Temperature and flow rate effects on mass median diameters of thermally generated malathion and naled fogs

The effects of temperature and flow rate on mass median diameters (mmds) of thermally generated aerosol clouds were studied. Number 2 fuel oil alone, undiluted and diluted malathion 91, and undiluted naled were examined. There was a significant flow rate x temperature interaction on the mmds of diluted malathion fogs: i.e., differences among flow rates depended on temperature and vice versa.

Substance P selectively activates TNF-alpha gene expression in murine mast cells

There is increasing evidence that the neurologic system is capable of modulating a wide range of immunologic responses, including certain inflammatory processes in the lung, gastrointestinal tract, and skin. It has been proposed that secreted neuropeptides such as substance P (SP) may mediate these neuroinflammatory interactions by binding to and stimulating immune cells such as mast cells and lymphoid cells. SP is secreted in a variety of tissues by an extensive network of neurosensory C and A5 fibers in response to a wide range of noxious stimuli and injury. Previous studies to examine the effect of SP on mast cells have focused on its role in triggering histamine release and mediating immediate hypersensitivity responses. Recently it was demonstrated that mast cells are also capable of secreting multiple cytokines including TNF-alpha, IL-1, IL-3, IL-4, IL-6, and GM-CSF. In this study we tested the possibility that SP may also influence mast cell-mediated late inflammatory events by modulating the production of one or several of these cytokines. Our results indicate that SP induces TNF-alpha mRNA expression and TNF-alpha secretion in a dose-dependent manner in a murine mast cell line, CFTL12. Likewise, SP stimulates TNF-alpha secretion in freshly isolated murine peritoneal mast cells. The induction of mast cell TNF-alpha is selective, since SP does not stimulate the production of IL-1, IL-3, IL-4, IL-6, or GM-CSF in these cells. The CFTL 12 mast cell line constitutively expresses high levels of SP receptor mRNA which is not modulated by PMA/cycloheximide treatment or SP. These results further support the concept that the neurologic system modulates inflammatory events by neuropeptide-mediated mast cell cytokine release.

Substance P selectively activates TNF-alpha gene expression in murine mast cells

There is increasing evidence that the neurologic system is capable of modulating a wide range of immunologic responses, including certain inflammatory processes in the lung, gastrointestinal tract, and skin. It has been proposed that secreted neuropeptides such as substance P (SP) may mediate these neuroinflammatory interactions by binding to and stimulating immune cells such as mast cells and lymphoid cells. SP is secreted in a variety of tissues by an extensive network of neurosensory C and A5 fibers in response to a wide range of noxious stimuli and injury. Previous studies to examine the effect of SP on mast cells have focused on its role in triggering histamine release and mediating immediate hypersensitivity responses. Recently it was demonstrated that mast cells are also capable of secreting multiple cytokines including TNF-alpha, IL-1, IL-3, IL-4, IL-6, and GM-CSF. In this study we tested the possibility that SP may also influence mast cell-mediated late inflammatory events by modulating the production of one or several of these cytokines. Our results indicate that SP induces TNF-alpha mRNA expression and TNF-alpha secretion in a dose-dependent manner in a murine mast cell line, CFTL12. Likewise, SP stimulates TNF-alpha secretion in freshly isolated murine peritoneal mast cells. The induction of mast cell TNF-alpha is selective, since SP does not stimulate the production of IL-1, IL-3, IL-4, IL-6, or GM-CSF in these cells. The CFTL 12 mast cell line constitutively expresses high levels of SP receptor mRNA which is not modulated by PMA/cycloheximide treatment or SP. These results further support the concept that the neurologic system modulates inflammatory events by neuropeptide-mediated mast cell cytokine release.

A cell culture model system for genetic analyses of the cell cycle by targeted homologous recombination

