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Ecotoxicological characteristics of a new insecticide synergist, MBB-599 (proposed common name: Verbutin) was investigated. The studies included the determination of the hydrolysis, the biodegradability, the adsorption and desorption characteristics in soil and the effects on living systems (bacterium, alga, Daphnia, and fish) as well.
BACKGROUND: Children with acute respiratory tract infection (ARTI) represent an important target group for efforts aimed at reducing unnecessary antibiotic use. OBJECTIVE: To present the epidemiological data and evaluate the effect of clinical, laboratory, radiological and microbiological data on the decision to prescribe antibiotics to pediatric patients with ARTI as well as to seek criteria that would justify antibiotic use. PATIENTS AND METHODS: A retrospective review was made of the clinical histories of 147 previously healthy children, consecutively admitted to our hospital with ARTI for 1 year (May 1996-April 1997). Patients were divided in two groups: those not treated with antibiotics (n = 92) and those treated (n = 55). Data from the two groups were compared with a statistical computer program (R-Sigma). RESULTS: Of the 147 patients studied, mean age was 2.5 years (range 0-14 years) and 85 (58%) males. One-hundred-and-five patients (72%) had previously been attended to in the emergency room, and 45 patients (30%) had been treated with antibiotics. Upper respiratory tract infection was diagnosed in 81 patients (54%), bronchitis in 28 (18%), bronchiolitis in 23 (15%) and pneumonia in 15 (10%). Ninety-seven patients (66%) had viral infection and only two (1%) had bacterial infection. Syncytial respiratory virus was isolated in 41 patients (28%) and adenovirus in 30 (20%). In the untreated group, the longer duration of symptoms before admission, lymphocytosis, clinical diagnosis of bronchiolitis and normal thorax X-ray, were statistically significant. In the treated group, fever, leukocytosis, neutrophilia and a diagnosis of pneumonia were statistically significant. Length of stay was longer in this group than in the untreated group. CONCLUSIONS: It is difficult to prescribe antibiotics on the basis of bacteriologic data. Laboratory, analytic and radiological data can be helpful in the rational use of antibiotics.
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We have investigated the application of Shewhart's p control charts in our external quality-assurance program to monitor the long-term performance of our laboratory's analytical quality. The p control charts have been able to detect long-term changes in our laboratory's analytical performance that would have been difficult to detect by more-conventional techniques. We have explored methods for interpreting these charts as well as some of their limitations, which include minimum subgroup size and dependence on constant specification limits. These charts may be not only a simple method for the long-term monitoring of analytical performance of a laboratory, but also of use to the organizers of external quality-assurance programs.
Novel analytic methods are required to assimilate the large volumes of structural and bioassay data generated by combinatorial chemistry and high-throughput screening programmes in the pharmaceutical and agrochemical industries. Recent work in visualisation and data mining has been used to develop structure--activity relationships from such chemical-biological datasets.
This data file standard for flow cytometry (FCS) provides a detailed description of a data file structure designed such that the file can include all of the information necessary to describe fully: 1) the instrument used to obtain the data; 2) the sample measured; 3) the data obtained; and 4) the results of analysis of the data. The file may contain one or more data sets. Each data set includes data from a single sample or acquisition run. Each data set consists of a minimum of four parts--HEADER, TEXT, DATA, and ANALYSIS--all of which are required. The file is structured such that the parts of a data set do not have to be in any particular order, except for the HEADER, which must always be first. The HEADER contains pointers to the beginning and end of each of the other three parts. The file is written as a continuous byte stream, with no line or page formating. The HEADER, TEXT, and ANALYSIS parts are written in ASCII format and the DATA part can be written in ASCII, binary integer or floating point. This Standard, noted as FCS2.0, is based on a standard proposed by Murphy and Chused (Cytometry 5:553-555, 1984). Data written utilizing their proposed format (FCS1.0) is compatible with the format described here. Future versions of the standard will maintain compatibility with older versions.
