Temporal structure of syntactic parsing: Early and late event-related brain potential effects.

Event-related brain potentials (ERPs) were recorded from participants listening to or reading sentences that were correct, contained a violation of the required syntactic category, or contained a syntactic-category ambiguity. When sentences were presented auditorily (Experiment 1), there was an early left anterior negativity for syntactic-category violations, but not for syntactic-category ambiguities. Both anomaly types elicited a late centroparietally distributed positivity. When sentences were presented visually word by word (Experiment 2), again an early left anterior negativity was found only for syntactic-category violations, and both types of anomalies elicited a late positivity. The combined data are taken to be consistent with a 2-stage model of parsing, including a 1st stage, during which an initial phrase structure is built and a 2nd stage, during which thematic role assignment and, if necessary, reanalysis takes place. Disruptions to the 1st stage of syntactic parsing appear to be correlated with an early left anterior negativity, whereas disruptions to the 2nd stage might be correlated with a late posterior distributed positivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

(3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1-yl]chroman-4,7-diol: a conformationally restricted analogue of the NR2B subtype-selective NMDA antagonist (1S,2S)-1-(4-hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)- 1-propanol

(1S,2S)-1-(4-Hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-propanol (CP-101,606, 1) is a recently described antagonist of N-methyl-D-aspartate (NMDA) receptors containing the NR2B subunit. In the present study, the optimal orientation of compounds of this structural type for their receptor was explored. Tethering of the pendent methyl group of 1 to the phenolic aromatic ring via an oxygen atom prevents rotation about the central portion of the molecule. Several of the new chromanol compounds have high affinity for the racemic [3H]CP-101,606 binding site on the NMDA receptor and protect against glutamate toxicity in cultured hippocampal neurons. The new ring caused a change in the stereochemical preference of the receptor-cis (erythro) compounds had better affinity for the receptor than the trans isomers. Computational studies suggest that steric interactions between the pendent methyl group and the phenol ring in the acyclic series determine which structures can best fit the receptor. The chromanol analogue, (3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1- yl]chroman-4,7-diol (12a, CP-283,097), was found to possess potency and selectivity comparable to CP-101,606. Thus 12a is a new tool to explore the function of the NR2B-containing NMDA receptors.     

Prevalence and implications of perinatal substance use in Missouri

A study was conducted to determine the prevalence of perinatal substance use in Missouri. The population sample studied was selected according to a multi-stage probability-proportional-to-size sampling. The weighted prevalence for perinatal exposure to alcohol, tobacco or illicit substances was 31.9%, 10.8% for illicit substances, 21.9% for tobacco use, and 7.9% for self-reported alcohol use. In 1993, an estimated 23,925 perinatal exposures to licit and illicit substances occurred.     

Clock-face drawing, reading and setting tests in the screening of dementia in Chinese elderly adults

Comprehensive neuropsychological batteries focus on the subtle cognitive deficits in dementia, but a brief screening instrument is also of immense practical value. As the clock-drawing test encompasses a number of cognitive domains frequently disturbed by the dementing process, it is considered to be a suitable screening instrument for the disorder. We documented the usefulness of a new scoring method of the clock-drawing test for screening of dementia in the elderly Chinese in Hong Kong. Fifty-three demented individuals and 53 healthy elderly controls were assessed. At a cutoff score of 3/4, the sensitivity and specificity of the clock-drawing test in screening of dementia was 83% and 79%. With a composite test of clock reading and clock setting, the positive predictive value of the clock face test was 98%. This new scoring method of clock-drawing proved to be a valid measure for screening of dementia. It is applicable in non-English speaking populations and should be a useful adjunct for quick screening assessment of dementia.     

Colonic hyperganglionosis presenting as neonatal enterocolitis and multiple strictures

Neuronal intestinal dysplasia (NID) usually mimics Hirschsprung's disease, but rarely presents as neonatal enterocolitis. The authors report a case of colonic hyperganglionosis, which is a form of NID, presenting with postenterocolitis intestinal strictures. NID should be considered as a possible (although rare) cause of neonatal enterocolitis and may present with intestinal strictures.     

