Visual Screening Procedure Research Articles

Synergistic and Additive Effects of Epigallocatechin Gallate and Digitonin on Plasmodium Sporozoite Survival and Motility

BackgroundMost medicinal plants contain a mixture of bioactive compounds, including chemicals that interact with intracellular targets and others that can act as adjuvants to facilitate absorption of polar agents across cellular membranes. However, little is known about synergistic effects between such potential drug candidates and adjuvants. To probe for such effects, we tested the green tea compound epigallocatechin gallate (EGCG) and the membrane permeabilising digitonin on Plasmodium sporozoite motility and viability.Methodology/Principal FindingsGreen fluorescent P. berghei sporozoites were imaged using a recently developed visual screening methodology. Motility and viability parameters were automatically analyzed and IC50 values were calculated, and the synergism of drug and adjuvant was assessed by the fractional inhibitory concentration index. Validating our visual screening procedure, we showed that sporozoite motility and liver cell infection is inhibited by EGCG at nontoxic concentrations. Digitonin synergistically increases the cytotoxicity of EGCG on sporozoite survival, but shows an additive effect on sporozoite motility.Conclusions/SignificanceWe proved the feasibility of performing highly reliable visual screens for compounds against Plasmodium sporozoites. We thereby could show an advantage of administering mixtures of plant metabolites on inhibition of cell motility and survival. Although the effective concentration of both drugs is too high for use in malaria prophylaxis, the demonstration of a synergistic effect between two plant compounds could lead to new avenues in drug discovery.

Development of an index assignment procedure compatible with the regional seismicity in the province of Quebec for the rapid visual screening of existing buildings

In the context of the seismic vulnerability evaluation of buildings, the score assignment method can be used as the first step of a multiphase procedure aimed at identifying hazardous buildings that must then be analysed in greater detail. Because the existing Canadian rapid visual screening procedure has not been updated since 1992, a new procedure is proposed based on a set of vulnerability indices for different cities in the province of Quebec. A seismicity level (low, moderate, or high) is attributed to each city using the spectral acceleration response values included in the 2005 edition of National building code of Canada (NBCC) and the criteria proposed in FEMA 310 Handbook for the seismic evaluation of buildings - a prestandard. The structural vulnerability indices (SVIs) are calculated using the recently improved nonlinear static analysis procedure in FEMA 440, Improvement of nonlinear static seismic analysis procedures for each seismicity level. The NBCC 2005 reference soil class C is considered in the calculation of the SVIs, and index modifiers for the building height, irregularities, and design and construction year. The application of these indices to the estimation of the probable damage distribution in building inventories is discussed at the end.

Comparative effects of gentle teaching and visual screening on self-injurious behaviour

Gentle teaching and visual screening procedures have been used to control severe behaviour problems in persons with mental retardation. An alternating treatments design was used to compare gentle teaching, visual screening and a task-training condition in the reduction of high levels of self-injury of an adult with profound mental retardation. Following baseline, a task-training condition using standard behavioural techniques was implemented to establish the effects of training the subject on age-appropriate tasks. Results showed a modest reduction in self-injury. This was followed by an alternating treatments phase in which visual screening, gentle teaching and no-treatment control conditions were compared. Both procedures were superior to the control condition in reducing self-injury, with visual screening being more effective than gentle teaching. When visual screening was implemented across two and then all three daily conditions, self-injury was further reduced to near-zero levels. Bonding occurred at the same low levels under both treatments, contrary to the predictions of gentle teaching's proponents.

Computer‐Aided Pre‐ and Post‐Earthquake Assessment of Buildings Involving Database Compilation, GIS Visualization, and Mobile Data Transmission

Abstract: The aim of this article is to present a computer‐aided comprehensive strategy for the rapid visual inspection of buildings and the optimal prioritization of strengthening and remedial actions that are necessary prior to, and after, a major earthquake event, respectively. Based on the visual screening procedures used in the United States and past experience in seismic assessment of buildings in Greece and Turkey (the two countries with the highest seismic risk in Europe), a building inventory is first compiled; then a vulnerability ranking procedure that is specifically tailored to the prevailing construction practice in Southeast Europe is implemented into a multi‐functional, georeferenced computer tool, that accommodates the management, evaluation, processing and archiving of the data stock gathered during the pre‐ and post‐earthquake assessment process, and the visualization of its spatial distribution. The methodology proposed and the computer system developed is then applied to the city of Düzce, Turkey, a city strongly damaged during the devastating 1999 earthquake.

