Language production: electroencephalographic localization in the normal human brain

Slow negative potentials, which are at a maximum over Broca's area in the left hemisphere, were recorded when normnal subjects spontaneously produced polysyllabic words. Bilaterally symmetrical potentials were seen with analogous, nonspeech control gestures. These potentials began up to 1 second before word or gesture articulation. These results are the first demonstration of localization of language production in normal human brain.     

Distribution of hydroxycinnamic acid conjugates in fruit of commercial eggplant (Solanum melongena L.) cultivars

There is gathering evidence that antioxidant phytonutrients in fruits and vegetables have health-promoting effects. Eggplant fruit have a high content of antioxidant phenolic compounds. We evaluated the main class of eggplant phenolics, hydroxycinnamic acid conjugates, in the fruit of seven commercial cultivars. Fourteen conjugates were quantified and identified by high-performance liquid chromatography, ES(-)-MS, and (1)H NMR data. Significant differences in their content and composition were evident among cultivars and in tissue from stem, middle, and blossom end segments. Chlorogenic acid (5-O-caffeoylquinic acid) was the predominant compound, and its 3-O-, 4-O-, and 5-O-cis isomers were also present. The 10 other phenolics fell into four groups, including 3,5- and 4,5-dicaffeoylquinic acid isomers, four amide conjugates, two unknown caffeic acid conjugates, and 3-O-acetyl esters of 5-O- and 4-O-caffeoylquinic acid. Dicaffeoylquinic and 3-O-acetyl chlorogenic acids were most variable among the cultivars. Dicaffeoyquinic acids were most abundant in the blossom end, whereas 3-O-acetyl esters were highest in the midsection.     

Evaluation of a testing program for aflatoxin in corn

A computer model that accounts for sampling and analytical variability was developed to simulate the aflatoxin testing program administered by the North Carolina Department of Agriculture (NCDA) to regulate aflatoxin in corn meal. Monte Carlo solution techniques were employed to account for conditional probabilities that rise from multiple samples being used in the testing program. The NCDA testing program was then evaluated by applying the computer model to a hypothetical group of 1000 corn meal lots with the same distribution of aflatoxin concentrations as was observed among aflatoxin assays made by NCDA on commercial lots of corn meal from 1977 to 1980. The average of the 1000 lots assayed was 17.7 parts per billion (ppb). The model predicted that 79.5% of the lots would be accepted and 20.5% of the lots would be rejected by the NCDA testing program. The accepted and rejected lots contained an average of 5.7 and 64.2 ppb aflatoxin, respectively. The testing program accepted 7.3% of the lots with more than 20 ppb aflatoxin (consumers' risk) and rejected 1.0% of the lots with 20 ppb or less (processors' risk). A correct decision was made 94% of the time.     

Development of a multianalyte enzyme-linked immunosorbent assay for permethrin and aroclors and its implementation for analysis of soil/sediment and house dust extracts

Development of a multianalyte enzyme-linked immunosorbent assay (ELISA) for detection of permethrin and aroclors 1248 or 1254 and implementation of the assay for analysis of soil/sediment samples are described. The feasibility of using the multianalyte ELISA to monitor aroclors 1254 and permethrin simultaneously was tested with permethrin and aroclor standards and with aroclor- and permethrin-containing soil/sediment and house dust samples. Comparison of the I?? and I?? values of the multianalyte with those of a single-analyte assay revealed similar results, and multianalyte ELISA determination of analyte amounts in soil/sediment dust samples yielded similar results to those of a single-analyte assay. A single-analyte assay of permethrin content in permethrin-containing dust samples showed that the ELISA can determine the analyte accurately in samples with dust matrix contents ranging from 6.25 to 100 mg as indicated by the good correlation between the results of the immunoassay and those of the gas chromatography analysis.     

