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PubMed1981

Duplicate prescriptions: an aid to research and review.

We describe a method of studying patterns of prescribing and related morbidity in general practice. Prescribing data were automatically duplicated onto a ;no-carbon-required' prescription-pad. Additional information about diagnosis and indications for each drug, an indication of whether the drug was newly prescribed or a repeat, and a patient identification code were entered onto the bottom copy. A computer was used to process the data, which were gathered over a period of seven months.The method offers an efficient means of collecting data which can be applied by individuals or groups of doctors to improve patient care and help achieve rational prescribing.

Data Collection↗
PubMed1997

Estimating the age of alleles by use of intraallelic variability.

A method is presented for estimating the age of an allele by use of its frequency and the extent of variation among different copies. The method uses the joint distribution of the number of copies in a population sample and the coalescence times of the intraallelic gene genealogy conditioned on the number of copies. The linear birth-death process is used to approximate the dynamics of a rare allele in a finite population. A maximum-likelihood estimate of the age of the allele is obtained by Monte Carlo integration over the coalescence times. The method is applied to two alleles at the cystic fibrosis (CFTR) locus, deltaF508 and G542X, for which intraallelic variability at three intronic microsatellite loci has been examined. Our results indicate that G542X is somewhat older than deltaF508. Although absolute estimates depend on the mutation rates at the microsatellite loci, our results support the hypothesis that deltaF508 arose < 500 generations (approximately 10,000 years) ago.

Alleles↗
PubMed2006

The impact of meaning and dimensionality on copying accuracy in individuals with autism.

Weak Central Coherence (Frith, 1989) predicts that, in autism, perceptual processing is relatively unaffected by conceptual analysis. Enhanced Perceptual Functioning (Mottron & Burack, 2001) predicts that the perceptual processing of those with autism is less influenced by conceptual analysis only when higher-level processing is detrimental to task performance. This research tested these theories using a copying task where one conceptual aspect enhances accuracy (meaningfulness) and another hinders it (three-dimensionality). Children and adolescents with and without autism copied meaningful and non-meaningful two-dimensional and three-dimensional line drawings. Drawing accuracy and strategy (global/local) were assessed. Participants with autism were less affected by dimensionality but not meaningfulness, apparently supporting EPF. Effects of dimensionality did not relate to drawing strategy, also contrary to WCC.

Adolescent↗
PubMed2002

Transcription and replication initiate at separate sites on the vesicular stomatitis virus genome.

The RNA-dependent RNA polymerase of the nonsegmented negative-strand RNA viruses carries out two distinct RNA synthetic processes: transcription of monocistronic, capped, and polyadenylated subgenomic messenger RNAs, and replication by means of the synthesis of a full-length positive-sense copy of the genome. The template for both processes is the negative-sense genomic RNA tightly encapsidated by the viral nucleocapsid protein. By applying UV transcriptional mapping to engineered variants of vesicular stomatitis virus, we discovered that, in infected cells, transcription and replication are controlled by initiation at different positions on the viral genome.

Animals↗
PubMed1989

Dimer structure of a neuropeptide precursor established: consequences for processing.

A prohormone (P1) of locust adipokinetic hormone I (AKH I) is shown here to be a homodimer of a 41 residue subunit called the A-chain. The A-chain, from the N terminal, consists of AKH I (10 amino acids starting with pyroglutamate) followed by a Gly-Lys-Arg processing site and then a 28 residues called the alpha chain containing a single cysteine and a potential Arg-Lys processing site. When processed each molecule of the homodimer precursor yields two copies of AKH I and one alpha chain homodimer. We call the alpha-alpha homodimer product of P1 processing AKH precursor related peptide 1 or APRP 1. The Arg-Lys dibasic pair found within the alpha chain is not cleaved in vivo. Our results show that neuropeptide precursors can be dimers and that dimer products can be synthesized by processing of a preformed dimer precursor rather than by dimerization of independent subunits.

Amino Acid Sequence↗
PubMedDate not supplied

Relations between drawing cubes and copying line diagrams of cubes in 7- to 10-year-old children.

