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At least 1,657 records · Page 92Linked to original sources
PubMed1995

[Demonstration of molecular forms of Rap 1 in cells or tissues deriving from normal or pathological human colonic epithelium].

Mutations of the cK-ras gene which confer oncogenic properties to the corresponding encoded small G protein, occur in 30 to 50% of the human colonic adenocarcinomas. Overexpression of Rap 1A, a member of the Ras family, in K-ras transformed fibroblasts, reverts the transforming properties of the oncogene. This indicates that Rap 1A may exert antagonistic properties towards the K-Ras protein. In this respect, we have been interested in comparing Rap 1 expression in the human adenocarcinoma cell line HT29 and in safe or pathological tissues deriving from the human colonic epithelium. In the human adenocarcinoma cells HT29, several immunoreactive forms of Rap 1 of 71 kDa, 47 kDa, 40 kDa and 24 kDa are detected. Extraction in Triton X-114 allows separation of HT29 cell proteins on the basis of their differential hydrophobic properties. Parallelly, proteins were separated in crude cytosolic or membrane fractions. Most of the immunoreactive material corresponding to the 24 kDa band may contain hydrophobic and membrane associated components. The molecular nature of the higher size components is also discussed here. In the tissues, the 47 kDa form which is common in all of the safe and pathological samples considered, appears to be specifically expressed in the colon. Besides, the 71, 68 and 24 kDa were found in pathological tissues. High expression of Rap 1 was demonstrated to be correlated with cell differentiation in the safe colonic epithelium and in the adenomas. Cloning of the Rap 1A cDNA is now in progress in the laboratory, using PCR detection in an HT29 expression library.

Adenocarcinoma↗
PubMed1997

Molecular genetic analyses of parapoxviruses pathogenic for humans.

The current members of the genus parapoxvirus are orf virus (ORFV), bovine papular stomatitis virus (BPSV), pseudocowpoxvirus (PCPV) and parapoxvirus of red deer in New Zealand (PVNZ). BPSV and PCPV are maintained in cattle while ORFV is maintained in sheep and goats, but all three are zoonoses. Only the recently reported PVNZ has yet to be recorded as infecting humans. Tentative members of the genus are camel contagious ecthyma virus, chamois contagious ecthyma virus and sealpoxvirus. The separation of the parapoxviruses into 4 distinct groups has been based on natural host range, pathology and, more recently, on restriction endonuclease and DNA/DNA hybridisation analyses. The latter studies have shown that the parapoxviruses share extensive homology between central regions of their genomes, but much lower levels of relatedness within the genome termini. The high G + C content of parapoxvirus DNA is in contrast to most other poxviruses and suggests that a significant genetic divergence from other genera of this family has occurred. DNA sequencing of portions of the genome of ORFV, the type species of the genus, has allowed a detailed comparison with the fully sequenced genome of the orthopoxvirus, vaccinia virus (VACV). These studies have provided a genetic map of ORFV and revealed a central core of 88 kbp within which the genomic content was strikingly similar to that of VACV. This conservation is not maintained in the genome termini where insertions, deletions and translocations have occurred. The characterisation of specific ORFV genes may lead to the construction of attenuated vaccine strains in which genes such as those with the potential to interfere with the immune response of the host have been deleted. The current ORFV vaccines are living unattenuated virus and vaccination lesions produce virus which contaminates the environment in a manner similar to natural infection. The virus in scab material is relatively resistant to inactivation and this virus both perpetuates the disease in sheep and provides the most likely source of human infections. A vaccine which immunises animals without perpetuating the disease could be the best way of reducing the incidence of ORFV infection of humans. It is likely that protection against infection by ORFV is cell mediated and will require the endogenous production of relevant antigens. We have recently constructed a series of VACV recombinants each of which contains a large multigene fragment of ORFV DNA. Together the recombinants represent essentially all of the ORFV genome in an overlapping manner. Vaccination of sheep with the recombinant library provided protection against challenge with virulent ORFV. Further studies with this library may enable dominant protective antigens of ORFV to be identified and lead to their incorporation into a subunit vaccine.

