Abnormal pontine activation in pathological laughing as shown by functional magnetic resonance imaging.

To explore the aetiology of pathological laughing, a 65-year-old woman with pathological laughing was examined by 3-T functional magnetic resonance imaging (fMRI) before and after treatment with drugs. Here, we report that the patient consistently showed exaggerated pontine activation during the performance of three tasks before treatment, whereas abnormal pontine activation was no longer found after successful treatment with the selective serotonin reuptake inhibitor, paroxetine. Our findings in this first fMRI study of pathological laughing suggest that serotonergic replacement decreases the aberrant activity in a circuit that involves the pons.

Antitumor activity of polysaccharide fractions from pine cone extract of Pinus parviflora Sieb. et Zucc.

Hot water extract of pine cone (PCE) of Pinus parviflora Sieb. et Zucc. dose-dependently suppressed both solid and ascites tumor cells transplanted into various mice. Acidic polysaccharides of PCE significantly increased the survival time of mice bearing ascites tumor cells, and activity increased with acidity. One of the four polysaccharide fractions obtained by NaOH extraction showed the most potent antitumor activity. This fraction significantly suppressed the growth of solid tumor cells, with occasional tumor regression and necrosis, and with little or no cytocidal effect on cultured tumor cells. All acidic polysaccharides were able to activate mouse macrophage-like cell line J774.1. There did not appear to be any correlation between the antitumor activity of these polysaccharides and their content of arabinose (or fucose), mannose, galactose, glucose, or uronic acid.

Structural changes of rat liver microsomal membranes induced by the oral administration of carbon tetrachloride. 31P-NMR and spin-label studies.

The acute effects of carbon tetrachloride (CCl4) on the membrane structure of rat liver microsomes were studied using 31P-NMR and spin-labeling techniques. 31P-NMR spectra of rat liver microsomes were not changed appreciably after the oral administration of CCl4, indicating that the surface structures of microsomal membranes probably are not influenced by the oral administration of CCl4. Four different spin-labeled stearic acids, 5-(N-oxyl-4',4'-dimethyloxazolidine)-stearic acid (5SLS), its methyl ester (5SLSM), 12-(N-oxyl-4',4'-dimethyloxazolidine)-stearic acid (12SLS) and its methyl ester (12SLSM), were used for the estimation of membrane fluidity. The apparent rotational correlation time of 12SLS decreased from 4.0 nsec to 3.0 nsec after the oral administration of CCl4, while the order parameter of 5SLS did not change. The results suggest that CCl4 or its metabolites increase the membrane fluidity of liver microsomes primarily at hydrophobic regions rather than at the surface layer. The ESR spectrum of 5SLSM in microsomal membranes comprised two different signals; one was an anisotropic signal and the other was a rather isotropic one. The ratio of the anisotropic signal to the isotropic one decreased markedly after the oral administration of CCl4 and depended on the dose of CCl4. The suitability of this ESR technique with 5SLSM for the estimation of membrane damage is discussed.