directly used for activity assay. Thus, additional assay time and possible enzyme or activity loss due to an enzyme release step required by other methods were avoided. Assay of ALP in human serum was successfully demonstrated, suggesting a promising prospect of the proposed method in real-world applications.

  20. Molecularly imprinted electrochemical sensor based on bioinspired Au microflowers for ultra-trace cholesterol assay.

    Science.gov (United States)

    Yang, Hua; Li, Li; Ding, Yaping; Ye, Daixin; Wang, Yingzi; Cui, Shiqiang; Liao, Lanfeng

    2017-06-15

    A novel imprinted sensor for ultra-trace cholesterol (CHO) detection based on electropolymerized aminothiophenol (ATP) molecularly imprinted polymer (MIP) on a glassy carbon electrode (GCE) modified with dopamine@graphene (DGr) and bioinspired Au microflowers has been developed in this work. As the specific recognition element, the bioinspired Au microflowers were formed by Au nanoparticles (AuNPs) and wrapped by bionic polydopamine film (PDA) through electropolymerization method. These excellent biocompatible materials could capture the target CHO effectively. The morphology of the MIP modified electrode was characterized by scanning electron microscopy (SEM) and atomic force microscope (AFM). The hydrogen-bonding interaction between templates and monomers was characterized by ultraviolet spectroscopy. Under the optimal experimental conditions, the sensor's linear response range was between 10(-18) and 10(-13) M, with a detection limit of 3.3×10(-19) M, which was much more sensitive than most available CHO detection methods in previously reports. Moreover, the MIP sensor exhibited high sensitivity for CHO, low interference, and good stability. The human serum samples analysis confirmed the applicability of this MIP sensor to quantitative analysis of ultra-trace CHO. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Preparation of an amperometric sensor for norfloxacin based on molecularly imprinted grafting photopolymerization.

    Science.gov (United States)

    Wang, Zhihua; Li, Jinshu; Liu, Xiaole; Yang, Jianming; Lu, Xiaoquan

    2013-03-01

    A sensitive amperometric sensor for norfloxacin (NF) was introduced. The receptor layer was prepared by molecularly imprinted photopolymerization of acrylamide and trimethylolpropane trimethacrylate on the surface of a gold electrode. The binding mechanism of the molecularly imprinted polymer was explored by ultraviolet (UV) and infrared (IR) spectroscopy. The chemosensor was characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance (EI), and scanning electron microscopy (SEM). The electrode prepared by photopolymerization has a better recognition ability to template molecules than that of electropolymerization and NIP. Some parameters affecting sensor response were optimized. Norfloxacin was detected by measurements of an amperometric i-t curve. The linear relationships between current and logarithmic concentration are obtained from 1.0 × 10(-9) to 1.0 × 10(-3) mol L(-1). The detection limit of the sensor was 1.0 × 10(-10) mol L(-1). The proposed method is sensitive, simple, and cheap, and is applied to detect NF in human urine successfully.

  2. A novel composite of SiO2-coated graphene oxide and molecularly imprinted polymers for electrochemical sensing dopamine.

    Science.gov (United States)

    Zeng, Yanbo; Zhou, Ying; Kong, Lei; Zhou, Tianshu; Shi, Guoyue

    2013-07-15

    A novel imprinting route based on graphene oxide (GO) was proposed for preparing a composite of SiO2-coated GO and molecularly imprinted polymers (GO/SiO2-MIPs). In this route, SiO2-coated GO sheets were synthesized in a water-alcohol mixture with sol-gel technique. Prior to polymerization, the vinyl groups were introduced onto the surface of GO/SiO2 through chemical modification with γ-methacryloxypropyl trimethoxysilane (γ-MAPS), which can direct the selective polymerization on the GO/SiO2 surface. Then a novel composite of GO/SiO2-MIPs was successfully obtained by the copolymerization in presence of vinyl groups functionalized GO/SiO2, dopamine (DA), methacrylic acid and ethylene glycol dimethacrylate. The GO/SiO2-MIPs composite was characterized by FTIR, TGA, Raman spectroscopy, SEM and AFM. The properties such as special binding, adsorption dynamics and selective recognition ability using differential pulse voltammetry (DPV) were evaluated. The DPV current response of GO/SiO2-MIPs sensor was nearly 3.2 times that of the non-imprinted polymers (NIPs). In addition, the GO/SiO2-MIPs sensor could recognize DA from its relatively similar molecules of norepinephrine and epinephrine, while the sensors based on GO/SiO2-NIPs and vinyl groups functionalized GO/SiO2 did not have the ability. The GO/SiO2-MIPs sensor had a wide linear range over DA concentration from 5.0 × 10(-8) to 1.6 × 10(-4)M with a detection limit of 3.0 × 10(-8)M (S/N=3). The sensor based on this novel imprinted composite was applied to the determination of DA in injections and human urine samples with satisfactory results.

  3. Influence of Exogenous Factors on Genomic Imprinting. 2. Effect of Bad Habits of Parents on Genomic Imprinting of the Descendants

    Directory of Open Access Journals (Sweden)

    A.E. Abaturov

    2016-11-01

    Full Text Available The article presents research data, which suggest that alcohol abuse and smoking of parents have an adverse effect on fetal development and the health of the child. These factors disrupt the processes of DNA methylation of imprinted genes, causing an increased risk of intrauterine growth retardation, and of pathological abnormalities in fetal neurogenesis.

  4. Rational preparation of dibenzothiophene-imprinted polymers by surface imprinting technique combined with atom transfer radical polymerization

    Science.gov (United States)

    Yang, Wenming; Liu, Lukuan; Zhou, Zhiping; Liu, Hong; Xie, Binze; Xu, Wanzhen

    2013-10-01

    A computational simulation method is introduced to simulate the dibenzothiophene-monomer pre-assembly system of molecular imprinted polymers. The interaction type and intensity between dibenzothiophene and monomer are discussed from the binding energy and spatial position distribution. The simulation and analysis results indicate that the amount of the function monomer is not the more the better in preparing molecular imprinted polymers. Based on the above results, a novel dibenzothiophene-imprinted polymers with the favorable specific adsorption effect was prepared by surface imprinting technique combined with atom transfer radical polymerization. This combined technologies are used for preparing a desulfurization adsorbent for the first time. Various measures were selected to characterize the structure and morphology of the prepared adsorbent. The characterization results show that the adsorbent has suitable features for further adsorption process. A series of static adsorption experiments were conducted to analyze its adsorption performance. The adsorption process follows Elovich model by the kinetic analysis and Sips equation by the isothermal analysis. The approach we described will provide another opportunity in the deep desulfurization field.

  5. Fingerprint-imprinted polymer: rational selection of peptide epitope templates for the determination of proteins by molecularly imprinted polymers.

    Science.gov (United States)

    Bossi, Alessandra M; Sharma, Piyush S; Montana, Luca; Zoccatelli, Gianni; Laub, Orgad; Levi, Raphael

    2012-05-01

    The pool of peptides composing a protein allows for its distinctive identification in a process named fingerprint (FP) analysis. Here, the FP concept is used to develop a method for the rational preparation of molecularly imprinted polymers (MIPs) for protein recognition. The fingerprint imprinting (FIP) is based on the following: (1) the in silico cleavage of the protein sequence of interest with specific agents; (2) the screening of all the peptide sequences generated against the UniProtKB database in order to allow for the rational selection of distinctive and unique peptides (named as epitopes) of the target protein; (3) the selected epitopes are synthesized and used as templates for the molecular imprinting process. To prove the principle, NT-proBNP, a marker of the risk of cardiovascular events, was chosen as an example. The in silico analysis of the NT-proBNP sequence allowed us to individuate the peptide candidates, which were next used as templates for the preparation of NT-pro-BNP-specific FIPs and tested for their ability to bind the NT-proBNP peptides in complex samples. Results indicated an imprinting factor, IF, of ~10, a binding capacity of 0.5-2 mg/g, and the ability to rebind 40% of the template in a complex sample, composed of the whole digests of NT-proBNP.

  6. A sensitive and selective molecularly imprinted sensor combined with magnetic molecularly imprinted solid phase extraction for determination of dibutyl phthalate.

    Science.gov (United States)

    Zhang, Zhaohui; Luo, Lijuan; Cai, Rong; Chen, Hongjun

    2013-11-15

    A highly sensitive and selective molecularly imprinted (MIP) sensor combined with magnetic molecularly imprinted solid phase extraction (MMISPE) was developed for the determination of dibutyl phthalate (DBP) in complex matrixes. The magnetic molecularly imprinted polymer (MMIP) was synthesized as solid phase extraction (SPE) sorbet to extract DBP from complex matrixes and as sensing element to improve the selectivity of the imprinted sensor. The morphologies of MMIP and MIP-sensor were characterized by using scanning electron microscope (SEM) and transmission electron microscopy (TEM). The electrochemical performances of MIP-sensor were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The conditions of preconcentration, elution and electrochemical determination were studied in detail. Under the optimized experimental conditions, the response currents of the MIP-sensor exhibited a linear relationship towards DBP concentrations ranging from 1.0 × 10(-8)g/L to 1.0 × 10(-3)g/L. The limit of detection of the MMIP-sensor coupled with the MMISPE was calculated as 0.052 ng/L. The MMIP-sensor coupled with the MMISPE was applied to detect DBP in complex samples successfully.

  7. A quick responding quartz crystal microbalance sensor array based on molecular imprinted polyacrylic acids coating for selective identification of aldehydes in body odor.

    Science.gov (United States)

    Jha, Sunil K; Hayashi, Kenshi

    2015-03-01

    In present work, a novel quartz crystal microbalance (QCM) sensor array has been developed for prompt identification of primary aldehydes in human body odor. Molecularly imprinted polymers (MIP) are prepared using the polyacrylic acid (PAA) polymer matrix and three organic acids (propenoic acid, hexanoic acid and octanoic acid) as template molecules, and utilized as QCM surface coating layer. The performance of MIP films is characterized by 4-element QCM sensor array (three coated with MIP layers and one with pure PAA for reference) dynamic and static responses to target aldehydes: hexanal, heptanal, and nonanal in single, binary, and tertiary mixtures at distinct concentrations. The target aldehydes were selected subsequent to characterization of body odor samples with solid phase-micro extraction gas chromatography mass spectrometer (SPME-GC-MS). The hexanoic acid and octanoic acid imprinted PAA exhibit fast response, and better sensitivity, selectivity and reproducibility than the propenoic acid, and non-imprinted PAA in array. The response time and recovery time for hexanoic acid imprinted PAA are obtained as 5 s and 12 s respectively to typical concentrations of binary and tertiary mixtures of aldehydes using the static response. Dynamic sensor array response matrix has been processed with principal component analysis (PCA) for visual, and support vector machine (SVM) classifier for quantitative identification of target odors. Aldehyde odors were identified successfully in principal component (PC) space. SVM classifier results maximum recognition rate 79% for three classes of binary odors and 83% including single, binary, and tertiary odor classes in 3-fold cross validation.

  8. Modified Au nanoparticles-imprinted sol-gel, multiwall carbon nanotubes pencil graphite electrode used as a sensor for ranitidine determination.

    Science.gov (United States)

    Rezaei, B; Lotfi-Forushani, H; Ensafi, A A

    2014-04-01

    A new, simple, and disposable molecularly imprinted electrochemical sensor for the determination of ranitidine was developed on pencil graphite electrode (PGE) via cyclic voltammetry (CV). The PGEs were coated with MWCNTs containing the carboxylic functional group (f-MWCNTs), imprinted with sol-gel and Au nanoparticle (AuNPs) layers (AuNP/MIP-sol-gel/f-MWCNT/PGE), respectively, to enhance the electrode's electrical transmission and sensitivity. The thin film of molecularly imprinted sol-gel polymers with specific binding sites for ranitidine was cast on modified PGE by electrochemical deposition. The AuNP/MIP-sol-gel/f-MWCNT/PGE thus developed was characterized by electrochemical impedance spectroscopy (EIS) and CV. The interaction between the imprinted sensor and the target molecule was also observed on the electrode by measuring the current response of 5.0mMK3[Fe(CN)6] solution as an electrochemical probe. The pick currents of ranitidine increased linearly with concentration in the ranges of 0.05 to 2.0μM, with a detection limit of (S/N=3) 0.02μM. Finally, the modified electrode was successfully employed to determine ranitidine in human urine samples.

