Possible association of actin filaments with chloroplasts of spinach mesophyll cells in vivo and in vitro.

In palisade mesophyll cells of spinach (Spinacia oleracea L.) kept under low-intensity white light, chloroplasts were apparently immobile and seemed to be surrounded by fine bundles of actin filaments. High-intensity blue light induced actin-dependent chloroplast movement concomitant with the appearance of a couple of long, straight bundles of actin filaments in each cell, whereas high-intensity red light was essentially ineffective in inducing these responses.

Photoreactivation in Paramecium tetraurelia under conditions of various degrees of ozone layer depletion.

Photoreactivation (PR) is an efficient survival mechanism that helps protect cells against the harmful effects of solar-ultraviolet (UV) radiation. The PR mechanism involves photolyase, just one enzyme, and can repair DNA damage, such as cyclobutane-pyrimidine dimers (CPD) induced by near-UV/blue light, a component of sunlight. Although the balance of near-UV/blue light and far-UV light reaching the Earth's surface could be altered by the atmospheric ozone layer's depletion, experiments simulating this environmental change and its possible effects on life have not yet been performed.

[Usefulness of spiral CT in the detection of hypovascular, well-differentiated hepatocellular carcinoma].

Whole liver scanning during artery-dominant phase using spiral CT was performed in 14 patients with 17 histologically proven well-differentiated HCCs, which were not depicted by hepatic digital subtraction angiography but by CT during arterial portography. The density of HCC relative to the liver was evaluated with conventional precontrast CT, spiral CT, and following conventional CT during the equilibrium phase. Comparison between spiral CT and magnetic resonance (MR) imaging of dynamic contrast studies was also investigated.

Pleural invasion by peripheral bronchogenic carcinoma: assessment with three-dimensional helical CT.

Purpose: To evaluate the potential role of three-dimensional (3D) computed tomography (CT) in assessment of pleural invasion by peripheral bronchogenic carcinoma.

Materials And Methods: Twenty-four-second helical CT scans were obtained during a single breath hold in 42 consecutive patients with peripheral bronchogenic carcinoma. Conventional two-dimensional (2D) images and 3D reconstruction images were reviewed independently by three blinded observers, who reached a decision by consensus.