Preliminary Screening Procedure Research Articles

Dynamic metabolic modelling predicts efficient acetogen-gut bacterium cocultures for CO-to-butyrate conversion.

While gas-fermenting acetogens have been engineered to secrete non-native metabolites such as butyrate, acetate remains the most thermodynamically favourable product. An alternative to metabolic engineering is to exploit native capabilities for CO-to-acetate conversion by coculturing an acetogen with a second bacterium that provides efficient acetate-butyrate conversion. We used dynamic metabolic modelling to computationally evaluate the CO-to-butyrate conversion capabilities of candidate coculture systems by exploiting the diversity of human gut bacteria for anaerobic synthesis of butyrate from acetate and ethanol. A preliminary screening procedure based on flux balance analysis was developed to identify 48 gut bacteria which satisfied minimal growth rate and acetate-to-butyrate conversion requirements when cultured on minimal medium containing acetate and a simple sugar not consumed by the paired acetogen. A total of 170 acetogen/gut bacterium/sugar combinations were dynamically simulated for continuous growth using a 70/30 CO/CO2 feed gas mixture and minimal medium computationally determined for each combination. While coculture systems involving the acetogens Eubacterium limosum or Blautia producta yielded low butyrate productivities and CO-to-ethanol conversion had minimal impact on system performance, dynamic simulations predicted a large number of promising coculture designs with Clostridium ljungdahlii or C. autoethanogenum as the CO-to-acetate converter. Pairings with the gut bacterium Clostridium hylemonae or Roseburia hominis were particularly promising due to their ability to generate high butyrate productivities over a range of dilution rates with a variety of sugars. The higher specific acetate secretion rate of C. ljungdahlii proved more beneficial than the elevated growth rate of C. autoethanogenum for coculture butyrate productivity. Our study demonstrated that metabolic modelling could provide useful insights into coculture design that can guide future experimental studies. More specifically, our predictions generated several favourable designs, which could serve as the first coculture systems realized experimentally.

The tongue features associated with type 2 diabetes mellitus.

Diabetes mellitus (DM) is a public problem closely associated with numerous oral complications, such as coated tongue, xerostomia, salivary dysfunction, etc. Tongue diagnosis plays an important role in clinical prognosis and treatment of diabetes in the traditional Chinese medicine (TCM). This study investigated discriminating tongue features to distinguish between type 2 DM and non-DM individuals through non-invasive TCM tongue diagnosis.The tongue features for 199 patients with type 2 DM, and 372 non-DM individuals, serving as control, are extracted by the automatic tongue diagnosis system (ATDS). A total of 9 tongue features, namely, tongue shape, tongue color, fur thickness, fur color, saliva, tongue fissure, ecchymosis, teeth mark, and red dot. The demography, laboratory, physical examination, and tongue manifestation data between 2 groups were compared.Patients with type 2 DM possessed significantly larger covering area of yellow fur (58.5% vs 22.5%, P < .001), thick fur (50.8% vs 29.2%, P < .001), and bluish tongue (P < .001) than those of the control group. Also, a significantly higher portion (72.7% vs 55.2%, P < .05) of patients with long-term diabetics having yellow fur color than the short-term counterparts was observed.The high prevalence of thick fur, yellow fur color, and bluish tongue in patient with type 2 DM revealed that TCM tongue diagnosis can serve as a preliminary screening procedure in the early detection of type 2 DM in light of its simple and non-invasive nature, followed by other more accurate testing process. To the best of our knowledge, this is the first attempt in applying non-invasive TCM tongue diagnosis to the discrimination of type 2 DM patients and non-DM individuals.