  9. Imprinting is also a mechanism for immediate or delayed hemizygous expression of several uniparental haplotypes selected from the genome of each sex.

    Science.gov (United States)

    Engel, E

    1997-05-02

    A peculiar and interesting aspect of monoallelic or hemizygous expression, resulting from genomic imprinting, should be a likeness or resemblance for some phenotypic traits between relatives inheriting identical active genes or domains. Although the word "likon," a neologism, is reminiscent of the above implication, it is here proposed for use in a broader sense, namely, to designate a haplotype or part of a haplotype of an imprinted domain. As learned from earlier studies of imprinting and uniparental disomies, haplotypes at loci of such domains may be expressed (E) or unexpressed (U) in somatic cells; they may also be transmitted to be expressed or not in the next generation by germ cells "acting" (A) or marked to be "resting" (R) for such loci. Thus the soma/germinal status of "likons" might for each genitor be abbreviated as EA, UA, ER, and UR. In an evolutionary sense the assumption is that the same monoallelically expressed loci and domains when carried by two or more relatives should be the source of identical transcripts contributing to a closely similar phenotype. If so, the overall phenotype would be distinct if arising from some 10 to 20 imprinted genes or domains potentially gaining expression from the germ cells of either one or the other sex in humans. The result may have evolutionary implications by narrowing the scope of random individual variation and by strengthening assortative and associative values (physical, behavioral, and instinctual) in one's own lineage and species.

  10. Desorption of 3,3′-diindolylmethane from imprinted particles: An impact of cross-linker structure on binding capacity and selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Klejn, Dorota; Luliński, Piotr; Maciejewska, Dorota, E-mail: dorota.maciejewska@wum.edu.pl

    2015-11-01

    Here, seven cross-linkers (six polar diacrylates or dimethacrylates of different lengths between double bonds, and one aromatic-divinylbenzene) were used to examine the impact of the cross-linker on binding capacity and selectivity of 3,3′-diindolylmethane (DIM) imprinted material. DIM participates in the suppression of viability of human ovarian and human breast cancer cell lines, but has low bioavailability. The investigations of novel imprinted polymer matrices for improvement of DIM release could allow to utilize not only a potency of DIM but also similar alkaloids, which are the important compounds with pharmacological activity. The bulk, thermal radical copolymerization of the cross-linkers in the presence of 3,3′-diindolylmethane (the template) and allylamine (the functional monomer) in dimethyl sulfoxide or in carbon tetrachloride (porogens) was carried out. The binding capacities of imprinted and non-imprinted polymers were compared, and two polymers (these were prepared using ethylene glycol dimethacrylate and polyethylene glycol dimethacrylate as the cross-linkers) with the highest selectivity and binding capacity were selected to desorption test. The desorption profile of polymer prepared using polyethylene glycol dimethacrylate as the cross-linker revealed sustained release of 3,3′-diindolylmethane, and this system was selected for further optimization of the cross-linker amounts. The morphology and structure of the selected particles were analyzed using SEM micrographs, {sup 13}C CP/MAS NMR spectroscopy, and BET measurements. The desorption of 3,3′-diindolylmethane from poly(allylamine-co-polyethylene glycol dimethacrylate) particles was in accordance with pseudo-second-order kinetics and the simplified Higuchi model indicated the diffusion controlled release of 3,3′-diindolylmethane. - Graphical abstract: Sustained release of 3,3′-diindolylmethane from cavity in imprinted poly(allylamine-co-polyethylene glycol dimethacrylate

  11. The effects of social rearing on preferences formed during filial imprinting and their neural correlates.

    Science.gov (United States)

    Town, Stephen Michael

    2011-08-01

    Filial imprinting was originally proposed to be an irreversible process by which a young animal forms a preference for an object experienced early in life. The present study examined the effects of experience after imprinting on the stability of preferences of domestic chicks (Gallus gallus domesticus) for an imprinting stimulus by rearing imprinted chicks socially or in isolation. Chicks reared socially or in isolation retained preferences for the imprinting stimulus; however, social rearing weakened the strength of preferences. The responses of neurons within the intermediate and medial mesopallium--a forebrain region necessary for imprinting were also recorded in socially reared and isolated chicks when presented with the visual component of the imprinting stimulus and novel object. Consistent with existing findings, neurons recorded from isolated chicks responded more strongly to the imprinting stimulus than novel object. However, social rearing diminished the disparity between responses to stimuli such that neurons recorded from socially reared chicks responded similarly to the imprinting stimulus and novel object. These findings suggest that social rearing may impair the retention of preferences formed during imprinting through mechanisms involving the IMM.

  12. Preparation and adsorption behaviors of Cu(Ⅱ) ion-imprinted polymers

    Institute of Scientific and Technical Information of China (English)

    ZHONG Shi-an; YUAN Zhou-lv; QIAO Rong; LI Wei

    2008-01-01

    Imprinted polymers were prepared for selective removal of Cu(II) ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid (MAA), acrylamide (AA) and N,N'-methylenebisacrylamide (MBAA) respectively as the functional monomers, ethleneglycoldimethacrylate (EGDMA) as the cross-linking agent, 2,2'-azobisisobutyronitrile (AIBN) as the initiator and Cu (II) ion as the imprint ion. The template Cu (II) ion was removed from the polymer by leaching with a liquid of a 1:1 volumetric ratio of HCl to ethylenediaminetetraacetic acid (EDTA). The capacity and selectivity of Cu(II) ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu(II) ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu(II) adsorption than non-imprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu (II) ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction (SPE).

  13. Non-coding RNAs and the acquisition of genomic imprinting in mammals

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Genomic imprinting,representing parent-specific expression of alleles at a locus,is mainly evident in flowering plants and placental mammals.Most imprinted genes,including numerous non-coding RNAs,are located in clusters regulated by imprinting control regions(ICRs).The acquisition and evolution of genomic imprinting is among the most fundamental genetic questions.Discoveries about the transition of mammalian imprinted gene domains from their non-imprinted ancestors,especially recent studies undertaken on the most ancient mammalian clades-the marsupials and monotremes from which model species genomes have recently been sequenced,are of high value.By reviewing and analyzing these studies,a close connection between non-coding RNAs and the acquisition of genomic imprinting in mammals is demonstrated.The evidence comes from two observations accompanied with the acquisition of the imprinting:(i) many novel non-coding RNA genes emerged in imprinted regions;(ii) the expressions of some conserved non-coding RNAs have changed dramatically.Furthermore,a systematical analysis of imprinted snoRNA(small nucleolar RNA) genes from 15 vertebrates suggests that the origination of imprinted snoRNAs occurred after the divergence between eutherians and marsupials,followed by a rapid expansion leading to the fixation of major gene families in the eutherian ancestor prior to the radiation of modern placental mammals.Involved in the regulation of imprinted silencing and mediating the chromatins epigenetic modification may be the major roles that non-coding RNAs play during the acquisition of genomic imprinting in mammals.

  14. Molecularly imprinted polymers prepared using protein-conjugated cleavable monomers followed by site-specific post-imprinting introduction of fluorescent reporter molecules.

    Science.gov (United States)

    Suga, Yusuke; Sunayama, Hirobumi; Ooya, Tooru; Takeuchi, Toshifumi

    2013-10-01

    Molecularly imprinted polymers were prepared using a protein-conjugated disulfide cleavable monomer. After removing the protein by disulfide reduction, a thiol-reactive fluorophore was introduced into the thiol residue located only inside the imprinted cavity, resulting in specific transduction of the binding events into fluorescence spectral change.

  15. Preparation of a Selective L-Phenylalanine Imprinted Polymer Implicated in Patients with Phenylketonuria

    Directory of Open Access Journals (Sweden)

    Parvaneh Najafizadeh

    2014-11-01

    Full Text Available Background: Molecular imprinting is a method for synthesizing polymers with structure-selective adsorption properties with applications such as, selectivity binding, drug delivery systems and anti-bodies. The present study aims at optimizing the preparation of molecularly imprinted polymer (MIP against l-phenylalanine, in order to increase phenylalanine-binding in Enzymatic Intestinal Simulated Fluid (ESIF. Methods: The MIP for l-phenylalanine, as a water-soluble template, was successfully synthesized without derivatization. Synthesization was done by a UV polymerization method in which methacrylic acid (MAA, as a functional monomer, and ethylene glycol dimethacrylate (EGDMA, as a cross-linker, were used in the presence of five different porogenic solvents including; acetonitrile, tetrahydrofuran (THF, chloroform, toluene and dimethyl sulfoxide (DMSO. The selectivity of the MIP was examined using 19 different amino acids in human serum and was evaluated by HPLC. In addition, morphological studies were conducted using SEM. Results: The results showed that the obtained MIP with acetonitrile had the highest capacity and selectivity compared with other solvents. The data indicated that Phe-binding to MIP was significantly more than the former binding to NIP in EISF (P≤0.05. Moreover, in comparison with NIP and control group, MIP showed a better selectivity and binding for Phe. This could be used for the reduction of Phe in human serum samples of Phenylketonuria. Conclusion: Our findings suggest that the MIP against Phe prepared with acetonitrile, showed a good selectivity and binding, which caused a reduction of blood Phe concentration in enzymatic simulated intestinal fluid and human serum sample of Phenylketonuria.

  16. Polyacrylamide gels with selective recognition of the tetrameric molecular form of human growth hormone

    Directory of Open Access Journals (Sweden)

    R. Kublickas

    2017-08-01

    Full Text Available Networks of polyacrylamide were studied for the possibility of imprinting of the oligomeric form of human growth hormone. The tetrameric molecular form of human growth hormone was molecularly imprinted for the first time. The results show that approximately 50–70% (w/w of the templates (depending on polymerization conditions could be extracted from the molecularly imprinted acrylamide polymers. The resulting ‘gel antibodies’ against this form of human growth hormone in the form of granules of polyacrylamide were compared with granules of non-imprinted polymer. The selectivity of the artificial gel antibodies was studied. Investigation of the binding to imprinted polymer of the template hormone, other molecular forms of the hormone and other proteins shows the selectivity of the developed artificial gel antibodies.

  17. High volume nanoscale roll-based imprinting using jet and flash imprint lithography

    Science.gov (United States)

    Ahn, Se Hyun; Miller, Mike; Yang, Shuqiang; Ganapathisubramanian, Maha; Menezes, Marlon; Singh, Vik; Choi, Jin; Xu, Frank; LaBrake, Dwayne; Resnick, Douglas J.; Sreenivasan, S. V.

    2013-09-01

    Extremely large-area roll-to-roll (R2R) manufacturing on flexible substrates is ubiquitous for applications such as paper and plastic processing. It combines the benefits of high speed and inexpensive substrates to deliver a commodity product at low cost. The challenge is to extend this approach to the realm of nanopatterning and realize similar benefits. In order to achieve low-cost nanopatterning, it is imperative to move toward high-speed imprinting, less complex tools, near zero waste of consumables, and low-cost substrates. We have developed a roll-based J-FIL process and applied it to a technology demonstrator tool, the LithoFlex 100, to fabricate large-area flexible bilayer wire-grid polarizers (WGPs) and high-performance WGPs on rigid glass substrates. Extinction ratios of better than 10,000 are obtained for the glass-based WGPs. Two simulation packages are also employed to understand the effects of pitch, aluminum thickness, and pattern defectivity on the optical performance of the WGP devices. It is determined that the WGPs can be influenced by both clear and opaque defects in the gratings; however, the defect densities are relaxed relative to the requirements of a high-density semiconductor device.

