Breastfeeding history, pregnancy experience and risk of breast cancer.

Epidemiological evidence suggests that breastfeeding protects against breast cancer. Whether an effect of age at first breastfeeding is independent of an effect of age at first birth is unclear. We hypothesized that nausea and vomiting in pregnancy, which are associated with elevated serum oestradiol levels during pregnancy, may increase risk. Cases were 452 parous, premenopausal women, 40 years or younger, diagnosed with breast cancer in Los Angeles County from July 1983 to December 1988. Control subjects were matched to cases on age, race, parity and neighbourhood. Pregnancy and breastfeeding histories were obtained from in-person interviews. Odds of breast cancer among women who breastfed for at least 16 months relative to those among women who did not breastfeed was 0.66 [95% confidence interval (CI) 0.41-1.05]. Number of children breastfed was not associated with risk. Risk was lower in women who first breastfed at older ages. Having ever been treated for nausea or vomiting during pregnancy was associated with an increased risk, especially in women experiencing recent pregnancies (OR = 2.03, 95% CI 1.05-3.92). These results support a protective role of breastfeeding and an adverse role of nausea or vomiting during pregnancy in the development of premenopausal breast cancer, especially in the years immediately following pregnancy

Optical angular momentum transfer to trapped absorbing particles

Particle rotation resulting from the absorption of light carrying angular momentum has been measured. When absorbing CuO particles (1-5μm) were trapped in a focused ‘‘donut’’ laser beam, they rotated, due to the helical phase structure of the beam. Changing the polarization of the light from plane to circular caused the rotation frequency to increase or decrease, depending on the sense of the polarization with respect to the helicity of the beam. Rotation frequencies were obtained by Fourier analysis of amplitude fluctuations in the backscattered light from the particles. © 1996 The American Physical Society

Non-invasive evaluation of the effect of metoprolol on the atrioventricular node during permanent atrial fibrillation.

During atrial fibrillation (AF), conventional electrophysiological techniques for assessment of refractory period or conduction velocity of the atrioventricular (AV) node cannot be used. We aimed at evaluating changes in AV nodal properties during administration of metoprolol from electrocardiogram data, and to support our findings with simulated data based on results from an electrophysiological study

Infrasound initiates directional fast-start escape responses in juvenile roach Rutilus rutilus

Acoustic stimuli within the sonic range are effective triggers of C-type escape behaviours in fish. We have previously shown that fish have an acute sensitivity to infrasound also, with acceleration thresholds in the range of 10(-5) m s(-2). In addition, infrasound at high intensities around 10(-2) m s(-2) elicits strong and sustained avoidance responses in several fish species. In the present study, the possible triggering of C-escapes by infrasonic single-cycle vibrations was examined in juvenile roach Rutilus rutilus. The fish were accelerated in a controlled and quantifiable manner using a swing system. The applied stimuli simulated essential components of the accelerations that a small fish would encounter in the hydrodynamic flow field produced by a predatory fish. Typical C- and S-type escape responses were induced by accelerations within the infrasonic range with a threshold of 0.023 m s(-2) for an initial acceleration at 6.7 Hz. Response trajectories were on average in the same direction as the initial acceleration. Unexpectedly, startle behaviours mainly occurred in the trailing half of the test chamber, in which the fish were subjected to linear acceleration in combination with compression, i.e. the expected stimuli produced by an approaching predator. Very few responses were observed in the leading half of the test chamber, where the fish were subjected to acceleration and rarefaction, i.e. the stimuli expected from a suction type of predator. We conclude that particle acceleration is essential for the directionality of the startle response to infrasound, and that the response is triggered by the synergistic effects of acceleration and compression

Fortilin Interacts with TGF-β1 and Prevents TGF-β Receptor Activation

Fortilin is a 172-amino acid multifunctional protein present in both intra- and extracellular spaces. Although fortilin binds and regulates various cellular proteins, the biological role of extracellular fortilin remains unknown. Here we report that fortilin specifically interacts with TGF-β1 and prevents it from activating the TGF-β1 signaling pathway. In a standard immunoprecipitation-western blot assay, fortilin co-immunoprecipitates TGF-β1 and its isoforms. The modified ELISA assay shows that TGF-β1 remains complexed with fortilin in human serum. Both bio-layer interferometry and surface plasmon resonance (SPR) reveal that fortilin directly bind TGF-β1. The SPR analysis also reveals that fortilin and the TGF-β receptor II (TGFβRII) compete for TGF-β1. Both luciferase and secreted alkaline phosphatase reporter assays show that fortilin prevents TGF-β1 from activating Smad3 binding to Smad-binding element. Fortilin inhibits the phosphorylation of Smad3 in both quantitative western blot assays and ELISA. Finally, fortilin inhibits TGFβ-1-induced differentiation of C3H10T1/2 mesenchymal progenitor cells to smooth muscle cells. A computer-assisted virtual docking reveals that fortilin occupies the pocket of TGF-β1 that is normally occupied by TGFβRII and that TGF-β1 can bind either fortilin or TGFβRII at any given time. These data support the role of extracellular fortilin as a negative regulator of the TGF-β1 signaling pathway