Concordance between ophtalmologists and paramedical professionals in screening for retinal abnormalities with ultrawide field imaging

PurposeThe decreasing number of ophthalmologists leads to evaluate preliminary screening procedures performed by paramedical professionnals. The ultrawide field retinography is a recent technique allowing to obtain, simply and reproducibly, central and peripheral retinal images with or without mydriasis.The main objective of this study was to evaluate the diagnostic agreement between the reading of the ultra wide field images by a paramedical professional compared to a doctor.MethodsA prospective diagnostic two‐center study was performed in the ophthalmological departments of two University Hospitals (Reims and Nancy) including all patients eligible in an outpatient clinic. For each patient, an ultra wide field retinography was taken with an Optomap (Optos) and an image analysis was performed by both a paramedical professional and an ophthalmologist. The agreement (kappa coefficient) between both image readings was evaluated.Results901 patients were included from July 2011 to November 2014. A good agreement was found between paramedical professionals and ophthalmologists for the global analysis (normal or abnormal image) (k = 0.62 [0.59 to 0.66]).This good concordance was also found for retinal lesions, including the macula (k = 0.70 [0.66 to 0.73]) and particularly for the analysis of red lesions such as hemorrhages, dilated veins and retinal detachment. However, the agreement was poor for optic disc analysis (k = 0.38 [0.32 to 0.44]).ConclusionsIn screening procedures, paramedical professionals were able to identify retinal abnormalities on ultra wide field image in a significant number of cases. However, the correct identification of optic disc abnormalities was poor.

TCM tongue diagnosis index of early-stage breast cancer

ObjectivesThis paper investigates discriminating tongue features to distinguish between early stage breast cancer (BC) patients and non-breast cancer individuals through non-invasive traditional Chinese medicine (TCM) tongue diagnosis. DesignThe tongue features for 67 patients with 0 and 1 stages of BC, and 70 non-breast cancer individuals are extracted by the automatic tongue diagnosis system (ATDS). A total of nine tongue features, namely, tongue color, tongue quality, tongue fissure, tongue fur, red dot, ecchymosis, tooth mark, saliva, and tongue shape are identified for each tongue. Features extracted are further sub-divided according to the areas located, i.e., spleen–stomach, liver–gall-left, liver–gall-right, kidney, and heart–lung areas. This study focuses on deriving significant tongue features (p<0.05) to discriminate early-stage BC patients from non-breast cancer individuals. ResultsThe Mann–Whitney test shows that the amount of tongue fur (p=0.024), maximum covering area of tongue fur (p=0.009), thin tongue fur (p=0.009), the average area of red dot (p=0.049), the maximum area of red dot (p=0.009), red dot in the spleen–stomach area (p=0.000), and red dot in the heart–lung area (p=0.000) demonstrate significant differences. The data collected are further classified into two groups. The training group consists of 57 early-stage BC patients and 60 non-breast cancer individuals, while the testing group is composed of 10 early-stage BC patients and 10 non-breast cancer individuals. The logistic regression by utilizing these 7 tongue features with significant differences in Mann–Whitney test as factors is performed. In order to reduce the number of tongue features employed in prediction, tongue features with the least amount of significant difference, namely, maximum area of red dot and average area of red dot, are removed progressively. The tongue features of the testing group are employed in the aforementioned three models to test the power of significant tongue features identified in predicting early-stage BC. An accuracy of 80%, 80% and 90% is reached on non-breast cancer individuals by applying the 7, 6 and 5 significant tongue features obtained through Mann–Whitney test, respectively, while 60%, 60% and 50% is reached on the corresponding early-stage BC patients. ConclusionThe TCM tongue diagnosis can serve as a preliminary screening procedure in the early detection of BC in light of its simple and non-invasive nature, followed by other more accurate testing process. To the best of our knowledge, this is the first attempt in applying non-invasive TCM tongue diagnosis to the discrimination of early-stage BC patients and non-breast cancer individuals.