  18. Tissue-specific and minor inter-individual variation in imprinting of IGF2R is a common feature of Bos taurus Concepti and not correlated with fetal weight.

    Directory of Open Access Journals (Sweden)

    Daniela Bebbere

    Full Text Available The insulin-like growth factor 2 receptor (IGF2R is essential for prenatal growth regulation and shows gene dosage effects on fetal weight that can be affected by in-vitro embryo culture. Imprinted maternal expression of murine Igf2r is well documented for all fetal tissues excluding brain, but polymorphic imprinting and biallelic expression were reported for IGF2R in human. These differences have been attributed to evolutionary changes correlated with specific reproductive strategies. However, data from species suitable for testing this hypothesis are lacking. The domestic cow (Bos taurus carries a single conceptus with a similar gestation length as human. We identified 12 heterozygous concepti informative for imprinting studies among 68 Bos taurus fetuses at Day 80 of gestation (28% term and found predominantly maternal IGF2R expression in all fetal tissues but brain, which escapes imprinting. Inter-individual variation in allelic expression bias, i.e. expression of the repressed paternal allele relative to the maternal allele, ranged from 4.6-8.9% in heart, 4.3-10.2% in kidney, 6.1-11.2% in liver, 4.6-15.8% in lung and 3.2-12.2% in skeletal muscle. Allelic bias for mesodermal tissues (heart, skeletal muscle differed significantly (P<0.05 from endodermal tissues (liver, lung. The placenta showed partial imprinting with allelic bias of 22.9-34.7% and differed significantly (P<0.001 from all other tissues. Four informative fetuses were generated by in-vitro fertilization (IVF with embryo culture and two individuals displayed fetal overgrowth. However, there was no evidence for changes in imprinting or DNA methylation after IVF, or correlations between allelic bias and fetal weight. In conclusion, imprinting of Bos taurus IGF2R is similar to mouse except in placenta, which could indicate an effect of reproductive strategy. Common minor inter-individual variation in allelic bias and absence of imprinting abnormalities in IVF fetuses suggest

  19. Thyroid hormone determines the start of the sensitive period of imprinting and primes later learning.

    Science.gov (United States)

    Yamaguchi, Shinji; Aoki, Naoya; Kitajima, Takaaki; Iikubo, Eiji; Katagiri, Sachiko; Matsushima, Toshiya; Homma, Koichi J

    2012-01-01

    Filial imprinting in precocial birds is the process of forming a social attachment during a sensitive or critical period, restricted to the first few days after hatching. Imprinting is considered to be part of early learning to aid the survival of juveniles by securing maternal care. Here we show that the thyroid hormone 3,5,3'-triiodothyronine (T(3)) determines the start of the sensitive period. Imprinting training in chicks causes rapid inflow of T(3), converted from circulating plasma thyroxine by Dio2, type 2 iodothyronine deiodinase, in brain vascular endothelial cells. The T(3) thus initiates and extends the sensitive period to last more than 1 week via non-genomic mechanisms and primes subsequent learning. Even in non-imprinted chicks whose sensitive period has ended, exogenous T(3) enables imprinting. Our findings indicate that T(3) determines the start of the sensitive period for imprinting and has a critical role in later learning.

  20. Enhanced adsorption of atrazine from aqueous solution by molecularly imprinted TiO2 film

    Science.gov (United States)

    Zhang, Chunjing; Yan, Jinlong; Zhang, Chunxiao; Yang, Zhengpeng

    2012-07-01

    TiO2 film imprinted by atrazine molecule at the surface of quartz crystal was prepared using molecular imprinting and surface sol-gel process. The molecularly imprinted TiO2 film was characterized by scanning electron microscopy and cyclic voltammetry, and the atrazine adsorption was investigated by quartz crystal microbalance (QCM) technique. In comparison with non-imprinted TiO2 film, the molecularly imprinted TiO2 film exhibits high selectivity for atrazine, better reversibility and a much higher adsorption capacity for the target molecule, the adsorption equilibrium constant estimated from the in situ frequency measurement is about 6.7 × 104 M-1, which is thirteen times higher than that obtained on non-imprinted TiO2 film.

  1. Recognizing Amino Acid Chirality with Surface-Imprinted Polymers Prepared in W/O Emulsions

    Directory of Open Access Journals (Sweden)

    Min Jae Shin

    2013-01-01

    Full Text Available A molecularly imprinted polymer was prepared by a surface molecular imprinting technique in water-in-oil (W/O emulsion. In this technique, the solid polymer, which is molecularly imprinted at the internal cavity surface, is prepared by polymerizing W/O emulsions consisting of a water-soluble imprinted molecule, a functional host molecule, an emulsion stabilizer, and a crosslinking agent. Dioleoyl phosphate was used as an emulsion stabilizer, and this compound also acted as a monomer and a host functional group in the imprinted cavity. Divinylbenzene was used as a crosslinker. Tryptophan methyl ester and phenylalanine methyl ester were used as the target template materials. These imprinted polymers exhibited enantiomeric selectivity in absorption experiments, and the maximum separation factor was 1.58. The enantiomeric selectivity with tryptophan methyl ester was higher than that with phenylalanine methyl ester.

  2. Microcontact imprinting of algae for biofuel systems: the effects of the polymer concentration.

    Science.gov (United States)

    Lee, Mei-Hwa; Thomas, James L; Lai, Ming-Yuan; Shih, Ching-Ping; Lin, Hung-Yin

    2014-11-25

    Microcontact imprinting of cells often involves the deposition of a polymer solution onto a monolayer cell stamp, followed by solvent evaporation. Thus, the concentration of the polymer may play an important role in the final morphology and efficacy of the imprinted film. In this work, various concentrations of poly(ethylene-co-vinyl alcohol) (EVAL) were dissolved in dimethyl sulfoxide (DMSO) for the microcontact imprinting of algae on an electrode. Scanning electron microscopy and fluorescence spectrometry were used to characterize the surface morphology and recognition capacity of algae to the algae-imprinted cavities. The readsorption of algae onto algae-imprinted EVAL thin films was quantified to obtain the EVAL concentration that maximized algal binding. Finally, the power and current density of an algal biofuel cell with the algae-imprinted EVAL-coated electrode were measured and found to be approximately double those of such a cell with a Pt/indium tin oxide (ITO)/poly(ethylene terephthalate) (PET) electrode.

  3. Characterization of the imprinting and expression patterns of ZAG2 in maize endosperm and embryo

    Directory of Open Access Journals (Sweden)

    Chaoxian Liu

    2015-02-01

    Full Text Available ZAG2 has been identified as a maternally expressed imprinted gene in maize endosperm. Our study revealed that paternally inherited ZAG2 alleles were imprinted in maize endosperm and embryo at 14 days after pollination (DAP, and consistently imprinted in endosperm at 10, 12, 16, 18, 20, 22, 24, 26, and 28 DAP in reciprocal crosses between B73 and Mo17. ZAG2 alleles were also imprinted in reciprocal crosses between Zheng 58 and Chang 7-2 and between Huang C and 178. ZAG2 alleles exhibited differential imprinting in hybrids of 178 × Huang C and B73 × Mo17, while in other hybrids ZAG2 alleles exhibited binary imprinting. The tissue-specific expression pattern of ZAG2 showed that ZAG2 was expressed at a high level in immature ears, suggesting that ZAG2 plays important roles in not only kernel but ear development.

  4. Rasgrf1 Imprinting Is Regulated by a CTCF-Dependent Methylation-Sensitive Enhancer Blocker

    Science.gov (United States)

    Yoon, Bongjune; Herman, Herry; Hu, Benjamin; Park, Yoon Jung; Lindroth, Anders; Bell, Adam; West, Adam G.; Chang, Yanjie; Stablewski, Aimee; Piel, Jessica C.; Loukinov, Dmitri I.; Lobanenkov, Victor V.; Soloway, Paul D.

    2005-01-01

    Imprinted methylation of the paternal Rasgrf1 allele in mice occurs at a differentially methylated domain (DMD) 30 kbp 5′ of the promoter. A repeated sequence 3′ of the DMD regulates imprinted methylation, which is required for imprinted expression. Here we identify the mechanism by which methylation controls imprinting. The DMD is an enhancer blocker that binds CTCF in a methylation-sensitive manner. CTCF bound to the unmethylated maternal allele silences expression. CTCF binding to the paternal allele is prevented by repeat-mediated methylation, allowing expression. Optimal in vitro enhancer-blocking activity requires CTCF binding sites. The enhancer blocker can be bypassed in vivo and imprinting abolished by placing an extra enhancer proximal to the promoter. Together, the repeats and the DMD constitute a binary switch that regulates Rasgrf1 imprinting. PMID:16314537

  5. Mom's shadow: structure-from-motion in newly hatched chicks as revealed by an imprinting procedure.

    Science.gov (United States)

    Mascalzoni, Elena; Regolin, Lucia; Vallortigara, Giorgio

    2009-03-01

    The ability to recognize three-dimensional objects from two-dimensional (2-D) displays was investigated in domestic chicks, focusing on the role of the object's motion. In Experiment 1 newly hatched chicks, imprinted on a three-dimensional (3-D) object, were allowed to choose between the shadows of the familiar object and of an object never seen before. In Experiments 2 and 3 random-dot displays were used to produce the perception of a solid shape only when set in motion. Overall, the results showed that domestic chicks were able to recognize familiar shapes from 2-D motion stimuli. It is likely that similar general mechanisms underlying the perception of structure-from-motion and the extraction of 3-D information are shared by humans and animals. The present data shows that they occur similarly in birds as known for mammals, two separate vertebrate classes; this possibly indicates a common phylogenetic origin of these processes.

  6. Microspheres Sensor Based on Molecularly Imprinted Polymer Synthesized by Precipitation Polymerization

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Zhao-Hui; LONG,Yu-Mei; LIU,Ying-Ju; YAO,Shou-Zhuo

    2003-01-01

    A new biomimetic bulk acoustic wave sensor based on molecularly imprinted microspheres(MIM) technique was described.The sensing materials were synthesized by precipitation polymerization.By using the Scatchard analysis,the equilibrium dissociation constant KD and the apparent maximum number Qmax of the binding sites were calculated to be 3.70 mmol·L-1 and 9.11 μmol·g-1,respectively.The sensor exhibited a sensitive response to detection limit of 2×10-9 mol·L-1.The recoveries of the sensor were 95.1%-105.4%.Studies presented in this paper show that the stability of this sensor is excellent.The sensor has been applied successfully to the determination of dipyridmaole in human urine.

  7. Preliminary evidence of a neurophysiological basis for individual discrimination in filial imprinting.

    Science.gov (United States)

    Town, Stephen Michael

    2011-12-01

    Filial imprinting involves a predisposition for biologically important stimuli and a learning process directing preferences towards a particular stimulus. Learning underlies discrimination between imprinted and unfamiliar individuals and depends upon the IMM (intermediate and medial mesopallium). Here, IMM neurons responded differentially to familiar and unfamiliar conspecifics following socialization and the neurophysiological effects of social experience differed between hemispheres. Such findings may provide a neurophysiological basis for individual discrimination in imprinting. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Ion imprinted polymers: fundamentals, preparation strategies and applications in analytical chemistry

    OpenAIRE

    Luiz Diego Marestoni; Maria Del Pilar Taboada Sotomayor; Mariana Gava Segatelli; Lucas Rossi Sartori; César Ricardo Teixeira Tarley

    2013-01-01

    Chemical imprinting technology has been widely used as a valuable tool in selective recognition of a given target analyte (molecule or metal ion), yielding a notable advance in the development of new analytical protocols. Since their discovery, molecularly imprinted polymers (MIPs) have been extensively studied with excellent reviews published. However, studies involving ion imprinted polymers (IIPs), in which metal ions are recognized in the presence of closely related inorganic ions, remain...

