Distinguishing Petroleum (Crude Oil and Fuel) From Smoke Exposure within Populations Based on the Relative Blood Levels of Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX), Styrene and 2,5-Dimethylfuran by Pattern Recognition Using Artificial Neural Networks.

Studies of exposure to petroleum (crude oil/fuel) often involve monitoring benzene, toluene, ethylbenzene, xylenes (BTEX), and styrene (BTEXS) because of their toxicity and gas-phase prevalence, where exposure is typically by inhalation. However, BTEXS levels in the general U.S. population are primarily from exposure to tobacco smoke, where smokers have blood levels on average up to eight times higher than nonsmokers. This work describes a method using partition theory and artificial neural network (ANN) pattern recognition to classify exposure source based on relative BTEXS and 2,5-dimethylfuran blood levels. A method using surrogate signatures to train the ANN was validated by comparing blood levels among cigarette smokers from the National Health and Nutrition Examination Survey (NHANES) with BTEXS and 2,5-dimethylfuran signatures derived from the smoke of machine-smoked cigarettes. Classification agreement for an ANN model trained with relative VOC levels was up to 99.8% for nonsmokers and 100.0% for smokers. As such, because there is limited blood level data on individuals exposed to crude oil/fuel, only surrogate signatures derived from crude oil and fuel were used for training the ANN. For the 2007-2008 NHANES data, the ANN model assigned 7 out of 1998 specimens (0.35%) and for the 2013-2014 NHANES data 12 out of 2906 specimens (0.41%) to the crude oil/fuel signature category.

Thomson scattering measurements of heat flux from ion-acoustic waves in laser-produced aluminum plasmas.

Thomson scattering (TS) measurements are performed at different locations in a laser-produced aluminum plasma. Variations of the separation, wavelength shift, and asymmetric distribution of the two ion-acoustic waves are investigated from their spectral-time-resolved TS images. Detailed information on the space-time evolution of the plasma parameters is obtained. Electron distribution and variation of the heat flux in the plasma are also obtained for a steep temperature gradient.

Some observations on the mechanism of benzodiazepine-barbiturate interactions in the mouse.

1 The prolongation of pentobarbitone sleeping by five benzodiazepines, administered by prior intraperitoneal injection, was measured in mice. The pentobarbitone was injected either intraperitoneally or intracerebroventricularly. For each benzodiazepine, the prolongation was dose-related and differences in potency between benzodiazepines were not marked. 2 The percentage prolongation of sleeping times produced by most of the benzodiazepines was greater when the pentobarbitone was given intracerebroventricularly and was explained by a preferential addition of CNS depressant effects associated with this route. 3 To test whether the action of intraperitoneally administered pentobarbitone had been influenced by a metabolic component, the effects of nitrazepam on drug metabolism, measured by changes in plasma phenazone levels in the mouse, were studied. Nitrazepam (32 mg/kg, i.p.) produced a 23% reduction in the rate of phenazone metabolism. 4 Nitrazepam was also shown to have produced a transient fall in body temperature. Calculations based on Q10 values suggested that this hypothermia accounted, at most, for half the metabolic change measured.

5-Nitro-4-(N,N-dimethylaminopropylamino)quinoline (5-nitraquine), a new DNA-affinic hypoxic cell radiosensitizer and bioreductive agent: comparison with nitracrine.

Targeting of electron-affinic radiosensitizers to DNA via noncovalent binding (e.g., intercalation) may offer the potential for increasing sensitizing efficiency. However, it has been suggested that high-affinity DNA binding may compromise sensitization by restricting the mobility of sensitizers along the DNA, and by decreasing rates of extravascular diffusion in tumors. The weak DNA intercalator nitracrine (1-NC) is a more efficient radiosensitizer than related nitroacridines with higher DNA-binding affinities (Roberts et al., Radiat. Res. 123, 153-164, 1990). The present study investigates whether electron-affinic agents of even lower DNA-binding affinity may be superior to nitroacridines. The quinoline analog of 1-NC, 5-nitraquine (5-NO), was shown to have an intrinsic association constant for calf thymus DNA in 20 mM phosphate buffer which was 12-fold lower than that of 1-NC. 5-Nitraquine was not accumulated as efficiently as 1-NC by AA8 cells, but, despite a similar one-electron reduction potential, was 2- to 3-fold more potent than 1-NC as a hypoxia-selective radiosensitizer in vitro when compared on the basis of average intracellular concentration. Thus the radiosensitizing potency of 5-NQ appears not to be compromised by its low DNA-binding affinity. The cytotoxic mechanisms of 5-NQ and 1-NC appear to be similar (hypoxia-selective formation of DNA monoadducts), but 5-NQ is 1200-fold less potent than 1-NC as a cytotoxin. Despite this advantage, 5-NQ was not active in vivo as a radiosensitizer in SCCVII tumors. This lack of activity appears to be due to its relatively high toxicity in vivo (intraperitoneal LD50 of 105 mumol kg-1 in C3H/HeN mice), high one-electron reduction potential (-286 mV), and rapid metabolism to the corresponding amine in mice. The in vitro therapeutic index (hypoxic radiosensitizing potency/aerobic cytotoxic potency) of this weak DNA binder was lower than that of the non-DNA targeted radiosensitizer misonidazole, suggesting that DNA targeting enhances cytotoxicity more than radiosensitization. Development of useful DNA-targeted radiosensitizers may require the exploitation of DNA binding modes different from those of the nitroacridines and nitroquinolines.

