Psychosocial stress and longitudinally measured gestational weight gain throughout pregnancy: The Ulm SPATZ Health Study.

Psychosocial stress is thought to influence gestational weight gain (GWG), but results are inconsistent. We investigated the relationship of questionnaire-based maternal stress and related constructs assessed at childbirth with maternal weight measured throughout pregnancy. Data were derived from the Ulm SPATZ Health Study, a birth cohort recruited from the general population (04/2012-05/2013, Ulm, Germany). Adjusted generalized estimating equations were performed. Regression coefficients (b) and 95% confidence intervals, each highest versus lowest tertile of stress or related constructs, are presented. In 748 women, we observed positive associations for maternal chronic stress (b = 4.36 kg (1.77; 6.95)), depressive symptoms (b = 2.50 kg (0.14; 4.86)), anxiety symptoms (b = 3.26 kg (0.62, 5.89)), and hair cortisol (b = 3.35 kg (0.86; 5.83)) with maternal weight at the first gestational month. GWG was considerably lower in mothers with higher chronic stress. Pregnancy-related anxiety was positively related to weight at first month (b = 4.16 kg (1.74; 6.58)) and overall GWG. In contrast, no association was observed between anxiety symptoms and GWG. Odds ratios for association with inadequate weight gain according to Institute of Medicine recommended cutoffs differed from the results presented obove. There is evidence of an association between stress and weight gain lying beyond the recommended cut-offs, which however needs further corroboration.

New approach shows no association between maternal milk fatty acid composition and childhood wheeze or asthma.

BACKGROUND: Previous observational studies have implied breastmilk fatty acid composition may play a role in the development of atopic eczema or atopic sensitization in breastfed infants and toddlers. However, studies investigating associations with wheeze and asthma in later childhood are scarce and did not account for inherent correlation of compositional data. Our aim was to explore the association of maternal milk fatty acid composition with childhood wheezing phenotypes and asthma up to age 13 years using a new statistical approach. METHODS: Breastmilk was collected 6 weeks and 6 months postdelivery in the Ulm Birth Cohort Study (n=720 and n=454, respectively). Concentrations of 28 fatty acids were measured by high-resolution capillary gas-liquid chromatography. To control for constant-sum constraint, concentration data were transformed using the centered log ratio method. Compositional biplots and correlation matrices were used to group centered log ratio transformed fatty acids. Adjusted risk ratios with parent-reported wheezing phenotypes and doctor-diagnosed asthma were computed using a modified Poisson regression. RESULTS: We observed no straightforward evidence of associations between overall breastmilk fatty acid composition and specific wheeze phenotypes or doctor-diagnosed asthma. CONCLUSION: Using appropriate statistical methodology, we report null associations. These findings may partly be attributable to several cohort-specific factors associated with breastfeeding and breastmilk collection. Further studies could improve on ours by analyzing samples of breastmilk and formula and by including all children for whom these are exclusively or together the major source of fatty acids in the first months of life.

"[A]re Norway rats...things?": diversity versus generality in the use of albino rats in experiments on development and sexuality.

In America by the 1930s, albino rats had become a kind of generic standard in research on physiology and behavior that de-emphasized diversity across species. However, prior to about 1915, the early work of many of the pioneer rat researchers in America and in central Europe reflected a strong interest in species differences and a deep regard for diversity. These scientists sought broad, often medical, generality, but their quest for generality using a standard animal did not entail a de-emphasis of organic diversity. They chose white rats as test animals for two primary reasons. First, rats develop very slowly. They therefore made features of physiological, neural and psychological development accessible to the experimental method at a time when its application to the phenomena of development remained controversial. Secondly, rats were thought to have unusually strong sex drives. For this reason they became central to the experimental study of sexuality and, in the work of the reproductive physiologist Eugen Steinach, sexual development. Connections among three research institutes that stressed experimental approaches to the study of brain and development demonstrate the importance of the rat's institutional role. As the emphasis on experimentation in the study of development grew, two of these institutes bred rats to provide uniform materials. Eventually, however, their reasons for selecting rats were lost; and the ready availability of a uniform test animal led to a shift in scientists' presumptions about diversity, as the standard rat became a tool for assuring generality.

The altered rationale for the choice of a standard animal in experimental psychology: Henry H. Donaldson, Adolf Meyer, and "the" albino rat.