Effect of processing on recovery and variability associated with immunochemical analytical methods for multiple allergens in a single matrix: dark chocolate

Immunodetection of allergens in dark chocolate is complicated by interference from the chocolate components. The objectives of this study were to establish reference materials for detecting multiple allergens in dark chocolate and to determine the accuracy and precision of allergen detection by enzyme-linked immunosorbent assay (ELISA) before and after chocolate processing. Defatted peanut flour, whole egg powder, and spray-dried milk were added to melted chocolate at seven incurred levels and tempered for 4 h. Allergen concentrations were measured using commercial ELISA kits. Tempering decreased the detection of casein and β-lactoglobulin (BLG), but had no significant effect on the detection of peanut and egg. Total coefficients of variation were higher in tempered than untempered chocolate for casein and BLG, but total and analytical CVs were comparable for peanut and egg. These findings indicate that processing has a greater effect on recovery and variability of casein and BLG than peanut and egg detection in a dark chocolate matrix.     

Effect of processing on recovery and variability associated with immunochemical analytical methods for multiple allergens in a single matrix: sugar cookies

Among the major food allergies, peanut, egg, and milk are the most common. The immunochemical detection of food allergens depends on various factors, such as the food matrix and processing method, which can affect allergen conformation and extractability. This study aimed to (1) develop matrix-specific incurred reference materials for allergen testing, (2) determine whether multiple allergens in the same model food can be simultaneously detected, and (3) establish the effect of processing on reference material stability and allergen detection. Defatted peanut flour, whole egg powder, and spray-dried milk were added to cookie dough at seven incurred levels before baking. Allergens were measured using five commercial enzyme-linked immunosorbent assay (ELISA) kits. All kits showed decreased recovery of all allergens after baking. Analytical coefficients of variation for most kits increased with baking time, but decreased with incurred allergen level. Thus, food processing negatively affects the recovery and variability of peanut, egg, and milk detection in a sugar cookie matrix when using immunochemical methods.     

Optimization of Hydrolysis Conditions for Production of Angiotensin-Converting Enzyme Inhibitory Peptides from Basa Fish Skin Using Response Surface Methodology

ABSTRACT

Basa fish skin free from fat and noncollagenous proteins was hydrolyzed by different proteinases to produce angiotensin-converting enzyme (ACE) inhibitory peptides. Protamex hydrolysates were found to have the highest ACE inhibitory activity. Response surface methodology (RSM) was applied to optimize the hydrolysis conditions of Protamex—including enzyme-to-substrate ratio, hydrolysis time, and solid (fish skin)-to-liquid (water for hydrolysis)—at a temperature of 50°C and a pH of 7.0. The mathematical model demonstrated a good fit with the experimental data. An enzyme-to-substrate ratio of 6,108 U/g, a hydrolysis time of 1.24 h, and a solid-to-liquid ratio of 1:8.05 g/mL were found to be the optimal conditions to achieve the highest value of ACE inhibitory activity. The IC₅₀ of the hydrolysates for ACE inhibitory activity was 1.417 mg/mL under these conditions.     

Characterization and Cytotoxicity Studies of the Rare 21:4 n-7 Acid and Other Polyunsaturated Fatty Acids from the Marine Opisthobranch Scaphander lignarius,Isolated Using Bioassay Guided Fractionation

The marine opisthobranch Scaphander lignarius has been analyzed in the systematic search for novel bioactive compounds in Arctic marine organisms using bioassay guided fractionation. A number of highly cytotoxic fractions were shown to contain mainly polyunsaturated fatty acids (PUFAs). Selected PUFAs were isolated and identified using both liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR). It was shown that the opisthobranch contained unusual PUFAs such as several ω3 fatty acids and the ω7 heneicosa-5,8,11,14-tetraenoic acid (21:4 n-7) not isolated before. The organism was shown to be a very rich source of PUFAs and the activity of the isolated compounds against a range of human cancer cell lines (melanoma, colon carcinoma and breast carcinoma) is further reported. The ω7 PUFA was significantly more cytotoxic in comparison with reference ω6 arachidonic and ω3 eicosapentaenoic acid. A noteworthy non-selective cytotoxicity against normal lung fibroblasts was also established. The paper contains isolation protocols in addition to cytotoxicity data of the isolated compounds. The potential of marine mollusks as a source for rare PUFAs is also discussed.