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Biomedical subjects

J Sandson

Publications and source records attributed to J Sandson.

At least 19 recordsLinked to original sources
PubMed1997

Verb retrieval in aphasia. 1. Characterizing single word impairments.

The ability of aphasic patients to produce words from the grammatical classes of nouns and verbs was investigated in tasks that elicited these types of words in isolation. Eleven chronic aphasic patients produced nouns and verbs in picture naming, videotaped scene naming, sentence completion, naming from definition, and oral reading. Comprehension of the meanings of nouns and verbs was tested in word/picture and word/video scene matching, and appreciation of noun/verb grammatical class differences was tested with two metalinguistic tasks. Five patients demonstrated significantly more difficulty producing verbs than nouns, two patients were significantly more impaired producing nouns than verbs, and the remaining four patients showed no difference between the two classes. There was no improvement in verb production when naming actions presented on videotape, suggesting that selective verb impairments are not attributable to conceptual difficulty in identifying actions in static pictures. Selective noun impairments occurred in the context of severe anomia, as reported in previous studies. Selective verb impairments were demonstrated for both agrammatic and fluent (Wernicke) patients, indicating that such deficits are not necessarily associated with the nonfluent and morphologically impoverished production that is characteristic of agrammatism. There was no indication that single word comprehension was affected in these patients in a manner consonant with their production impairments. Results are interpreted in light of current models of lexical organization and processing.

Adult↗
PubMed1997

Verb retrieval in aphasia. 2. Relationship to sentence processing.

Sentence comprehension and production were evaluated for 10 chronic aphasic patients who have been shown to demonstrate one of three patterns in the relative case of retrieval of nouns and verbs. Although these patterns of noun/verb production were not entirely predictable from patients' clinical classifications, they were found here to be significantly correlated with several structural indices of sentence production and with failure to comprehend semantically reversible sentences. Noun/ verb retrieval patterns were not strongly correlated with speech fluency nor with morphological characteristics of sentence production. Patients with relative impairment in the production of verbs were found to rely on high frequency, semantically empty, "light" verbs when producing sentences and to favor simple syntactic structures in which verbs do not require inflections. When forced to produce substantive verbs (in picture and scene descriptions), verb retrieval continued to undermine the production of well-formed sentences for the verb-impaired patients. In addition, two of five such patients also showed some evidence of poor realization of noun arguments for verbs they could not produce. Results are interpreted as indicating multiple contribution to patients' sentence processing impairments, one of which may be selective difficulty retrieving verbs.

Adult↗
PubMed1990

Progressive aphasia: a precursor of global dementia?

We studied 8 subjects longitudinally in whom isolated language dysfunction had developed gradually at a mean age of 62.8 years. The language deficits initially displayed by the subjects were characteristic of the syndrome of "progressive aphasia without dementia." By 5 years after onset of progressive aphasia, however, 7 of the 8 subjects additionally had developed mild dementia as diagnosed by clinical means, and the remaining subject demonstrated declining performance in both verbal and nonverbal psychometric measures. Thus, generalized cognitive impairment occurred in all. Neuropathologic evidence of a diffuse dementing disorder was present in the 2 subjects studied postmortem. One had Alzheimer's disease with disproportionate involvement of the left inferior parietal cortex, and the other displayed widespread neocortical neuronal loss and microvacuolation in the absence of specific histopathologic markers. In this series, progressive aphasia was a precursor of global dementia.

Aged↗
PubMed1987

Perseveration in behavioral neurology.

We tested a new taxonomy of perseverative behavior consisting of three categories: (1) repetition of a previous response to a subsequent stimulus (recurrent), (2) inappropriate maintenance of a category of activity (stuck-in-set), and (3) abnormal prolongation of a current activity (continuous). Three groups of neurologically impaired subjects (with aphasia, right hemisphere damage, and Parkinson's disease) were administered tests to elicit each category of perseveration. Patients with aphasia produced significantly more recurrent perseveration than did patients with right hemisphere damage or healthy controls. Stuck-in-set perseveration was associated with dopamine system dysfunction, and continuous perseveration with right hemisphere damage. We propose a theory of perseveration dependent on anatomic, neuropsychological, and pharmacologic factors related to cerebral dominance. According to this theory, disruption of specific anatomic and pharmacologic systems produces different forms of perseveration which, in turn, underlie particular neurobehavioral disorders.