  9. Removal of Toxic Mercury from Petroleum Oil by Newly Synthesized Molecularly-Imprinted Polymer

    OpenAIRE

    Nor Ain Shahera Khairi; Nor Azah Yusof; Abdul Halim Abdullah; Faruq Mohammad

    2015-01-01

    In recent years, molecularly-imprinted polymers (MIPs) have attracted the attention of several researchers due to their capability for molecular recognition, easiness of preparation, stability and cost-effective production. By taking advantage of these facts, Hg(II) imprinted and non-imprinted copolymers were prepared by polymerizing mercury nitrate stock solution (or without it) with methacrylic acid (MAA), 2-hydroxyl ethyl methacrylate (HEMA), methanol and ethylene glycol dimethacrylate (E...

  10. Molecularly Imprinted Polymers: Thermodynamic and Kinetic Considerations on the Specific Sorption and Molecular Recognition

    OpenAIRE

    Kejun Tong; Wuke Li; Mingxia Zheng; Xing Huang; Songjun Li

    2008-01-01

    This article presents a work aiming at thermodynamically and kinetically interpreting the specific sorption and recognition by a molecularly imprinted polymer. Using Boc-L-Phe-OH as a template, the imprinted material was prepared. The result indicates that the prepared polymer can well discriminate the imprint species from its analogue (Boc-D-Phe-OH), so as to adsorb more for the former but less for the latter. Kinetic analysis indicates that this specific sorption, in nature, can be a result...

  11. Preparation and Chromatographic Application of β-Cyclodextrin Molecularly Imprinted Microspheres for Paeoniflorin

    OpenAIRE

    Wei Zhang; Bofeng Wei; Shoujiang Li; Yueming Wang; Shaoyan Wang

    2017-01-01

    The application of molecular imprinting technology in the separation and purification of active ingredients in natural products was widely reported, but remains a challenge. Enrichment and separation are especially limited. A surface imprinting technique was reported to synthesize molecularly imprinted microspheres (MIMs) in this article. With paeoniflorin (PF) as the template molecule, β-cyclodextrin (β-CD) and acrylamide (AA) as the functional monomers, and poly(glycidyl methacrylate, GMA) ...

  12. Preparation and Cyclic Voltammetry Characterization Of Cu-dipyridyl Imprinted Polymer

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Polymer capable of specific binding to Cu-dipyridyl complex was prepared by molecular imprinting technology.The binding specificity of the polymer to the template (Cu-dipyridyl complex) was investigated by cyclic voltametric scanning using the carbon paste electrode modified by polymer particles in phosphate buffer solution.Factors that influence rebinding of the imprinted polymer were explored.The result demonstrated that the cyclic voltammetry was an efficient approach to explore interactions between template and imprinted polymers.

  13. Molecular Imprinting Fibrous Membranes of Poly(acrylonitrile-co-acrylic acid) Prepared by Electrospinning

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Introduction Over the past few decades, molecular imprinting has been described as a technology for preparing "molecular doors" which can be matched to "template keys". It has been found to be a simple and effective approach to introduce specific recognition sites into synthetic polymers, namely, to create molecular imprinting polymers[1-4]. Remarkable features such as stability,ease of preparation and low cost, have made molecular imprinting polymers particularly attractive in chemical sensors, catalysis, drug delivery, and dedicated separations.

  14. The Prader-Willi syndrome murine imprinting center is not involved in the spatio-temporal transcriptional regulation of the Necdin gene

    Directory of Open Access Journals (Sweden)

    Dandolo Luisa

    2005-01-01

    Full Text Available Abstract Background The human Prader-Willi syndrome (PWS domain and its mouse orthologue include a cluster of paternally expressed genes which imprinted expression is co-ordinately regulated by an imprinting center (IC closely associated to the Snurf-Snrpn gene. Besides their co-regulated imprinted expression, two observations suggest that the spatio-temporal expression of these genes could also be co-regulated. First, the PWS genes have all been reported to be expressed in the mouse nervous system. Second, Snurf-Snrpn and its associated IC are the most ancient elements of the domain which later acquired additional functional genes by retrotransposition. Although located at least 1.5 megabases from the IC, these retroposons acquired the same imprinted regulation as Snurf-Snrpn. In this study, we ask whether the IC, in addition to its function in imprinting, could also be involved in the spatio-temporal regulation of genes in the PWS domain. Results We compared the expression pattern of Snurf-Snrpn and C/D-box small nucleolar RNAs (snoRNAs MBII-85 and MBII-52 to the expression pattern of the two evolutionary related retroposons Ndn and Magel2, in the developing mouse embryo. We show that these genes have highly similar expression patterns in the central nervous system, suggesting that they share a common central nervous system-specific regulatory element. Among these genes, Ndn and Magel2 display the most similar expression patterns. Using transgenic mice containing the Ndn and Magel2 genes, we show that the transgenic Ndn gene whereas not imprinted is correctly expressed. Search for DNase I hypersensitive sites in the Ndn-Magel2 genomic region and comparative genomic analyses were performed in order to identify potential transcriptional cis-regulatory elements. Conclusions These results strongly suggest that paternally expressed genes of the PWS domain share a common central nervous system-specific regulatory element. We proposed that this

  15. Imprints of a Primordial Preferred Direction on the Microwave Background

    CERN Document Server

    Ackerman, L; Wise, M B; Ackerman, Lotty; Carroll, Sean M.; Wise, Mark B.

    2007-01-01

    Rotational invariance is a well-established feature of low-energy physics. Violations of this symmetry must be extremely small today, but could have been larger in earlier epochs. In this paper we examine the consequences of a small breaking of rotational invariance during the inflationary era when the primordial density fluctuations were generated. Assuming that a fixed-norm vector picked out a preferred direction during the inflationary era, we explore the imprint it would leave on the cosmic microwave background anisotropy, and provide explicit formulas for the expected amplitudes $$ of the spherical-harmonic coefficients. We suggest that it is natural to expect that the imprint on the primordial power spectrum of a preferred spatial direction is approximately scale-invariant, and examine a simple model in which this is true.

  16. Composite vascular repair grafts via micro-imprinting and electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuanyuan, E-mail: yuanyuan-liu@shu.edu.cn; Hu, Qingxi, E-mail: huqingxi@shu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China); Shanghai Key Laboratory of Intelligent Manufacturing and Robotics, Shanghai 200072 (China); Xiang, Ke, E-mail: xiangke@shu.edu.cn; Chen, Haiping, E-mail: 519673062@qq.com; Li, Yu, E-mail: liyu@hpu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China)

    2015-04-15

    Composite vascular grafts formed by micro-imprinting and electrospinning exhibited improved mechanical properties relative to those formed by electrospinning alone. The three-layered composite grafts mimic the three-layered structure of natural blood vessels. The middle layer is made by micro-imprinting poly-p-dioxanone (PPDO), while the inner and outer layers are electrospun mixtures of chitosan and polyvinyl alcohol. The graft morphology is characterized with scanning electron microscopy. For constant graft thicknesses, the PPDO increases the mechanical strength. Cells cultivated on the vascular grafts adhere and proliferate better because of the natural, biological chitosan in the inner and outer layers. Overall, the composite scaffolds could be good candidates for blood vessel repair.

  17. Magnetic molecularly imprinted polymer for aspirin recognition and controlled release

    Science.gov (United States)

    Kan, Xianwen; Geng, Zhirong; Zhao, Yao; Wang, Zhilin; Zhu, Jun-Jie

    2009-04-01

    Core-shell structural magnetic molecularly imprinted polymers (magnetic MIPs) with combined properties of molecular recognition and controlled release were prepared and characterized. Magnetic MIPs were synthesized by the co-polymerization of methacrylic acid (MAA) and trimethylolpropane trimethacrylate (TRIM) around aspirin (ASP) at the surface of double-bond-functionalized Fe3O4 nanoparticles in chloroform. The obtained spherical magnetic MIPs with diameters of about 500 nm had obvious superparamagnetism and could be separated quickly by an external magnetic field. Binding experiments were carried out to evaluate the properties of magnetic MIPs and magnetic non-molecularly imprinted polymers (magnetic NIPs). The results demonstrated that the magnetic MIPs had high adsorption capacity and selectivity to ASP. Moreover, release profiles and release rate of ASP from the ASP-loaded magnetic MIPs indicated that the magnetic MIPs also had potential applications in drug controlled release.

  18. Consequences of Morphology on Molecularly Imprinted Polymer-Ligand Recognition

    Directory of Open Access Journals (Sweden)

    Annika M. Rosengren

    2013-01-01

    Full Text Available The relationship between molecularly imprinted polymer (MIP morphology and template-rebinding over a series of warfarin-imprinted methacrylic acid co(ethylene dimethacrylate polymers has been explored. Detailed investigations of the nature of template recognition revealed that an optimal template binding was obtained with polymers possessing a narrow population of pores (~3–4 nm in the mesopore size range. Importantly, the warfarin-polymer rebinding analyses suggest strategies for regulating ligand binding capacity and specificity through variation of the degree of cross-linking, where polymers prepared with a lower degree of cross-linking afford higher capacity though non-specific in character. In contrast, the co-existence of specific and non-specific binding was found in conjunction with higher degrees of cross-linking and resultant meso- and macropore size distributions.

  19. Imprint reduction in rotating heavy ions beam energy deposition

    Energy Technology Data Exchange (ETDEWEB)

    Bret, A., E-mail: antoineclaude.bret@uclm.es [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51, Cambridge, MA 02138 (United States); ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Piriz, A.R., E-mail: Roberto.Piriz@uclm.es [ETSI Industriales, Universidad Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Tahir, N.A., E-mail: n.tahir@gsi.de [GSI Darmstadt, Plankstrasse 1, 64291 Darmstadt (Germany)

    2014-01-01

    The compression of a cylindrical target by a rotating heavy ions beam is contemplated in certain inertial fusion schemes or in heavy density matter experiments. Because the beam has its proper temporal profile, the energy deposition is asymmetric and leaves an imprint which can have important consequences for the rest of the process. In this paper, the Fourier components of the deposited ion density are computed exactly in terms of the beam temporal profile and its rotation frequency Ω. We show that for any beam profile of duration T, there exist an infinite number of values of ΩT canceling exactly any given harmonic. For the particular case of a parabolic profile, we find possible to cancel exactly the first harmonic and nearly cancel every other odd harmonics. In such case, the imprint amplitude is divided by 4 without any increase of Ω.

  20. Chemical Sensors Based on Molecularly Imprinted Sol-Gel Materials

    Directory of Open Access Journals (Sweden)

    Franz L. Dickert

    2010-03-01

    Full Text Available The sol-gel technique is earning the worldwide attention of researchers in the field of material science, due to its versatility in synthesizing inorganic ceramic materials at mild conditions. High purity, homogeneity, controlled porosity, stable temperature and nanoscale structuring are the most remarkable features offered by this method for generating highly sensitive and selective matrices to incorporate analyte molecules. The crafting of sol-gel sensors through molecular imprinting has put great influence on the development of innovative chemical sensors, which can be seen from the growing number of publications in this field. The review provides a brief overview of sol-gel sensor applications, and discusses the contribution of molecular imprinting in exploring the new world of sensors.