Analysis of how external proliferation signals impinge on the regulation of the cell cycle is ideally performed in cells that are capable of normal physiological withdrawal into the quiescent (G0) phase of the cell cycle as well as resumption of growth following appropriate stimuli. Targeted homologous recombination (gene targeting) provides an important new approach to determine the function of specific genes in these cellular processes. Current gene targeting methodology necessitates the use of immortal and stably diploid cell lines. This report investigates several rodent cell lines, by both genetic and physiological criteria, for use in gene targeting studies of the G0 to G1 transition. All murine cell lines examined were aneuploid. Some rat cell lines were euploid by chromosome number, but three specific genes, c-myc, c-raf-1 and Rb, were not always diploid. Only one cell line, an early-passage subclone of the Rat-1 cell line, was diploid for c-myc, c-raf-1 and Rb. An hprt- derivative of this cell line was isolated (designated TGR-1) and its karyotype was established by G-banding. TGR-1 cells were shown to withdraw into G0 upon serum starvation and to uniformly enter S phase after refeeding. Expression patterns of the c-myc, c-raf-1 and Rb genes and several properties of the gene products were found to be normal. The frequency of targeted homologous recombination of the c-myc and c-raf-1 loci was found to be within values observed with other cell lines. Thus, by both genetic and physiological criteria the TGR-1 cell line is a good model system for the analysis of the roles of c-myc, c-raf-1 and Rb in signal transduction, and will probably prove useful in studies involving other genes.

A comparison of Teflon slides and the Army Insecticide Measuring System for sampling aerosol clouds

The effects of method of droplet analysis, reader of Teflon slides and distance on mass median diameter of a Cythion aerosol cloud were examined in the calibration of an Army Insecticide Measuring System (AIMS). There were no significant differences in results among readers and between the AIMS and readers. There were slight but statistically significant differences between readers of Teflon slides and between the methods of analysis. Data supports the manufacturer's recommendation that, for the AIMS, the distance at which an aerosol generator air blast is between 3 and 7 m3 s-1 must be determined.

Intraspecific DNA sequence variation of the mitochondrial control region of white sturgeon (Acipenser transmontanus)

Intraspecific sequence variation in the D-loop region of mtDNA in white sturgeon (Acipenser transmontanus), a relict North American fish species, was examined in 27 individuals from populations of the Columbia and Fraser rivers. Thirty-three varied nucleotide positions were present in a 462-nucleotide D-loop sequence, amplified using the polymerase chain reaction. Bootstrapped neighbor-joining and maximum-parsimony trees of sequences from 19 haplotypes suggest that the two populations have recently diverged. This is consistent with the hypothesis that the Columbia River, a Pleistocene refugium habitat, was the source of founders for the Fraser River after the last glacial recession. On the basis of a divergence time of 10-12 thousand years ago, the estimated substitution rate of the white sturgeon D-loop region is 1.1-1.3 x 10(-7) nucleotides/site/year, which is comparable to rates for hypervariable sequences in the human D-loop region. Furthermore, the ratio of mean percent nucleotide differences in the D-loop (2.27%) to that in whole mtDNA (0.54%, as estimated from restriction-enzyme data) is 4.3, which is similar to the fourfold-to-fivefold-higher substitution rate estimated for the human D-loop. The high nucleotide substitution rate of the hypervariable region indicates that the vertebrate D-loop has potential as a genetic marker in molecular population studies.

Malathion aerosol cloud behavior in a Coastal Plains pine flatwoods

The study examines malathion aerosol cloud behavior in a North Florida pine flatwoods. Droplet mass median diameters (MMD) decreased over distance in both open and pine flatwoods. A sharp decrease in number of aerosol droplets per cm2 occurred between 3.1 and 15.2 m and a gradual decline in droplets per cm2 occurred beyond 15.2 m in both treatment areas. There were no interactions between habitat and distance in regard to MMD or droplets per cm2. Analysis of variance models accounted for 82% of the variability in the MMD data and 79% of the variability in the number of droplets per cm2.

Feeding wash water solids to sows during gestation and lactation: sow productivity, pig performance, and tissue compositions

Diets containing 0, 10, or 20% dried wash water solids (WWS) from a milk processing plant were fed to 54 Yorkshire gilts (160 to 270 kg) for five parities. Feed intake, weight changes, and morbidity of sows were measured; number of pigs per litter, birth weight, and weight gain of pigs were also determined. Blood, tissue, and milk samples were taken from sows for hematological and mineral analyses, and tissue samples were taken from newborn pigs from each treatment per parity. Overall, initial sow weight, sow weight at weaning, and weight losses were not affected (P greater than .05) by treatment. At 107 d of gestation, overall weights decreased (P less than .05) linearly with level of WWS in the diet. The number of pigs per litter and weight of pigs were not affected (P greater than .10) by diet. Concentrations of NA (P less than .10) and Cd (P less than .05) were lower in kidney of sows fed 20% WWS, and concentrations of Zn were lower in bone and in kidney of sows fed the 20% WWS diet. The Sr and Ba concentrations increased (P less than .05, P less than .10) linearly in bone from sows with level of WWS in the diet. In pigs, concentrations of Mn in kidney and Zn in liver were lower for the 20% WWS treatment. In conclusion, feeding WWS to sows over five parities had minimal adverse effects on sow productivity and pig performance; the reduction in Zn concentrations in tissues of sows and pigs seemed to be related to the Ca content of WWS.