Comparison of two different methods for gross alpha and beta activity determination in water samples

Abstract Measurement of the gross alpha and beta activity concentrations in various matrices is suitable as a preliminary screening procedure to determine whether further analysis related to specific radionuclide is necessary. In Serbia, according to current regulations, radioactivity concentrations in drinking water for gross alpha and gross beta should be &lt; 0.5 and &lt; 1.0 Bq L−1, respectively. The generally accepted methods for gross alpha and beta activity analysis of drinking water in different countries are: EPA 900.0 and ISO methods (ISO 9696, water quality – measurement of gross alpha activity in non-saline water – thick source method, and ISO 9697, water quality – measurement of gross beta activity in non-saline water). This paper describes comparison of preparations and measurement gross alpha and beta activity in bottled mineral waters as well as in tap waters in Serbia using two methods: EPA 900.0 with and without ash, and ISO methods. Concentration of total dissolved solids (TDS) in investigated water samples was determined. Based on obtained TDS, certain volume was evaporated. The instrumentation used to count the gross alpha and gross beta activities for both methods is α/β low level proportional counter Thermo Eberline FHT 770 T.

Inhibition of Proinflammatory Cytokine Generation in Lung Inflammation by the Leaves of Perilla frutescens and Its Constituents

This study was designed to find some potential natural products and/or constituents inhibiting proinflammatory cytokine generation in lung inflammation, since cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) are pivotal for provoking airway inflammation. In our preliminary screening procedure, the 70% ethanol extract of the leaves of Perilla frutescens (PFE) was found to clearly inhibit TNF-α production in the lung at 100 mg/kg, after intranasal lipopolysaccharide treatment of mice. Based on this result, ten constituents including phenylpropanoids (allyltetramethoxybenzene, caffeic acid, dillapiole, elemicin, myristicin, nothoapiole, rosmarinic acid methyl ester, rosmarinic acid) and monoterpenes (perilla aldehyde and perilla ketone) were successfully isolated from the extract. Among them, elemicin and myristicin were found for the first time to concentration-dependently inhibit IL-1β-treated IL-6 production from lung alveolar epithelial cells (A549) at concentrations of 10-100 μM. These findings suggest that the phenylpropanoids including elemicin and myristicin have the potential to be new inhibitory agents against lung inflammation and they may contribute, at least in part, to the inhibitory activity of PFE on the lung inflammatory response.

Chiral separations on multichannel microfluidic chips

Chiral separations of FITC-labeled basic drugs on multichannel microfluidic chips with LIF detector were investigated. A preliminary screening procedure for seven neutral CDs was performed under optimized conditions for chiral separations of three FITC-labeled drugs (baclofen, norfenefrine, and tocainide) on a mono-channel microfluidic chip. According to the results of screening, FITC-baclofen and FITC-norfenefrine as well as two chiral selectors including gamma-CD and dimethyl-beta-CD (DM-beta-CD) were selected as models to perform chiral separations on a two-channel chip. FITC-baclofen enantiomers were separated completely by gamma-CD in one channel, while resolution of FITC-norfenefrine enantiomers was achieved by DM-beta-CD in the other channel in the same run. Furthermore, the feasibility of using one chiral selector to separate multiple chiral samples was studied on a four-channel chip. These results show that multichannel chip has a potential for chiral high-throughput screening.

A modular plate for the optimization of protein crystallization conditions

A modular crystallization plate that simplifies the optimization of crystallization conditions after a preliminary screening procedure has been designed and manufactured.

Establishment of a chick embryo shell-less culture system and its use to observe change in behavior caused by nicotine and substances from cigarette smoke

Early detection and removal of harmful factors are essential to the proper physical and psychological development of the fetus, presumably showing the effects during the prenatal period and after birth. As one procedure to aid in understanding such factors, we have established a shell-less culture system for video monitoring to observe change in behavior of 7-day-old chick embryos. Nicotine and aqueous cigarette smoke extract (ACSE) were selected for the present experiments, and the results showed a complete stoppage of swing-like movements by administrations of 10 μg nicotine and 1×ACSE, possibly displaying paralytic symptoms. Quantitative analysis of nicotine in 1×ACSE indicated that more than 10 μg of nicotine were contained in 100 μl of the extract. The present system, although in initial stage of development, may be a useful preliminary screening procedure for perhaps supervision and warning about the environment surrounding pregnant women.

