Psychological Sequelae of Elective Abortion

A mild, short, depressive and guilt ridden period following abortion is quite common, but a severe psychological reaction is rare. The indication for the abortion and the preabortal psychological state of the patient are the two most important factors. Almost all reported instances of postabortion psychoses have occurred in patients who had severe preabortal psychiatric problems. Women undergoing abortion for socioeconomic or psychosocial indications appear to be at minimal risk for long-term negative psychological sequelae. In contrast, women in whom abortion is carried out because of exposure to rubella and the risk of fetal malformation, maternal organic disease or the prenatal diagnosis of a genetically defective fetus are at greater risk and may need supportive psychotherapy.     

Do Femtonewton Forces Affect Genetic Function? A Review

Protein-Mediated DNA looping is intricately related to gene expression. Therefore any mechanical constraint that disrupts loop formation can play a significant role in gene regulation. Polymer physics models predict that less than a piconewton of force may be sufficient to prevent the formation of DNA loops. Thus, it appears that tension can act as a molecular switch that controls the much larger forces associated with the processive motion of RNA polymerase. Since RNAP can exert forces over 20 pN before it stalls, a ‘substrate tension switch’ could offer a force advantage of two orders of magnitude. Evidence for such a mechanism is seen in recent in vitro micromanipulation experiments. In this article we provide new perspective on existing theory and experimental data on DNA looping in vitro and in vivo. We elaborate on the connection between tension and a variety of other intracellular mechanical constraints including sequence specific curvature and supercoiling. In the process, we emphasize that the richness and versatility of DNA mechanics opens up a whole new paradigm of gene regulation to explore.     

Pheromones linked to sexual behaviors excite the appetitive phase of feeding behavior of Aplysia fasciata. I. Modulation and excitation of appetitive behaviors

Pheromones presumably secreted by mating conspecifics – as well as homogenates containing tissue that is homologous with the atrial gland – increase the time that Aplysia fasciata spend feeding. This effect is caused by increasing the number of feeding episodes initiated in response to food, whereas the duration of a feeding bout remains unchanged. The increase in the number of feeding episodes is related to increases in head waving and crawling, i.e., appetitive movements that bring the animal into contact with food, as well as an increase in the responsiveness to food after it is contacted. Releasing a homogenate containing atrial gland tissue, or egg laying hormone, in the water near the animal elicited head lifting similar to that seen when animals are food aroused. The data indicate that the facilitation of Aplysia feeding caused by pheromones arises in part by an excitation of appetitive behaviors. These findings suggest that neurons generating appetitive behaviors will be affected by pheromones. Accepted: 28 November 1997     

A split zinc-finger protein is required for normal yeast growth.

We have identified a gene that, when present in multiple copies, partially inhibits nuclear protein localization in Saccharomyces cerevisiae. This gene encodes a protein that is a unique member of the Cys2His2 zinc-finger family of DNA-binding proteins. It is designated SFP1 for split finger protein because its two zinc-finger domains are separated from one another by 40 amino acids (aa) as opposed to the usual spacing of 7 or 8 aa for Cys2His2 proteins. Disruption of the SFP1 gene results in slow cell growth, with cells having multiple, nucleated buds.