Halothane-induced sleeping time in the mouse: its modification by benzodiazepines.

The conditions under which prolongation of halothane-induced sleeping time in the mouse may be used as a test for centrally acting drugs are described. The test can be recommended for its practical advantages over methods using barbiturates to induce hypnosis; due cognizance must be taken of a diurnal variation in the response of mice to halothane. To assess the usefulness of the test the effects of amphetamine, chlorpromazine, histamine, morphine, nikethamide, pentobarbitone and SKF 525A have been investigated. The interaction between 5 benzodiazepines and halothane has been studied in particular. Results from sleeping time experiments, measurements of body temperature and of brain halothane concentrations suggest that the halothane-benzodiazepine interaction is due to additive CNS depressant effects. It was found that nitrazepam and diazepam were clearly more potent than chlorodiazepoxide, medazepam and oxazepam in respect of their interactions with halothane.

K-shell spectroscopy of an independently diagnosed uniaxially expanding laser-produced aluminum plasma.

We present detailed spectroscopic analysis of the primary K-shell emission lines from a uniaxially expanding laser-produced hydrogenic and heliumlike aluminum plasma. The spectroscopic measurements are found to be consistent with time-dependent hydrodynamic properties of the plasma, measured using Thomson scattering and shadowgraphy. The K-shell population kinetics code FLY with the measured hydrodynamic parameters is used to generate spectra that are compared to the experimental spectra. Excellent agreement is found between the measured and calculated spectra for a variety of experimental target widths employed to produce plasmas with different optical depths. The peak emission from the hydrogenic Lyman series is determined to be from a temporal and spatial region where the hydrodynamic parameters are essentially constant. This allows a single steady-state solution of FLY to be used to deduce the electron temperature and density, from the measured line ratios and linewidths, for comparison with the Thomson and shadowgraphy data. These measurements are found to agree well with time-dependent calculations, and provide further validation for the FLY calculations of the ionization and excitation balance for a K-shell aluminum plasma. We also discuss the possible application of this data as a benchmark for hydrodynamic simulations and ionization/excitation balance calculations.

Backyard mosquito larval habitat availability and use as influenced by census tract determined resident income levels.

One hundred and eighty premises in each of three distinct economic income levels within the urbanized area of East Baton Rouge Parish, Louisiana were inspected for artificial containers producing mosquitoes. Census tracts, and their accompanying descriptive statistics were used to objectively quantify each of the income levels studied. Differences, presumably due to living conditions associated with income level, were found for the amount, type and condition of the containers encountered in each area, as well as between species composition and the extent of production. Overall, low income areas produced more mosquitoes than either of the other two areas, mainly as a result of the types of containers present.

Isolation and mapping of novel mouse brain cDNA clones containing trinucleotide repeats, and demonstration of novel alleles in recombinant inbred strains.

Abnormal expansion of trinucleotide repeats (TRs) has now been implicated in the pathogenesis of at least nine human genetic disorders, particularly those in which anticipation and/or fragile sites have been demonstrated. Anticipation, the phenomenon of increasing severity of phenotype in successive generations, has never been seen in species other than man. Nevertheless, animal models for the dynamic mutation of TRs would be extremely valuable. We have screened a mouse brain cDNA library in an attempt to identify clones representing each of the 10 possible classes of trinucleotide repeat. Thirty-seven clones were analyzed in detail. Of the 37 sequences, 18 displayed significant levels of homology with sequences in GenBank, 10 of them with human expressed sequence tags (ESTs). We then analyzed 25 of the clones by PCR of the sequence containing the repeat in a number of different mouse strains and species to assess levels of variability of repeat length. Of the 25 clones analyzed in this way, 64% showed length variation between Mus musculus spp. and Mus spretus, and 32% showed variation between Mus musculus musculus-derived standard laboratory inbred strains. Where variation was detected (17 repeat-containing clones in all), the gene was mapped by linkage analysis. None of the repeats isolated showed any signs of extreme expansion. However, two of the repeats were shown to have undergone size changes during the establishment of a number of recombinant inbred strains, suggesting that these repeats are at least moderately unstable.

