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.     

The membrane-cytoplasm interface of integrin alpha subunits is critical for receptor latency

Localization of integrin receptors to focal contact sites occurs upon ligand binding. This activity is latent, since unoccupied integrin receptors do not localize to focal contacts. Deletion analysis has revealed that the alpha cytoplasmic domains is required for the maintenance of integrin receptor latency. Our current hypothesis for the mechanism of integrin post-ligand binding events is that there is a change in relationship of alpha and beta cytoplasmic domains, which overcomes receptor latency. One possible mechanism for such a change would involve the amino acid residues at the membrane-cytoplasm interface. To test this hypothesis, we have produced point mutations in the human integrin alpha 1 subunit. These mutations had no effect on the adhesion via alpha 1 beta 1 to its ligand, collagen IV. However, receptor latency is lost in one of these mutants, leading to constitutive focal contact localization. This effect did not occur in receptors with an exchange of intracellular domains, suggesting that the mechanism of loss of latency involves a relative motion of the integrin chains. These results suggest a model in which post-ligand binding events in integrin receptors are associated with changes in the position of the alpha and beta cytoplasmic domains.     

Eye gaze and dominance hierarchy in profoundly mentally retarded males

A new method to measure gastric functions after meal-stimulation without infusion of bicarbonate into the stomach is presented. Six healthy volunteers were investigated after stimulation of the gastric functions with a 300-ml fluid test meal with and without cimetidine infusion. Cimetidine reduced the acid output substantially but had no effect on gastric emptying.     

The effect of an infusion of low molecular weight dextran on peripheral resistance in patients with arteriosclerosis

Low molecular weight dextran is frequently given to improve the flow of blood to the periphery, but its mode of action is uncertain. We measured the effect of an infusion of 500 ml of Dextran 40 on the peripheral resistance in 12 patients undergoing reconstructive surgery for atherosclerotic occlusion of the superficial femoral artery. After the infusion, values of packed cell volume and blood viscosity indicated haemodilution. There was a consistent increase in mean flow and a fall in peripheral resistance. There was no correlation between change in viscosity and change in peripheral resistance, but there was a good correlation between the percentage change in resistance and the initial resistance. This suggests that the increase in flow of blood was due to reflex vasodilatation rather than to any reduction in viscosity.     

Steering molecular organization and host-guest interactions using two-dimensional nanoporous coordination systems

Metal-organic coordination networks (MOCNs) have attracted wide interest because they provide a novel route towards porous materials that may find applications in molecular recognition, catalysis, gas storage and separation. The so-called rational design principle-synthesis of materials with predictable structures and properties-has been explored using appropriate organic molecular linkers connecting to metal nodes to control pore size and functionality of open coordination networks. Here we demonstrate the fabrication of surface-supported MOCNs comprising tailored pore sizes and chemical functionality by the modular assembly of polytopic organic carboxylate linker molecules and iron atoms on a Cu(100) surface under ultra-high-vacuum conditions. These arrays provide versatile templates for the handling and organization of functional species at the nanoscale, as is demonstrated by their use to accommodate C(60) guest molecules. Temperature-controlled studies reveal, at the single-molecule level, how pore size and chemical functionality determine the host-guest interactions.     

Intraclass correlation vs. factor analytic techniques for determining groups of profiles.

This study compares several methods for estimating the homogeneity of a group and the proper membership of individuals in the group from profile data. A total of 12 MMPI scales were administered to Ss diagnosed in 3 clinical groups and serve as the basic data. Generally the results indicate that the product moment rs and the coefficients of intraclass correlation (R) provide more efficient, flexible and at least as meaningful answers to the basic issues involved in the study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal abuse from outsiders versus insiders: Comparing frequency, impact on emotional exhaustion, and the role of emotional labor.

Research on aggression from organizational outsiders (customers, clients or patients) has ignored insider-instigated aggression, and has been limited to employees in emotional labor jobs (e.g., social work and customer services). The authors argue that customer-employee interactions have distinct characteristics from organizational insider interactions, and provide two studies to compare the frequency and strain of verbal abuse from customers, supervisors and coworkers. Furthermore, they assess whether customer verbal abuse is only a critical issue for employees in jobs requiring emotional labor, measured with both O*NET job codes and self-reported display rules. With a national random sample of U.S. employees (n = 2446) and a convenience sample of U.S. employees who have customer contact (n = 121), the authors find that verbal abuse from outsiders (1) occurs more frequently than insider verbal abuse, particularly for those with higher emotional labor requirements, and (2) predicts emotional exhaustion over and above insider verbal abuse, regardless of emotional labor requirements. The authors conclude that better integration of customer aggression and insider aggression research is needed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Output feedback control of general linear heterodirectional hyperbolic PDE-ODE systems with spatially-varying coefficients

This paper presents a backstepping solution for the output feedback control of general linear heterodirectional hyperbolic PDE-ODE systems with spatially varying coefficients. Thereby, the ODE is coupled to the PDE in-domain and at the uncontrolled boundary, whereas the ODE is coupled with the latter boundary. For the state feedback design, a two-step backstepping approach is developed, which yields the conventional kernel equations and additional decoupling equations of simple form. In order to implement the state feedback controller, the design of observers for the PDE-ODE systems in question is considered, whereby anti-collocated measurements are assumed. Exponential stability with a prescribed convergence rate is verified for the closed-system pointwise in space. The resulting compensator design is illustrated for a 4 × 4 heterodirectional hyperbolic system coupled with a third-order ODE modelling a dynamic boundary condition.