Mitochondrial DNA length variation and heteroplasmy in populations of white sturgeon (Acipenser transmontanus)

Southern blot analysis was used to quantify the extent of mtDNA D-loop length variation in two populations of white sturgeon, Acipenser transmontanus. Over 42% of individuals were heteroplasmic for up to six different mtDNA length variants attributable to varying copy numbers of an 82-bp repeat sequence. Chi-square analyses revealed that the frequencies of length genotypes and the incidence of heteroplasmy were significantly different between Fraser and Columbia River sturgeon populations but not between restriction site haplotypes. Heteroplasmic fish have, on average, higher copy number than homoplasmic fish. Forty-five of 101 homoplasmic individuals carry only a single copy of the repeat, while none of the 73 heteroplasmic fish has the single repeat as the predominant variant. On the basis of differences in frequency distributions of copy number within and between fish, we suggest that (1) heteroplasmy is maintained by high recurrent mutation of multiple copy genomes, favoring increased copy number and (2) the mutation pressure toward higher copy number heteroplasmy is partially offset by selection to reduced genome size and segregation to the homoplasmic condition.

Passive exposure to cocaine in medical personnel and its effect on urine drug screening tests

This report studies the importance of passive exposure of medical personnel to cocaine hydrochloride and its impact on urine screening testing. Eleven medical staff members were exposed to cocaine hydrochloride by means of aerosol and cutaneous application, similar to that which may occur in medical practice. Urine drug screening tests were negative for everyone tested. This finding is supported by known drug kinetics. It is unlikely that a single passive exposure of medical staff to cocaine hydrochloride will produce a positive urine screening test. In all cases of positive urine tests, contaminants should be tested for which may indicate a source of the drug. The routine use of gloves and masks--which is recommended to prevent HIV infection--should further decrease medical personnel's passive exposure to cocaine hydrochloride.

Office diagnosis of lower extremity venous insufficiency and treatment with the use of nonprescription support hose

A two-part crossover study assessed the efficacy of nonprescription support pantyhose by evaluating the relative performance of sheer- versus firm-support types in 30 women with lower extremity complaints. In this clinical trial, 23 women wore nonprescription firm-support pantyhose and seven wore sheer-support pantyhose during the initial 4-week treatment period. Next, treatment was discontinued for 2 weeks, after which a 4-week crossover trial was started. During the crossover, the 23 women who had worn the firm-support hose during the initial trial wore the sheer-support hose, and the seven who had worn the sheer-support hose switched to wearing the firm-support hose. The 2-week washout period did not prove sufficient to allow measured values to return to baseline, thus invalidating the crossover comparisons between the sheer- and firm-support pantyhose. However, the direct comparison of results showed that patients generally experienced an improvement in venous circulation by using either firm- or sheer-support hose as evaluated by venous index measurements and a corresponding decrease in subjective complaints. One year after this study was completed, the patients were recalled. Of the 25 who were seen at this follow-up, 91% continued to use support hose, either when they had symptoms or on a regular daily basis. Venous circulation, as evaluated by noninvasive Doppler ultrasound and photoplethysmography, remained improved.

Talk with your mother or your sibling? Developmental changes in early family conversations about feelings

Developmental changes in the pattern of family conversations and talk about feelings were examined in a longitudinal study of 50 families observed at home when the second-born children were 33 and 47 months old. Significant increases were noted in the total amount of talk and the frequency of talk about feelings between sibling pairs as well as decreases in the amount of mother-child conversation and references to feelings. Differences in whose feelings were discussed and in the context of references to feelings were found for mother-child and sibling-child dyads. Developmental changes in the children's use of feeling state language co-occurred with the increase in interaction between children and their siblings. The findings contrast the "complementary" nature of mother-child interaction and the "reciprocal" nature of child-sibling interaction and support the argument that the quality of particular relationships influences the use children make of their communicative competence.

Evidence for sulfite as an essential metabolite for human peripheral lymphocytes

Sulfite has been identified as an essential metabolite by means of growth studies using a chemically-defined, protein-free medium for culture of human peripheral lymphocytes. Sulfite reduced the amount of cysteine required for optimum growth by at least four-fold. In some subjects, sulfite stimulated growth even in the presence of optimal amounts of cysteine indicating that lymphocytes of some individuals are unable to convert cysteine to sulfite in adequate amounts.

