Methyl poisoning

In another case series, Thiermann et al. (1999) reported that in parathion poisoning, reactivation was possible 7 days after poisoning, whereas with oxydemeton methyl, response was only seen when obidoxime therapy was instituted soon after poisoning. Similarly, Zilker et al. (1997) reported that obidoxime (750 mg/day by infusion) drastically reduced the need for atropine in parathion poisoning, but that demeton-5-methyl poisoning only responded to obidoxime if therapy was instituted soon after intoxication. 

It was reported that in parathion poisoning, an obi-doxime dose of 250 mg intravenously administered as a bolus followed by infusion of 750mg/day was effective, but AChE reactivation after severe poisoning did not occur until the concentration of paraoxon in plasma became low (Thiermann et al., 1997,1999). Oxydemeton methyl poisoning responded to obidoxime therapy only when the oxime was instituted soon after poisoning. In cases when obidoxime treatment was started too late, there was no reactivation of erythrocyte AChE and one out of six patients died. 

Experiments involving the use of dimethyl sulphate should be carried out by students only under immediate supervision. Not only is the vapour of dimethyl sulphate highly poisonousy but the cold liquid itself is absorbed easily through the skin, with toxic results individual susceptibility to ditnethyl sulphate poisoning varies and may be very high. If the sulphate is splashed on to the hands, wash immediately with plenty of concentrated ammonia solution in order to hydrolyse the methyl sulphate before it can be absorbed through the skin (see p. 528). 

Other mixtures which may be employed are carbon tetrachloride (b.p. 77°) and toluene (b.p. 110-111°) chloroform (b.p. 61°) and toluene methyl alcohol (b.p. 65°) and water (b.p. 100°). The last example is of interest because almost pure methyl alcohol may be isolated no constant boiling point mixture (or azeotropic mixture) is formed (compare ethyl alcohol and water, Sections 1,4 and 1,5). Attention is directed to the poisonous character of methyl alcohol the vapour should therefore not be inhaled. 

Diethyl sulphate, b.p. 210° (decomp.), does not ordinarily react so vigor ously as dimethyl sulphate, but is nevertheless of great value for ethylations. It is somewhat leas poisonous than the methyl analogue, but the same pre cautions should be taken. Both sulphates should be stored in glass stoppered bottles sealed with paraffin wax, for they attack cork. 

Nitrobenzene (and many other liquid organic compoimds containing nitrogen) is appreciably toxic and its vapour should not be allowed to escape into the atmosphere of the laboratory the delivery tube of the condenser should pass well into the mouth of the receiver flask. The liquid is also a skin poison if it Is accidentally spilled on the skin, it should be removed by washing with a litt e methylated spirit, followed by soap and warm water. 

Rya.nia., The root and stem of the plant yania speciosa family Flacourtiaceae, native to South America, contain from 0.16—0.2% of iasecticidal components, the most important of which is the alkaloid ryanodine [15662-33-9] C25H250 N (8) (mp 219—220°C). This compound is effective as both a contact and a stomach poison. Ryanodine is soluble ia water, methyl alcohol, and most organic solvents but not ia petroleum oils. It is more stable to the action of air and light than pyrethmm or rotenone and has considerable residual action. Ryania has an oral LD q to the rat of 750 mg/kg. The material has shown considerable promise ia the control of the European com borer and codling moth and is used as a wettable powder of ground stems or as a methanohc extract. Ryanodine uncouples the ATP—ADP actomyosia cycle of striated muscle. 

Arsenic. Arsenic is under consideration for inclusion as an essential element. No clear role has been estabHshed, but aresenic, long thought to be a poison, may be involved in methylation of macromolecules and as an effector of methionine metaboHsm (158,160). Most research has focused on the toxicity or pharmaceutical properties of arsenic (158). 