Percutaneous electrical nerve stimulation (PENS): a complementary therapy for the management of pain secondary to bony metastasis

BACKGROUND: Metal skin clips are used in surgery. They may contain metals that might cause allergic reactions and delayed wound healing. METHODS: The metal composition of 18 different surgical clamps was examined. The allergy status of 184 patients was determined by patch tests and was correlated with the clinical outcome of wound healing after application of skin clips. RESULTS: Skin clips contained chromium, nickel, molybdenum, cobalt, and titanium in concentrations high enough to cause allergic reactions. Eighteen percent of the men and 23% of the women were sensitive to nickel and 16% of the men to chromium. We found a positive correlation between the grade of nickel allergy and the reaction to the skin clips. CONCLUSIONS: Our study suggests that allergic reactions and delayed wound healing can be caused by the use of surgical skin clips. Therefore skin clips are not recommended for patients with a history of contact dermatitis to metals and/or atopy.     

Evaluation of the potential carcinogenicity and genetic toxicity to humans of the herbicide acetochlor

Comprehensive toxicological studies of the herbicide acetochlor are presented and discussed. Although it gave a negative profile of responses in the many toxicity tests conducted there were some findings that prompted further investigation. First, although non-mutagenic in the Salmonella assay, acetochlor was clastogenic to mammalian cells treated in vitro. This clastogenic potential was not expressed in vivo in four rodent cytogenetic assays (bone marrow and germ cells). Second, although acetochlor gave a negative response in rat liver UDS assays when tested at the acute MTD, gavage administration of a single, supra-MTD dose (2000 mg/kg) gave a weak positive assay response. This dose-level (2000 mg/kg) was necrotic to the liver, depressed hepatic glutathione levels by up to approximately 80%, altered the metabolism of acetochlor, and was associated with up to 33% lethality. In contrast, reference liver genotoxins such as DMN, DMH and 2AAF were shown to elicit UDS in the absence of such effects, and at approximately 400 x lower dose-levels. Finally, microscopic nasal polypoid adenomas were induced in the rat when acetochlor was administered for two years at the maximum tolerated dose (MTD). The tumours were not life-threatening, they did not metastasize, and no DNA damage was induced in the nasal cells of rats maintained on a diet containing the MTD of acetochlor for either 1 or 18 weeks (comet assay). In order to probe the mechanism of action of these high dose toxicities a series of chemical and genetic toxicity studies was conducted on acetochlor and a range of structural analogues. These revealed the chloroacetyl substructure to be the clastogenic species in vitro. Although relatively inert, this substituent is preferentially reactive to sulphydryl groupings, most evidently, to glutathione (GSH). Similar chemical reactivity and clastogenicity in vitro was observed for two related chemicals bearing a chloroacetyl group, both of which have been defined as non-carcinogens in studies reported by the US.NTP. These collective observations indicate that the source of the clastogenicity of acetochlor in vitro is also the source of its rapid detoxification in the rat in vivo, via reaction with GSH. Metabolic studies of acetochlor are described which reveal the formation of a series of GSH-associated biliary metabolites in the rat that were not produced in the mouse. The metabolism of acetochlor in the rat changes with increasing dose-levels, probably because of depletion of hepatic GSH. It is most likely that a rat-specific metabolite is responsible for the rat nasal tumours observed uniquely at elevated dose-levels. The absence of genetic toxicity to the nasal epithelium of rats exposed acutely or subchronically to acetochlor favours a non-genotoxic mechanism for the induction of these adenomas. The observation of a time- and dose-related increase in S-phase cells in the nasal epithelium is consistent with this conclusion. Despite some confusion caused by the early use of perilethal gavage administrations of acetochlor to rodents, and supra-MTD dietary concentrations in some of the chronic studies, the available MTD data are consistent with acetochlor not posing a genetic or carcinogenic hazard to humans.