Previous research has suggested both links and differences between children's copying of line diagrams and their drawings of solid objects. If the diagram represents a familiar object, children make more errors than when copying a diagram of a nonobject or unfamiliar object, as if they are drawing from their representation of the object rather than copying the surface features of the diagram. However, copying a diagram yields fewer and different types of errors than drawing the equivalent solid, which suggests a different process. In Experiment 1 (n = 72), possible relations between copying and drawing are investigated by asking children to draw a solid cube, then to copy or trace a line diagram of the cube in oblique projection, and finally to draw the solid again. Copying was better than drawing, and there was positive transfer to a subsequent drawing. Tracing was very accurate, but transfer to drawing did not occur, possibly because of the automatic nature of tracing. In Experiment 2 (n = 120) different groups received versions of the copying task that differed in the extent to which temporal order of line copying was structured. Asking children to copy the lines in a systematic order led to improved copies, but this performance did not carry over to a subsequent drawing of the solid. In contrast, when temporal ordering of line copying was not manipulated, there was positive transfer from copying to the subsequent drawing. In Experiment 3 (n = 80), provision of structure that emphasized faces by color-groupings of lines or coloring faces led to improved copies and did not hinder transfer to drawing the solid. Experiment 4 (n = 90) showed that in a solid drawing task emphasis on faces but not edges produced a positive effect, both on the immediate drawing and on a subsequent drawing of a plain cube. We conclude that emphasis on order of line copying improves performance in a copying task because in that case line-to-line matching is an important element of the skill, whereas this does not aid drawing of the solid object, in which the focus is primarily on representation of faces and their interrelations.

Child↗
PubMed2003

Study on the evolution of the grande retrotransposon in the zea genus.

The study of Grande retrotransposon (RTN) variation reported here comprises the intrinsic element variability and the changes that element insertion provokes in the Zea genome, including its abundance among species. Sequence analysis of a defined long-terminal repeat (LTR) region from Grande RTN revealed a high level of sequence divergence since no identical sequences were found among the 65 clones examined that belong to different Zea species or maize inbred lines. Average diversity values within accessions ranged from 0.17 to 0.37 substitutions per nucleotide. Phylogenetic analysis revealed a lack of concordance between the phylogenetic tree obtained from LTR sequences and the conventional taxonomic tree, suggesting that different subfamilies of Grande elements existed before Zea speciation. When sequence-specific amplification polymorphism (SSAP) marker data, which combines genomic and RTN variation, are used, the derived trees reflect the established species phylogeny and allow, as well, differentiating among some maize lines. Finally, the evaluation of Grande abundance, using different element probes in all the Zea species but Z. luxurians, revealed around 5,700 copies per haploid genome in all the diploid species examined, indicating a similar expansion process of Grande in all the Zea genomes. This number of copies represents in all cases around a 3% of the genome, which implies that Grande RTN is an important component of the maize genome. The copy number ratio LTR/gag is around 2 in all the species analyzed, indicating that overwhelming majority of elements have internal region. Thus, mechanisms such as homologous recombination between LTRs of a single RTN, which would remove the internal region and one LTR, leaving behind a single recombinant LTR, seems not to be active in maize for Grande RTN.

Base Sequence↗
PubMed2004

Influence of flanking sequences on presentation efficiency of a CD8+ cytotoxic T-cell epitope delivered by parvovirus-like particles.

We have previously developed an antigen-delivery system based on hybrid recombinant porcine parvovirus-like particles (PPV-VLPs) formed by the self-assembly of the VP2 protein of PPV carrying a foreign epitope at its N terminus. In this study, different constructs were made containing a CD8(+) T-cell epitope of chicken ovalbumin (OVA) to analyse the influence of the sequence inserted into VP2 on the correct processing of VLPs by antigen-presenting cells. We analysed the presentation of the OVA epitope inserted without flanking sequences or with either different natural flanking sequences or with the natural flanking sequences of a CD8(+) T-cell epitope from the lymphocytic choriomeningitis virus nucleoprotein, and as a dimer with or without linker sequences. All constructs were studied in terms of level of expression, assembly of VLPs and ability to deliver the inserted epitope into the MHC I pathway. The presentation of the OVA epitope was considerably improved by insertion of short natural flanking sequences, which indicated the relevance of the flanking sequences on the processing of PPV-VLPs. Only PPV-VLPs carrying two copies of the OVA epitope linked by two glycines were able to be properly processed, suggesting that the introduction of flexible residues between the two consecutive OVA epitopes may be necessary for the correct presentation of these dimers by PPV-VLPs. These results provide information to improve the insertion of epitopes into PPV-VLPs to facilitate their processing and presentation by MHC class I molecules.

