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Biomedical subjects

L Goldstein

Publications and source records attributed to L Goldstein.

At least 181 records · Page 10Linked to original sources
PubMed1981

The quantitative hemispheric EEG in adolescent psychiatric patients with depressive or paranoid symptomatology.

The quantitated EEG of a clinically heterogeneous small group of 13 adolescent psychiatric patients with paranoid or depressive symptoms was compared to that of 26 normal adolescents. While in most controls the variances of the distributions of EEG amplitudes were similar between right and left hemispheres, it was found that higher variances in the right than in the left were significantly more prevalent in patients with depressive symptomatology while it was the reverse in patients with paranoid symptomatology in whom the variances were significantly higher in the left than in the right hemisphere.

Adolescent↗
PubMed1980

Techniques for purifying L-cell karyoplasts with minimal amounts of cytoplasm.

Mouse L-929 cells centrifuged in the presence of cytochalasin B (CB) separate into cytoplasmic (cytoplasts) and nuclear (karyoplasts) fractions, but both of these fractions contain some whole-cell contaminants. We describe here two techniques for eliminating most of these whole cells from the karyoplast population. The first involves incubating cells in the presence of tantalum (Ta) particles, followed by enucleation and separation, on a Ficoll gradient. The small karyoplasts separate from the whole cells which contain a greater number of Ta particles. The second procedure uses a cell sorter that allows purification of karyoplasts from whole cells on the basis of light scatter. Both methods remove the whole-cell contaminants and the larger, and possibly viable, karyoplasts from the smaller karyoplast population. These purified karyoplasts are unable to regenerate but may be rescued by fusion with cytoplasts.

Animals↗
PubMed1980

Categorical features in speech perception and production.

Multidimensional scaling analyses of three types of English consonant confusions are reported: consonant substitutions in spontaneous speech errors, CV perceptural confusions, and VC perceptual confusions. Two data sets of each type are analyzed to assess reliability. Three reliable dimensions emerge in all data sets, corresponding to voicing, stop/fricative, and place of articulation. Representation of consonants in terms of categorical phonological features exhaustively describes what is common to the configurations of different data types, even though there is reliable detail within each data type that is not captured by categorical features. Such features can be viewed as groupings of speech sounds common to various perception and production processes.

Humans↗
PubMed1980

Effect of salicylates and phenobarbital on hepatic glutathione in the rat.

Phenobarbital and salicylates were shown to have opposite effects on hepatic glutathione. Phenobarbital increased glutathione concentration by approximately 20 to 30%. This increase occurred within 48 hr and could be attributed almost exclusively to an increase in bound glutathione. No changes in ATP, substrate amino acids for glutathione synthesis or the level of gamma-glutamylcysteine synthetase, the rate limiting enzymatic step in glutathione synthesis, were found with phenobarbital. Phenobarbital, which induces hepatic proteins that bind glutathione, increased bound glutathione but did not affect unbound glutathione. Therefore, the concentration of the latter probably regulates glutathione synthesis. Salicylates (aspirin and sodium salicylate) were found to deplete hepatic glutathione in both saline- and phenobarbital-treated rats. Maximum depletion (approximately 40%) was seen 4 to 6 hr after salicylate administration and returned toward the control level by 12 hr. The salicylate effect was not related to a change in gamma-glutamylcysteine synthetase, gamma-glutamyl transpeptidase or the concentrations of free hepatic glycine, glutamate, cysteine and methionine. An increase in concentration of glutathione both in vivo in plasma from salicylate-treated rats and in vitro in buffer from the incubation of liver slices with salicylate suggests that glutathione leakage from hepatocytes is an important factor in salicylate-induced hepatic glutathione depletion.

Amino Acids↗
PubMed1980

[Some data of quantitative E.E.G. in the study of brain mechanisms of human behavior (author's transl)].

Quantitative electroencephalographic methods (amplitude analysis) have been used to measure the relative degree of hemispheric activation (temporal lobes) in normal subjects, mild psychopathological states, and certain mental diseases. Special tasks were used to elicit either verbal (left hemispheric) or non-verbal (right hemispheric) processes. In normal subjects, the E.E.G. data obtained are in good agreement with mental performance. Under mild to severe psychopathology they reveal functional impairments of within- as well as of between-hemispheric activities. There are also indications of disorganization in the left in the case of acute paranoid schizophrenia and in the right in the case of affective disorders.

Behavior↗
PubMed1979

Isonitrile derivatives of polysaccharides as supports for the covalent fixation of proteins and other ligands.

A method for the introduction of side chains containing isonitrile (isocyanide, functional group) on the backbone of polysaccharides and other hydroxylic polymers was developed. The method was based on (a) ionization of some of the hydroxyl groups on the polymer by treatment with a strong base (tert-butoxide) in a polar aprotic solvent (dimethylsulfoxide), and (b) introduction of side chains containing isonitrile groups by nucleophilic attack of the polymeric alkoxide ions on a low molecular weight isonitrile containing a good leaving group in the omega-position, (1-tosyl-3-isocyanopropane). By this method, the side chains containing the-NC functional groups are attached to the polymeric backbone via stable ether bonds. The isonitrile derivatives of cellulose, linear and cross-linked dextran and cross-linked agarose utilized for the covalent fixation of high and low molecular weight ligands by four-component reactions carried out in aqueous medium, at neutral pH.

Cellulose↗
PubMed1979

Multilayer immobilized-enzyme filter reactors: urease bound to nylon fabric filters.

Urease was bound to commercially available nonwoven nylon fabric filters. Multilayer immobilized-enzyme filter reactors were constructed by packing varying numbers of urease-nylon filters in a column. Owing to the relatively open structure and high mechanical strength of the filter fabric, compaction and pressure drop effects were minimal. The reactors could be operated in a wide range of substrate concentrations and flow rates under conditions where mass-transfer limitations could be neglected. The kinetic behavior of the immobilized-enzyme filter reactors could be described by a linear form of the integrated Michaelis-Menten equation using a model based on the sequential action of the enzyme filters.

Acrylamides↗
PubMed1979

Successful and unsuccessful university students: quantitative hemispheric EEG differences.

Quantitative measurements of EEG amplitudes were obtained on academically successful and unsuccessful university students during a 5 min, eyes closed, relaxed state. Integrations measured continuously the fully rectified amplitudes of brain waves cumulated over successive epochs of 5 s, regardless of the correlation of a wave to a particular frequency band. The poor academic students, as a group, displayed a significantly higher right/left variance ratio of the cumulated amplitudes at both the temporal and occipital sites than the academically successful group. Upon examining the histograms for these cumulated amplitudes, it was found that the unsuccessful students displayed a greater number of polymodal (non-Gaussian) distributions, particularly in the right hemisphere. These data, which resemble patterns often found in depression, suggest a relative disorganization of right hemispheric activity in the unsuccessful students, and within limits, seems related to the cognitive and/or emotional stability of these students.

Achievement↗