Animals↗
PubMed2006

Detection of transgenic and endogenous plant DNA in digesta and tissues of sheep and pigs fed Roundup Ready canola meal.

The persistence of plant-derived recombinant DNA in sheep and pigs fed genetically modified (Roundup Ready) canola was assessed by PCR and Southern hybridization analysis of DNA extracted from digesta, gastrointestinal (GI) tract tissues, and visceral organs. Sheep (n = 11) and pigs (n = 36) were fed to slaughter on diets containing 6.5 or 15% Roundup Ready canola. Native plant DNA (high- and low-copy-number gene fragments) and the cp4 epsps transgene that encodes 5-enolpyruvyl shikimate-3-phosphate synthase were tracked in ruminal, abomasal, and large intestinal digesta and in tissue from the esophagus, rumen, abomasum, small and large intestine, liver, and kidney of sheep and in cecal content and tissue from the duodenum, cecum, liver, spleen, and kidney of pigs. High-copy chloroplast-specific DNA (a 520-bp fragment) was detected in all digesta samples, the majority (89-100%) of intestinal tissues, and at least one of each visceral organ sample (frequencies of 3-27%) from sheep and swine. Low-copy rubisco fragments (186- and 540-bp sequences from the small subunit) were present at slightly lower, variable frequencies in digesta (18-82%) and intestinal tissues (9-27% of ovine and 17-25% of porcine samples) and infrequently in visceral organs (1 of 88 ovine samples; 3 of 216 porcine samples). Each of the five cp4 epsps transgene fragments (179-527 bp) surveyed was present in at least 27% of ovine large intestinal content samples (maximum = 64%) and at least 33% of porcine cecal content samples (maximum = 75%). In sheep, transgene fragments were more common in intestinal digesta than in ruminal or abomasal content. Transgene fragments were detected in 0 (esophagus) to 3 (large intestine) GI tract tissues from the 11 sheep and in 0-10 of the duodenal and cecal tissues collected from 36 pigs. The feed-ingested recombinant DNA was not detected in visceral tissues (liver, kidney) of lambs or in the spleen from pigs. Of note, however, one liver and one kidney sample from the pigs (different animals) were positive for a 278-bp fragment of the transgenic cp4 epsps (denoted F3). Examination of genomic libraries from these tissues yielded no conclusive information regarding integration of the fragment into porcine DNA. This study confirms that feed-ingested DNA fragments (endogenous and transgenic) do survive to the terminal GI tract and that uptake into gut epithelial tissues does occur. A very low frequency of transmittance to visceral tissue was confirmed in pigs, but not in sheep. It is recognized that the low copy number of transgenes in GM feeds is a challenge to their detection in tissues, but there was no evidence to suggest that recombinant DNA would be processed in the gut in any manner different from endogenous feed-ingested genetic material.

Animal Feed↗
PubMed2005

Traffic of genetic information between segmental duplications flanking the typical 22q11.2 deletion in velo-cardio-facial syndrome/DiGeorge syndrome.

Velo-cardio-facial syndrome/DiGeorge syndrome results from unequal crossing-over events between two 240-kb low-copy repeats termed LCR22 (LCR22-2 and LCR22-4) on Chromosome 22q11.2, comprised of modules, each of which are >99% identical in sequence. To delineate regions in the LCR22s that might contain hotspots for 22q11.2 rearrangements, we scanned the interval for increased rates of recombination with the hypothesis that these regions might be more prone to breakage. We generated an algorithm to detect sites of altered recombination by searching for single nucleotide polymorphic positions in BAC clones from different libraries mapped to LCR22-2 and LCR22-4. This method distinguishes single nucleotide polymorphisms from paralogous sequence variants and complex polymorphic positions. Sites of shared polymorphism are considered potential sites of gene conversion or double cross-over between the two LCR22s. We found an inverse correlation between regions of paralogous sequence variants that are unique to a given position within one LCR22 and clusters of shared polymorphic sites, suggesting that these clusters depict altered recombination and not remnants of ancestral single nucleotide polymorphisms. We postulate that most shared polymorphic sites are products of past transfers of DNA information between the LCR22s, suggesting that frequent traffic of genetic material may induce genomic instability in the two LCR22s. We also found that gaps up to 1.5 kb long can be transferred between LCR22s.

