Childhood chronic daily headache: a biopsychosocial perspective.

The aim of our observational study was to highlight some clinical observations on chronic daily headache (CDH) in children and adolescents. Data on patients < or =18 years aged presenting with CDH to the Pediatric Headache Clinic at the Royal University Hospital, Saskatoon, Canada, were collected prospectively and sequentially from February 2004 to July 2006. Standardized data sheets and definitions were used. Follow-up information on the 70 participants (22 males, 48 females) was current to February 2007. Fifty-four participants (77%) had had recurrent headaches before transformation to CDH. Comorbid chronic migraine and chronic tension-type headache was the most frequent subtype of CDH (37 participants; 53%). Anxiety and mood disorders were diagnosed in 17 and 15 children respectively. Stressors that precipitated or contributed to the maintenance of CDH were judged important in 44 (63%). The possibility of a somatoform disorder was considered in five children, a factitious disorder in one, and malingering in another. We suggest that CDH be viewed from a biopsychosocial rather than a narrow biomedical perspective and the classification improved to enhance clinical utility.

Bound on Lorentz and CPT violating boost effects for the neutron.

A search for an annual variation of a daily sidereal modulation of the frequency difference between colocated 129Xe and 3He Zeeman masers sets a stringent limit on boost-dependent Lorentz and CPT violation involving the neutron, consistent with no effect at the level of 150 nHz. In the framework of the general standard-model extension, the present result provides the first clean test for the fermion sector of the symmetry of spacetime under boost transformations at a level of 10(-27) GeV.

Atomic memory for correlated photon states.

We experimentally demonstrate emission of two quantum-mechanically correlated light pulses with a time delay that is coherently controlled via temporal storage of photonic states in an ensemble of rubidium atoms. The experiment is based on Raman scattering, which produces correlated pairs of spin-flipped atoms and photons, followed by coherent conversion of the atomic states into a different photon beam after a controllable delay. This resonant nonlinear optical process is a promising technique for potential applications in quantum communication.

Storage of light in atomic vapor.

We report an experiment in which a light pulse is effectively decelerated and trapped in a vapor of Rb atoms, stored for a controlled period of time, and then released on demand. We accomplish this "storage of light" by dynamically reducing the group velocity of the light pulse to zero, so that the coherent excitation of the light is reversibly mapped into a Zeeman (spin) coherence of the Rb vapor.

Effects of soy-protein supplementation on epithelial proliferation in the histologically normal human breast.

A high dietary intake of soy products (eg, as in Japan and Singapore) has been associated with a reduction in the incidence of breast cancer in premenopausal women. Phytoestrogens present in soybeans inhibit human breast cancer cell proliferation in vitro and breast cancer development in animal models, but no data exist on the effects of phytoestrogens on histologically normal human breasts. This study examines the effects of dietary soy supplementation on the proliferation rate of premenopausal, histologically normal breast epithelium and the expression of progesterone receptor. Women (n = 48) with benign or malignant breast disease were randomly assigned to receive their normal diet either alone or with a 60-g soy supplement (containing 45 mg isoflavones) taken daily for 14 d. Biopsy samples of normal breasts were labeled with [3H]thymidine to detect the number of cells in S phase and were immunocytochemically stained for the proliferation antigen Ki67. The phytoestrogens genistein, daidzein, equol, enterolactone, and enterodiol were measured in serum samples obtained before and after supplementation. Serum concentrations of the isoflavones genistein and daidzein increased in the soy group at 14 d. Results showed a strong correlation between Ki67 and the thymidine labeling index (r = 0.868, P < or = 0.001). The proliferation rate of breast lobular epithelium significantly increased after 14 d of soy supplementation when both the day of menstrual cycle and the age of patient were accounted for. Progesterone receptor expression increased significantly in the soy group. Short-term dietary soy stimulates breast proliferation; further studies are required to determine whether this is due to estrogen agonist activity and to examine the long-term effects of soy supplementation on the pituitary gland and breast.