Rapid screening procedures for the hydrolysis products of chemical warfare agents using positive and negative ion liquid chromatography–mass spectrometry with atmospheric pressure chemical ionisation

Qualitative screening procedures have been developed for the rapid detection and identification of the hydrolysis products of chemical warfare agents in aqueous samples and extracts, using liquid chromatography–mass spectrometry with positive and negative atmospheric pressure chemical ionisation (APCI). Previously reported screening procedures, which used positive APCI or electrospray ionisation (ESI), were modified by using LC conditions that allowed acquisition of positive and negative ion mass spectra. APCI was generally found to be more robust than ESI, probably due to variable adduct ion formation with ESI, depending on the condition of the sample and the system. Negative APCI provided selective detection of acidic analytes and allowed facile differentiation of alkyl alkylphosphonic acids from isomeric dialkyl alkylphosphonates. The combination of positive and negative APCI, using a C 18 column and water–methanol mobile phase modified with ammonium formate, provides a rapid screening procedure for chemical warfare agent degradation products, with limits of detectability in the range 10–100 ng/ml. In the case of proficiency test samples, where analyte concentrations are in the range 1–10 ppm, introduction of the sample by infusion may provide an even faster preliminary screening procedure.

Estimation of Annual Pollutant Loads under Wet-Weather Conditions

The Continuous Simulation Method (CSM) has been used to predict average annual total nitrogen storm-water loads, under wet-weather conditions, for various sites in Tampa, Florida. Predicted loads are compared to those predicted by other existing “spreadsheet” models, namely the Storm Water Management Model (SWMM) Level I—Preliminary Screening Procedure, the Simple Method, and the U.S. Geological Survey (USGS) Regression Model. Comparisons showed that the USGS Regression Model predictions were vastly different from those of the other models. The predictions by SWMM Level I, the Simple Method, and the CSM were closer, although there were substantial differences under certain conditions. Of the four models, the CSM provides the greatest flexibility to a model user; it has the capability to (1) model different soil types within a watershed; (2) model loading variations due to geographical (location) and demographic (land use and cover) differences between watersheds; and (3) simulate confidence intervals arou...

Optimal siting of transfer station locations in a metropolitan solid waste management system

System analysis for solid waste management currently receives wide attention from both economic and environmental planners because of their complexity during the coordination of various management strategies. This paper deals with the development and application of an operational solid waste management model through a hierarchical approach, in which the siting problem of transfer stations in a large scale metropolitan region is decomposed into two different levels. This analytical approach encompasses a preliminary screening procedure using the Geographical Information System (GIS) and an optimization analysis by a mixed integer programming model. Four criteria are employed in the screening of initial candidate sites and the optimization of a solid waste collection, recycling, treatment, and disposal system is used to direct waste generation to existing or proposed transfer stations, treatment plants and disposal facilities at minimum cost. A case study in Taiwan shows that the optimal siting strategies of transfer stations can successfully reduce system direct cost and generate relatively reasonable operational programs.

A Pot Technique to Screen Pigeonpea Cultivars for Resistance to Waterlogging

AbstractTo develop a preliminary screening procedure for waterlogging resistance, a waterlogging resistant ICP 8379 and a waterlogging susceptible cultivar ICP 7035 were grown i n pots using different growth media and subjected to 6 days of waterlogging. Waterlogging caused a significant reduction in root dry mass of both cultivars which was greater in ICP 7035 than tn ICP 8379, The reduction i n shoot dry mass was comparatively small. The most conspicuous differences between the two cultivars occurred in terms of plant survival. In different soil treatments, ICP S379 showed 0–38 % mortality and ICP 7035 showed 63–100% mortality. The variation in mortality occurred in response to differences in growth medium. Using the growth medium that gave maximum differences, eight additional cultivars were compared along with ICP 7035 and JCP 8379. Significant differences m plant mortality among different cultivars were observed, A number of cultivars showed similar low mortality as ICP 8379, Therefore, there appears to be a potential t o use this method for preliminary screening of a large number of pigeonpea cultivars for waterlogging resistance.

