Exposure reducing

After 10 days of exposure, reduced social behavior and reduced exploratory behavior were observed in rats exposed to 100 ppm trichloroethylene 6 hours per day 5 days per week for a total of 5 weeks (Silverman and Williams 1975). In rats exposed to 50 or 100 ppm trichloroethylene 8 hours/day, 5 days/week for 6 weeks, effects on sleep patterns were observed (Arito et al. 1994a). At 50 ppm decreased wakefulness was observed during the exposure. Effects remaining at 22 hours after the end of the 6-week exposure included decreased heart rate during sleep at 50 ppm and decreased wakefulness after exposure of 100 ppm (Arito et al. 1994a). Based on the 50-ppm LOAEL identified in the Arito et al. (1994a) study, an intermediate-duration inhalation MRL of 0.1 ppm was calculated as described in the footnote in Table 2-1. 

Applications Extraction is typically accomplished by refluxing the polymer in an appropriate solvent for l-48h [84,199]. In many cases, ultrasonic exposure reduces the extraction time [90,200], According to Table 3.5 there are several reports of US extraction from polymers. Ultrasonic extraction has been used for HDPE/(BHT, Irganox antioxidants, Isonox, Cyasorb, Am 340, MD 1024, Irgafos 168) [56], LDPE/Chimassorb 81 [201], SBR/tri(nonylphenyl) phosphite [200], HDPE/(Tinuvin 770, Chimassorb 944) [114], etc. Nielson [90] compared the recoveries obtained for a variety of analytes from PP, LDPE and HDPE with Soxhlet, ultrasonic bath and microwave oven. For all samples, the ultrasonic extraction could be achieved within 1 h. For LDPE and PP most compounds (except Irganox 1010) were extracted within 10 min. Further experiments by Nielson [56] on extraction from HDPE confirmed these results. Where phosphite antioxidants (such as Irgafos 168) are present the use of the solvent mixture DCM-cyclohexane was preferred as it prevented hydrolysis of the phosphite by extraction solvents such as alcohols [56]. Similarly, phosphite esters also undergo hydrolysis... 

The majority of early publications that can be reasonably identified as comprising immunotoxicology reported altered resistance to infection in animals exposed to various environmental or industrial chemicals. Authors logically concluded that xenobiotic exposure suppressed immune function since the immune system is ultimately responsible for this resistance to infection. Subsequent studies demonstrated that suppression of various cellular and functional endpoints accompanied or preceded increased sensitivity to infection, and that administration of known immunosuppressants likewise decreased host resistance. The human health implications of these studies, that chemical exposure reduced resistance to infection, drove the initial focus of many immunotoxicologists on functional suppression, and provided the theoretical and practical underpinnings of immunotoxicity testing. 

A series of pyrazoles was disclosed in a patent application claiming members of this series as AKT inhibitors [27]. The pyrazole 15 is representative of this series, with AKT activity reported as IC50<0.1pM. In the patent application, these compounds were specifically claimed to have oral exposure, reduced or no... 

Hazardous substances can be distributed in plumes of dust or smoke, or can be contained in or on debris scattered about the site of an attack. An individual who uses common sense when he sees a plume of smoke should try to avoid direct contact by retreating into a nearby building. Because fine particles may also be in the air and not easily observed, the potential for exposure reduces as distance from the site increases. Risk from exposure may also be reduced by seeking shelter in a nearby building. 

Lin Y, Phillis JW. (1990). Chronic caffeine exposure reduces the excitant action of acetylcholine on cerebral cortical neurons. Brain Res. 524(2) 316-18. 

No information was available that described specific methods for reducing peak absorption following exposure, reducing body burden, interfering with the mechanism of action of toxic effects, or reducing toxic effects in children exposed to 1,4-dichlorobenzene. The following texts provide specific information about treatment following exposures to 1,4-dichlorobenzene ... 

Although it is possible that chronic exposure reduces the mutation frequency, the low mutation frequencies found for chemicals other than ENU have made it difficult to test this question. One notable exception is procarbazine, with which the first demonstration was made of a fractionation effect in mice.108 A pronounced fractionation effect has recently been demonstrated for ENU.380 383 Ten fractions of 10 mg/kg administered at weekly intervals yielded only 13% as many mutations as a single injection of 100 mg/kg. 

Krajnak K, Nunez AA (1996) Short-photoperiod exposure reduces L-aromatic-amino-acid decarboxylase immunostaining in the arcuate nucleus and median eminence of male Syrian hamsters. Brain Res 772 95-101. 

Mining Waste Estimated 10-20 cancers aimually, largely due to arsenic. Remote locations and snuill population exposure reduce overall risk though individual risk may be high. 