  1. Monocrotophos Molecularly Imprinted Microspheres Prepared by Precipitation Polymerization in Acetonitrile

    Institute of Scientific and Technical Information of China (English)

    Shoulei Yan; Zhixian Gao; Yanjun Fang; Yiyong Cheng

    2006-01-01

    Molecularly imprinted microspheres (MIP) for monocrotophos have been prepared by precipitation polymerization in acetonitrile (CAN) 60℃, 24 h, using methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA) and 2,2-azobisiobutyronitrile (AIBN) as functional monomer, cross-linker and initiator, respectively. The recognition mechanism was elucidated by UV-vis spectra and computer modeling. Equilibrium binding experiment was employed to investigate the rebinding properties, Scatchard analysis showed that specific binding sites formed in the imprinted microspheres, and there were two kinds of binding sites, one was high binding sites, the other was low binding sites. This microspheres can be useful affinity absorbent used for organophosphorus pesticides separation and purification in food and environmental analysis.

  2. The ISW imprints of voids and superclusters on the CMB

    Science.gov (United States)

    Hotchkiss, S.; Nadathur, S.; Gottlöber, S.; Iliev, I. T.; Knebe, A.; Watson, W. A.; Yepes, G.

    2016-10-01

    We examine the stacked integrated Sachs-Wolfe (ISW) imprints on the CMB along the lines of sight of voids and superclusters in galaxy surveys, using the Jubilee ISW simulation and mock luminous red galaxy (LRG) catalogues. We show that the expected signal in the concordance \\Lam CDM model is much smaller than the primary anisotropies arising at the last scattering surface and therefore any currently claimed detections of such an imprint cannot be caused by the ISW effect in \\Lam CDM. We look for the existence of such a signal in the Planck CMB using a catalogue of voids and superclusters from the Sloan Digital Sky Survey (SDSS), but find a result completely consistent with \\Lam CDM - i.e., a null detection.

  3. Chiral separation of racemic drugs using molecular imprinting

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Molecularly imprinted polymers (MIPs) of (S)-ketoprofen and (S)-naproxen are prepared using non-covalent imprinting in the presence of template molecules. The prepared MIPs are used as the chiral stationary phase to separate ramemic naproxen and ketoprofen. The results show that racemic naproxen and ketoprofen are efficiently resolved on MIPs. The effect of concentration of acetic acid in the mobile phase is studied, and the data are analyzed using the affinity chromatography model, and the close agreement is achieved between the simulated and experimental curves. The results suggest that the affinity chromatography mechanism controls the retention in this system. Moreover, the affinity chromatography equilibrium constants on (S)-naproxen and (S)-ketoprofen are estimated.

  4. Biotin-specific synthetic receptors prepared using molecular imprinting

    Energy Technology Data Exchange (ETDEWEB)

    Piletska, Elena; Piletsky, Sergey; Karim, Kal; Terpetschnig, Ewald; Turner, Anthony

    2004-02-16

    The composition of new molecularly imprinted polymers (MIPs) specific for biotin was optimised using molecular modelling software. Three functional monomers: methacrylic acid (MAA), 2-(trifluoromethyl)acrylic acid (TFAA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPSA), which demonstrated the highest binding scores with biotin, were tested on their ability to generate specific binding sites. The imprinted polymers were photografted to the surface of polystyrene microspheres in water. The affinity of the synthetic 'receptor' sites was evaluated in binding experiments using horseradish peroxidase-labelled biotin. Good correlation was found between the modelling results and the performance of the materials in the template re-binding study. The dissociation constants for all MIPs were 1.4-16.8 nM, which is sufficient for most analytical applications where biotin is used as a label.

  5. Magnetization dynamics of imprinted non-collinear spin textures

    Energy Technology Data Exchange (ETDEWEB)

    Streubel, Robert, E-mail: r.streubel@ifw-dresden.de; Kopte, Martin; Makarov, Denys, E-mail: d.makarov@ifw-dresden.de [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Fischer, Peter [Center for X-Ray Optics, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, UC Santa Cruz, Santa Cruz, California 95064 (United States); Schmidt, Oliver G. [Institute for Integrative Nanosciences, IFW Dresden, 01069 Dresden (Germany); Material Systems for Nanoelectronics, Chemnitz University of Technology, 09107 Chemnitz (Germany)

    2015-09-14

    We study the magnetization dynamics of non-collinear spin textures realized via imprint of the magnetic vortex state in soft permalloy into magnetically hard out-of-plane magnetized Co/Pd nanopatterned heterostructures. Tuning the interlayer exchange coupling between soft- and hard-magnetic subsystems provides means to tailor the magnetic state in the Co/Pd stack from being vortex- to donut-like with different core sizes. While the imprinted vortex spin texture leads to the dynamics similar to the one observed for vortices in permalloy disks, the donut-like state causes the appearance of two gyrofrequencies characteristic of the early and later stages of the magnetization dynamics. The dynamics are described using the Thiele equation supported by the full scale micromagnetic simulations by taking into account an enlarged core size of the donut states compared to magnetic vortices.

  6. Magnetic molecularly imprinted polymer for aspirin recognition and controlled release

    Energy Technology Data Exchange (ETDEWEB)

    Kan Xianwen; Geng Zhirong; Zhao Yao; Wang Zhilin; Zhu Junjie [State Key Laboratory of Coordination Chemistry, MOE Key Lab of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)], E-mail: wangzl@nju.edu.cn, E-mail: jjzhu@nju.edu.cn

    2009-04-22

    Core-shell structural magnetic molecularly imprinted polymers (magnetic MIPs) with combined properties of molecular recognition and controlled release were prepared and characterized. Magnetic MIPs were synthesized by the co-polymerization of methacrylic acid (MAA) and trimethylolpropane trimethacrylate (TRIM) around aspirin (ASP) at the surface of double-bond-functionalized Fe{sub 3}O{sub 4} nanoparticles in chloroform. The obtained spherical magnetic MIPs with diameters of about 500 nm had obvious superparamagnetism and could be separated quickly by an external magnetic field. Binding experiments were carried out to evaluate the properties of magnetic MIPs and magnetic non-molecularly imprinted polymers (magnetic NIPs). The results demonstrated that the magnetic MIPs had high adsorption capacity and selectivity to ASP. Moreover, release profiles and release rate of ASP from the ASP-loaded magnetic MIPs indicated that the magnetic MIPs also had potential applications in drug controlled release.

  7. Imprint of DES superstructures on the cosmic microwave background

    Science.gov (United States)

    Kovács, A.; Sánchez, C.; García-Bellido, J.; Nadathur, S.; Crittenden, R.; Gruen, D.; Huterer, D.; Bacon, D.; Clampitt, J.; DeRose, J.; Dodelson, S.; Gaztañaga, E.; Jain, B.; Kirk, D.; Lahav, O.; Miquel, R.; Naidoo, K.; Peacock, J. A.; Soergel, B.; Whiteway, L.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Rosell, A. Carnero; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Eifler, T. F.; Finley, D. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Giannantonio, T.; Goldstein, D. A.; Gruendl, R. A.; Gutierrez, G.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Nord, B.; Ogando, R.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Sobreira, F.; Suchyta, E.; Swanson, M.; Tarle, G.; Thomas, D.; Walker, A. R.; DES Collaboration

    2017-03-01

    Small temperature anisotropies in the cosmic microwave background (CMB) can be sourced by density perturbations via the late-time integrated Sachs-Wolfe (ISW) effect. Large voids and superclusters are excellent environments to make a localized measurement of this tiny imprint. In some cases excess signals have been reported. We probed these claims with an independent data set, using the first year data of the Dark Energy Survey (DES) in a different footprint, and using a different superstructure finding strategy. We identified 52 large voids and 102 superclusters at redshifts 0.2 < z < 0.65. We used the Jubilee simulation to a priori evaluate the optimal ISW measurement configuration for our compensated top-hat filtering technique, and then performed a stacking measurement of the CMB temperature field based on the DES data. For optimal configurations, we detected a cumulative cold imprint of voids with ΔTf ≈ -5.0 ± 3.7 μK and a hot imprint of superclusters ΔTf ≈ 5.1 ± 3.2 μK; this is ∼1.2σ higher than the expected |ΔTf| ≈ 0.6 μK imprint of such superstructures in Λ cold dark matter (ΛCDM). If we instead use an a posteriori selected filter size (R/Rv = 0.6), we can find a temperature decrement as large as ΔTf ≈ -9.8 ± 4.7 μK for voids, which is ∼2σ above ΛCDM expectations and is comparable to previous measurements made using Sloan Digital Sky Survey superstructure data.

  8. Photoconjugation of molecularly imprinted polymer with magnetic nanoparticles

    OpenAIRE

    Xu, Changgang; Uddin, Khan Mohammad Ahsan; Shen, Xiantao; Jayawardena, Surangi; Yan, Mingdi; Ye, Lei

    2013-01-01

    Because of their synthetic accessibility, molecularly imprinted polymer (MIP) nanoparticles are ideal building blocks for preparing multifunctional composites. In this work we developed a general photo-coupling chemistry to enable simple conjugation of MIP nanoparticles with inorganic magnetic nanoparticles. We first synthesized MIP nanoparticles using propranolol as a model template and perfluorophenylazide-modified silica-coated magnetic nanoparticles. Using a simple photoactivation followe...

  9. Chemical Sensors Based on Molecularly Imprinted Sol-Gel Materials

    OpenAIRE

    Dickert, Franz L.; Lieberzeit, Peter A.; Adnan Mujahid

    2010-01-01

    The sol-gel technique is earning the worldwide attention of researchers in the field of material science, due to its versatility in synthesizing inorganic ceramic materials at mild conditions. High purity, homogeneity, controlled porosity, stable temperature and nanoscale structuring are the most remarkable features offered by this method for generating highly sensitive and selective matrices to incorporate analyte molecules. The crafting of sol-gel sensors through molecular imprinting has pu...

  10. Imprint of DES superstructures on the cosmic microwave background

    Energy Technology Data Exchange (ETDEWEB)

    Kovács, A.; Sánchez, C.; García-Bellido, J.; Nadathur, S.; Crittenden, R.; Gruen, D.; Huterer, D.; Bacon, D.; Clampitt, J.; DeRose, J.; Dodelson, S.; Gaztañaga, E.; Jain, B.; Kirk, D.; Lahav, O.; Miquel, R.; Naidoo, K.; Peacock, J. A.; Soergel, B.; Whiteway, L.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Rosell, A. Carnero; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D' Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Eifler, T. F.; Finley, D. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Giannantonio, T.; Goldstein, D. A.; Gruendl, R. A.; Gutierrez, G.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Marshall, J. L.; Melchior, P.; Menanteau, F.; Nord, B.; Ogando, R.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Sobreira, F.; Suchyta, E.; Swanson, M.; Tarle, G.; Thomas, D.; Walker, A. R.

    2016-11-17

    Small temperature anisotropies in the Cosmic Microwave Background can be sourced by density perturbations via the late-time integrated Sachs-Wolfe effect. Large voids and superclusters are excellent environments to make a localized measurement of this tiny imprint. In some cases excess signals have been reported. We probed these claims with an independent data set, using the first year data of the Dark Energy Survey in a different footprint, and using a different super-structure finding strategy. We identified 52 large voids and 102 superclusters at redshifts $0.2 < z < 0.65$. We used the Jubilee simulation to a priori evaluate the optimal ISW measurement configuration for our compensated top-hat filtering technique, and then performed a stacking measurement of the CMB temperature field based on the DES data. For optimal configurations, we detected a cumulative cold imprint of voids with $\\Delta T_{f} \\approx -5.0\\pm3.7~\\mu K$ and a hot imprint of superclusters $\\Delta T_{f} \\approx 5.1\\pm3.2~\\mu K$ ; this is $\\sim1.2\\sigma$ higher than the expected $|\\Delta T_{f}| \\approx 0.6~\\mu K$ imprint of such super-structures in $\\Lambda$CDM. If we instead use an a posteriori selected filter size ($R/R_{v}=0.6$), we can find a temperature decrement as large as $\\Delta T_{f} \\approx -9.8\\pm4.7~\\mu K$ for voids, which is $\\sim2\\sigma$ above $\\Lambda$CDM expectations and is comparable to previous measurements made using SDSS super-structure data.

