Development of malathion resistance in Culex quinquefasciatus Say (Diptera: Culicidae).

A malathion resistant colony of C. quinquefasciatus was developed in the laboratory. LC50 and LC90 for larvae were calculated at every generation and the values were 0.3 ppm and 1.13 ppm for first generation and 61.09 ppm, 136.3 ppm for 25th generation respectively. The fold increase in LC50 and LC90 were 2036 and 2726 folds respectively. Cross resistance against propoxur and chlorpyrifos showed 6.64 and 6.52 fold and 600 and 720 fold increase in their LC50 and LC90 values respectively. Triphenyl phosphate (TPP) and piperonyl butoxide (PB) were used as synergists and TPP indicated proportional decrease in LC50 and LC90 values while not much change was observed with PB. No change in biotic potential (larval hatchability, adult emergence and male and female ratio) between susceptible and malathion resistant colonies was observed.

Quantitative and temporal relationships of alcohol use in narcotic addicts and methadone maintenance patients undergoing alcohol detoxification.

Evidence exists that alcohol abuse frequently coexists with narcotic addiction and methadone maintenance treatment, and it is the major factor in the development of cirrhosis and liver failure. This study of patients hospitalized for alcohol detoxification compares the quantity of alcohol consumed by alcohol abusers, addicted to narcotics or in a methadone maintenance treatment program, to that consumed by patients not involved with narcotic addiction. Mean daily alcohol consumption was not significantly different in either group using narcotics, including methadone, or in the subgroup of methadone maintenance patients, from the amount consumed by nonnarcotic abusers. Determination of temporal sequence in the use of these substances revealed that in 68% regular alcohol abuse preceded narcotic use. Alcohol abuse reportedly began after entering a methadone maintenance treatment program in 29% of our patients. Alcohol abusers who were in a methadone maintenance treatment program were significantly younger than those who did not use narcotics, including methadone. Time interval according to the patients' estimates, from onset of regular alcohol consumption to heavy drinking, was not significantly different in the two groups.