Algorithms↗
PubMed1990

Family of human neuronal external surface epitopes defined by Torpedo monoclonal antibodies.

We are employing a library of monoclonal antibodies (MAbs) that were made to Torpedo cholinergic synaptosomes to identify conserved, physiologically vital epitopes of the neuronal surface. Our particular interest is in those epitopes that are present on some but not all neurons. In the present study we screened this library on different cell lines, the neuronal cell lines PC12, NG108, MC-IXC, and SY5Y, and the endocrine cell lines GH-3 and HIT. Of these cell lines, only SY5Y cells bind MAbs that define neuronal surface subsets. Utilizing its parent cell line, SK-N-SH, we verified that six MAbs, Tor 25, Tor 103, Tor 190, Tor 201, Tor 219, and Tor 233, bind the external neuronal surface. The cytolocalization of all six MAbs is very similar: the membrane of the cell body and its processes are finely outlined in a punctate distribution. Western blot analyses of Torpedo electric organ homogenates, a highly enriched source of antigenic material, revealed that each MAb identifies multiple polypeptides, two of which have the relative mobilities of 180 kD and 67 kD. In a screen of peripheral nerves from cases of amyotrophic lateral sclerosis (ALS), we found that all these MAbs revealed surface alterations; some displayed a decrease in binding, while others displayed an increase. The combined data provide evidence that these epitopes belong to an important, complex family of polypeptides of the external neuronal surface.

Amyotrophic Lateral Sclerosis↗
PubMed1997

[An entire rain forest can be screened at pharmaceutical industry's laboratories].

The pharmaceutical industry has long been heavily reliant on natural products, and today more than half of the twenty best-selling pharmaceuticals are derived from natural sources. Hitherto sample collection from fauna and flora has been based on an ethnobotanical approach involving traditional healers and oral histories of indigenous peoples as sources of information on folk uses of plants and organisms. In the future, however, random sampling combined with automated high-throughput screening (HTS) may come to the forefront in drug design, enabling extensive libraries of active compounds to be built up, and rendering local knowledge largely irrelevant. New technological advances in chemistry, molecular biology and data processing are combined in automated systems whereby HTS, based on bioassay-guided fractionation procedures, is used to isolate active compounds, and enabling the chemical structure of isolated compounds to be determined within 24 hours. The combination of the speed of HTS, and a remarkable decrease in the amount of sample required for the isolation and structure determination of natural compounds, has improved our ability to find unique natural products for drug development. Moreover, it has already been demonstrated that, owing to the relatively minute amounts of material required for HTS, this random sampling approach to bioprospecting for the purposes of drug will benefit efforts to conserve such sensitive biosystems as the rain forests and marine ecosystems. Thus, this technology would seem to be more compatible with the needs of modern drug design in the pharmaceutical industry that the ethnobotanical approach.

Drug Industry↗
PubMed2000

Risperidone versus typical antipsychotic medication for schizophrenia.