Methyl bromide is sold both as the essentially pure compound, 99.5% minimum, with not more than 0.010% water and 0.001% acidity as HBr, and with small amounts of chloropicrin [76-06-2], CCI2NO2. During 1992 methyl bromide in tank cars was priced at 1.70/kg. Methyl bromide is suppHed in 37,850- and 60,560-L tank cars and in 12,220-L ISO cylinders. Repackagers supply methyl bromide in 0.45 kg or 0.68 kg cans for such appHcations as fumigating tobacco seed beds. Alone or in formulations, it is classified as a poison, class B, and requires a poison label. 

Benzyldiethyl[(2,6-xylylcarbamoyl)methyl]ammoniumbenzoate (denatonium benzoate [3734-33-6] Bitrex) is an extremely bitter tasting, nonirritating, and nonmutagenic compound that has been widely used in many household products such as detergents, nail poHsh removers, and cleaning agents, to prevent childhood poisoning. It is also used as an alcohol denaturant. 

Hydroxymethyl-6-methyluracil (1043) was prepared many years ago from 6-methyl-uracil and formaldehyde, or in other ways. Since 1956 it has received much attention in the USSR under the (transliterated) name pentoxyl or pentoxil. It is used in several anaemic and disease conditions. For example, a mixture of folic acid and pentoxyl quickly reduces the anaemia resulting from lead poisoning pentoxyl stimulates the supply of serum protein after massive blood loss it stimulates wound healing it stimulates the immune response in typhus infection and it potentiates the action of sulfonamides in pneumococcus infections (70MI21300). 

Mercury is emitted from the mercury cell process from ventilation systems and by-product streams. Control techniques include (1) condensation, (2) mist elimination, (3) chemical scrubbing, (4) activated carbon adsorption, and (5) molecular sieve absorption. Several mercury cell (chloralkali) plants in Japan have been converted to diaphragm cells to eliminate the poisonous levels of methyl mercury found in fish (9). 

Cytisine. This base belongs to the same pharmacological group as nicotine.It is a powerful poison causing nausea, convulsions and death by failure of respiration. The nicotine-like action is shared by A -methyl-cytisine but the latter, according to Scott and Chen, who have made a detailed study of its action, is weaker and has about one-fortieth the toxicity of nicotine. 

The worst disaster in the history of the chemical industry occurred in Bhopal, in the state of Madhya Pradesh in central India, on December 3, 1984. A leak of methyl isocyanate (MIC) from a chemical plant, where it was used as an intermediate in the manufacture of the insecticide car-baryl, spread beyond the plant boundary and caused the death by poisoning of more than 2,000 people. The official figure was 2,153, but some unofficial estimates were much higher. In addition, about 200,000 people were injured. Most of the dead and injured were living in a shanty town that had grown up next to the plant. 

As diseussed earlier, nuelear aeeidents have not been the only aeeidents to oeeur in reeent times. Other disasters at ehemieal plants have been responsible for a mueh greater loss of life. The worst disaster in the reeent history of the ehemieal industry oeeurred in Bhopal, in eentral India, on Deeember 3, 1984. A leak of methyl isoeyaiiate (MIC) from a ehemieal plant, where it was used as an intermediate in the manufaeture of a pesiieide, spread into tlie adjaeent eity and eaused the poisoning deatli of more tlian 2500 people approximately 20,000 others were injured. 

In a penicillin synthesis, the carboxyl group was protected as a / -bromophenacyl ester that was cleaved by nucleophilic displacement (PhSK, DMF, 20°, 30 min, 64% yield). Hydrogenolysis of a benzyl ester was difficult (perhaps because of catalyst poisoning by sulfur) basic hydrolysis of methyl or ethyl esters led to attack at the /3-lactam ring. ... 

The concentration of a solute has a considerable effect on the viscosity of the fluid and so on the surface convective resistance to heat flow. There is little published data on these effects, so applications need to be checked from basic principles. Industrial alcohol (comprising ethyl alcohol with a statutory addition of methyl alcohol to render it poisonous) may be used as a secondary refrigerant, either at 100% concentration or mixed with water. The fluid has a low viscosity and good heat transfer, but is nowlittle used on account of its toxicity and the fire risk in high concentrations. Other nonfreeze heat transfer fluids are used in specialist trades. 

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