Prostate enlargement in mice due to fetal exposure to low doses of estradiol or diethylstilbestrol and opposite effects at high doses

On the basis of results of studies using high doses of estrogens, exposure to estrogen during fetal life is known to inhibit prostate development. However, it is recognized in endocrinology that low concentrations of a hormone can stimulate a tissue, while high concentrations can have the opposite effect. We report here that a 50% increase in free-serum estradiol in male mouse fetuses (released by a maternal Silastic estradiol implant) induced a 40% increase in the number of developing prostatic glands during fetal life; subsequently, in adulthood, the number of prostatic androgen receptors per cell was permanently increased by 2-fold, and the prostate was enlarged by 30% (due to hyperplasia) relative to untreated males. However, as the free serum estradiol concentration in male fetuses was increased from 2- to 8-fold, adult prostate weight decreased relative to males exposed to the 50% increase in estradiol. As a model for fetal exposure to man-made estrogens, pregnant mice were fed diethylstilbestrol (DES) from gestation days 11 to 17. Relative to controls, DES doses of 0.02, 0.2, and 2.0 ng per g of body weight per day increased adult prostate weight, whereas a 200-ng-per-g dose decreased adult prostate weight in male offspring. Our findings suggest that a small increase in estrogen may modulate the action of androgen in regulating prostate differentiation, resulting in a permanent increase in prostatic androgen receptors and prostate size. For both estradiol and DES, prostate weight first increased then decreased with dose, resulting in an inverted-U dose-response relationship.     

A physiologically based approach to the study of bisphenol A and other estrogenic chemicals on the size of reproductive organs, daily sperm production, and behavior

Two chemicals previously shown to have estrogenic activity, bisphenol A and octylphenol, were examined for their effects on accessory reproductive organs and daily sperm production in male offspring of mice fed these chemicals during pregnancy. These chemicals are used in the manufacture of plastics and other products, and have been detected in food and water consumed by animals and people. From gestation day 11-17 female mice were fed an average concentration (dissolved in oil) of bisphenol A or octylphenol of 2 ng/g body weight (2 ppb) and 20 ng/g (20 ppb). The 2 ppb dose of bisphenol A is lower than the amount reported to be swallowed during the first hour after application of a plastic dental sealant (up to 931 micrograms; 13.3 ppb in a 70 kg adult). We found that the 2 ng/g dose of bisphenol A permanently increased the size of the preputial glands, but reduced the size of the epididymides; these organs develop from different embryonic tissues. At 20 ng/g, bisphenol A significantly decreased efficiency of sperm production (daily sperm production per g testis) by 20% relative to control males. The only significant effect of octylphenol was a reduction in daily sperm production and efficiency of sperm production at the 2 ng/g dose. A new approach to studying physiologically relevant doses of environmental endocrine disruptors is discussed, particularly with regard to the development of the reproductive organs, the brain, and behavior.     

Evidence incompatible with a cognitive compatibility theory of rating behavior.

Assessed the cognitive complexity of 96 undergraduates with the group version of the Role Construct Repertory (REP) Test, a factor analysis of REP test data, and a sorting task. Performance ratings for 3 of the Ss' instructors were obtained with behaviorally anchored rating scales, mixed standard rating scales, graphic rating scales, and simple "alternate" 3-point rating scales. No differences in leniency, halo, or range restriction emerged either as a function of raters' cognitive complexity or a Cognitive Complexity?×?Scale Format interaction. Raters' confidence in their ratings was not associated with either cognitive complexity or rating scale format. It is concluded that researchers of performance ratings should exercise restraint before confidently conferring moderator variable status on a cognitive complexity construct. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Summary of the CALPHAD XXXVI 2007 conference

From 6–11 May 2007, 147 registered participants met at State College, Pennsylvania, for the thirty-sixth CALPHAD meeting organized by Zi-Kui Liu, Steve Hansen, Joanne Murray and Phillip Spencer. Activities were held at Toftrees Golf Resort and Conference Center with logistics run by graduate students and postdoctoral fellows from The Pennsylvania State University. Over the course of six days, 57 oral presentations and 84 posters were offered, the abstracts and titles of which are summarized in this report. Posters were on display from Sunday evening until Friday morning. In addition to the continuous display of the posters, two dedicated poster sessions were held in the Monday and Tuesday evenings, which were overwhelmingly enjoyed by the participants.

The CALPHAD Gibbs Triangle Award, an honor given only every three to five years, was bestowed upon Gunnar Eriksson. Fourteen CALPHAD scholarships were awarded to promising students in the field, the Best Paper Award for papers published in 2006 in the CALPHAD journal was conferred, and a Best Poster Award was chosen for one of the conference’s posters.     

Buckling behaviour of large steel cylinders with patterned welds

Steel silos and tanks are commonly constructed by welding together a large number of curved steel panels. The panels are first connected with short meridional welds to form circular strakes (or courses), which are then connected by continuous circumferential welds to form the entire shell wall. Associated with the large number of welds are welding-induced shrinkage deformations and residual stresses, both of which may have a significant effect on the buckling strength of the shell wall. In this paper, a simple method for the simulation of the weld depressions and associated residual stresses is first introduced. The results of a series of finite element buckling analyses of a typical steel cylinder with such simulated welding effects are next presented and discussed, leading to a number of significant conclusions. One of these conclusions is that a weld depression pattern produced using the present weld simulation method can offer a suitable equivalent imperfection form for use in the non-linear analysis of shells for stability design, as it leads to buckling loads in close agreement with predictions by the new European code for steel shell structures.     

Stiffness and critical buckling load of perforated sheeting

This paper deals with selected foundations of the design of perforated trapezoidal sheeting. Based on numerical analysis, graphs on effective stiffness values for perforated sheeting with different arrays of holes are provided. As an outlook on further research, the calculation of the buckling coefficient for a perforated plate under uniform in-plane compression loading and for an infinitely long perforated plate under shear loading is presented.     

Diarylsulfonamides as selective, non-peptidic thrombin inhibitors

Based on the structures of aminopyridine thrombin inhibitors (1), a series of aminoalkyl- and guanidinoalkyl-substituted diarylsulfonamides were prepared. The most potent derivative, N-[3-(4-guanidinobutoxy)-5-methyl-phenyl]-benzenesulfonamide (6c) had Ki = 0.18 microM for thrombin and did not inhibit trypsin, plasmin, or factor Xa. Comparison of the X-ray structures of the thrombin/1b and the thrombin/6c complexes revealed important aspects which govern the binding of such diarylsulfonamides to thrombin.     

Electrically conductive and optically transparent Sb-doped SnO2 STM-probe for local excitation of electroluminescence

We demonstrate that an optically transparent and electrically conductive antimon-doped tin-oxide tip that is prepared in a sol-gel process can be used as a probe for scanning tunnelling microscopy (STM), yielding atomic vertical and nanometre lateral resolution. Emission of visible light from the tunnelling junction between gold particles and the tip is observed for bias voltages above 7 V. In contrast to the metallic tips generally used in STM, this tip does not significantly perturb the local optical response. Therefore, the tunnelling induced light can be used to map the optical near-field of surface structures with the tunnel gap acting as highly localised light source for the investigation of near-field enhancement in complex metal structures.