BACKGROUND: The 'conventional' neuroleptic drugs, such as haloperidol and chlorpromazine, are frequently used as the first line treatment for people with schizophrenia. However, about 5-25% of these people show poor response to these treatments and side effects often makes compliance with the 'older generation' of drug treatment problematic. Although the efficacy of these medications with respect to 'positive' symptoms is well described, little evidence exists that 'conventional' antipsychotic treatment has any effect on the 'negative' symptoms of schizophrenia. Risperidone is one of the 'new generation' neuroleptic compounds. As well as its reputed tendency to cause fewer movement disorders it is claimed that risperidone may improve negative symptoms. OBJECTIVES: To evaluate the effectiveness of risperidone for schizophrenia in comparison to 'conventional' neuroleptic drugs. SEARCH STRATEGY: Electronic searches of Biological Abstracts (1980-1997), Cochrane Schizophrenia Group's Register (1997), The Cochrane Library (1997, Issue1), EMBASE (1980-1997), MEDLINE (1966-1997), PsycLIT (1974-1997), and SCISEARCH (1997) were undertaken. References of all identified studies were searched for further trial citations. Pharmaceutical companies and authors of trials were contacted. SELECTION CRITERIA: All randomised trials comparing risperidone to any 'conventional' neuroleptic treatment for those with schizophrenia or other serious mental illnesses. DATA COLLECTION AND ANALYSIS: Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were also independently extracted. Sensitivity analyses on dose of risperidone, haloperidol and duration of illness were undertaken for the primary outcomes of clinical improvement, side effects (movement disorders) and acceptability of treatment. For homogeneous dichotomous data the odds ratio (OR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis. MAIN RESULTS: Twelve short-term studies and two long term studies provided data on 3401 people. This review provides no evidence relating to the effect of risperidone on cognitive or social functioning, quality of life, employment status, discharge from hospital and relapse rates. Risperidone increases the odds of moderate clinical improvement (OR 0.65, CI 0.55-0.77, NNT 10, CI 7-16). It appears to have little or no additional effect on the positive and negative symptoms of schizophrenia but did have less tendency to cause movement disorders, largely in comparison with haloperidol (OR 0.43, CI 0.34-0.55, NNT 7, CI 5-10) for use of antiparkinsonian medication. Risperidone seems to be more acceptable to those with schizophrenia (OR 0.69 CI 0.57-0.83, NNT 15, CI 10-30, 30% baseline risk of dropping out). Those taking risperidone are also marginally less likely to experience somnolence (OR 0.78, CI 0. 61-0.99, NNT 22). Weight gain, however, is more likely with risperidone (OR 1.51 CI 1.14-2.00, NNT 13). Funnel plots show that smaller studies generally show greater benefit for risperidone than larger studies. A publication bias in favour of risperidone amongst the included studies may explain this effect. Sensitivity analyses on dose of risperidone (excluding those receiving 1 or 2 mg) did not materially change the results for the principal outcomes. Excluding data from those on higher doses of haloperidol (>10mg/day) does marginally change the results. Risperidone is less effective in achieving clinical improvement and preventing dropout but outcomes relating to movement disorders change little. REVIEWER'S CONCLUSIONS: Little can be concluded about the long term effects of risperidone and generalising results beyond a comparison with haloperidol would be imprudent. Risperidone may be more acceptable to those with schizophrenia and have marginal benefits in terms of limited clinical improvement and side

Antipsychotic Agents↗
PubMed1994

Gastrin-releasing peptide is produced in the pregnant ovine uterus.

Our previous finding of appreciable quantities of a gastrin-releasing peptide (GRP)-like immunoreactive (GRPLI) entity in ovine fetal and maternal plasma led us to examine the ovine pregnant uterus as a possible source of this material. At term, intense immunohistochemical staining for GRPLI occurred in the endometrial epithelial cells, and the term ovine uterus also contained abundant GRP messenger RNA (mRNA). In contrast, GRP mRNA was not detected in fetal membranes. GRP mRNA was present in the uterus on gestational day 63; a significant increase in GRP mRNA had occurred by day 100. Thereafter, levels remained elevated until term, but 3 months postpartum, GRP mRNA levels were greatly reduced. As previous studies suggested the GRPLI entity to be of greater molecular size than GRP-(1-27), we deduced the primary structure of ovine uterus GRP by sequencing a complementary DNA clone isolated from a complementary DNA library constructed from term ovine uterus polyadenylated RNA. Ovine uterine GRP is composed of 27 amino acid residues and has a conserved C-terminal region, similar to GRP structures in other species. We conclude that during pregnancy, the ovine uterus produces considerable quantities of GRP, which may play an important but hitherto unrecognized role in utero-placental development and possibly in fetal development after transfer to the fetus.

Amino Acid Sequence↗
PubMed2006

Synthesis of metallothionein-mimic decapeptides with heavy atom signaling properties.

