Gonadotropin levels in urine during early postnatal period in small for gestational age preterm male infants with fetal growth restriction.

OBJECTIVE: The objective of this study was to estimate gonadotropin concentrations in small for gestational age (SGA) male infants with the reactivation of the hypothalamic-pituitary-gonadal axis during the first few months of life that is important for genital development. STUDY DESIGN: We prospectively examined 15 SGA and 15 appropriate for gestational age (AGA) preterm male infants between 2013 and 2014 at Kyoto University Hospital. Gonadotropin concentrations (luteinizing hormone (LH) and follicle-stimulating hormone (FSH)) were measured in serial urine samples from the postnatal days 7 to 168 and compared between SGA and AGA infants using the Mann-Whitney test. RESULTS: A longitudinal analysis showed that SGA infants had higher LH and lower FSH concentrations (P=0.004 and P=0.006, respectively) than AGA infants. CONCLUSION: Male infants who are SGA at birth because of fetal growth restriction have gonadotropin secretion abnormalities in the first few months of life.

Imitation of intentional manipulatory actions in chimpanzees (Pan troglodytes).

In this study, the authors investigated the understanding of other's actions in 5 adult chimpanzees (Pan troglodytes). A human demonstrated an attempt to open different containers. Each container required a different motor pattern to open it. Along with the container, a 2nd object was made available. After a free play period in which the chimpanzees' natural behaviors toward the objects were recorded, the authors tested the following 2 phases: The demonstrator (a) tried but failed to open and (b) opened the container successfully, with 1 of 2 alternative strategies, either using an "irrelevant tool" or by hand. The chimpanzees did not reproduce the demonstrator's motor patterns precisely but did reproduce the demonstrated strategies in both phases. These results suggest that chimpanzees anticipate the intentions of others by perceiving the directionality and causality of object(s) as available cues.

Factors influencing imitation of manipulatory actions in chimpanzees (Pan troglodytes).

The purpose of the study was to investigate what kind of factors determine the degree of difficulty for chimpanzees (Pan troglodytes) when they imitate actions. Five adult chimpanzees were instructed to perform 48 arbitrary manipulatory actions consisting of different bodily motor patterns and object directionality. Results showed that actions in which an object is directed toward another external location (another object and one's own body) were easier to perform than those that involved manipulating a single object alone. Actions involving unfamiliar motor patterns were more difficult to perform than those involving familiar motor patterns that were already present in the subject's repertoire. Error responses were characterized as perseverative repetition of previously instructed actions. These findings suggest that chimpanzees find the directionality of manipulated objects a more salient cue than details of the demonstrator's body movements performing the manipulation.