The mid 20th-century dominance of albino rats in nonhuman experimental psychology research often presumed that the animal embodied fundamental psychological processes that could generalize to a wide range of vertebrates. The author describes the conceptual basis for the original choice of white rats by the 2 individuals most responsible for establishing rats as a prominent animal model in the life sciences at the turn of the century: Henry H. Donaldson and Adolf Meyer. The author stresses the comparative rationale that justified their choice and argues that they sought generality through attention to diversity and species differences. Their approach contrasts sharply with the later view of the rat as a generic animal model that could represent similarities shared by all vertebrates. It is suggested that the change resulted from an emphasis on standardization produced by the growing industrialization of the life sciences in America.

Hormonal correlates of breeding status, nest construction, and parental care in multiple-brooded northern mockingbirds, Mimus polyglottos.

Blood samples were taken from free-living male and female mockingbirds to determine correlations between plasma steroids and breeding behavior. Plasma levels of testosterone (T), estradiol (E2), progesterone (P), and corticosterone (B) were assessed during pre-breeding courtship, while males built nests, while females incubated, while parents fed young, and while males built new nests as pairs continued to care for dependent fledglings. Samples were also taken from unmated males holding spring territories. In males, T and P fluctuated with breeding phase, and in all groups, male T levels exceeded basal values measured in autumn. But, when mated males built nests in the absence of young, T levels were higher than in all other conditions, though only for early broods. In females too, T and P levels changed with breeding phase; T levels rose during courtship and while males built first nests and were intermediate during nest construction for later broods. Male and female P levels rose during courtship and when males built nests with young present. While feeding young in the nest, males showed significantly higher corticosterone levels than females, though in females, both P and B levels increased during incubation for replacement broods. These findings strengthen an earlier finding that T may activate male nest construction, and they suggest that breeding behavior may be related to T in females as well. Progesterone data raise the possibility that P too, may be linked to breeding behavior in male and female mockingbirds. Sex differences in corticosterone levels during the nestling period may reveal subtle costs associated with male mockingbirds' highly aggressive defense against predators.

Leiomyosarcoma of the larynx.

Leiomyosarcoma (LMS) is an uncommon tumor among the spectrum of soft tissue sarcomas. It is exceedingly rare in the head and neck regions. We report a case of laryngeal LMS that presented with obstructive symptoms, which was amenable to conservative surgery and postoperative irradiation. There is no evidence of recurrent disease at 18-month follow-up.

Testosterone stimulates reproductive behavior during autumn in mockingbirds (Mimus polyglottos).

Mockingbirds normally secrete little or no testosterone during the period of autumnal territoriality. To determine the behavioral effects of exogenously administered testosterone, 20-mm lengths of Silastic tubing filled with crystalline testosterone were implanted into free-living resident mockingbirds during the autumn. Control residents were given sealed empty implants. Focal animal sampling showed that T-implanted males sang significantly more than controls. Perhaps as a consequence, a significantly greater percentage of the T-implanted males acquired mates. Though nest building does not naturally occur in autumn, T-implanted males also showed significantly more nest building than control males. However, T-implanted males only built if there was a female in the territory, suggesting a synergy between the presence of testosterone and social cues provided by the female. Examination of the effects of testosterone on territorial aggression showed that despite the high levels of territorial activity common in this species in autumn, territorial fights were unaffected by the presence of testosterone. One aggressive call, known to function in fall territorial defense, was significantly decreased in T-implanted versus control males. The presence of fall testosterone appears to stimulate a number of reproductive activities in mockingbirds, leaving autumnal aggressive interactions either unchanged or decreased. We discuss the application of these data to the effects of testosterone on the mockingbird's reproductive behavior during the breeding season.

Autumnal territorial aggression is independent of plasma testosterone in mockingbirds.

Mockingbirds (Mimus polyglottos) show intense territorial activity in the autumn as newcomers attempt to establish space within resident populations. Examination of autumnal territorial behavior showed that unmated males sing more and engage in more territorial fights than mated males. Newcomers that have just acquired space also sing more and show more territorial fights than birds resident to the population for at least one prior season. Among established residents, the average number of territorial fights was greater in birds that shared more territory boundaries with new residents. Radioimmunoassay of plasma samples taken from males during the molt and following the onset of territorial defense showed that during both periods plasma concentrations of testosterone (T), dihydrotestosterone (DHT), and estradiol were basal or below the sensitivity of the assay system. Moreover, groups of males that differed in song and territorial aggression did not differ in plasma concentrations of T, DHT, or luteinizing hormone (LH). Hormone analyses confirm measurements on several other avian species suggesting that sex steroid concentrations are low in the fall and winter and that variations in aggressive behavior at this time of year may be unrelated to LH and androgen levels. Our observations contribute to a growing body of work in temperate passerines indicating that the role of androgens in mediating aggressive challenge may be restricted to the breeding season. The possible hormonal basis (if any) of song and territorial aggression in mockingbirds outside the breeding season remains obscure.