The automated parallel solid-phase synthesis of a 17-member library of metallothionein-mimic decapeptides carrying a Lariat ether group is described. The peptides were synthesized in good yield and the identity and quality of each product were performed by mass spectrometry and IR. Subsequently, in the presence of europium(III) ions as fluorescent reporter, each compound was screened, both attached to the resin and cleaved off, for their sensing behavior towards metal ions (Cd(2+),Hg(2+), Cu(2+), Mg(2+) and Ca(2+)) using fluorimetric techniques. Several of these Cys-enriched synthetic peptides showed surprisingly low detection limits for Cd(2+) and Hg(2+). The analytical potential of these metallothionein-mimic decapeptides as metal ion recognition materials for sensor development is outlined. Finally, the sensing response mechanism, based on an energy transfer process and a metal ion allosteric interaction, is proposed.

Allosteric Site↗
PubMed1999

Complexity and expression of the glutamine synthetase multigene family in the amphidiploid crop Brassica napus.

In the amphidiploid genome of oilseed rape (Brassica napus) the diploid ancestral genomes of B. campestris and B. oleracea have been merged. As a result of this crossing event, all gene loci, gene families, or multigene families of the A and C genome types encoding a certain protein are now combined in one plant genome. In the case of the multigene family for glutamine synthetase, the key enzyme of nitrogen assimilation, six different cDNA sequences were isolated from leaf and root specific libraries. One sequence pair (BnGSL1/BnGSL2) was characterized by the presence of amino-terminal transit peptides, a typical feature of all nuclear encoded chloroplast proteins. Two other cDNA pairs (BnGSR1-1/BnGSR1-2 and BnGSR2-1/BnGSR2-2) with very high homology between each other were found in a root specific cDNA library and represent protein subunits for cytosolic glutamine synthetase isoforms. Comparative PCR amplifications of genomic DNA isolated from B. napus, B. campestris and B. oleracea followed by sequence-specific restriction analyses of the PCR products permitted the assignment of the cDNA sequences to either the A genome type (BnGSL1/BnGSR1-1/BnGSR2-1) or the C genome type (BnGSL2/BnGSR1-2/BnGSR2-2). Consequently, the ancestral GS genes of B. campestris and B. oleracea are expressed simultaneously in oilseed rape. This result was also confirmed by RFLP (restriction fragment length polymorphism) analysis of RT-PCR products. In addition, the different GS genes showed tissue specific expression patterns which are correlated with the state of development of the plant material. Especially for the GS genes encoding the cytosolic GS isoform BnGSR2, a marked increase of expression could be observed after the onset of leaf senescence.

Blotting, Northern↗
PubMed2005

A potent transactivation domain mimic with activity in living cells.

Transcriptional coactivator-binding peptoids were isolated from a large combinatorial library. One of these molecules is shown to function as a potent activation domain surrogate in mammalian cells. Up to a 900-fold increase in expression of a Gal4-responsive reporter gene is observed when a steroid conjugate of the peptoid is incubated with HeLa cells expressing a Gal4 DNA-binding domain (DBD)-glucocorticoid receptor ligand-binding domain (GRLBD) fusion protein.

Animals↗
PubMed2004

Embryogenomics of pre-implantation mammalian development: current status.

Pre-implantation development is marked by many critical molecular events, including the maternal to zygotic transition and the first differentiation of cells. Understanding such events is important, for both basic reproductive biology and practical applications, including regenerative medicine and livestock production. Scarcity of materials has hampered the progress of the field, but systematic genomics approaches are beginning to be applied to the study of pre-implantation development, resulting in unprecedented amounts of data about the pre-implantation process. The first step in embryogenomics is to collect and sequence cDNAs (expressed sequence tags (ESTs)) for genes that are expressed and function in these early embryos. Mouse work is the most advanced, with 140 111 ESTs derived from all stages of pre-implantation development currently available in the public sequence database. For other mammals, at present only approximately 1000 ESTs can be found in the public database, but efforts by several groups are generating cDNA libraries and ESTs. In the present review, the current status of the implementation of these investigative tools for mammalian pre-implantation embryos is discussed.

Animals↗
PubMed2000

Local information for primary care: the St Albans WAX Project (STAPCIS).

