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[Human brain activity in response to emotional visual stimuli: open issues and recent data].

INTRODUCTION: The traditional circumplex model on the structure of emotion postulates that this process is organized in two basic dimensions: valence (positive negative) and activation (relaxing activating). This model assumes that the valence activates a single evaluative system. With regard to cerebral activity, two ideas are derived from this assumption: 1) a single set of mechanisms and neural circuits becomes activated in response to both positive and negative events, 2) the faculty of response to adverse and pleasant responses (i.e., latency and intensity with which the neural structures involved can respond) is potentially balanced. DEVELOPMENT: We describe the debates on these two issues and, subsequently, the current data regarding them are also described. These data indicate that, in response to aversive stimuli (often noxious), neural systems characterized by their ability to produce an immediate response are preferentially activated. On the other hand, pleasant stimuli (which lead to an approaching behavior towards the stimulus) preferentially activate systems associated with more intense and precise information processing. This is a slower but longer lasting type of activity. CONCLUSION: The data suggest that there are separate mechanisms for the evaluation and preparation of a response according to whether the stimulus is negative or positive.

Affect↗
PubMed1988

Surface modeling of craniofacial form in human embryos with a limited graphics terminal.

Three-dimensional morphology of the human embryo typically is visualized through computerized modeling techniques utilizing planar contours as the data base. Through this approach, tissue outlines are digitized, and contour lines are superimposed, providing a depth perspective. However, these techniques represent embryonic tissues as discontinuous surfaces and therefore ignore morphological information between sections. The purpose of this study was to develop a computerized routine for the three-dimensional surface modeling of craniofacial morphology in human embryos. Tissue outlines are digitized, thus converting contour information into x,y,z coordinate data. The three-dimensional reconstruction program BCSURF opens the data file and plots each tissue polygon. A center is determined for each contour, and this value is used to divide each polygon into four segments. Surface patches are generated by mapping each segment onto the corresponding segment of subsequent sections. A face table is constructed representing the surface patches and plane normals are generated for each patch. The normal and depth values are appended to the face table, and these measures determine the color intensity for each patch. Finally, patches are plotted providing a polygon mesh model, and each patch is filled with a dither pattern according to shading values. Three-dimensional reconstructions of the craniofacial region in Carnegie embryos (stages 15-17) are generated, and major morphological features are observed. Although bilevel shading capabilities cause discontinuous shading textures, this simple and inexpensive system can be easily upgraded for high-resolution graphics.

Computer Simulation↗
PubMed1997

Progress with cholecystectomy: improving results in England and Wales.

BACKGROUND: The Comparative Audit Service of the Royal College of Surgeons of England studied laparoscopic cholecystectomy in England and Wales during 1990-1991. The follow-on study undertaken during 1994 provides data to assess progress. METHODS: Pro formas were sent to consultant surgeons, requesting data on open and laparoscopic cholecystectomies performed in their units during 1994 with data on mean stay, mortality, complications, and the use of peroperative cholangiography and bile duct exploration. The identity of the consultants was treated confidentially. RESULTS: Data were provided by 110 surgeons on 4823 cholecystectomies (1019 open and 3804 laparoscopic) and outcome was compared with that of 3319 attempted laparoscopic and 8035 open cholecystectomies carried out during 1990-1991. The proportion of cases attempted laparoscopically rose from 27.2 per cent in 1990-1991 to 78.9 per cent in 1994, and conversion to open cholecystectomy rose from 5.3 to 6.7 per cent respectively. During 1994 peroperative cholangiography was undertaken in 22.9 per cent of laparoscopic and 44.6 per cent of open cases. Complication rates were similar in the two study periods, except the number of reported haemorrhagic complications was reduced by 40 per cent and bile duct injuries by fivefold (from 0.33 to 0.07 per cent). CONCLUSION: During 1994 the audit sampled approximately 10 per cent of all cholecystectomies performed in England and Wales. The results suggest progress in surgical techniques compared with findings in 1990-1991.

Cholangiography↗
PubMed1997

Commercial wrist extensor orthoses: a descriptive study of use and preference in patients with rheumatoid arthritis.

