Verbal problem-solving in agenesis of the corpus callosum: Analysis using semantic similarity.

OBJECTIVE: Previous studies demonstrated that individuals with agenesis of the corpus callosum (AgCC) experience difficulties in novel and complex problem-solving. The present study investigated verbal problem-solving, deductive reasoning, and semantic inference in AgCC. METHOD: Capacity for semantic inference was tested in 25 individuals with AgCC and normal-range intelligence compared to 29 neurotypical controls. The Word Context Test (WCT) of Delis-Kaplan Executive Function System was used, employing a novel method of analysis (semantic similarity) to detect trial-by-trial progress toward a solution. RESULTS: With respect to the typical WCT scores, persons with AgCC had fewer total consecutive correct responses. In addition, semantic similarity to the correct word was significantly lower overall in persons with AgCC than in controls. CONCLUSION: These findings indicated that individuals with AgCC who have intelligence in the normal range are less able at the WCT taking all trials into account, although they often solve the problem eventually. This outcome is consistent with previous research indicating that callosal absence in AgCC results in a restricted imagination for possibilities, limiting their problem-solving and inferential capacities. The results also highlight the usefulness of semantic similarity as a means of scoring the WCT. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Activation of estrogen receptor-alpha by the anion nitrite.

In this study, the ability of nitrite and nitrate to mimic the effects of estradiol on growth and gene expression was measured in the human breast cancer cell line MCF-7. Similar to estradiol, treatment of MCF-7 cells with either 1 mumol/L nitrite or 1 mumol/L nitrate resulted in approximately 4-fold increase in cell growth and 2.3-fold to 3-fold increase in progesterone receptor (PgR), pS2, and cathepsin D mRNAs that were blocked by the antiestrogen ICI 182,780. The anions also recruited estrogen receptor-alpha (ERalpha) to the pS2 promoter and activated exogenously expressed ERalpha when tested in transient cotransfection assays. To determine whether nitrite or nitrate was the active anion, diphenyleneiodonium was used to inhibit oxidation/reduction reactions in the cell. The ability of diphenyleneiodonium to block the effects of nitrate, but not nitrite, on the induction of PgR mRNA and the activation of exogenously expressed ERalpha suggests that nitrite is the active anion. Concentrations of nitrite, as low as 100 nmol/L, induced a significant increase in PgR mRNA, suggesting that physiologically and environmentally relevant doses of the anion activate ERalpha. Nitrite activated the chimeric receptor Gal-ER containing the DNA-binding domain of GAL-4 and the ligand-binding domain of ERalpha and blocked the binding of estradiol to the receptor, suggesting that the anion activates ERalpha through the ligand-binding domain. Mutational analysis identified the amino acids Cys381, His516, Lys520, Lys529, Asn532, and His547 as important for nitrite activation of the receptor.