Dichloroacetamide antidotes for thiocarbamate herbicides: mode of action.

Thiocarbamate sulfoxides formed on metabolic sulfoxidation of thicoarbamate herbicides in plants and mammals are effective carbamoylating agents for glutathione and other tissue thiols. Dichloracetamides that protect corn from thiocarbamate herbicide injury more rapid detoxification of the thiocarbamate sulfoxides by increasing their rate of carbamoylation of glutathione through elevation of the root glutathione level and glutathione s-transferase activity.

2,4-Diamino-5-benzylpyrimidines and analogues as antibacterial agents. 9. Lipophilic trimethoprim analogues as antigonococcal agents.

Lipophilic analogues of trimethoprim (1) bearing 3,5-dialkyl-4-hydroxy substituents in the benzene ring are much more active in vitro against Neisseria gonorrhoeae than is 1. The 3,5-diisopropyl-4-hydroxy derivative (2) was selected as a candidate for clinical evaluation as an antigonococcal agent, and as part of the preliminary evaluation it was submitted to extended pharmacokinetic and metabolism studies in dogs. Although the compound was not extensively conjugated by metabolic enzymes, one of the methyl groups was metabolized to produce a 3-isopropyl-4-hydroxy-5-(alpha-carboxyethyl)benzyl derivative (43), which was rapidly excreted. Related analogues were likewise extensively metabolized.

Association between maternal diabetes and the respiratory-distress syndrome in the newborn.

Perinatal data on 805 infants of diabetic mothers and 10,152 infants of nondiabetic mothers were examined for a relation between maternal diabetes and respiratory-distress syndrome of the newborn. The syndrome occurred in 23.4 per cent of the diabetic vs. 1.3 per cent of the nondiabetic group. The risk of the syndrome in an infant of a diabetic mother was 23.7 times greater than that for an infant of a nondiabetic mother (P less than 0.00001). Further analysis to control for features associated with diabetes but also in themselves risk factors, such as gestational age and route of delivery, showed that respiratory-distress syndrome in infants of diabetic mothers was 5.6 times as likely to develop as in infants of nondiabetic mothers (P less than 0.00001). Thus, maternal diabetes mellitus per se predisposes to newborn respiratory-distress syndrome.

Reduction in reperfusion-induced myocardial necrosis in dogs by RheothRx injection (poloxamer 188 N.F.), a hemorheological agent that alters neutrophil function.

BACKGROUND: Reperfusion after prolonged coronary artery occlusion may be followed by additional myocardial necrosis persisting for hours to days. Potential mechanisms include neutrophil-mediated injury and compromised flow within the microcirculation of the reperfused myocardium. Poloxamer 188 is a nonionic surfactant with beneficial hemorheological and neutrophil-inhibitory properties. The purpose of the present study was to determine if poloxamer 188 is capable of reducing the myocardial injury associated with sustained reperfusion and to examine the effect of treatment duration. METHODS AND RESULTS: Three groups of closed-chest dogs underwent 90 minutes of left anterior descending coronary artery occlusion (angioplasty balloon) and 72 hours of reperfusion. Poloxamer 188, formulated as RheothRx Injection (Burroughs Wellcome Co), was given as a 75 mg/kg IV bolus 15 minutes before reperfusion followed by a 150 mg.kg-1.h-1 continuous IV infusion for 4 hours (n = 13) or 48 hours (n = 13); control dogs (n = 12) received saline for 48 hours. The 48-hour infusion of poloxamer 188 resulted in a 42% reduction in infarct size (as a percent of the area at risk) compared with the control group (25.0 +/- 4.2% versus 43.3 +/- 4.3%, P D .01), whereas the 4-hour group demonstrated a 25% reduction in infarct size compared with the control group (32.4 +/- 4.3%, P = .08). ANCOVA demonstrated that the 48-hour infusion of poloxamer 188 reduced myocardial infarct size independent of differences in collateral blood flow (P = .002 versus control). A trend toward infarct size reduction was observed in the 4-hour infusion group (P = .098 versus control by ANCOVA). Plasma creatine phosphokinase concentration was lower in both poloxamer 188-treated groups (P < .05 versus control). Global left ventricular ejection fraction at 72 hours of reperfusion was improved in the 48-hour infusion group compared with the control group (43 +/- 3.1% versus 33 +/- 2.0%, P < .05), whereas ejection fraction in the 4-hour group was 37 +/- 1.3% (P = NS versus control). Regional ventricular function was also significantly better in the 48-hour infusion group compared with the control group. In vitro studies demonstrated that at concentrations comparable to those achieved in vivo, poloxamer 188 inhibited neutrophil chemotaxis. This finding may represent a beneficial mechanism of action. CONCLUSIONS: A 48-hour infusion of poloxamer 188 reduced myocardial infarct size and improved left ventricular function in this dog model of 90 minutes of coronary artery occlusion and 72 hours of reperfusion. The finding that the 4-hour infusion of poloxamer 188 did not result in similar benefits suggests that additional reperfusion injury occurred between 4 and 48 hours.