Pre-earthquake fuzzy logic and neural network based rapid visual screening of buildings

When assessing buildings that may collapse during a large earthquake, conventional rapid visual screening procedures generally provide good results when identifying buildings for further investigation. Unfortunately, their accuracy at identify buildings at risk is not so good. In addition, there appears to be little room for improvement. This paper investigates an alternative screening procedure based on fuzzy logic and artificial neural networks. Two databases of buildings damaged during the Athens earthquake of 1999 are used for training purposes. Extremely good results are obtained from one database and not so good results are obtained from the second database. This finding illustrates the importance of specifically collecting data tailored to the requirements of the fuzzy logic based rapid visual screening procedure. In general, results demonstrate that the trained fuzzy logic based rapid visual screening procedure represents a marked improvement when identifying buildings at risk. In particular, when smaller percentages of the buildings with high damage scores are extracted for further investigation, the proposed fuzzy screening procedure becomes more efficient. This paper shows that the proposed procedure has a significant optimisation potential, is worth pursuing and, to this end, a strategy that outlines the future development of the fuzzy logic based rapid visual screening procedure is proposed.

First-Level Pre-earthquake Assessment of Buildings Using Fuzzy Logic

This paper discusses the performance of a fuzzy logic–based rapid visual screening procedure that results in the categorization of buildings into five different types of possible damage with respect to the potential occurrence of a major seismic event. In order to provide results representing expected damage, adaptive neural networks were used to train the method according to information obtained from the vulnerability of 102 buildings stricken by the Athens earthquake of 1999. The precision of the method was thereby enhanced, implying an improvement in efficiency and presenting remarkable advantages when compared to probabilistic approaches to rapid visual screening. Due to the small size of the database used for the training procedure, however, the prospects of the method remain to be discussed. Nonetheless, by using information from larger databases, the method has the potential for self-improvement, a fact that underlines a good prospect for the formation of reliable and robust pre-earthquake assessment methods.

Isolation of peroxisome-defective CHO mutant cells using green fluorescent protein.

The authors constructed a recombinant green fluorescent protein (GFP) (PTS-GFP), which carries peroxisome targeting signal (PTS1 or PTS2) as an additional sequence, by polymerase chain reaction. The gene encoding for the recombinant GFP was constructed into an eukaryotic expression vector, and stable transformant of CHO cell expressing PTS-GFP was isolated, following the transfection of the plasmid encoding for the GFP. Each expressed PTS-GFP appeared to be localized in peroxisomes, because the GFP was observed in cellular structures, as was catalase. The observation proposed a visual screening procedure for isolating peroxisome-defective mutant. Following an enrichment of mutant cells by use of 9-(1'-pyrene)nonanol/ultraviolet irradiation (P9OH/UV) method, five peroxisome-defective mutants were isolated by pursuing the fluorescent signals from GFP. Two mutants (SK24 and SK32) were isolated from CHO cells expressing PTS1-GFP, and three mutants (PT13, PT32, and PT54) were isolated from cells expressing PTS2-GFP. Four mutants, except for PT13, showed cytosolic distributions of both PTS-GFP and catalase. On the other hand, mutant PT13 showed a cytosolic distribution on PTS2-GFP, but a peroxisomal distribution on catalase. Cell fusion analysis between SK24 mutant and other mutants indicated that PT54 mutant is in the same complementation group (CG) as SK24, but that SK32, PT13, and PT32 mutants are in different complementation group(s) from SK24.

The Rosat All-Sky Survey Bright Source Catalog

In order to ensure the quality of the source catalogue derived from the SASS processing an automatic as well as a visual screening procedure was applied to 1378 survey fields. Most (94%) of the 18,811 sources were confirmed by this screening process. The rest is flagged for various reasons. Broad band images are available for a subset of the flagged sources. Details of the screening process can be found at www.rosat.mpe-garching.mpg.de/survey/rass-bsc/doc.html.

Comparison of Commercial Screening Tests for Glucose-6-Phosphate Dehydrogenase Deficiency in the Neonatal Period

Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is a commonly occurring erythrocyte enzyme abnormality, estimated to affect hundreds of millions of people worldwide. The condition is frequently associated with neonatal hyperbilirubinemia (1)(2) that may be severe enough to cause kernicterus and death (3). It is therefore imperative, in high-risk populations, to accurately and rapidly diagnose the condition early in the neonatal period, before the onset of jaundice, and before discharging the infant from the hospital. Many screening tests are available for this purpose; however, the efficacy of two readily available commercially produced kits [qualitative, visual fluorescence screening procedure in blood, procedure no. 202; and visual qualitative determination for G-6-PD deficiency in red blood cells (RBCs), procedure no. 400, both produced by Sigma Diagnostics, St. Louis, MO] has not been evaluated in the neonatal period. As levels of G-6-PD activity may frequently be higher in neonates than in adults (4), and as the screening tests are manufactured primarily according to adult standards, we felt it necessary to test their reliability against newborn standards. The aim of this study was to compare the accuracy of these two tests in screening for G-6-PD deficiency in the first 48 h of life, to determine if any one was superior to the other. The principle of all the tests involves the oxidation of glucose-6 phosphate to 6-phosphogluconate, and the concomitant reduction of NADP+ to NADPH. These reactions occur in the presence of G-6-PD, and the rate of NADPH formation is proportional to G-6-PD activity. For the quantitative testing, NADPH activity was determined in a narrow-width spectrophotometer (Ocean Scientific Co., Garden Grove, CA) and the G-6-PD activity calculated in relation to RBC count. Fluorescence of NADPH is the basis of the fluorescent screening test, for the detection of which a long-wave ultraviolet …

