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Biomedical subjects

E Strauss

Publications and source records attributed to E Strauss.

At least 127 records · Page 7Linked to original sources

An examination of the crowding hypothesis in epileptic patients who have undergone the carotid amytal test.

Epileptic patients who had undergone the carotid amytal test were assessed on a variety of measures of verbal and non-verbal ability. All patients had left hemisphere dysfunction of early onset. Patients with atypical speech patterns performed as well as patients with left hemisphere speech on most, though not all, measures of language function. Transfer of language to the right hemisphere, however, occurred at a heavy cost. Patients with atypical speech patterns performed more poorly than their left hemisphere speech counterparts on a wide variety of non-verbal tests. These results are discussed in terms of the "crowding" hypothesis.

Adolescent↗

The ontogeny of hemispheric specialization: some old hypotheses revisited.

This paper re-examines two hypotheses on the ontogeny of hemispheric specialization that long ago fell into disfavor in neuropsychology. It is argued that these hypotheses, equipotentiality and progressive lateralization, may have suffered from misinterpretation that fostered premature acceptance of the developmental invariance view of hemispheric specialization. An alternative view is presented that incorporates both hypotheses within a neurodevelopmental context using anatomical (postmortem) and childhood aphasia data.

Adolescent↗

A comparison of the Rey and Taylor figures.

Forty healthy young adults were given the Rey-Osterrieth or Taylor Complex Figures in order to evaluate the comparability of these two measures. Copy trials of the Rey and Taylor Figures proved to be of equivalent difficulty. By contrast, 30-minute delayed recall of the Rey Figure was considerably more difficult than that of the Taylor Figure.

Journal Article↗

Early image acquisition after administration of indium-111 platelets in clinically suspected deep venous thrombosis.

Indium-111 platelet scintigraphy accurately detects acute deep venous thrombosis in asymptomatic high-risk patients and may be used as a surveillance test. However, its value in symptomatic patients and its accuracy early after platelet injection are not satisfactorily established. The latter is important for timely institution of therapy. Accordingly, 65 patients (67 limbs) with suspected deep venous thrombosis (symptom duration 8 +/- 10 days, mean +/- standard deviation) were prospectively studied with platelet scintigraphy and contrast venography. Platelets were labeled with 405 +/- 101 mCi indium-111 oxine. The labeling efficiency was 80 +/- 10%. All images were acquired within 120 minutes after intravenous administration of the platelet suspension. Both platelet scintigraphy and venography were interpreted independently by 2 blinded observers (for each technique). Five separate analyses were performed. Each scintigraphic reader was compared to each venographic reader. A fifth analysis--consisting of readings with blinded agreement of both readings of the platelet scans and both readings of the venograms--was performed. Interobserver agreement was 92% for venography and 79% for scintigraphy. Excluding anticoagulated patients, the sensitivity of platelet scintigraphy was between 38 and 46% and the specificity was between 92 and 100%. Thus, early imaging of labeled platelets for the diagnosis of symptomatic deep venous thrombosis carries a high specificity but a much lower sensitivity. It is speculated that the low sensitivity is related to the inactivity of the thrombus. This may suggest that early imaging will only be useful in patients whose symptoms are of recent onset.

Blood Platelets↗

The corpus callosum is larger with right-hemisphere cerebral speech dominance.

Variations in the size of the human corpus callosum were examined as a possible morphological substrate of functional asymmetries of the cerebral hemispheres, such as cerebral speech dominance. The midsagittal surface area of the corpus callosum, obtained by magnetic resonance imaging, was measured in 50 patients with epilepsy and 50 neurologically normal control subjects. The mean callosal area did not differ significantly between patients and control subjects, between left-handed and right-handed subjects, or between men and women. When measurements were compared among 44 patients, whose cerebral speech dominance had been determined by the intracarotid injection of sodium amytal, the area of the corpus callosum was significantly greater in patients with right-hemisphere cerebral speech dominance. The mean callosal area was greater by 109 to 159 square millimeters (18-28%) when compared to that of patients with either left-hemisphere speech dominance or bilateral speech representation. This difference in midsagittal surface area could represent as many as 37 to 54 million additional callosal axons in subjects with right-hemisphere cerebral speech dominance.

Adolescent↗

Some correlates of intra- and interhemispheric speech organization after left focal brain injury.

Determinants of inter- and intrahemispheric organization following left focal injury were examined with data deriving from four different studies that used three different assessment methods (amobarbital, temporal lobectomy, dichotic listening). With regard to interhemispheric reorganization, the results revealed that the earlier the lesion onset, the higher the probability of a biomodal hemispheric reorganization (speech and hand). A unimodal reorganization (speech only) was tied to a later occurring lesion, but one before age six. Furthermore, interhemispheric speech reorganization was associated with an early lesion onset while intrahemispheric speech maintenance was linked to a later lesion onset. The results are discussed in terms of hemispheric plasticity and functional maturity.

Brain↗

Results of anterior corpus callosum section in 24 patients with medically intractable seizures.