  11. Imprints of a critical point on photon emission

    Energy Technology Data Exchange (ETDEWEB)

    Wunderlich, F.; Kaempfer, B. [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universitaet Dresden, Institut fuer Theoretische Physik, Dresden (Germany)

    2016-08-15

    The linear sigma model with linearized fluctuations of all involved fields facilitates the onset of a sequence of first-order phase transitions at a critical point. This phase structure has distinctive imprints on the photon emission rates. We argue that analogously a critical point in the QCD phase diagram manifests itself by peculiarities of the photon spectra, in particular when the dynamical expansion path of matter crosses the phase transition curve in the vicinity of the critical point. (orig.)

  12. Influence of salt ions on binding to molecularly imprinted polymers.

    OpenAIRE

    Kempe, Henrik; Kempe, Maria

    2010-01-01

    Salt ions were found to have an influence on template binding to two model molecularly imprinted polymers (MIPs), targeted to penicillin G and propranolol, respectively, in water-acetonitrile mixtures. Water was detrimental to rebinding of penicillin G whereas propranolol bound in the entire water-acetonitrile range tested. In 100% aqueous solution, 3-M salt solutions augmented the binding of both templates. The effects followed the Hofmeister series with kosmotropic ions promoting the larges...

  13. Optimization of Shipboard Manning Levels Using Imprint Pro Forces Module

    Science.gov (United States)

    2015-09-01

    fleet we believe suffered because of it” ( Fuentes , 2011). In the case of the LCS, the initial aim was to achieve a core crew of only 40 sailors...software, with the assistance of Alion, in order to increase IMPRINT Pro utility for conducting Monte- Carlo simulations. We will also explore the...Department of the Navy. (2007). Navy total force manpower policies procedures – OPNAVIST 1000.16K. Washington, D.C.: Department of the Navy. Fuentes , G

  14. Production of abiotic receptors by molecular imprinting of proteins.

    OpenAIRE

    Braco, L.; Dabulis, K; Klibanov, A M

    1990-01-01

    When a protein is dissolved in a concentrated aqueous solution of a multifunctional organic compound, freeze-dried, and washed with an anhydrous organic solvent to remove the ligand, the resultant "imprinted" protein preparation binds up to 30-fold more of the template compound in anhydrous solvents than the nonimprinted protein in the same solvent (and both proteins in water). These artificial receptors exhibit marked ligand selectivity as well as stability in anhydrous media. This phenomeno...

  15. Absolute configuration determination using enantiomeric pairs of molecularly imprinted polymers.

    Science.gov (United States)

    Meador, Danielle S; Spivak, David A

    2014-03-07

    A new method for determination of absolute configuration (AC) is demonstrated using an enantiomeric pair of molecularly imprinted polymers, referred to as "DuoMIPs". The ratio of HPLC capacity factors (k') for the analyte on each of the DuoMIPs is defined as the γ factor and can be used to determine AC when above 1.2. A mnemonic based on the complementary binding geometry of the DuoMIPs was used to aid in understanding and prediction of AC.

  16. Enhanced Absorption in Organic Thin-Films from Imprinted Concave Nanostructures

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Rubahn, Horst-Günter; Madsen, Morten

    2017-01-01

    In this work, a rapid, replicable method for imprinting concave nanostructures to be used as functional light-trapping nanostructures in organic thin-films is presented. Porous anodic alumina templates were fabricated both by anodization of thick Al foils and by anodization of submicrometer thin Al...... patterns and used for imprinting of spin coated photoresist on glass substrates. We have investigated semi-periodic and aperiodic imprinted large concave patterns fabricated from rigid masters after anodization of Al in H3PO4. We show that metal covered imprinted concaves show enhancement in absorption...

  17. Sexual imprinting on ecologically divergent traits leads to sexual isolation in sticklebacks.

    Science.gov (United States)

    Kozak, Genevieve M; Head, Megan L; Boughman, Janette W

    2011-09-07

    During sexual imprinting, offspring learn parental phenotypes and then select mates who are similar to their parents. Imprinting has been thought to contribute to the process of speciation in only a few rare cases; this is despite imprinting's potential to generate assortative mating and solve the problem of recombination in ecological speciation. If offspring imprint on parental traits under divergent selection, these traits will then be involved in both adaptation and mate preference. Such 'magic traits' easily generate sexual isolation and facilitate speciation. In this study, we show that imprinting occurs in two ecologically divergent stickleback species (benthics and limnetics: Gasterosteus spp.). Cross-fostered females preferred mates of their foster father's species. Furthermore, imprinting is essential for sexual isolation between species; isolation was reduced when females were raised without fathers. Daughters imprinted on father odour and colour during a critical period early in development. These traits have diverged between the species owing to differences in ecology. Therefore, we provide the first evidence that imprinting links ecological adaptation to sexual isolation between species. Our results suggest that imprinting may facilitate the evolution of sexual isolation during ecological speciation, may be especially important in cases of rapid diversification, and thus play an integral role in the generation of biodiversity.

  18. Development of a roll-to-roll thermal imprinting system with seamless belt-type template

    Science.gov (United States)

    Shan, X. C.; Chen, S. H.; Mohahidin, M. Bin; Wei, J.

    2017-08-01

    Compared to conventional thermal imprinting using a flat mold, roll-to-roll (R2R) thermal imprinting using a roller mold is a high-speed, high through-put process. In an R2R thermal imprinting process, however, the contact duration between a mold and a thermoplastic substrate is extremely short. This results in insufficient heating and pressing, leading to low fidelity of the imprinted microstructures. We have developed an R2R thermal imprinting system, which allows us to extend the contact duration between the mold and substrate. This system consists of two continuous, seamless belts that are made of metal foil. Each belt is driven by an individual hot roller; at least one belt is used as an imprinting mold, another as a carrier belt. A thermoplastic film to be imprinted is sandwiched between the two belts that provide preheating, heating and pressing, holding, and cooling for demolding during imprinting, leading to extended mold-substrate contact duration and enhanced heat transfer from the belt mold to the polymer film. R2R thermal imprinting has been performed successfully and promising results have been demonstrated.

  19. Demonstration of a neural circuit critical for imprinting behavior in chicks.

    Science.gov (United States)

    Nakamori, Tomoharu; Sato, Katsushige; Atoji, Yasuro; Kanamatsu, Tomoyuki; Tanaka, Kohichi; Ohki-Hamazaki, Hiroko

    2010-03-24

    Imprinting behavior in birds is elicited by visual and/or auditory cues. It has been demonstrated previously that visual cues are recognized and processed in the visual Wulst (VW), and imprinting memory is stored in the intermediate medial mesopallium (IMM) of the telencephalon. Alteration of neural responses in these two regions according to imprinting has been reported, yet direct evidence of the neural circuit linking these two regions is lacking. Thus, it remains unclear how memory is formed and expressed in this circuit. Here, we present anatomical as well as physiological evidence of the neural circuit connecting the VW and IMM and show that imprinting training during the critical period strengthens and refines this circuit. A functional connection established by imprint training resulted in an imprinting behavior. After the closure of the critical period, training could not activate this circuit nor induce the imprinting behavior. Glutamatergic neurons in the ventroposterior region of the VW, the core region of the hyperpallium densocellulare (HDCo), sent their axons to the periventricular part of the HD, just dorsal and afferent to the IMM. We found that the HDCo is important in imprinting behavior. The refinement and/or enhancement of this neural circuit are attributed to increased activity of HDCo cells, and the activity depended on NR2B-containing NMDA receptors. These findings show a neural connection in the telencephalon in Aves and demonstrate that NR2B function is indispensable for the plasticity of HDCo cells, which are key mediators of imprinting.

  20. In Pursuit of New Imprinting Syndromes by Epimutation Screening in Idiopathic Neurodevelopmental Disorder Patients

    Directory of Open Access Journals (Sweden)

    Sonia Mayo

    2015-01-01

    Full Text Available Alterations of epigenetic mechanisms, and more specifically imprinting modifications, could be responsible of neurodevelopmental disorders such as intellectual disability (ID or autism together with other associated clinical features in many cases. Currently only eight imprinting syndromes are defined in spite of the fact that more than 200 genes are known or predicted to be imprinted. Recent publications point out that some epimutations which cause imprinting disorders may affect simultaneously different imprinted loci, suggesting that DNA-methylation may have been altered more globally. Therefore, we hypothesised that the detection of altered methylation patterns in known imprinting loci will indirectly allow identifying new syndromes due to epimutations among patients with unexplained ID. In a screening for imprinting alterations in 412 patients with syndromic ID/autism we found five patients with altered methylation in the four genes studied: MEG3, H19, KCNQ1OT1, and SNRPN. Remarkably, the cases with partial loss of methylation in KCNQ1OT1 and SNRPN present clinical features different to those associated with the corresponding imprinting syndromes, suggesting a multilocus methylation defect in accordance with our initial hypothesis. Consequently, our results are a proof of concept that the identification of epimutations in known loci in patients with clinical features different from those associated with known syndromes will eventually lead to the definition of new imprinting disorders.

  1. Imprinting Salmon and Steelhead Trout for Homing, 1983 Annual Report of Research.

    Energy Technology Data Exchange (ETDEWEB)

    Slatick, Emil

    1984-09-01

    The National Marine Fisheries Service (NMFS), under contract to the Bonneville Power Administration, began conducting research on imprinting Pacific salmon and steelhead for homing in 1978. In the juvenile marking phase, over 4 million juvenile salmon and steelhead were marked and released in 23 experiments. The primary objectives were to determine a triggering mechanism to activate the homing imprint, if a single imprint or a sequential imprint is necessary to assure homing, and the relationship between the physiological condition of fish and their ability to imprint. Ten experimental studies are discussed. Six of the studies employed a variety of techniques for imprinting fish. The remaining four tested the feasibility of imprinting fish by a short-distance voluntary migration before transport. In five experiments, survival was enhanced by the imprint-transportation procedures, and homing to the homing site area was partly successful. Returns from the Astoria, Oregon, release of fall chinook salmon from Big Creek Hatchery (Knappa, Oregon), for example, showed that limited short distance migration imprinting should provide 2-3 time more fish to the various fisheries while providing adequate returns to the hatchery for egg take each year. 21 refs., 12 figs, 12 tabs.

  2. Selective Solid-phase Extraction of Aloe Emodin from Aloe by Molecularly Imprinted Polymers

    Institute of Scientific and Technical Information of China (English)

    TIAN Ming-lei; LEE Yu-ri; PARK Dong-wha; ROW Kyung-ho

    2013-01-01

    The extraction and separation of aloe emodin were optimized via selective molecularly imprinted solid-phase extraction.Molecularly imprinted polymer was prepared from the functional monomer,methacrylic acid and a mixture of ethanol/dodecanol(90/10,volume ratio) as porogen.It overcomes the common problems of imprinting biological polar compounds and shows high selectivity compared favorably with those of non-imprinted polymer and commercially available C18 and silica cartridges in similar aloe emodin tests.Good linearity was obtained between 0.002 and 2.5 mg/mL(r2=0.998) with relative standard deviations below 3.3%.