Antipyrine estimations in the rabbit using gas--liquid chromatography: a reliable method for studying factors affecting oxidative drug metabolism.

The application of a gas--liquid chromatographic (GLC) method to measurements of antipyrine in plasma for the estimation of antipyrine half-life (T1/2) in the rabbit is described and is compared with previous GLC methods. It has been established that the estimation of antipyrine can be achieved with acceptable precision and that rabbits can act as their own controls in the study of factors that might alter T1/2. Iproniazid phosphate, 50 mg/kg IP, was shown to produce a mean increase of 170% in T1/2.

Effects of drug pretreatment on antipyrine elimination in the rabbit.

Iproniazid (25-100 mg/kg) produced a marked, dose-related reduction in antipyrine elimination in the rabbit, whereas reductions produced by nitrazepam (32 mg/kg) or SKF 525A (25 and 40 mg/kg) were small. Phenobarbitone, 10 mg/kg chronically, increased antipyrine elimination. The small inhibitory effect of SKF 525A on antipyrine metabolism in the rabbit was unexpected compared to the marked effect in the rat.

Comparative genomic analysis of genes encoding translation elongation factor 1B(alpha) in human and mouse shows EEF1B1 to be a recent retrotransposition event.

We have characterized genomic loci encoding translation elongation factor 1B(alpha) (eEF1B(alpha)) in mice and humans. Mice have a single structural locus (named Eef1b2) spanning six exons, which is ubiquitously expressed and maps close to Casp8 on mouse chromosome 1, and a processed pseudogene. Humans have a single intron-containing locus, EEF1B2, which maps to 2q33, and an intronless paralogue expressed only in brain and muscle (EEF1B3). Another locus described previously, EEF1B1, is actually a processed pseudogene on chromosome 15 corresponding to an alternative splice form of EEF1B2. Our study illustrates the value of comparative mapping in distinguishing between processed pseudogenes and intronless paralogues.

The lethal mutation of the mouse wasted (wst) is a deletion that abolishes expression of a tissue-specific isoform of translation elongation factor 1alpha, encoded by the Eef1a2 gene.

We have identified the mutation responsible for the autosomal recessive wasted (wst) mutation of the mouse. Wasted mice are characterized by wasting and neurological and immunological abnormalities starting at 21 days after birth; they die by 28 days. A deletion of 15.8 kb in wasted mice abolishes expression of a gene called Eef1a2, encoding a protein that is 92% identical at the amino acid level to the translation elongation factor EF1alpha (locus Eef1a). We have found no evidence for the involvement of another gene in this deletion. Expression of Eef1a2 is reciprocal with that of Eef1a. Expression of Eef1a2 takes over from Eef1a in heart and muscle at precisely the time at which the wasted phenotype becomes manifest. These data suggest that there are tissue-specific forms of the translation elongation apparatus essential for postnatal survival in the mouse.

Lidar calibration technique using laboratory-generated aerosols.

A new calibration technique for continuous-wave Doppler lidars that uses an aerosol scattering target has been developed. Calibrations with both single- and many-particle scattering were performed at the same lidar operating conditions as in atmospheric measurements. The calibrating targets, simulating atmospheric aerosols, were laboratory-generated spherical silicone oil droplets with known complex refractive indices and sizes, hence with known single-particle backscatter cross sections as obtained from Mie theory. Measurements of lidar efficiency with the conventional hard target calibration method were consistently higher by a factor of ~2 than measurements with the aerosol calibration technique. This result may have important implications for lidar backscatter estimates both for aerosol modeling efforts and for optimal design of future lidar systems. The aerosol calibration method provides a validation of basic lidar theory for particle scattering for coherent detection.

Adaptation and serial passage of porcine group C rotavirus in ST-cells, an established diploid swine testicular cell line.

A porcine group C rotavirus (strain Cowden-AmC-1) was adapted and serially passaged in an established diploid swine testicular cell line (ST cells). Growth of group C rotavirus in ST cells, which in maintenance medium required trypsin, but not pancreatin resulted in cytopathic effect characterized by cellular stranding and subsequent cell lysis. Active replication and assembly were confirmed by RNA profile analysis, immune electron microscopy and immunofluorescence. Adaptation of non-group A rotavirus to a continuous cell line has not previously been reported and should facilitate progress in diagnostic procedures and vaccine development.

The tyrosinase-related protein-1 gene has a structure and promoter sequence very different from tyrosinase.