Amino Acid Sequence↗
PubMed1985

Processed pseudogenes: characteristics and evolution.

The processed pseudogenes reported to date fall into three categories: those that are a complete copy of the mRNA transcribed from the functional gene, those that are only a partial copy of the corresponding mRNA, and those that contain sequences in addition to those expected to be present in the mRNA. The general structural characteristics of these processed pseudogenes include the complete lack of intervening sequences found in the functional counterparts, a poly A tract at the 3' end, and direct repeats flanking the pseudogene sequence. In all the cases studied, these pseudogenes have been found to be on a different chromosome from their functional counterpart. These characteristics have led investigators to suggest that an RNA intermediate, in many cases the mRNA of the functional gene, is involved in the production of these pseudogenes. The mechanism by which processed pseudogenes arose involves the integration of the mRNA, or its cDNA copy, into a staggered chromosome break, followed by DNA synthesis and repair. I suggest that all the transcripts that gave rise to these pseudogenes were actually produced in the germ line cell. The transcripts that gave rise to the processed pseudogenes that are direct copies of the corresponding mRNA resulted from RNA polymerase II transcription of the functional counterpart. Pseudogenes that are not a direct copy of the corresponding mRNA may have resulted from RNA polymerase III transcription. If this is indeed the case, one need not postulate the involvement of retroviruses to explain the presence of processed pseudogenes corresponding to genes that are not expressed in the germ line. Following the integration event, processed pseudogenes can no longer be transcribed to produce the functional mRNA from which they arose. This inability to be transcribed by RNA polymerase II is not surprising considering that processed pseudogenes seem to be randomly integrated into the genome. Therefore, integration of a processed pseudogene such that RNA polymerase II transcriptional promoters are correctly positioned 5' to the resultant pseudogene is an unlikely event. The presence of processed pseudogenes seems peculiar to mammals. In fact, evolutionary studies indicate that processed pseudogenes are of relatively recent origin. In fact, at least one processed pseudogene, the human DHFR psi 1, has been formed so recently that it is polymorphic.

Animals↗
PubMed1984

Pencil and paper tests--sensitivity to psychotropic drugs.

The literature on pencil and paper tests and the effects of psychotropic drugs is reviewed. Performance at digit symbol substitution, symbol copying, letter cancellation, arithmetic, logic and cognitive processing with a relatively constant level of triazolam was compared with placebo. Analysis of variance, covariance analysis and principal component analysis were applied to the data. Pencil and paper tests which measure various skills are useful for detecting drug effects. Letter cancellation, arithmetic and DSST appear to be most sensitive, although logic and symbol copying may be useful.

Anti-Anxiety Agents↗
PubMed2004

Evolution of the digital revolution: a radiologist perspective.

The transformation from film-based to filmless operation has become more and more challenging, as imaging studies expand in size and complexity. To adapt to these changes, radiologists must proactively develop new workflow strategies to compensate for increasing work demands and the existing workforce shortage. This article addresses the evolutionary changes underway in the radiology interpretation process and reviews changes that have occurred in the past decade. These include a number of developments in soft-copy interpretation, which is migrating from a relatively static process, duplicating film-based interpretation, to a dynamic process, using multi-planar reconstructions, volumetric navigation, and electronic decision support tools. The result is optimization of the human-computer interface with improved productivity, diagnostic confidence, and interpretation accuracy.

Humans↗
PubMed1992

A rabbit AldA pseudogene derived from a partially spliced primary aldolase A transcript.

The entire AldA processed pseudogene of rabbit was isolated and characterized. The pseudogene encodes the C-terminal portion of the protein from amino acids (aa) 126-363. There are deletions, insertions and nucleotide (nt) substitutions distributed throughout the 931 bp of identity shared with the 1.4-kb mRNA. There are 21 replacement codon substitutions, including a clearly deleterious change in the stop codon. This processed pseudogene has several uncommon features: (i) it has a 5'-boundary coincident with an intron/exon junction and does not encode the entire mRNA, (ii) there is a broken direct repeat that overlaps the region of shared identity with the mRNA rather than flanking it, and (iii) there is no poly(A) sequence. This processed pseudogene probably arose by integration of a DNA copy of a partially spliced primary transcript. The structure of this gene has added implications for the timing of posttranscriptional processing events.

Amino Acid Sequence↗
PubMed2002

Complementary DNA analysis, expression and subcellular localization of hnRNP E2 gene in Xenopus laevis.

