The inhibition of DMBA-induced carcinogenesis by neoxanthin in hamster buccal pouch

Neoxanthin, a major carotenoid pigment of spinach, is found in the Chloroplast membrane and has an unknown function in plants. Neoxanthin inhibited the production of superoxide anions in an artificial xanthine and xanthine oxidase system and depressed DNA synthesis in methylcholanthrene (MCA)-initiated C3H10T1/2 fibroblasts. in two-stage carcinogenesis experiments, neoxanthin at 0.2 micrograms/0.2 ml inhibited the formation of tumors that were induced sequentially by 7,12-dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) in the buccal pouch of Syrian Golden hamsters. To assess the ongoing process of carcinogenesis, the activity of ornithine decarboxylase (ODC), required for cell proliferation, was analyzed. Neoxanthin inhibited the activity of ODC when animals were treated with neoxanthin one hour before the application of TPA in two-stage carcinogenesis. However, neoxanthin did not inhibit ODC activity when animals were treated with neoxanthin one hour before the application of DMBA in two-stage carcinogenesis, and there was no subsequent tumor formation. In a short-term anti-initiation experiment, neoxanthin inhibited the covalent binding of isotope-labeled DMBA to DNA by 53%. These results indicate that neoxanthin inhibits the initiation stage and the promotion stage in two-stage carcinogenesis. This suggests that neoxanthin may act as a potential chemopreventive agent.     

Therapeutic evaluation of compounds in the SCID-RA papillomavirus model

A previous study by Kreider (Kreider et al., 1979) indicated that rabbit skin, which had been transplanted to immunodeficient nude mice, could be successfully infected with cottontail rabbit papillomavirus (CRPV). We have extended this observation in developing a rodent model for evaluation of compounds for activity against the papillomaviruses. In this model (called the SCID-Ra model), rabbit ear skin is transplanted to the dorsum of SCID mice and allowed to heal for 3 weeks. Infection with CRPV by scarification leads to the growth of warty lesions within 2 3 weeks in >95% of the animals. Topical and/or systemic therapy can be initiated at various times post infection (PI). Weekly lesion scores are recorded and compounds are evaluated for their ability to suppress wart growth when compared to untreated control mice. Ribavirin, which has had a suppressive effect both in the clinic for the treatment of respiratory papillomatosis and on the growth of warts in the rabbit back model, was evaluated and showed significant anti-proliferative activity with oral dosing. Both antiviral and antiproliferative compounds including podophyllin and 5-fluorouracil, which have been used clinically for the treatment of human papillomavirus (HPV) infections, were evaluated in this model. The anti-mitotic compound, Navelbine (vinorelbine tartrate), which is used for the treatment of non-small cell lung carcinoma was evaluated in this system and showed significant inhibition of wart growth with somewhat less topical cytotoxicity when compared to podophyllotoxin.     

Pronoun resolution without pronouns: some consequences of memory-based text processing

A memory-based processing approach to discourse comprehension emphasizes the rapid deployment of information in memory to facilitate understanding of the text that is currently being read. S. B. Greene, R. J. Gerrig, G. McKoon, and R. Ratcliff (1994) demonstrated that when a text described the reunion of 2 characters who had previously discussed a 3rd character, the accessibility of the 3rd character increased, and the use of an unheralded pronoun (R. J. Gerrig, 1986) to refer to that character was felicitous. In experiments in this article, the authors demonstrate that concepts related to the unheralded pronoun also increase in accessibility and that those concepts form associations in memory with concepts present in the discourse at the time the pronoun is used. The authors also show that the increase in accessibility for the referent of the pronoun, as well as the appropriate long-term memory associations, occurs even in the absence of the pronoun.     

Central poststroke pain and Wallenberg''s lateral medullary infarction: frequency, character, and determinants in 63 patients

BACKGROUND: Questionnaire-based surveys from several countries have consistently detected adverse health associated with home dampness and mould growth. METHODS: To test the validity of questions commonly used to indicate the presence of indoor mould, questionnaires were administered in 403 homes where dust samples were taken for viable fungi and air samples for ergosterol. RESULTS: Geometric mean concentrations of the total viable fungi were 255 (SE 116) x 10(3) CFU/g when mouldy odours were reported and 155 (SE 55) when odours were not reported (P = 0.01). Similarly, reported water damage was associated with a 50% increase (P = 0.06). Geometric mean concentrations of the predominantly indoor-source fungi, Aspergillus plus Penicillium, were twice as high when mould or mildew was reported than when not mentioned (P = 0.01). The presence of reported mould or water damage was unrelated to the presence of detectable levels of ergosterol. There was evidence for reporting bias: in the presence of low concentrations of viable fungi in dust, respondents reporting allergies were more likely to report visible mould growth (odds ratio [OR] = 1.8, 95% confidence interval [CI]: 0.9-3.5, P = 0.10. In the presence of elevated concentrations of dust fungi, respondents who smoked were less likely to report visible mould growth, (OR = 0.4, 95% CI: 0.2-0.7, P = 0.005). CONCLUSIONS: Reported mould, water damage, and mouldy odours were associated with elevated levels of indoor fungi. However, inaccuracy was high and there was evidence of a systematic reporting bias. Future research should concentrate on developing accurate objective measures of exposure to fungi, and then use this information to develop valid questionnaires. Currently, objective measures not questionnaires, are recommended to clarify the health effects of indoor fungi.     

Deep brain stimulation for essential tremor

We examined the effects and safety of deep brain stimulation (DBS) as a treatment for essential tremor (ET). Ten ET patients with disabling medication-refractory tremor underwent stereotactic implantation of a DBS lead in the left Vim thalamic nucleus and completed a 6-month follow-up. The Clinical Tremor Rating Scale and disability assessments were performed at baseline, 1-, 3-, and 6-month follow-up. There were significant improvements in dressing, drinking, eating, bathing, and handwriting as reported by the subjects. Tremor severity, writing, pouring, and spiral and line drawing were significantly improved as rated by the examiner. Improvements persisted through the 6-month follow-up period. Although global disability significantly lessened in the group as a whole, one subject with hand-finger tremor accentuated by writing had no change in disability status. In this 6-month open-label study, DBS was effective and safe in reducing tremor and functional disability in ET.     

Lexical familiarity and processing efficiency: Individual differences in naming, lexical decision, and semantic categorization.

College students were separated into 2 groups (high and low) on the basis of 3 measures: subjective familiarity ratings of words, self-reported language experiences, and a test of vocabulary knowledge. Three experiments were conducted to determine if the groups also differed in visual word naming, lexical decision, and semantic categorization. High Ss were consistently faster than low Ss in naming visually presented words. They were also faster and more accurate in making difficult lexical decisions and in rejecting homophone foils in semantic categorization. Taken together, the results demonstrate that Ss who differ in lexical familiarity also differ in processing efficiency. The relationship between processing efficiency and working memory accounts of individual differences in language processing is also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)