Suicide in elementary school-aged children is not well studied, despite a recent increase in the suicide rate among US black children. The objectives of this study were to describe characteristics ...and precipitating circumstances of suicide in elementary school-aged children relative to early adolescent decedents and identify potential within-group racial differences.
We analyzed National Violent Death Reporting System (NVDRS) surveillance data capturing suicide deaths from 2003 to 2012 for 17 US states. Participants included all suicide decedents aged 5 to 14 years (N = 693). Age group comparisons (5-11 years and 12-14 years) were conducted by using the χ
test or Fisher's exact test, as appropriate.
Compared with early adolescents who died by suicide, children who died by suicide were more commonly male, black, died by hanging/strangulation/suffocation, and died at home. Children who died by suicide more often experienced relationship problems with family members/friends (60.3% vs 46.0%; P = .02) and less often experienced boyfriend/girlfriend problems (0% vs 16.0%; P < .001) or left a suicide note (7.7% vs 30.2%; P < .001). Among suicide decedents with known mental health problems (n = 210), childhood decedents more often experienced attention-deficit disorder with or without hyperactivity (59.3% vs 29.0%; P = .002) and less often experienced depression/dysthymia (33.3% vs 65.6%; P = .001) compared with early adolescent decedents.
These findings raise questions about impulsive responding to psychosocial adversity in younger suicide decedents, and they suggest a need for both common and developmentally-specific suicide prevention strategies during the elementary school-aged and early adolescent years. Further research should investigate factors associated with the recent increase in suicide rates among black children.
The selective grass herbicides diclofop, haloxyfop, and trifop were found to be potent reversible inhibitors of acetyl-CoA carboxylase from the susceptible species barley, corn, and wheat. Kis values ...with variable concentrations of acetyl-CoA ranged from 0.01 to 0.06 microM at pH 8.5 depending on the species of grass. Inhibition of the wheat enzyme by diclofop was noncompetitive versus acetyl-CoA with Kis less than Kii and noncompetitive versus MgATP and bicarbonate, but with Kis approximately equal to Kii. Since the apparent inhibition constant was most sensitive to the level of acetyl-CoA, these compounds probably interact with the transcarboxylase site rather than the biotin carboxylation site. With the wheat enzyme the Kis value for the R-(+)-enantiomer of trifop was 1.98 +/- 0.22 times lower than that of the racemic mixture. This confirms the stereoselectivity observed in the whole plant. The enzyme from tolerant broadleaf species (spinach and mung bean) was much less sensitive to these herbicides (Kis values varied from 16 to 515 microM). These data confirm that acetyl-CoA carboxylase is the site of action for the aryloxyphenoxypropionic acid herbicides and may explain their selectivity for monocotyledenous species.
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