Lethality of suicidal organophosphorous poisoning in Karachi in 2010

The study was aimed to evaluate the cases of suicide using organophosphorous compounds as intoxicant with the objective to bring up possible preventive measures based upon modifiable factors associated with lethality. Cross-sectional analytical Study. This retrospective study was based upon 66 patients of poisoning treated at intensive care unit of Ward No.5, JPMC Karachi during a period of one year from January 2010 to December 2010. Out of total 66 cases of poisoning 38 were of organophosphorous compounds [OPC] poisoning, 20 males and 18 females. Most of the cases [63%] of OPC poisoning were in age range of 20-40 years, 33 [86.84%] were of suicidal poisoning while 5 [13.16%] had accidental poisoning and 57% reported to treatment facility within 6 hours. All the cases of OPC poisoning had severe symptoms with fatal out come. Suicidal ratio was quite high. The period between the ingestion of poison and initiation of treatment plays vital role. In order to reduce fatality rate urgent intervention is required by government by improving the treatment facilities at local level hospitals i.e. primary health care centres and banning of highly toxic organophosphorous compounds. Additional measures which can help include improving the public awareness regarding recognition of toxic symptoms and importance of prompt referral to an appropriate facility

Erythrocyte antioxidant enzymes in toxicological evaluation of commonly used organophosphate pesticides.

Erythrocytes are excellent models for the study of interactions of xenobiotics with biomembranes. Present work is designed to study the in vitro effects of some organophosphates (ethion, chlorpyrifos, dimethoate and monocrotophos) on rat erythrocytes. Treatment of erythrocytes with organophosphates resulted in decreased erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) activity, whereas activities of glutathione-s-transferase (GST) and glutathione reductase (GR) were increased. Reduced Glutathione (GSH) content of RBCs was decreased after treatment with the pesticides. Increased activities of GST and GR were due to induction of natural defense mechanism of erythrocytes against the toxicity of the pesticides. Membrane bound enzymes like acetylcholinesterase (AChE), Na(+)-K(+)-ATPase and Ca(2+)-ATPase were also inhibited. Altered activities of these enzymes along with decreased GSH content indicate increased oxidative stress in erythrocytes after treatment with organophosphates.

Evaluation of the HI-6 ability on reversal or prevention of paraoxon-induced changes in the function of Chichen Biventer cervices nerve-muscle preparation

Paralysis of skeletal muscles,which can lead to paralysis of respiratory muscles and death, is one of the most toxic effects of organophosphates [Ops],and oximes are almost the only known antidotes that can reverse or prevent such toxic effects. In the present research work, possible reversal or preventive effect of different concentrations of the relatively new oxime [HI-6] on paraoxon-induced changes on function of skeletal muscle of chicken biventer cervices [CBC] nerve- muscle preparation were studied using twitch tension recording technique. This is experimental study. For this purpose,twitches of the CBC muscle were evoked by stimulating the motor nerve at 0.1 Hz with pulses of 0.2 msec duration and a voltage of greater than that required to produce the maximum response. Twitches were recorded isotonically using Narco Biosystem. Our prior findings revealed that paraoxon at a concentration of 0.1 micro M induces a significant increase [more than 100%] in the twitch amplitude, and therefore, this concentration was used to examine the efficacy of HI-6 to reverse or prevent such effects. HI-6 at 1000 micro M could almost fully reverse [when it was used as post treatment] or prevent [when it was used as pretreatment or at the same time as toxin] the effect of paraoxon. It could also reverse or reduce this effect to about 25%, 50% and 75% at 300,100 and 30 micro M, respectively. Furthermore, HI-6 at 10 micro M produced no significant preventive or reversal effect. However, HI-6 alone at 1000 micro M increased the twitch amplitude by about 20%.These data indicated that HI-6 could be recognized as an antidote of paraoxon, although it may have other effects at high concentrations

Efficacy of different organophosphate and synthetic pyrethroid insecticides to the larvae of malaria vector Anopheles stephensi, Liston.

Evaluation of the potency of four organophosphate (OP) (Malathion, Fenthion, Fenitrothion and Temephos) and two synthetic pyrethroid (SP) compounds (cypermethrin and deltamethrin) was carried out against larvae of Anopheles stephensi, the major malaria vector in district Bikaner (Rajasthan). Different concentrations supplied by WHO were used for determining the percent mortalities. LC50 values as calculated by probit analysis were 1.2740, 0.0600, 0.0405, 0.0046, 0.0019 and 0.0016 mg/l respectively for the above six insecticides. Both SP compounds were found more toxic followed by temephos among the OP compounds. Malathion was found the least toxic while fenthion and fenitrothion were in between these two extremes.

Effects of dimethyl methylphosphonate (DMMP) and trimethylphosphate (TMP) on spermatogenesis of rat testis

Both dimethyl methylphosphonate (DMMP) and trimethylphosphate (TMP) are organophosphorous compounds that can evoke sterility in male rodents. The following studies examined the pathology of reproductive organ, especially on the testis, by light microscopy after treatment with both agents. Adult male rats were treated per oral with DMMP, 1,750 mg/Kg, for up to 12 weeks and per oral with TMP, 400 mg/Kg for up to 5 weeks. After 5 weeks of treatment with DMMP there were occasional multinucleated giant cells composed of late spermatids in stages X, XI, XII as well as cytoplasmic vacuolation of Sertoli cell. Anachronistic spermiations were seldom, if ever, seen throughout the experiment. After 7 weeks of DMMP those were markedly diminished. The overall changes after treatment with TMP are somewhat similar to those treated with DMMP. The major changes were composed of aggregate of multinucleated giant cells and maturation arrest at spermatid level, which appear immediately after administration of TMP. The peak frequency in the emergence of multinucleated giant cells in treatment with TMP was noted just a week after treatment, but afterwards declined. Maturation arrest was prominent after 3 weeks in the cases treated with TMP.