OBJECTIVE: To describe patients' functional uses of 3 commercial wrist orthoses, to describe patients' preference patterns for the orthoses, and to clarify orthotic attributes that are viewed positively and negatively. METHODS: Using a cross-over design, 42 patients with definite rheumatoid arthritis used each of 3 commercial orthoses for one week. There was a one-week wash-out between each week of use. At the end of the study, private semi-structured interviews were conducted with each participant. Data from close-ended questions were tabulated. Open-ended data were analyzed using qualitative methods. RESULTS: Patients reported that the 3 commercial wrist orthoses reduced wrist pain similarly, but that comfort and a sense of security during functional tasks were only found if the orthoses were comfortable and well-fitting. Most subjects preferred the padded, short forearm orthosis, though a small number found it uncomfortably warm, and many complained that it was difficult to use when wearing long-sleeved garments. Common complaints about the two elastic orthoses included chafing at the thumb webspace and chafing at the proximal closures. Longer forearm length was often perceived as providing unnecessarily high levels of wrist support. CONCLUSIONS: No single orthosis suited all subjects. Satisfaction with an orthosis appears to be based not only on its therapeutic effect, but also the comfort and ease of its use. To maximize patient satisfaction and improve the likelihood of appropriate fit and comfort, several styles of commercial orthoses should be available. The current trend toward restricted clinic stocks appears contrary to both therapeutic goals and patient satisfaction.

Activities of Daily Living↗
PubMed2001

Increased throughput in quantitative bioanalysis using parallel-column liquid chromatography with mass spectrometric detection.

The feasibility of quantitative bioanalysis by parallel-column liquid chromatography in conjunction with a conventional single-source electrospray mass spectrometer has been investigated using plasma samples containing a drug and its three metabolites. Within a single chromatographic run time, sample injections were made alternately onto each of two analytical columns in parallel at specified intervals, with a mass spectrometer data file opened at every injection. Thus, the mass spectrometer collected data from two sample injections into separate data files within a single chromatographic run time. Therefore, without sacrificing the chromatographic separation or the selected reaction monitoring (SRM) dwell time, the sample throughput was increased by a factor of two. Comparing the method validation results obtained using the two-column system with those obtained using the corresponding conventional single-column approach, the methods on the two systems were found to be equivalent in terms of accuracy and precision. The parallel-column system is simple and can be implemented using existing laboratory equipment with no additional capital outlays. A parallel-column system configured in this manner can be used not only for the within-a-run analysis of two samples containing two different sets of chemical entities, but also for the within-a-run analysis of two samples containing the same set of chemical entities.

Chromatography, Liquid↗
PubMed2005

Stakeholder position paper: epidemiological perspectives on antibiotic use in animals.

Epidemiologists studying antimicrobial resistance are often interested in analyzing the association between antimicrobial resistance and antimicrobial use in animals, and on the impact of antimicrobial use in animals on the occurrence of resistance in bacteria affecting human populations. Given the various potential antimicrobial use data sources, it seems likely there will be some variability in the utility of the data for interpreting trends in antimicrobial resistance and investigating the relationship between antimicrobial use in animals and antimicrobial resistance in bacteria affecting human health. From an epidemiologic perspective, the major issues related to incorporation of antimicrobial use data into antimicrobial resistance monitoring programs are the further development of epidemiologic methods for collecting, quantifying, analyzing and interpreting use data; an open and realistic consideration of the limitations of the data; developing an understanding of scaling, temporal and spatial heterogeneity issues; and the interpretative problems of ecologic and atomistic fallacy. Given the many potential biases in antimicrobial use data, attempts to relate levels of antimicrobial use to levels of antimicrobial resistance should be done with caution until the data are better understood and the aforementioned issues have been addressed.

Animal Diseases↗
PubMed2002

Cloning and characterization of the canine photoreceptor specific cone-rod homeobox (CRX) gene and evaluation as a candidate for early onset photoreceptor diseases in the dog.

PURPOSE: The cone-rod homeobox protein (CRX) is a member of the homeodomain-containing protein family expressed in the retinal photoreceptors and pinealocytes; it is involved in the regulation of the coordinate expression of multiple photoreceptor specific genes during retinal development. Mutations in the CRX gene are causally associated with retinal degeneration phenotypes in man. To clone the full length cDNA, characterize the genomic organization of canine CRX, map the gene in a radiation hybrid (RH) panel, and evaluate it as a candidate for canine inherited retinal degenerations. METHODS: cDNA representational difference analysis (RDA) was done using normal and cone degeneration (cd) affected retinas. Exonic primers designed from consensus sequences of mammalian CRX cDNA were used to amplify and sequence dog genomic DNA. Canine specific primers were used for RH mapping of CRX on the RH3000 cell line. Linkage, sequencing and/or mapping the disease locus was used to evaluate CRX as a disease associated candidate gene. RESULTS: The gene comprises three exons and two introns and codes for a transcript with a 900 bp open reading frame (ORF). In agreement with human map data, RH mapping placed canine CRX on the proximal end of CFA1, in a region of synteny with HSA19q13-q13.3. Based on RH mapping, meiotic linkage or sequencing data, we excluded CRX as the cause of canine early onset photoreceptor degenerations affecting Alaskan malamutes (cd), collies (rod-cone dysplasia 2, rcd2), American Staffordshire terriers, and Tibetan terriers. CONCLUSIONS: Canine CRX has a high level of nucleotide and amino acid sequence identity with orthologous sequences reported for other species. The gene is excluded from causal association with 4 early onset photoreceptor diseases affecting cones (cd) or rods and cones (rcd2, PRA in American Staffordshire terriers, and Tibetan terriers).