We have determined the exon structure of the mouse tyrosinase-related protein-1 (TRP-1) gene. The gene is only 15kb in length, but contains seven introns, in contrast to the tyrosinase gene which is almost 100kb long with only four introns. Only two introns are located in homologous positions in both genes. Intron I of TRP-1 has three alternative 5' splice sites clustered within 21bp, which all splice to the same 3' site. Intron V has a very unusual 5' splice site, which has the dinucleotide GC rather than the conventional GT. We show that as little as 370bp of 5'-flanking DNA is sufficient to direct cell-specific expression of the chloramphenicol acetyl transferase gene. The flanking DNA of TRP-1, unlike tyrosinase, does not contain a TATA box or a CCAAT box. Both mouse genes, however, share an 11bp sequence, also found in human tyrosinase, which we suggest may be a melanocyte-specific promoter element.

Antipyrine elimination in saliva after low-dose combined or progestogen-only oral contraceptive steroids.

1 A 'low-dose' combined oral contraceptive steroid (OCS) preparation containing 30 microgram ethinylo-estradiol and 150 microgram levonorgestrel was found to reduce significantly antipyrine clearance in a group of women acting as their own controls. 2 An OCS preparation containing only a progestogen (75 microgram norgestrel) did not reduce antipyrine clearance in a second group of women. 3 The evidence suggesting that the oestrogen component of combined OCS preparations could be responsible for the reduction in antipyrine clearance is discussed.

PIP: This study investigates the ability of a single preparation of either the low-dose combined or progestogen-only type of oral contraceptives (OCs) to alter antipyrine elimination in 2 groups of women. 6 patients aged 22-28 were given a low-dose combined OC preparation containing 30 mcg ethinyl estradiol and 150 mcg levonorgestrel; 12 patients aged 18-41 were given a preparation containing only a progestogen, 75 mcg norgestrel. Antipyrine elimination kinetics was setermined during the menstrual cycle, and at 11 weeks for the 1st group, and at between 11-14 weeks for the 2nd group, in saliva samples. There was a significant reduction of 29% in antipyrine clearance in the 1st group, and no significant change in antipyrine elimination in the 2nd group. These results are in agreement with previous published results; it is possible that the estrogen component of combined OC preparations could be responsible for the reduction in antipyrine clearance. If it is confirmed that progestogen-only OCs are without effect on antipyrine elimination, then it does imply that the concern that the elimination of any drug which is metabolized by liver microsomal enzymes will be impaired when the drug is administered with an OC is not applicable to progestogen-only preparations.

Evaluation of Lama5 as a candidate for the mouse ragged (Ra) mutation.

The laminin alpha5 chain is a component of the basement membranes of many developing and adult tissues. The mouse laminin alpha5 chain gene (Lama5) has been mapped close to the locus of the semidominant ragged (Ra) mutation on distal chromosome 2. The cause of the Ra mutation, which is usually lethal in the homozygous state, has not been determined. We have investigated whether a defect in Lama5 is responsible for the ragged mutation, using the RaJ strain. No differences in the level of the laminin alpha5 chain transcript were found in placental RNA from homozygous RaJ mutant embryos compared to normal littermates. Antiserum raised against a recombinant laminin alpha5 chain polypeptide stained the basement membranes of both normal and homozygous mutant embryos to a similar extent. More precise mapping of Lama5 on an interspecific Ra backcross indicated that Lama5 is proximal to the Ra locus. These results exclude Lama5 as a candidate gene for the Ra mutation.

Signal processing and calibration of continuous-wave focused CO(2) Doppler lidars for atmospheric backscatter measurement.

Two continuous-wave (CW) focused CO(2) Doppler lidars (9.1 and 10.6 µm) were developed for airborne in situ aerosol backscatter measurements. The complex path of reliably calibrating these systems, with different signal processors, for accurate derivation of atmospheric backscatter coefficients is documented. Lidar calibration for absolute backscatter measurement for both lidars is based on range response over the lidar sample volume, not solely at focus. Both lidars were calibrated with a new technique using well-characterized aerosols as radiometric standard targets and related to conventional hard-target calibration. A digital signal processor (DSP), a surface acoustic wave spectrum analyzer, and manually tuned spectrum analyzer signal analyzers were used. The DSP signals were analyzed with an innovative method of correcting for systematic noise fluctuation; the noise statistics exhibit the chi-square distribution predicted by theory. System parametric studies and detailed calibration improved the accuracy of conversion from the measured signal-to-noise ratio to absolute backscatter. The minimum backscatter sensitivity is ~3 × 10(-12) m(-1) sr(-1) at 9.1 µm and ~9 × 10(-12) m(-1) sr(-1) at 10.6 µm. Sample measurements are shown for a flight over the remote Pacific Ocean in 1990 as part of the NASA Global Backscatter Experiment (GLOBE) survey missions, the first time to our knowledge that 9.1-10.6-µm lidar intercomparisons were made. Measurements at 9.1 µm, a potential wavelength for space-based lidar remote-sensing applications, are to our knowledge the first based on the rare isotope (12)C (18)O(2) gas.