The cloning and sequencing of complementary DNAs corresponding to the two copies (a and b) of the Xenopus laevis gene for hnRNP E2 is presented. Comparison of the two sequences reveals that while they are somewhat divergent at the nucleotide level, they are very conserved at the amino acid level. The analysis also showed two transcripts of different length (alpha and beta), likely generated by alternative processing. There are indications that either gene copy can generate both type of transcripts. Northern blot analysis in oocytes and developing embryos showed that hnRNP E2 RNA is constantly present and that increases in amount at tadpole stage. A semiquantitative reverse transcriptase polymerase chain reaction analysis performed with RNA from developing embryos showed that long (alpha) transcript accumulation is constant during development, whereas the short one (beta) accumulation increases at later stages, thus determining the observed increase in total RNA. Nucleo-cytoplasm localization experiments indicated that in oocyte hnRNP E2 is exclusively cytoplasmic, whereas in somatic cells it is distributed in both compartments. Comparison of the amino acid sequence of the two X. laevis hnRNP E2 with the corresponding mammalian sequences shows a high homology along the molecule except for the region subjected to alternative splicing, which is completely different. Moreover, there are indications that the homologous of mammalian hnRNP E1 gene, very related to and derived from hnRNP E2 by retrotransposition, is not expressed or even not present in X. laevis, suggesting that mammalian hnRNP E1 gene may have originated after mammal/amphybia divergence.

Amino Acid Sequence↗
PubMed1999

Differential priming of RNA templates during cDNA synthesis markedly affects both accuracy and reproducibility of quantitative competitive reverse-transcriptase PCR.

Quantitative competitive reverse-transcriptase PCR is the most sensitive method for studying gene expression. To investigate whether the accuracy of the calculated target mRNA copy number is affected by the cDNA priming process, we utilized primers of different lengths, concentrations and primer sequences to prime cDNA synthesis reactions. Our results show a approximately 19-fold increase in the calculated mRNA copy number from cDNA synthesis reactions primed with random hexamers (P<0.001, n=4), and a approximately 4-fold increase in copy number with a specific hexamer (P<0.001, n=4) compared with that obtained with a 22-mer-sequence-specific primer. The increase in calculated mRNA copy number obtained by priming cDNA synthesis with the shorter specific and non-specific primers could be explained largely by the synthesis of truncated standard cDNA molecules lacking a requisite binding site for amplification with PCR primers. Since these truncated standard cDNA molecules could not be amplified and standard RNA is used to quantify target mRNA copy number, this phenomenon resulted in overestimation of target mRNA copy number. In conclusion, accurate determination of target mRNA copy number is most likely if a long specific antisense primer is used to prime cDNA synthesis.

Base Sequence↗
PubMed1997

CpG-rich sequences close to the site of duplication within the human IGH constant region.

Human immunoglobulin heavy chains are encoded by a highly complex locus, IGH, which encompasses many transcriptional units, including nine alternative constant region genes. Much of the constant region gene cluster was duplicated during hominoid evolution. In rodents, IGH is known to be regulated by multiple elements, including several enhancers 3' of the alpha chain-encoding A constant region gene, CA, the last transcribed region. Sequences downstream of the two human CA genes, possibly containing homologous enhancer elements, have not yet been reported. By long-range mapping of genomic DNA, a cluster of unmethylated rare restriction sites, representing a potential CpG island, was previously reported downstream of each CA gene, close to the 3' end of the duplicated region. Such potential CpG islands are candidates for additional IGH regulatory elements. We isolated bacteriophage clones containing these clusters of methylation-sensitive restriction sites, which lie within short CpG-rich stretches. Some of these sites showed tissue-specific methylation. 3' of the unmethylated CpG-rich sequences, clones derived from the 5' (telomeric) copy of the duplicated region, contained, in order, endogenous retroviral sequences, a processed ELK1 pseudogene, and the pseudogene IGHGP. Comparison with the presumed 3' (centromeric) copy of the duplicated region showed that similarity was lost exactly at the end of the retroviral long terminal repeat sequences. These results imply that an endogenous retroviral integration was present immediately 3' of IGH in the common hominoid ancestor and suggest models for the duplication of the region.

Base Sequence↗
PubMed2003

Neural activity in prefrontal cortex during copying geometrical shapes. I. Single cells encode shape, sequence, and metric parameters.