Kinetics of the DNA binding of 2-substituted anthraquinones

The DNA-binding properties of the 2-substituted-1,4-dihydroxyanthraquinones 5-12 were examined. Compounds 5 and 6 were synthesized in this study, 7-12 were already available. Spectral studies were consistent with intercalation of 5, 6 and 8 into DNA. Affinity constants were in the range of 3 x 10(4)M-1. Compounds 7 and 10-12 showed no DNA binding, presumably being sterically excluded from binding. The kinetics of the DNA interaction of 5, 6 and 8 were studied. There is a biphasic process. This may reflect an initial reaction, with drug from this first mode of binding moving into the second binding mode (a sequential process) or independent binding of drug in two sets of sites (a parallel process). The methods used in this study do not allow us to discriminate between these models. However, if the parallel binding model is correct, the compounds show sequence selectivity of binding, and provide a lead for further development of neutral DNA-binding ligands with sequence selectivity.

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Length heteroplasmy of sturgeon mitochondrial DNA: an illegitimate elongation model

Extensive length polymorphism and heteroplasmy (multiple forms within an individual) of the D-loop region are observed in mitochondrial DNA of the white sturgeon (Acipenser transmontanus). The nucleotide sequence of this region, for both a short and a long form, shows that the differences are due to variable numbers of a perfect 82-bp direct repeat. We propose a model for the replicative origin of length differences, involving a competitive equilibrium between the heavy strand and the D-loop strand. This model suggests that frequent misalignment in the repeat region prior to elongation, facilitated by a stable secondary structure in the displaced strand, can explain both the polymorphism and heteroplasmy in this species.

Involvement of hydroxyl radical formation and DNA strand breakage in the cytotoxicity of anthraquinone antitumour agents

Four 9,10-anthraquinones (AQ) mono- or bis-substituted with the -NH(CH2)2NH(CH2)2OH group were studied. 1-AQ, 1,5-AQ and 1,8-AQ but not 1,4-AQ (100 microM) generated pBR322 plasmid DNA single strand breaks in the presence of purified NADPH dependent cytochrome P450 reductase. 1-AQ, 1,5-AQ and 1,8-AQ (at 100 microM) stimulated hydroxyl radical formation in MCF-7 S9 cell fraction (as measured by dimethyl pyrolline N-oxide spin trapping) and MCF-7 DNA strand breaks as measured by alkaline filter elution. In contrast 1,4-AQ did not stimulate hydroxyl radical formation and produced considerably less strand breaks in MCF-7 cells compared to the other AQ's. It would appear that the position of the -NH(CH2)2NH(CH2)2OH groups on the chromophore is an important determinant in the metabolic activation of cytotoxic anthraquinones. This may contribute to the cytotoxicity (ID50 values) of 1-AQ (0.06 microM), 1-8-AQ (0.5 microM) and 1,5-AQ (12.3 microM) but not the 1,4-AQ (1.2 microM).

Redox cycling in MCF-7 human breast cancer cells by antitumor agents based on mitozantrone

In a series of hydroxyethylaminoalkylaminoanthraquinones (AQ's) based on mitozantrone, 1-AQ (340%) and 1,8-AQ (137%) stimulated basal rate NADPH oxidation (72 + 18 pmol min-1 mg S9 protein-1) whilst 1,4-AQ, 1,5-AQ and mitozantrone had no effect. A similar trend was observed for O2.- generation (measured as nmol acet. cyt c reduction min-1 mg protein-1) by these compounds in MCF-7 S9 fraction: 1-AQ (9.5) and 1,8-AQ (7.9), whilst 1,5-AQ, 1,4-AQ and mitozantrone showed no significant effect. All the AQ's including mitozantrone were cytotoxic to MCF-7 cells in a dose dependent manner with EC50 values as follows: 1-AQ (0.01 micron) greater than doxorubicin (0.4 microM) greater than mitozantrone (0.6 microM) greater than 1,8-AQ (2.0 microM) greater than 1,5-AQ (4.0 microM) greater than 1,4-AQ (8.0 microM). Thus the redox active AQ's were also the most cytotoxic. Mitozantrone however was not redox active but was more cytotoxic than all but 1-AQ hence it would appear that factors other than free radical generation contribute to the antitumor activity of this group of compounds.