Aged↗
PubMed1986

Confabulation in aphasia.

We describe a brain-damaged patient who produced two distinctive forms of confabulation, typical and atypical (aphasic), both of which were associated with perseveration, poor self-monitoring, and denial of deficit. We propose that the typical confabulations are triggered by gaps in memory for the period surrounding the onset of his illness, while the aphasic (fantastic) confabulations are triggered by gaps in semantic representation. These observations suggest that confabulations may comprise a portion of the language deficit in patients with other varieties of fluent aphasia.

Aged↗
PubMed1986

Perseveration in aphasia.

We developed a battery of tests to evaluate the relationship of perseveration to aphasia, and tested 44 subjects (18 with aphasia, 13 with right hemispheric lesions, 13 normal controls). Several major findings emerged: left hemispheric, posteriorly located, aphasia producing lesions also produced abundant perseverations, both verbal and non-verbal, which were primarily recurrent in type; right hemispheric lesions produced few perseverations, and these were primarily of the continuous type; more than half of the verbal recurrent perseverations of aphasia on a naming task were semantic in nature. We conclude that recurrent perseveration has a special, perhaps integral, link to language disorders of aphasia, particularly fluent aphasia associated with posterior lesions.

Anomia↗
PubMed1984

Varieties of perseveration.

We propose a new taxonomy for perseveration consisting of three categories which are distinctive at the levels of clinical features, process, and neuroanatomy. Stuck-in-set perseveration, the inappropriate maintenance of a current category or framework, involves an underlying process deficit in executive functioning and is related neuroanatomically to frontal lobe damage. Recurrent perseveration, the unintentional repetition of a previous response to a subsequent stimulus, involves an abnormal post-facilitation of memory traces and is related neuroanatomically to posterior left hemisphere damage. Continuous perseveration is the inappropriate prolongation or repetition of a behavior without interruption. It involves a deficit in motor output and is most common in patients with damage to the basal ganglia.

Aged↗
PubMed1967

Synovial cell synthesis of a substance immunologically like cartilage proteinpolysaccharide.

Fluids from joints contain a substance that reacts immunologically like one of two known antigenic components of articular cartilage proteinpolysaccharide. This newly recognized substance occurs in the lining cells of synovial membranes as shown by indirect immunofluorescence. The localization of this substance in tissue culture cells derived from synovial membranes and its identification in the culture medium supports the suggestion that it is synthesized by lining cells. Rheumatoid synovial cells contain less of this substance.

Cartilage, Articular↗
PubMed1967

Human synovial fluid: detection of a new component.

A new component has been detected in synovial fluid by the agar double-diffusion technique. This component is closely related immunologically to the proteinpolysaccharides of cartilage, and is the first probable degradation product of the cartilage matrix to be consistently identified in human synovial fluid.

Animals↗
PubMed1966

The antigenic determinants of the protein-polysaccharides of cartilage.

1. Protein-polysaccharides isolated from bovine, human, and porcine cartilage are antigenic in the rabbit. 2. PP-L from each of these species contains a minimum of two antigenic determinants; one is species specific, and one is common to all three species. Human PP-H also contains these two determinants. 3. Both antigenic determinants are in, or closely associated with, the protein moiety of the compound. Chondroitin sulfate and keratan sulfate were not demonstrated to be antigenic in these studies.

Agglutination Tests↗
PubMed1965

Cellular origin of hyaluronateprotein in human synovial membrane.

Bright fluorescent staining, which indicates the presence of hyaluronateprotein, was observed in the lining cells of the synovial membrane following application of rabbit antiserum to hyaluronateprotein and a fluorescein-labeled antiserum to rabbit gamma-globulin. Staining was shown to be specific and due to antigenic determinants on or closely associated with the protein moiety of hyaluronateprotein.

Animals↗