In drawing a copy of a geometrical shape, a sequence of movements must be produced to represent the sides of the object in the proper spatial relationship. We investigated neural mechanisms of this process by training monkeys to draw (using a joystick) copies of geometrical shapes (triangles, squares, trapezoids and inverted triangles) presented on a video monitor while recording single cell activity in prefrontal cortex. The drawing trajectories monkeys produced were divided into a series of discrete segments, varying in direction and length. We performed a stepwise multiple linear regression analysis to identify those copy parameters significantly influencing cell activity. The copied shape (e.g., triangle, square) and the serial position of the segment within each trajectory were the most prevalent effects (in 46% and 43% of cells, respectively), followed by segment direction (32%) and length (16%). Effects of temporal factors (maximum segment speed and time to maximum segment speed) were less frequent. These results demonstrate that prefrontal neurons encode several spatial and sequence variables that define copy trajectories. We also found that specific groupings of significant effects tended to occur together in single neurons. Specifically, single neurons simultaneously processed the serial position of a segment within each trajectory along with the corresponding spatial (but not temporal) attributes of that segment (i.e., direction and length), as well as with the overall shape to which the segments belong. Finally, we discovered that relationships between neural activity and segment serial position were systematic in many instances, described by monotonically increasing and decreasing functions, as well as parabolic functions. These findings indicate that, within the copying task, the serial segment position is a key factor for neural activity in the periprincipalis area of the prefrontal cortex.

Action Potentials↗
PubMed2004

The dissemination of the British Guideline on the Management of Asthma 2003.

The BTS/SIGN British Guideline on the Management of Asthma was published in February 2003 (4). If health outcomes are to be influenced successfully, dissemination of the guideline and implementation of recommendations is essential. We report the dissemination activities undertaken during the 18 weeks following the guideline launch. To facilitate implementation a range of educational materials were produced reflecting the key messages from the guideline. In addition to postal mailing of the guideline to appropriate healthcare professionals, both educational materials and the guidelines were made freely available from the BTS and SIGN websites. In total, 135,710 copies of the guideline and 90,198 copies of the Quick Reference Guide were downloaded in the first 18 weeks, representing a considerable increase over the number of copies of the 1997 guidelines disseminated by mailing alone. Large quantities of educational materials were downloaded with many used for teaching purposes. An on-line survey suggested that most respondents rated the materials as useful or very useful. Using websites to disseminate guidelines is a cost-effective method of informing health professionals of their content and is a more active process than the passive receipt of mailed copies. The availability of interactive educational materials for use in teaching appears to have been popular.

Asthma↗
PubMed1997

Does Saccharomyces need an organized nucleolus?

The ribosomal RNA (rRNA) genes of most eukaryotic organisms are arranged in one or more tandem arrays, often termed nucleolar organizer regions. The biological implications of this tandem organization are not known. We have tested the requirement for such a chromosomal organization by directly comparing the transcription and processing of rRNA in isogenic strains of Saccharomyces cerevisiae that differ only in the organization of their rRNA genes. Strain L-1489 carries the RDN locus, consisting of 100-150 copies of the rRNA genes in a tandem array on chromosome XII. Strain L-1521 has a complete deletion of the RDN array, but carries many copies of a plasmid that includes a single rRNA gene. While this strain grows reasonably well, the average transcriptional activity of the plasmid genes is substantially less than that of the chromosomal copies. However, there is little difference in the processing of the 35S pre-rRNA to the mature 25S:5.8S and 18S products. Thus, neither a chromosomal location nor a tandem repeat of the rRNA genes is important for the assembly and function of the many protein and RNA molecules necessary for the processing of the rRNA transcripts. We investigated the consequence of a dispersed gene arrangement on nucleolar structure. Immunofluorescence microscopy revealed that in strain L-1521 the yeast fibrillarin, Nop1p, rather than being confined to a defined nucleolus at the edge of the nucleus as it is in cells with the normal arrangement of rRNA genes, is spread throughout the nucleus. This observation implies that each plasmid rRNA gene can serve as a nucleolar organizer. Finally, data from pulse-labeling experiments show that the repression of rRNA transcription due to failure of the secretory pathway is independent of whether the rRNA genes are at the RDN locus on chromosome XII or on plasmids. This result suggests that the regulation of rRNA transcription occurs at the level of soluble factors rather than chromatin structure.

Cell Nucleolus↗