  3. MOLECULAR IMPRINTED SOLID PHASE EXTRACTION FOR DETERMINATION OF ATRAZINE IN ENVIRONMENTAL SAMPLES

    Directory of Open Access Journals (Sweden)

    A. R. Koohpaei ، S. J. Shahtaheri ، M. R. Ganjali ، A. Rahimi Forushani

    2008-10-01

    Full Text Available Solid phase extraction is one of the major applications of molecularly imprinted polymers fields for clean-up of environmental and biological samples namely molecularly imprinted solid-phase extraction. In this study, solid phase extraction using the imprinted polymer has been optimized with the experimental design approach for a triazine herbicide, named atrazine with regard to the critical factors which influence the molecular imprinted solid phase extraction efficiency such as sample pH, concentration, flow-rate, volume, elution solvent, washing solvent and sorbent mass. Optimization methods that involve changing one factor at a time can be laborious. A novel approach for the optimization of imprinted solid-phase extraction using chemometrics is described. The factors were evaluated statistically and also validated with spiked water samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. Also, in order to the evaluate efficiency of the optimized molecularly imprinted solid-phase extraction protocols, enrichment capacity, reusability and cross-reactivity of cartridges have been also evaluated. Finally, selective molecularly imprinted solid-phase extraction of atrazine was successfully demonstrated with a recovery above 90% for spiked drinking water samples. It was concluded that the chemometrics is frequently employed for analytical method optimization and based on the obtained results, it is believed that the central composite design could prove beneficial for aiding the molecularly imprinted polymer and molecularly imprinted solid-phase extraction development.

  4. Selective enrichment and separation of phosphotyrosine peptides by thermosensitive molecularly imprinted polymers.

    Science.gov (United States)

    Yang, Xiaoqing; Xia, Yan

    2016-01-01

    Novel thermosensitive molecularly imprinted polymers were successfully prepared using the epitope imprinting approach in the presence of the mimic template phenylphosphonic acid, the functional monomer vinylphosphonic acid-Ti(4+) , the temperature-sensitive monomer N-isopropylacrylamide and the crosslinker N,N'-methylenebisacrylamide. The ratio of the template/thermosensitive monomers/crosslinker was optimized, and when the ratio was 2:2:1, the prepared thermosensitive molecularly imprinted polymers had the highest imprinting factor. The synthetic thermosensitive molecularly imprinted polymers were characterized by Fourier transform infrared spectroscopy to reveal the combination and elution processes of the template. Then, the adsorption capacity and thermosensitivity was measured. When the temperature was 28°C, the imprinting factor was the highest. The selectivity and adsorption capacity of the thermosensitive molecularly imprinted polymers for phosphotyrosine peptides from a mixture of three tailor-made peptides were measured by high-performance liquid chromatography. The results showed that the thermosensitive molecularly imprinted polymers have good selectivity for phosphotyrosine peptides. Finally, the imprinted hydrogels were applied to specifically adsorb phosphotyrosine peptides from a sample mixture containing phosphotyrosine and a tryptic digest of β-casein, which demonstrated high selectivity. After four rebinding cycles, 78.9% adsorption efficiency was still retained.

  5. Ordered macroporous quercetin molecularly imprinted polymers: Preparation, characterization, and separation performance.

    Science.gov (United States)

    Feng, Yonggang; Liu, Qin; Ye, Lifang; Wu, Quanzhou; He, Jianfeng

    2017-02-01

    Ordered macroporous molecularly imprinted polymers were prepared by a combination of the colloidal crystal templating method and the molecular imprinting technique by using SiO2 colloidal crystal as the macroporogen, quercetin as the imprinting template, acrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and tetrahydrofuran as the solvent. Scanning electron microscopy and Brunauer-Emmett-Teller measurements show that the ordered macroporous molecularly imprinted polymers have a more regular macroporous structure, a narrower pore distribution and a greater porosity compared with the traditional bulk molecularly imprinted polymers. The kinetic and isothermal adsorption behaviors of the polymers were investigated. The results indicate that the ordered macroporous molecularly imprinted polymers have a faster intraparticle mass transfer process and a higher adsorption capacity than the traditional bulk molecularly imprinted polymers. The ordered macroporous molecularly imprinted polymers were further employed as a sorbent for a solid-phase extraction. The results show that the ordered macroporous molecularly imprinted polymers can effectively separate quercetin from the Gingko hydrolysate.

  6. Genomic imprinting in the Arabidopsis embryo is partly regulated by PRC2.

    Science.gov (United States)

    Raissig, Michael T; Bemer, Marian; Baroux, Célia; Grossniklaus, Ueli

    2013-01-01

    Genomic imprinting results in monoallelic gene expression in a parent-of-origin-dependent manner and is regulated by the differential epigenetic marking of the parental alleles. In plants, genomic imprinting has been primarily described for genes expressed in the endosperm, a tissue nourishing the developing embryo that does not contribute to the next generation. In Arabidopsis, the genes MEDEA (MEA) and PHERES1 (PHE1), which are imprinted in the endosperm, are also expressed in the embryo; whether their embryonic expression is regulated by imprinting or not, however, remains controversial. In contrast, the maternally expressed in embryo 1 (mee1) gene of maize is clearly imprinted in the embryo. We identified several imprinted candidate genes in an allele-specific transcriptome of hybrid Arabidopsis embryos and confirmed parent-of-origin-dependent, monoallelic expression for eleven maternally expressed genes (MEGs) and one paternally expressed gene (PEG) in the embryo, using allele-specific expression analyses and reporter gene assays. Genetic studies indicate that the Polycomb Repressive Complex 2 (PRC2) but not the DNA METHYLTRANSFERASE1 (MET1) is involved in regulating imprinted expression in the embryo. In the seedling, all embryonic MEGs and the PEG are expressed from both parents, suggesting that the imprint is erased during late embryogenesis or early vegetative development. Our finding that several genes are regulated by genomic imprinting in the Arabidopsis embryo clearly demonstrates that this epigenetic phenomenon is not a unique feature of the endosperm in both monocots and dicots.

  7. Genomic imprinting in the Arabidopsis embryo is partly regulated by PRC2.

    Directory of Open Access Journals (Sweden)

    Michael T Raissig

    Full Text Available Genomic imprinting results in monoallelic gene expression in a parent-of-origin-dependent manner and is regulated by the differential epigenetic marking of the parental alleles. In plants, genomic imprinting has been primarily described for genes expressed in the endosperm, a tissue nourishing the developing embryo that does not contribute to the next generation. In Arabidopsis, the genes MEDEA (MEA and PHERES1 (PHE1, which are imprinted in the endosperm, are also expressed in the embryo; whether their embryonic expression is regulated by imprinting or not, however, remains controversial. In contrast, the maternally expressed in embryo 1 (mee1 gene of maize is clearly imprinted in the embryo. We identified several imprinted candidate genes in an allele-specific transcriptome of hybrid Arabidopsis embryos and confirmed parent-of-origin-dependent, monoallelic expression for eleven maternally expressed genes (MEGs and one paternally expressed gene (PEG in the embryo, using allele-specific expression analyses and reporter gene assays. Genetic studies indicate that the Polycomb Repressive Complex 2 (PRC2 but not the DNA METHYLTRANSFERASE1 (MET1 is involved in regulating imprinted expression in the embryo. In the seedling, all embryonic MEGs and the PEG are expressed from both parents, suggesting that the imprint is erased during late embryogenesis or early vegetative development. Our finding that several genes are regulated by genomic imprinting in the Arabidopsis embryo clearly demonstrates that this epigenetic phenomenon is not a unique feature of the endosperm in both monocots and dicots.

  8. In Pursuit of New Imprinting Syndromes by Epimutation Screening in Idiopathic Neurodevelopmental Disorder Patients.

    Science.gov (United States)

    Mayo, Sonia; Monfort, Sandra; Roselló, Mónica; Oltra, Silvestre; Orellana, Carmen; Martínez, Francisco

    2015-01-01

    Alterations of epigenetic mechanisms, and more specifically imprinting modifications, could be responsible of neurodevelopmental disorders such as intellectual disability (ID) or autism together with other associated clinical features in many cases. Currently only eight imprinting syndromes are defined in spite of the fact that more than 200 genes are known or predicted to be imprinted. Recent publications point out that some epimutations which cause imprinting disorders may affect simultaneously different imprinted loci, suggesting that DNA-methylation may have been altered more globally. Therefore, we hypothesised that the detection of altered methylation patterns in known imprinting loci will indirectly allow identifying new syndromes due to epimutations among patients with unexplained ID. In a screening for imprinting alterations in 412 patients with syndromic ID/autism we found five patients with altered methylation in the four genes studied: MEG3, H19, KCNQ1OT1, and SNRPN. Remarkably, the cases with partial loss of methylation in KCNQ1OT1 and SNRPN present clinical features different to those associated with the corresponding imprinting syndromes, suggesting a multilocus methylation defect in accordance with our initial hypothesis. Consequently, our results are a proof of concept that the identification of epimutations in known loci in patients with clinical features different from those associated with known syndromes will eventually lead to the definition of new imprinting disorders.

  9. Allelic expression of mammalian imprinted genes in a matrotrophic lizard, Pseudemoia entrecasteauxii.

    Science.gov (United States)

    Griffith, Oliver W; Brandley, Matthew C; Belov, Katherine; Thompson, Michael B

    2016-03-01

    Genomic imprinting is a process that results in the differential expression of genes depending on their parent of origin. It occurs in both plants and live-bearing mammals, with imprinted genes typically regulating the ability of an embryo to manipulate the maternal provision of nutrients. Genomic imprinting increases the potential for selection to act separately on paternally and maternally expressed genes, which increases the number of opportunities that selection can facilitate embryonic control over maternal nutrient provision. By looking for imprinting in an independent matrotrophic lineage, the viviparous lizard Pseudemoia entrecasteauxii (Scincidae), we test the hypothesis that genomic imprinting facilitates the evolution of substantial placental nutrient transport to embryos (matrotrophy). We sequenced transcriptomes from the embryonic component of lizard placentae to determine whether there are parent-of-origin differences in expression of genes that are imprinted in mammals. Of these genes, 19 had sufficiently high expression in the lizard to identify polymorphisms in transcribed sequences. We identified bi-allelic expression in 17 genes (including insulin-like growth factor 2), indicating that neither allele was imprinted. These data suggest that either genomic imprinting has not evolved in this matrotrophic skink or, if it has, it has evolved in different genes to mammals. We outline how these hypotheses can be tested. This study highlights important differences between mammalian and reptile pregnancy and the absence of any shared imprinting genes reflects fundamental differences in the way that pregnancy has evolved in these two lineages.

  10. Evidence of Olfactory Imprinting at an Early Life Stage in Pink Salmon (Oncorhynchus gorbuscha).

    Science.gov (United States)

    Bett, Nolan N; Hinch, Scott G; Dittman, Andrew H; Yun, Sang-Seon

    2016-11-09

    Pacific salmon (Oncorhynchus spp.) navigate towards spawning grounds using olfactory cues they imprinted on as juveniles. The timing at which imprinting occurs has been studied extensively, and there is strong evidence that salmon imprint on their natal water during the parr-smolt transformation (PST). Researchers have noted, however, that the life histories of some species of Pacific salmon could necessitate imprinting prior to the PST. Juvenile pink salmon (O. gorbuscha) spend less time in fresh water than any other species of Pacific salmon, and presumably must imprint on their natal water at a very young age. The time at which imprinting occurs in this species, however, has not been experimentally tested. We exposed juvenile pink salmon as alevins to phenethyl alcohol (PEA) or control water, reared these fish to adulthood, and then tested their behavioural responses to PEA to determine whether the fish successfully imprinted. We found that pink salmon exposed to PEA as alevins were attracted to the chemical as adults, suggesting that imprinting can occur during this stage. Our finding provides some of the first evidence to support the long-standing belief that imprinting can occur in pink salmon prior to the PST.