Optimal Siting of Transfer Station Locations in a Metropolitan Solid Waste Management System

System analysis for solid waste management currently receives wide attention from both economic and environmental planners because of their complexity during the coordination of various management strategies. This paper deals with the development and application of an operational solid waste management model through a hierarchical approach, in which the siting problem of transfer stations in a large scale metropolitan region is decomposed into two different levels. This analytical approach encompasses a preliminary screening procedure using the Geographical Information System (GIS) and an optimization analysis by a mixed integer programming model. Four criteria are employed in the screening of initial candidate sites and the optimization of a solid waste collection, recycling, treatment, and disposal system is used to direct waste generation to existing or proposed transfer stations, treatment plants and disposal facilities at minimum cost. A case study in Taiwan shows that the optimal siting strategies of transfer stations can successfully reduce system direct cost and generate relatively reasonable operational programs.

Spermatozoal DNA flow cytometry and recurrent miscarriage.

Clinical investigations of the male partner of couples with recurrent miscarriage involves investigation of abnormalities in paternal chromosomes. This route of investigation does not include analysis of semen parameters. This investigation was conducted to evaluate DNA flow cytometry profiles of spermatozoa following staining with propidium iodide of couples attending the Pregnancy Loss Clinic for recurrent miscarriage. Ejaculates of 21 men were included in this study. DNA fluorescence was measured on the Becton Dickinson Fac Star Plus. Data were correlated with spermiogram parameters. The neat semen median minus peak channel values were negatively correlated with motility (p < .05). Therefore, DNA flow cytometry can provide confirmatory evidence for conventional semen analysis and is useful as a preliminary screening procedure for clinical management of the couple. It could also be used in association with programs for the assessment of possible reproductive toxicity and infertility in couples with recurrent miscarriage.

Preliminary screening procedure for the MINLP synthesis of process systems—I. aggregation and decomposition techniques

The objective of this paper is to develop a new framework for the synthesis of process systems that can address the question of how to rigorously combine preliminary screening and MINLP optimization techniques. The proposed method is based on rigorous preliminary screening using aggregated models. These are simplified representations of the MINLP models, may be lower dimensional, and are based on linear, fixed-charge underestimations of the cost and convex overestimations of the feasible region. Thus, the solution to the aggregated model provides a rigorous lower bound to the global optimal solution of the MINLP problem. Furthermore, the objective function evaluated using aggregated models provides a rigorous lower bound to the cost of the NLP subproblem having the identical topology. A screening strategy is outlined that consists of successively solving the aggregated model to identify solutions whose cost is below an upper bound on cost. This upper bound is determined from a base-case design, that is defined as a good, but not necessarily optimal solution to the original MINLP problem. In the second stage a reduced MINLP model is formulated that contains only the alternatives found in the preliminary screening. Application of the proposed search strategy is illustrated with the optimization of a superstructure for heat-integrated distillation columns. This example shows that the size of the superstructure can be reduced, the robustness of the solution improved, the computational efficiency enhanced, and the global optimal solution of the MINLP problem bounded.