The St. Albans Primary Care Information Service (STAPCIS) is a database of locally focused information designed to be of use for GPs and the Primary Care team as a whole in a particular area. It is currently being used by practices in the St. Albans, Dacorum and Watford & Three Rivers Primary Care Groups. STAPCIS developed from a project initiated in late 1997 to pilot the use of the WAX software to improve access to directory-type and full-text material needed for easy access by primary care staff and traditionally difficult to manage. The database is updated centrally by the STAPCIS Librarian who distributes the new editions to the practices. The WAX software itself was developed by the Cambridge Centre for Clinical Informatics. STAPCIS contains locally and nationally produced relevant information from a variety of sources, including full-text clinical guidelines and directories of Trusts. Decisions on new content are made by a Steering Group and the GPs and Primary Care teams are particularly encouraged to make suggestions regarding new content. The service is financially supported by the three primary care groups. The STAPCIS Librarian is project-managed by the Library & Information Development Unit (North Thames ), which also provides additional equipment and expertise. A new software company, WaX Info Ltd ( ), will soon be releasing a new version of the software, WaX. WaX consists of a WaX client and WaX ActiveLibrary server software. With the new version, the 'books' of information will still be stored on the user's PC, retaining the speed of access, but the server will enable users to 'borrow' books from remote locations and will provide automatic updates of all books. The new software will improve the management and distribution processes of STAPCIS once all of the practices have Internet connectivity.

Community Health Services↗
PubMed1991

Developmental genetic studies of the moss, Physcomitrella patens.

The development of the haploid gametophyte stage of Physcomitrella patens presents excellent opportunities for the detailed study of plant morphogenesis at the cellular level. The filamentous protonema undergoes a number of developmental transitions that can be observed directly in living material using time-lapse video microscopy and that can be manipulated both by treatment with phytohormones and by environmental stimuli. Mutants affecting these processes can be isolated and can be analysed using conventional as well as parasexual methods. Molecular biological techniques are now being established since these will be essential if the mechanisms that bring about morphogenetic processes are to be understood at the molecular level. A technique for genetic transformation has been devised and is being exploited to attempt to tag developmentally-relevant genes using maize transposons. Changes in gene activity associated with developmental transitions and in response to treatment with phytohormones and environmental stimuli are being studied using cDNA library subtraction techniques. Heterologous genes involved in the control of transcription and of the cell cycle are being used to probe the P. patens genome to identify possible homologues involved in developmental regulation.

Cytokinins↗
PubMed2006

Genes involved in oxidative phosphorylation are coordinately upregulated with fasting hyperglycaemia in livers of patients with type 2 diabetes.

AIMS/HYPOTHESIS: Mitochondrial oxidative phosphorylation (OXPHOS) plays an important role in the pathophysiology of type 2 diabetes. Genes involved in OXPHOS have been reported to be down-regulated in skeletal muscle from patients with type 2 diabetes; however, hepatic regulation is unknown. MATERIALS AND METHODS: We analysed expression of genes involved in OXPHOS from the livers of 14 patients with type 2 diabetes and 14 subjects with NGT using serial analysis of gene expression (SAGE) and DNA chip analysis. We evaluated the correlation between expression levels of genes involved in OXPHOS and the clinical parameters of individuals with type 2 diabetes and NGT. RESULTS: Both gene analyses showed that genes involved in OXPHOS were significantly upregulated in the type 2 diabetic liver. In the SAGE analysis, tag count comparisons of mitochondrial transcripts showed that ribosomal RNAs (rRNA) were 3.5-fold over-expressed, and mRNAs were 1.2-fold over-expressed in the type 2 diabetes library. DNA chip analysis revealed that expression of genes involved in OXPHOS, which correlated with several nuclear factors, including estrogen-related receptor-alpha or peroxisome proliferator-activated receptor-gamma, was a predictor of fasting plasma glucose levels, independently of age, BMI, insulin resistance and fasting insulin levels (p = 0.04). Surprisingly, genes involved in OXPHOS did not correlate with peroxisome proliferator-activated receptor-gamma coactivator-1alpha or nuclear respiratory factor 1. CONCLUSIONS/INTERPRETATION: Our results indicate that upregulation of genes involved in OXPHOS in the liver, which are regulated by different mechanisms from genes in the skeletal muscle, is associated with fasting hyperglycaemia in patients with type 2 diabetes.