  11. Touch imprint cytology: a rapid diagnostic tool for oral squamous cell carcinoma.

    Science.gov (United States)

    Geetha, L; Astekar, M; Ashok, K N; Sowmya, G V

    2015-07-01

    Techniques for intraoperative pathologic examination of oral squamous cell carcinoma are rare in the literature. We evaluated the advantages and limitations of touch imprint cytology for intraoperative diagnosis of oral squamous cell carcinoma. We used 30 incisional biopsies of clinically diagnosed oral squamous cell carcinoma and compared touch imprint cytology to histopathological sections. Touch imprint cytology showed 24 specimens positive for malignancy, two suspicious for malignancy and four inadequate specimens. The accuracy of the test was 93.2%. Touch imprint cytology is an accurate, simple, rapid and cost-effective method that aids diagnosis of oral squamous cell carcinoma during operation, but it does not replace incisional biopsy.

  12. Sexual imprinting can induce sexual preferences for exaggerated parental traits.

    Science.gov (United States)

    ten Cate, Carel; Verzijden, Machteld N; Etman, Eric

    2006-06-06

    Sexual preferences in animals are often skewed toward mates with exaggerated traits. In many vertebrates, parents provide, through the learning process of "sexual imprinting," the model for the later sexual preference. How imprinting can result in sexual preferences for mates having exaggerated traits rather than resembling the parental appearance is not clear. We test the hypothesis that a by-product of the learning process, "peak shift", may induce skewed sexual preferences for exaggerated parental phenotypes. To this end, zebra finch (Taeniopygia guttata) males were raised by white parents, with beak color as the most prominent sexual dimorphism. We manipulated this feature with nail varnish. At adult age, each male was given a preference test in which he could choose among eight females with beak colors ranging from more extreme on the paternal to more extreme on the maternal side. The males preferred females with a beak of a more extreme color than that of their mothers, i.e., they showed a peak shift. Sexual imprinting can thus generate skewed sexual preferences for exaggerated maternal phenotypes, phenotypes that have not been present at the time of the learning. We suggest that such preferences can drive the evolution of sexual dimorphism and exaggerated sexual traits.

  13. Detour behaviour, imprinting and visual lateralization in the domestic chick.

    Science.gov (United States)

    Vallortigara, G; Regolin, L; Pagni, P

    1999-01-01

    Detour behaviour was studied in chicks faced with a vertical-bar barrier behind where an imprinting object (a red ball) was located. Right-eyed chicks took less time to detour the barrier than left-eyed chicks, and binocular chicks showed a bias to detour the barrier on the left side, thus maintaining visual contact with the imprinting object using the lateral field of the right eye, while circling around the barrier. In males, the asymmetries were consistent all along the first two weeks of life, whereas in females they disappeared on days 8 and 11. When tested with a slightly novel version of the original imprinting object (i.e., a ball of a different color), binocular chicks showed a bias to detour the barrier on the right side, thus showing preferential use of the left eye. The same bias occurred when unfamiliar conspecifics were used as goal-objects. Results suggest that cerebral lateralization in birds can directly affect visually-guided motor responses through selective use of the lateral field of vision of the eye contralateral to the hemisphere which has to be put in charge of control of overt behaviour. Copyright 1999 Elsevier Science B.V.

  14. Critical review and perspective of macromolecularly imprinted polymers.

    Science.gov (United States)

    Kryscio, David R; Peppas, Nicholas A

    2012-02-01

    Molecular recognition is a fundamental and ubiquitous process that is the driving force behind life. Natural recognition elements - including antibodies, enzymes, nucleic acids, and cells - exploit non-covalent interactions to bind to their targets with exceptionally strong affinities. Due to this unparalleled proficiency, scientists have long sought to mimic natural recognition pathways. One promising approach is molecularly imprinted polymers (MIPs), which are fully synthetic systems formed via the crosslinking of organic polymers in the presence of a template molecule, which results in stereo-specific binding sites for this analyte of interest. Macromolecularly imprinted polymers, those synthesized in the presence of macromolecule templates (>1500 Da), are of particular importance because they open up the field for a whole new set of robust diagnostic tools. Although the specific recognition of small-molecular-weight analytes is now considered routine, extension of these efficacious procedures to the protein regime has, thus far, proved challenging. This paper reviews the main approaches employed, highlights studies of interest with an emphasis on recent work, and offers suggestions for future success in the field of macromolecularly imprinted polymers.

  15. Absence of genomic imprinting at the DiGeorge locus

    Energy Technology Data Exchange (ETDEWEB)

    Theophile, D.; Berube, D.; Auge, J.; Vekemans, M. [Hopital Necker-Enfants Malades, Paris (France)

    1994-09-01

    In situ hybridization with fluorescence probes (FISH) on interphase nuclei allows evaluation of the stage of DNA replication. For example, in a diploid cell in G1, unreplicated DNA gives two single dots of hybridization whereas in a diploid cell in G2, for loci which have already replicated, the hybridization signal is seen as two pairs of doublets. In contrast, sequences which have an asynchronous replication are characterized by one double hybridization signal and one single hybridization signal. It has been shown recently that sequences subject to genomic imprinting have an asynchronous replication, i.e., the two homologous alleles have a different pattern of replication. We have tested the replication pattern of different sequences of the DiGeorge critical region using FISH. The results obtained with probes 48F8, C350, C237 and COS40 show no evidence of asynchronous replication. This suggests that these loci are not subject to imprinting. These results are in agreement with recent observation of cases of uniparental disomy of chromosome 22 without phenotypic features. Further studies are necessary to exclude other regions of chromosome 22 which might be subject to genomic imprinting.

  16. Shape-engineered multifunctional porous silicon nanoparticles by direct imprinting.

    Science.gov (United States)

    Mares, Jeremy W; Fain, Joshua S; Beavers, Kelsey R; Duvall, Craig L; Weiss, Sharon M

    2015-07-10

    A versatile and scalable method for fabricating shape-engineered nano- and micrometer scale particles from mesoporous silicon (PSi) thin films is presented. This approach, based on the direct imprinting of porous substrates (DIPS) technique, facilitates the generation of particles with arbitrary shape, ranging in minimum dimension from approximately 100 nm to several micrometers, by carrying out high-pressure (>200 MPa) direct imprintation, followed by electrochemical etching of a sub-surface perforation layer and ultrasonication. PSi particles (PSPs) with a variety of geometries have been produced in quantities sufficient for biomedical applications (≫10 μg). Because the stamps can be reused over 150 times, this process is substantially more economical and efficient than the use of electron beam lithography and reactive ion etching for the fabrication of nanometer-scale PSPs directly. The versatility of this fabrication method is demonstrated by loading the DIPS-imprinted PSPs with a therapeutic peptide nucleic acid drug molecule, and by vapor deposition of an Au coating to facilitate the use of PSPs as a photothermal contrast agent.

  17. Monolithic molecularly imprinted polymeric capillary columns for isolation of aflatoxins.

    Science.gov (United States)

    Szumski, Michał; Grzywiński, Damian; Prus, Wojciech; Buszewski, Bogusław

    2014-10-17

    Monolithic molecularly imprinted polymers extraction columns have been prepared in fused-silica capillaries by UV or thermal polymerization in a two-step process. First, a poly-(trimethylolpropane trimethacrylate) (polyTRIM) core monolith was synthesized either by UV or thermal polymerization. Then it was grafted with the mixture of methacrylic acid (MAA) as a functional monomer, ethylene dimethacrylate (EDMA) as a cross-linking agent, 5,7-dimethoxycoumarin (DMC) as an aflatoxin-mimicking template, toluene as a porogen solvent and 2,2-azobis-(2-methylpropionitrile) (AIBN) as an initiator of the polymerization reaction. Different thermal condition of the photografting and different concentrations of the grafting mixture were tested during polymerization. The extraction capillary columns were evaluated in the terms of their hydrodynamic and chromatographic properties. Retention coefficients for aflatoxin B1 and DMC were used for assessment of the selectivity and imprinting factor. The obtained results indicate that the temperature of photografting and concentration of the grafting mixture are key parameters that determine the quality of the prepared MIPs. From the MIP columns characterized by the highest permeability the column of the highest imprinting factor was applied for isolation of aflatoxins B1, B2, G1 and G2 from the model aqueous sample followed by on-line chromatographic separation. The process was performed using a micro-MISPE-microLC-LIF system of a novel design, which allowed for detection of the eluates from the sample preparation part as well as from the chromatographic separation.

  18. Feature detection on 3D images of dental imprints

    Science.gov (United States)

    Mokhtari, Marielle; Laurendeau, Denis

    1994-09-01

    A computer vision approach for the extraction of feature points on 3D images of dental imprints is presented. The position of feature points are needed for the measurement of a set of parameters for automatic diagnosis of malocclusion problems in orthodontics. The system for the acquisition of the 3D profile of the imprint, the procedure for the detection of the interstices between teeth, and the approach for the identification of the type of tooth are described, as well as the algorithm for the reconstruction of the surface of each type of tooth. A new approach for the detection of feature points, called the watershed algorithm, is described in detail. The algorithm is a two-stage procedure which tracks the position of local minima at four different scales and produces a final map of the position of the minima. Experimental results of the application of the watershed algorithm on actual 3D images of dental imprints are presented for molars, premolars and canines. The segmentation approach for the analysis of the shape of incisors is also described in detail.

  19. Morpho peleides butterfly wing imprints as structural colour stamp.

    Science.gov (United States)

    Zobl, Sigrid; Salvenmoser, Willi; Schwerte, Thorsten; Gebeshuber, Ille C; Schreiner, Manfred

    2016-02-02

    This study presents the replication of a color-causing nanostructure based on the upper laminae of numerous cover scales of Morpho peleides butterfly wings and obtained solely by imprinting their upper-wing surfaces. Our results indicate that a simple casting technique using a novel integrated release agent can obtain a large positive replica using negative imprints via Polyvinylsiloxane. The developed method is low-tech and high-yield and is thus substantially easier and less expensive than previous methods. The microstructures were investigated with light microscopy, the nanostructures with both scanning and transmission electron microscopy, and the reflections with UV visible spectrometry. The influence of the release agent and the quality of the master stamp were determined by comparing measurements of the cover-scale sizes and their chromaticity values obtained by their images and with their positive imprints. The master stamp provided multiple positive replicas up to 3 cm(2) in just 1 h with structural coloration effects visible to the naked eye. Thus, the developed method proves the accuracy of the replicated nanostructure and its potential industrial application as a color-producing nanostamp.

  20. Three-phase molecularly imprinted sol-gel based hollow fiber liquid-phase microextraction combined with liquid chromatography-tandem mass spectrometry for enrichment and selective determination of a tentative lung cancer biomarker.

    Science.gov (United States)

    Moein, Mohammad Mahdi; Javanbakht, Mehran; Karimi, Mohammad; Akbari-Adergani, Behrouz; Abdel-Rehim, Mohamed

    2015-07-15

    In the present study, the modification of a polysulfone hollow fiber membrane with in situ molecularly imprinted sol-gel process (as a novel and one-step method) was prepared and investigated. 3-(propylmethacrylate)trimethoxysilane (3PMTMOS) as an inorganic precursor was used for preparation of molecularly imprinted sol-gel. The modified molecularly imprinted sol-gel hollow fiber membrane (MSHM) was used for the liquid-phase microextraction (LPME) of hippuric acid (HA) in human plasma and urine samples. MSHM as a selective, robust, and durable tool was used for at least 50 extractions without significant decrease in the extraction efficiency. The non-molecularly imprinted sol-gel hollow fiber membrane (NSHM) as blank hollow fiber membrane was prepared by the same process, only without HA. To achieve the best condition, influential parameters on the extraction efficiency were thoroughly investigated. The capability of this robust, green, and simple method for extraction of HA was successfully accomplished with LC/MS/MS. The limits of detection (LOD) and quantification (LOQ) in human plasma and urine samples were 0.3 and 1.0nmolL(-1), respectively. The standard calibration curves were obtained within the concentration range 1-2000nmolL(-1) for HA in human plasma and urine. The coefficients of determination (r(2)) were ≥0.998. The obtained data exhibited recoveries were higher than 89% for the extraction of HA in human plasma and urine samples.