Effects of thioridazine and visual screening on stereotypy and social behavior in individuals with mental retardation

Thioridazine and visual screening procedures are effective in reducing the stereotypic behaviors of individuals with mental retardation. A double-blind, placebo-controlled study, using alternating treatments within a multiple-base-line across subjects design, was conducted to assess the effects of two doses of thioridazine (1.25 and 2.5 mg/kg/day) and visual screening, alone and combined, on stereotypy and social behavior of three individuals with profound mental retardation. Functional analyses did not show demand, alone, social attention, or differential reinforcement conditions to maintain the subjects' stereotypy. Thioridazine was effective in producing modest reductions in stereotypy and minor increases in social behavior across subjects. The higher dose of thioridazine (2.5 mg/kg/day) was slightly more effective than the lower dose (1.25 mg/kg/day), and thioridazine plus visual screening was more effective than thioridazine alone. The most effective treatment was visual screening when used in the absence of thioridazine. This study demonstrates a method for assessing the impact of psychopharmacological and behavioral interventions in individuals for whom a behavioral treatment cannot be easily derived from a functional analysis of the maintaining conditions of the target behavior.

Reducing Self-Injury in a Boy with Intellectual Disability Using Visual Screening, Toy Play Training and Contingent Social Interaction

In this study a visual screening procedure and a forced arm training procedure were compared within an alternating treatments design in terms of their effects in reducing self-injury in an intellectually disabled boy. Visual screening was found to be clearly the superior procedure, producing a marked decrease in the rate of self-injury. Subsequent experimental phases combined visual screening first with toy play training and then with contingent social interaction. Further marked decreases in self-injury occurred, which remained in evidence at a four month follow-up. Generalisation data were obtained from both morning and afternoon sessions. Collateral behaviour change was monitored in both treatment and generalisation sessions, generally indicating increases in neutral behaviours and reductions in self-stimulatory behaviours accompanying reductions in self-injury. Implications of these results for examining the wider physical and social contexts in which self-injury occurs were noted.

Visual Screening versus Auditory Screening: An Alternating Treatments Design

An alternating treatment design was used to measure the differing impact of visual screening and an auditory blocking procedure in the suppression of the screaming behaviour of a profoundly retarded girl. The auditory blocking procedure made use of white noise to mask any background or personal sounds. During separate sessions both screening procedures were applied for a duration of 1 minute following an occurrence of the screaming behaviour. Results showed that both techniques were successful in reducing the frequency of the behaviour. The visual screening procedure was the preferred treatment for maintaining and generalizing the suppression, because of ease of use and mobility.

Acceptability of a Visual Screening Procedure for Reducing Stereotypy in Mentally Retarded Children: Evaluation by New Zealand Institutional Staff

The acceptability of three treatments for the maladaptive, but not injurious, repetitive stereotyped behaviour of a mentally retarded child was evaluated. Evaluation was conducted by questionnaires to two groups of staff (nurses and teachers) at two New Zealand institutions for mentally retarded people. A differential reinforcement procedure was found to be most acceptable. A visual screening procedure was judged as being more than moderately acceptable by nurses but less than moderately acceptable by teachers. When visual screening and reinforcement were combined in a treatment package and a rationale for so doing was provided, acceptability was increased significantly for both groups of staff. Teachers rated visual screening, when explicitly prescribed with differential reinforcement, as more than moderately acceptable. The implications of the finding of differential rating of acceptability across and within occupational groups was discussed.

Cloning the cyd gene locus coding for the cytochrome d complex of Escherichia coli

Two plasmids containing the two structural genes for the inner-membrane-bound cytochrome d complex (Cyd) have been isolated from the Clarke and Carbon Escherichia coli DNA bank. A 5.4-kb DNA fragment from one plasmid was subcloned in both orientations into pBR322. The promoter(s) and both genes must have been present within this fragment since the two orientations yielded similar levels of Cyd. Recombination and transduction studies indicated that the cyd gene locus had been isolated. These results demonstrate that cyd contains all the structural information for the complex. Overproduction of Cyd has yielded a visual screening procedure for plasmids bearing cyd that is unique to colored proteins like cytochromes. Colonies of E. coli bearing the cloned cyd gene are yellow-green. The cyd gene can, therefore, be used as a vehicle for detection of inserted DNA fragments.

The reduction of stereotypic screaming in a severely retarded boy through a visual screening procedure

The stereotypic screaming of a 4.2 yr old severely retarded boy was successfully reduced with a visual screening procedure in both school and home settings. Treatment gains were maintained over time and there was some evidence of treatment generalizing across time and persons. Social validation ratings confirmed the effectiveness of the program.