UV light treatment (circles) and without treatment (triangles). For the hybrid film with UV-light treatment, a sharp growth of diffraction efficiency was observed at an early exposure stage (circles). The diffraction efficiency reached a maximum of 1.1% in 250 mj cm", corresponding to ca. 5.0 s exposure at 50 mW cm". Further exposure reduced the efficiency to give a constant value around 0.5%. 

The Environmental Protection Agency (Cincinnati, OH, USA) reported investigations regarding the health effects of antimony and its compounds. The conclusion of the report is as follows Oral reference dose values (RfDo) were derived for antimony and selected compounds based on the LOAEL (lowest-observed-adverse-effect-level) for antimony of 350/zgkg" day" associated with potassium antimony tartrate (15) in the drinking water of rats for lifetime exposure. Reduced lifespan was observed in both sexes and altered blood biochemical characters in males. The only concentration tested was of 5 ppm antimony. RfDo values for antimony of 24.5/ig dayfor antimony potassium tartrate of 65.5 fig day and for antimony tri-, tetra- and pentoxides of 29.3, 30.9 and 32.5 /igday" respectively, were calculated. It should be noted that orally administered antimony has been inadequately tested for carcinogenicity. 

Other iron-based photographic systems have been devised. For example, the complex (119) can be coated with a suitable binder. Exposure reduces Fe to Fe. Treating the coating with water produces intensely colored Fe bipy complexes in exposed areas and washes unreacted salt out of unexposed areas.A system in which a ferrioxaiate complex is photolyzed to form Fe, which is then selectively complexed with a dye indicator, was discussed in Section 59.4.2. An obsolete palladiotype process relied on the photolysis of ferrioxaiate complexes to produce Fe, which in turn reduced a Pd salt to produce an image in Pd . More economical and sensitive processes today are based on amplifying a weak image in Fe or palladium nuclei by physical development. 

The onset of toxicity is usually rapid, occurring within minutes of exposure. Reduced acetylcholine levels are indicators of nerve agent exposure. Signs and symptoms are dependent on the degree of intoxication and may include the following ... 

Helium is nontoxic at normal temperature and pressure. The primary concern is its ability to displace oxygen in the air. Oxygen content must remain above 19% by volume in order to prevent symptoms of oxygen deficiency. At extremely low temperatures, a clinical case of quick freeze injury to both hands due to helium was reported. The exposed individual was wearing protective gloves which, upon rapid removal after exposure, reduced the depth and severity of the injury. Skin contact with liquid helium can cause frostbite. 

Hypotension (low blood pressure) and ischemia (restricted blood flow) associated with exposure reduces the delivery of oxygen to tissues and cells and may lead to sever damage and/or death of nerve cells (neuronal necrosis). 

Ergotamine Rat Pre-exposure reduced mortali ty Post-exposure no effect 1744-1746... 

Antiserum Guinea pig Pre-exposure gave immunity Post-exposure reduced mortality. Anaphylactic shock produced. 1567... 

Corchero J, Garcia-GU L, Manzanares J, Fernandez-Ruiz JJ, Fuentes JA, Ramos JA (1998) Perinatal A -tetrahydrocannabinol exposure reduces proenkephalin gene expression in the caudate-putamen of adult female rats. Life Sci 63 843-850... 

Major metabolites of CS are 2-chlorobenzyl malononitrile, o-chlorobenzaldehyde and o-chlorohippuric acid, the glycine conjugate of o-chlorobenzaldehyde (Feinsilver el al., 1971 Leadbeater, 1973). Exposure of cats and rats to aerosols of CS results in absorption of the material with its presence being detectable in blood along with two metabolites, o-chlorobenzaldehyde and o-chlorobenzylmalononitrile (Leadbeater, 1973). Over a 1-h exposure of cats to 750 mg m 3 CS aerosol, the blood concentrations of CS and o-chlorobenzylmalononitrile rapidly reached plateau levels, but that of o-chlorobenzaldehyde continued to rise throughout exposure. Reducing the aerosol exposure concentration to cats by a factor of 10 did not produce a proportionate decrease in the blood... 

Morata et al. (1995) reported metabolic and toxic interactions between toluene and several components of jet fuels. In rats exposed to toluene and hexane for 18 hr/day for 61 days, a synergistic reduction in auditory sensitivity occurred in the toluene-plus-hexane group that persisted for 365 days. Pryor and Rebert (1992) evaluated possible interactions between toluene and n-hexane exposures (individual vs. mixture protocols). Generally, the addition of toluene to the -hcxanc exposure reduced -hcxanc-induccd neuropathy. Perbellini et al. (1992) showed that inhibition of -hcxanc-induccd neuropathy by toluene was related to inhibition of -hcxanc metabolism to its neurotoxic metabolite, 2,5-hexanedione. -l lexanc and toluene use similar oxidative pathways for their primary metabolism. 

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