Twenty-four medically refractory seizure patients, who did not qualify for excisional surgery, had anterior two-thirds corpus callosum section. Three to 11 years' postoperative follow-up suggests that this procedure can (1) lateralize a frontal lobe focus, which may lead to subsequent localized excision and (2) significantly reduce seizure frequency and severity in 75% of the patients without giving any permanent neurologic deficits. Patients with an ictal focus confined to one frontal lobe did best (8/8 improved), followed by patients with secondarily generalized seizures and multifocal bilateral foci (5/6 improved). Patients with mental retardation benefited less frequently (5/10 improved), but 4/4 from this group with ictal falls associated with Lennox-Gastaut syndrome did benefit. In this series, the improvements following the anterior partial section were lasting if present at 1 year of follow-up. Anterior corpus callosum section should be considered as a diagnostic (lateralizing) and therapeutic option in appropriately defined medically refractory patients who do not qualify for excisional surgery.

Adolescent↗

Performance on a free-recall verbal dichotic listening task and cerebral dominance determined by the carotid amytal test.

Epileptic patients whose speech dominance had been ascertained using the carotid amytal technique were given a verbal dichotic listening test. Patients with left hemisphere speech dominance, like normal controls, showed a REA. Patients with right hemisphere speech representation, as a group, tended not to show a bias toward either ear. Moreover, repeated administrations of the verbal dichotic listening test yielded similar results.

Adolescent↗

Unexpected low prevalence of delta antibodies in the east Amazon region and São Paulo: evidence for regional differences in the epidemiology of delta hepatitis virus within Brazil.

Antibodies (anti-HD) to hepatitis delta virus (HDV) were tested by radioimmunoassay in 207 human serum samples from the eastern Amazon (states of Pará and Amapá) and São Paulo, Brazil. 42 Amazon HBsAg asymptomatic carriers were negative for anti-HD. 84 São Paulo HBsAg asymptomatic carriers were also negative. Among the 81 HBsAg patients from São Paulo with different liver diseases, only one had anti-HD. Liver biopsy of this chronic active hepatitis case was positive for HBsAg, HBcAg and HDAg in liver, by an immunoperoxidase technique. The low prevalence of HDV infections in São Paulo and eastern Amazon was unexpected and contrasts with the recent reports of high prevalence in the western Amazon region. Such regional differences emphasize the need for extensive and precise worldwide epidemiological studies of HDV.

Adult↗

Lateral preferences and performance on non-verbal laterality tests in a normal population.

The goal of the present study was to determine if, in a normal population, handedness, footedness, eyedness, earedness and overall congruency across lateral preferences were predictive of perceptual asymmetry on non-verbal tasks. In Experiment 1, subjects had to decide whether a laterally presented facial expression matched a previously presented target. In Experiment 2, subjects had to determine whether the tone of voice heard on dichotic and binaural presentations was the same or different. Eye preference was the most successful variable in predicting both visual field and ear advantages. Knowledge of a person's eye preference however, did not allow for a very accurate prediction of perceptual asymmetry. Nonetheless, the findings suggest that eye preference should be taken into account in future non-verbal laterality studies.

Adult↗

An epileptic syndrome caused by mesial frontal lobe seizure foci.

We describe an epileptic syndrome of bilaterally coordinated limb movements, axial movements, vocalization, and nonmasticatory oral activity. EEG and physiologic evidence indicates the syndrome is caused by ictal discharge in the mesial frontal lobes. Two of 12 patients were not helped by anterior temporal lobectomy, and 3 others improved after section of the anterior two-thirds of the corpus callosum.

Adolescent↗

Molecular analysis of the hotspot of recombination in the murine major histocompatibility complex.

Biological and serological assays have been used to define four subregions for the I region of the major histocompatibility complex (MHC) in the order I-A, I-B, I-J, and I-E. The I-J subregion presumably encodes the I-J polypeptide of the elusive T-cell suppressor factors. Restriction enzyme site polymorphisms and DNA sequence analyses of the I region from four recombinant mouse strains were used to localize the putative I-B and I-J subregions to a 1.0-kilobase (kb) region within the E beta gene. Sequencing this region from E beta clones derived from the two mouse strains: B10.A(3R), I-Jb and B10.A(5R), I-Jk initially used to define the I-J subregion revealed that these regions are identical, hence the distinct I-Jb and I-Jk molecules cannot be encoded by this DNA. In addition, the DNA sequence data also refute the earlier mapping of the I-B subregion. Analysis of the DNA sequences of three parental and four I region recombinants reveals that the recombinant events in three of the recombinant strains occurred within a 1-kb region of DNA, supporting the proposition that a hotspot for recombination exists in the I region. The only striking feature of this hotspot is a tetramer repeat (AGGC)n that shows 80 percent homology to the minisatellite sequence which may facilitate recombination in human chromosomes.

Animals↗

Demonstration of superior sagittal sinus thrombosis by indium-111 platelet scintigraphy.

Superior sagittal sinus thrombosis, documented by cerebral angiography, was demonstrated by indium-111 platelet scintigraphy in a 40-year-old man presenting with seizures and intracerebral hematoma. Early scintigraphy demonstrated focal increased indium-111 activity at the two ends of the thrombus, while later scintigraphy showed diffuse increased activity in the area of the sinus. This initial experience suggests that platelet scintigraphy may provide unique information regarding the natural history of intracranial venous thrombosis.

Adult↗