Aged↗
PubMed2005

Dioxin-binding pentapeptide for use in a high-sensitivity on-bead detection assay.

The purpose of this study is to develop a dioxin detection method using a short peptide alternative to an immunoantibody. A full peptide library consisting of 2.5 million possible amino acid combinations was constructed by a solid-phase split synthesis approach using 19 natural amino acids. The peptide beads were subjected to a competitive binding assay between 2,3,7-trichlorodibenzo-p-dioxin and N-NBD-3-(3',4'-dichlorophenoxy)-1-propylamine (NBD-DCPPA) in a buffer containing 20% 1,4-dioxane. Two almost identical pentapeptides, FLDQI and FLDQV, that could bind dioxin were screened from the combinatorial library. NBD-DCPPA and the peptide synthesized on resin beads could be utilized to determine dioxin concentrations. The fluorescence intensity of the beads was measured using fluorescence microscopy to make a calibration curve for the dioxin concentrations. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-TeCDD) could also detected in the presence of 30% 1,4-dioxane. To optimize the peptide sequence, a one-amino acid-substituted library was prepared using amino acids including nonnatural amino acids. The internal amino acids, LDQ, could not be substituted by any other amino acids. This result indicates that these three side chains are essential to recognize dioxins. The peptide C terminus substituted by phenylglycine showed a 10 times lower detection limit of 2,3,7,8-TeCDD of 150 pM (50 pg/mL) than the original sequence FLDQV. The cross reactivity of the dioxin binding peptides including the secondary derivatives was investigated. Some polycyclic aromatic hydrocarbons bound to the peptide beads, but nonchlorinated dibenzo-p-dioxin and PCB did not. From these results, we demonstrate the potential of short peptides as a practical sensor material targeting low molecular weight compounds such as dioxin.

Dioxins↗
PubMed1993

Cloning, heterologous expression, and characterization of the Erysipelothrix rhusiopathiae DnaK protein.

The dnaK (hsp70) gene from the facultative intracellular pathogen Erysipelothrix rhusiopathiae was cloned by heterologous DNA hybridization of a genomic library using the Escherichia coli dnaK gene as a probe. A 3.2-kb fragment which encoded an 1,800-bp open reading frame was recovered. The deduced amino acid sequence of this open reading frame shares 56% identity with the E. coli DnaK protein. Expression of the encoded protein in E. coli by using the phage T7 promoter/polymerase system resulted in accumulation of a unique 65-kDa protein. Western blot (immunoblot) analysis of extracts from a recombinant E. coli strain using anti-E. coli DnaK polyclonal antibodies confirmed that the cloned gene encodes a DnaK homolog. The recombinant E. rhusiopathiae DnaK protein was purified to 80% homogeneity by ATP affinity chromatography. The purified material hydrolyzed ATP with a specific activity of 100 nmol min-1 mg of protein-1. Analysis of total protein extracts from E. rhusiopathiae indicates that DnaK is a highly expressed protein in this organism.

Adenosine Triphosphate↗
PubMedDate not supplied

Cultural discovery: an innovative philosophy for creative learning activities.

The purpose of this article is to describe a philosophical approach for integrating general transcultural nursing concepts and skills within a first semester associate degree nursing course. The authors wished to design a learning activity that would provide meaningful experiences and stimulate critical thinking among nontraditional, culturally diverse students who must learn to care for many clients of diverse cultural backgrounds. With a focus on culture, aging, and health, this creative learner-centered approach, called Cultural Discovery, emphasizes learning outcomes in both the cognitive and affective domains. Cultural Discovery includes several components in conjunction with the Leininger Acculturation Health Care Assessment Enabler for Cultural patterns in Traditional and Nontraditional Lifeways, specifically: background reading assignments, classroom activity component, collaborative library introductory program, videotape program, interview, literature review, reflection, and written paper assignment. Implemented over an eight week period, Cultural Discovery assisted beginning nursing students to systematically conduct a basic general cultural assessment, identify some similarities and differences among individuals within cultural groups, distinguish between varying dimensions of acculturation, and discover the importance of culturally congruent nursing care.

Acculturation↗