Preliminary screening procedure for the MINLP synthesis of process systems-II. Heat exchanger networks

The objective of this paper is to present an implementation of the preliminary screening procedure for the MINLP synthesis of heat exchanger networks, based on the MINLP model by Yee and Grossmann, and utilizing as the aggregated model an MILP reformulation of the transshipment model. It is shown that the MILP reformulation of the transshipment model can be derived mathematically as an aggregation of the MINLP model. Several important aspects that enhance the preliminary screening are the following: First, the generation of the superstructure, as originally proposed, is modified in a preliminary analysis step. The resulting modified superstructure is shown to require no more, and generally fewer units than the original superstructure. Secondly, the transshipment model incorporates the aggregated area cost as an optimization variable, yielding a tight lower bound to the global optimal solution and better cost estimates of alternative solutions. Numerical examples are presented to show: (1) the extent to which the size of the original MINLP problem can be reduced, and thus the computational efficiency enhanced; (2) the robustness of the solution improved through the elimination of poor alternatives; and (3) the value of the global optimal solution of the reduced MINLP bounded.

Von willebrand's disease: laboratory investigation using an improved functional assay for von willebrand factor

This report details extensive studies investigating an improved screening procedure for the laboratory confirmation of clinically suspected von Willebrand's disease (vWD). Over the past two years, over 400 plasma samples, comprising samples derived from both normal individuals (n = 112) and from patients undergoing investigation on clinical grounds, underwent analysis in this screening procedure, comprising three distinct assays: a standard ELISA assay for von Willebrand Factor (vWF) antigen levels (vWF:Ag), a standard ristocetin cofactor (R Cof) assay, and a functional collagen based ELISA assay for vWF ('CBA'). Normal individual plasma samples yielded normal reference values (mean +/- 2SD) approximating 50-200% (vWF:Ag, R Cof) or 50-250% (CBA). In order to permit comparative analysis, and based upon derived assay values, and subsequent multimer analysis, patient samples were either deemed to derive from persons unlikely to suffer vWD ('non-vWD' patient group) or those potentially suffering vWD. The latter group was further separated into subgroups based upon the likelihood, and probable subtype of vWD. In conjunction with the vWF:Ag assay, the CBA provides the basis by which an effective predictor system (likelihood and probable subtype of vWD) can be offered on the basis of preliminary screening procedures. To date, there has been no overlap in vWF:Ag to CBA ratios (vWF:CBA) between patients yielding Type II vWD like multimer patterns and those yielding Type I vWD, or normal, multimer patterns. Thus, high vWF:CBA (i.e. > or = 3.0) would suggest a Type II, or pseudo, -vWD like defect, whereas low vWF:CBA (< or = 2.5) would likely derive from either normal individuals, or persons suffering from Type I vWD.(ABSTRACT TRUNCATED AT 250 WORDS)

The OASIS concept for predicting the biological activity of chemical compounds

The existing QSAR approaches are critically assessed. The OASIS methodology is outlined as a generalization of the Hansch method. A large set of calculable geometric (topological, steric) and electronic indices is used to characterize molecular structure. The number of descriptors is reduced stepwise in a preliminary screening procedure, thus strongly diminishing the risk of a chance correlation. The non-formal parameters included in the ultimate mathematical model provide opportunities for shedding light on the biological interaction mechanism. Implemented as an IBM PC pack, the OASIS system is applied to various series of drugs, arriving at successful regression models.

An immunoenzymatic staining assay (ISA) for the rapid screening of monoclonal antibodies detecting membrane and cytoplasmic antigens

We report a rapid and very sensitive immunoenzymatic staining assay (ISA) for the determination of the fine specificity of monoclonal antibodies directed against cellular antigens. Reactivity is analysed at the single cell level by light microscopy using alkaline phosphatase-conjugated second and third antibodies on cells bound to Terasaki plates. Reactive cells can be defined by their morphology even in preliminary screening procedures. Only small numbers of cells are necessary for this assay which is comparable to radioimmunoassays in its sensitivity. Plates with fixed cells can be stored at 4°C so that a permanent ‘library’ of various cell types is always immediately available for use. The test is also suitable for human blood cell phenotyping. Moreover, a simple modification of the procedure by short pretreatment of the cells with the detergent Brij allows the detection of antigens within the cytoplasm. The importance of evaluating the cytoplasmic compartment in order to define antibody specificity and study the distribution of different cytoplasmic and membrane antigens is emphasized.