Data are presented for 45 Long Island groundwater samples each measured for 90Sr using four different analytical methods. 90Sr levels were first established by two New York State certified laboratories, one of which used the U.S. Environmental Protection Agency Radioactive Strontium in Drinking Water Method 905.0. Three of the 90Sr methods evaluated at Brookhaven National Laboratory can reduce analysis time by more than 50%. They were (a) an Environmental Measurements Laboratory Cerenkov technique and (b) two commercially available products that utilize strontium-specific crown-ethers supported on either a resin or membrane disk. Method independent inter-laboratory bias was <12% based on 90Sr results obtained using both U.S. Department of Energy/Environmental Measurements Laboratory and U.S. EPA/National Environmental Radiation Laboratory samples of known activity concentration. Brookhaven National Laboratory prepared a National Institute of Standards and Technology traceable 90Sr tap-water sample used to quantify test method biases. With gas proportional or liquid scintillation counting, minimum detectable levels (MDLs) of 37 Bq m(-3) (1 pCi L(-1)) were achievable for both crown-ether methods using a 1-L processed sample beta counted for 1 h. The primary radiological contaminants of the Brookhaven National Laboratory groundwater samples were 3H (14.8-518 kBq m(-3)) and 90Sr/Y (37 Bq m(-3)-18.5 kBq m(-3)). Thirty samples were above the U.S. EPA drinking water standard of 300 Bq m(-3) for beta emitting 90Sr. Regression of paired data sets showed that both crown-ether methods quantified 90Sr levels to within 5% of the "EPA method results" for samples greater than the drinking water standard and within 30-40% for samples less than the drinking water standard. The Cerenkov method, with a minimum detectable level of 150 Bq m(-3), was only useful for samples greater than the drinking water standard and underestimated 90Sr levels by 13%. Precision, as measured by the relative percent difference and mean difference statistics, was acceptable for both crown-ether methods when compared to the paired "EPA method" results. Cerenkov method precision exceeded pre-defined acceptance criteria for 12 of 33 samples analyzed.
A system for the acquisition of digital data from the analytical ultracentrifuge which uses a commercially available data acquisition board, a standard IBM compatible personal computer (PC), and an interface circuit has been developed. The system uses the signal from the standard Beckman scanner. Preliminary analysis and data reduction are performed at the PC within minutes of data acquisition using simple commercially available software, and final data fitting is performed with a mainframe computer. Procedures are described which allow approach to equilibrium to be followed and attainment of equilibrium to be demonstrated. Data density of approximately 200 points per millimeter column height (approximately 500 points per 100 microliters of sample) allows the use of short columns and hence short run times. Only 2 min are required to collect a complete scan, which is recorded in a format suitable for direct analysis by standard spreadsheet software. This allows multiple sequential scans to be quickly recorded at equilibrium and averaged to reduce noise prior to analysis. The combination of characteristics allows molecular weight determinations to be performed relatively quickly with only a few micrograms of protein. The system is inexpensive and easy to assemble given the centrifuge and a PC.
Fractions containing polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were extracted from river sediments by various extraction methods. The amount of individual pollutants was determined analytically and data compared with biological assays. These were based on the induction of cytochrome P450 1A1 (CYPIA1) after treatment with sediment fractions in two different biological model systems, a mouse hepatoma cell line Hepa-1 and a chick embryo. In the hepatoma cell culture Hepa-1 significant correlations with analytical results were found for fractions containing PCDD/Fs and planar and mono-ortho-chlorinated PCBs. However for PAH fraction an undesirable decrease of P450 1A1 induction was observed in higher concentrations of this fraction. This decrease was not observed in the chick embryo liver microsomes and biological responses towards the PAH fractions correlated with analytical data. Comparative investigations demonstrated that the chicken embryo hepatic microsomes were more sensitive for PAHs, and the hepatoma cell line Hepa-1 for PCDD/Fs and planar and mono-ortho-chlorinated PCBs.
Data on the incidence and levels of chemical contaminants in foods are needed for continuous assessment of the safety of the food supply and to inform the public about the safety of food. A larger share of the total analytical resource--federal and state government, private sector, and academia--could profitably be directed to collection and publication of data on the occurrence of chemical contaminants in foods. The quest for more data must be accompanied by measures to ensure data reliability and comparability and to estimate the uncertainty of measurements. Research to improve the efficiency of analysis may be the top priority for future methods improvement studies. Analytical chemistry will continue to be an essential factor in assuring a safe food supply and in communicating to the public accurate information and conclusions about food safety.
An analytical procedure has been developed for the formulation of tissue substitute materials for use with photons and electrons. This method, called the basic data method, is based upon interaction data and enables two-component substitutes to be formulated with radiation characteristics within specified limits. Another feature of the procedure is the ability, once a primary material has been chosen, to select the best corrective additives from a library of compounds. The theoretical aspects are discussed followed by a discussion of the practical applications of the method.
Survey data on analytical x-ray devices were reviewed to provide an overview of safety problems. It was found that old equipment with one or more safety deficiencies is being used in many research laboratories and that predictions of long-term risks are difficult. Assessment of the problems against recently revised radiation risks in BEIR V (NAS 1990) and occupational dose equivalent limits in ICRP Publication 60 (1991), together with reasonable extrapolations and safety considerations, suggest that improvements in several areas are necessary in order to prevent or reduce potentially adverse health effects. Certain recommendations are, therefore, proposed: the annual occupational limit of 500 mSv to the hands and the skin as recommended by the ICRP (1991) should still apply; however, estimates of the bone dose should account for the differential absorption between bone and soft tissue at the low-energy photons encountered in analytical x-ray operations; general guidance to improve safety of old equipment and open-beam devices should be made available; user education and instruction need improvement on specific issues; and survey methods need revision and updating.