Amino Acid Sequence↗
PubMed2006

Interphotoreceptor retinoid-binding protein gene structure in tetrapods and teleost fish.

PURPOSE: The interphotoreceptor retinoid-binding protein (IRBP) gene possesses an unusual structure, encoding multiple Repeats, each consisting of about 300 amino acids. Our goals were to gain insight into the function of IRBP, and to test the current model for the evolution of IRBP, in which Repeats were replicated from a simpler ancestral gene. METHODS: We employed a bioinformatics approach to analyze IRBP loci in recently completed or near-complete genome sequences of several vertebrates and nonvertebrate chordates. IRBP gene expression in zebrafish was evaluated by reverse transcriptase PCR (RT-PCR) and in situ mRNA hybridizations with gene-specific probes. RESULTS: Patterns of exons and introns in the IRBP genes of tetrapods were highly similar, as were predicted amino acid sequences and Repeat structures. IRBP gene structure in teleost fish was more variable, and we report a new gene structure for two species, the Japanese puffer fish (Takifugu rubripes) and the zebrafish (Danio rerio). These teleost genomes contain a two-gene IRBP locus arranged head-to-tail in which the first gene, Gene 1, is intronless and contains a single large exon encoding three complete Repeats. It is followed by a second gene, Gene 2, which corresponds to the previously reported gene consisting of two Repeats spread across four exons and three introns. Each of the two zebrafish genes is transcribed. Gene 2 is expressed in the photoreceptors and RPE, and Gene 1 is expressed in the inner nuclear layer and weakly in the ganglion cell layer. CONCLUSIONS: The tetrapod IRBP gene structure is highly conserved while the teleost fish gene structure was a surprise: It appears to be a two-gene locus with distinct Repeat organization in each open reading frame. This gene structure and gene expression data are consistent with possible neofunctionalization or sub-function partitioning of Gene 1 and Gene 2 in the zebrafish. We suggest that the two-gene locus in teleost fish arose as a consequence of either the known whole genome duplication or single gene tandem duplication.

Animals↗
PubMed1997

Open versus closed establishment of pneumoperitoneum in laparoscopic surgery.

BACKGROUND: Closed laparoscopy, employing a Veress needle and blind insertion of the first trocar, is favoured by most laparoscopic surgeons. The potential danger of this technique is the occurrence of visceral or vascular injury. Establishment of pneumoperitoneum by an open technique using a blunt-tipped trocar may be a safer alternative. METHODS AND RESULTS: Retrospective review of the literature and the authors' experience was used to compare closed and open laparoscopy. Data on closed laparoscopy in 489335 patients and on open laparoscopy in 12444 patients were culled. Rates of visceral and vascular injury were respectively 0.083 and 0.075 per cent after closed laparoscopy, and 0.048 per cent and zero after open laparoscopy. Mortality rates after closed and open laparoscopy were respectively 0.003 per cent and zero. Pearson chi 2 analysis demonstrated a statistically significant difference in terms of visceral and vascular injury between closed and open laparoscopy (P = 0.002); there was no such difference for mortality rates. CONCLUSION: Open establishment of pneumoperitoneum is advocated in laparoscopic surgery because it is safer than the closed method.

Humans↗
PubMed1995

Evaluation of dose delivery based on a comparison of dosimetry calculations using open beam and wedged beam depth dose data.

The purpose of this study is to evaluate the magnitude of the error in dose delivery caused by the use of open beam depth dose data in dosimetry calculations for wedged photon beams. Isodose plans were calculated for treatments given in a 3-field isocentric prostate or rectal setup using an open AP beam with two lateral wedged beams. The dose distributions were first calculated using open beam depth dose data for all three fields. Next, the open beam data was used only for the AP field and true wedged beam depth dose data was substituted for the two lateral wedged fields. The magnitude of the depth dose variations for wedged vs open beams depends on the nominal beam energy, the wedge angle, and the depth of measurement. Consequently, isodose distributions calculated for wedged fields were found to be different when true wedged beam depth dose data was used instead of open beam data as is commonly done. Monitor unit calculations using a field size specific wedge factor show that dose delivery errors up to 4% can result from the use of open beam depth dose data in wedged beam dose distribution calculations for a 6-MV photon beam. Accurate treatment planning for wedged fields requires the use of wedged beam depth dose data specific to each wedge. Simply using open beam depth dose data in dose calculations for wedged beams will result in dose delivery errors, the magnitude of which depends on the combination of wedge angle, field size, and nominal beam energy.

Evaluation Studies as Topic↗