Biomedical subjects
Publications and source records attributed to D Becker.
With the aid of a modification of the NBT test it has been shown in in vitro and in vivo studies that levamisole does not affect the NBT reduction capacity of neutrophil granulocytes. The increased NBT positivity of these cells under the influence of levamisol is due to stimulation of ingestion.
Meningiomas have been reported to have associated areas of surrounding low density on computerized tomography (CT). These low-density areas may represent edema, widened subarachnoid spaces, loculated cerebrospinal fluid, demyelination, or adjacent tumor. Two cases are presented in which this adjacent area of low density represented a tumor cyst. Recognition is important as the CT appearance of these lesions may simulate a metastatic tumor.
A study has been undertaken of the psychological problems of more than 250 adolescents and young adults with chronic renal failure in a dialysis and transplantation programme. The centre provided treatment and helped the patients to adapt to their illness. As the illness is of indefinite duration observations could be made of the course and the outcome. The individuals reaction to different forms of treatment, the possible final outcome and the institution were studied.
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Two siblings with Hallervorden-Spatz syndrome showed striking homotypism and homochronism. Neuropathologic examination and electron microscopic studies were done; neutron activation analysis showed an increase in the uptake of iron in the basal ganglia. Of particular relevance is the application of radioactive iron studies in the clinical course of this syndrome. These studies disclosed an increase in the uptake of iron in the area of the basal ganglia in one sibling and in another isolated patient. This procedure will be helpful toward the clinical diagnosis.
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Eight transformation-defective, temperature-sensitive (ts) mutants of the Prague strain of Rous sarcoma virus, subgroup A, have been isolated after mutagenesis with 5-bromodeoxyuridine followed by selection on the basis of focus tests. Five of these mutants, ts GI201, GI202, GI203, GI204, and GI205, exhibit properties like most previously reported isolates in that they show a temperature-sensitive response to each of a variety of transformation-specific parameters tested. Interestingly, GI201, in addition to the temperature-sensitive defect, carries a lesion that was observed as a nonconditional loss of expression of plasminogen activator protease. Three mutants, ts GI251, GI252, and GI253 have been disignated partial transformation-defective (PTD) mutants since they behave as ts mutants according to some tests for transformation and as wild type according to others. These three mutants fail to form foci at the nonpermissive temperature (41 degrees C) and art nontumorigenic in 3-week-old chickens (body temperature, 42 degrees C). The agglutinability by concanavalin A of cells infected with these mutants shows a definite temperature sensitivity, as do the rate of 2-deoxyglucose uptake and the disappearance of the 250, 000-dalton normal cell glycoprotein (large, external, transformation sensitive [LETS]). Although the PTD mutant-infected cells, unlike cells infected with other transformation mutants, exhibit a cell-bound plasminogen activator protease at the nonpermissive temperature, this activator is not detectable as a free protease in the medium, as it is with wild-type, virus-infected cells. The PTD mutants behave like the wild-type parent in their ability to induce transformed growth properties in the infected cells, i.e., growth beyond normal cell saturation density with or without serum-supplemented medium and growth leading to colony formation in soft-agar- or methyl cellulose-containing suspension media.
The ipsilateral registration of impedance change is necessary in case of unilateral cochlear or retrocochlear disease with middle ear impairment of the other ear and, therefore, impossibility of contralateral evocation of the reflex. If contralateral evocation fails, moreover, it will be useful in order to clarify, whether the evocation did not succeed or the registration at the contralateral ear; thus enabling a differentiation between lesions of the reflexe's afferent and efferent way. In ipsilateral impedance-change-measurements it should be distinguished between an increase of the acoustic impedance (as searched for--turn to the right at the balancemeter) and a decrease of it (turn to the left at the balancemeter). The "turns to the left" at ipsilateral evocation occur without latency and only at SPL 100 dB or more. They can be observed in patients suffering from otosclerosis, complete deafness and indissected temporal bones as well. This acoustic-mechanical effect rises at high sound pressures from the non-linearity of the sound-field, which produces an extra pressure unbalancing the pressure before and behind the tympanic membrane. This effect may interfere with the real reflex-response, but only at more than 100 dB SPL; however, it must be distinguished from the proper response in order not to find the reflex falsely positive. In three clinical examples (angioblastoma of the right cerebellum hemisphere, multiple sclerosis, cerebello-pontine angle lesion) the absence of ipsilateral impedance reflexes (isolated or additional) is demonstrated.
1. EEG (occipito-central, anterior and posterior temporo-central), blood concentration of hormones (oestradiol, progesterone, prolactin, folliculo-stimulating (FSH) and luteinizing (LH) hormones) and psychometric tests (reaction time, concentration, simple calculations, visual orientation and simple motor performance tasks) were recorded from 16 young women during a spontaneous menstrual cycle (s.c.w. group) and from 16 women taking combined oral contraceptives (o.c.w. group). All data were collected every second day except Sundays. 2. The EEGs underwent power spectrum analysis. Power and weighted mean frequency were determined for different frequency bands (theta, alpha and beta). The most constant finding in the s.c.w. group was a slight increase of mean alpha frequency during the luteal phase until menstruation (mean of occipital alpha acceleration = +0.3c/sec). The average time course of this acceleration fitted the time course of progesterone increase, but no direct correlation could be established. No such acceleration of alpha frequency could be found in the o.c.w. group, but the mean frequency in this group was about 0.5c/secslower than that of the s.c.w. group. In addition, minor cyclic changes of EEG paramenters in the s.c.w. group were observed in the occipital and temporal theta activity, the temporal alpha activity, but none in the beta range. 3. Reaction times to simple tasks, simple arithmetic, etc. were slightly but significantly decreased in the s.c.w. group during the luteal phase with a minimum on the day before or during menstruation. No such changes were observed in the o.c.w. group, which performed, in all tasks, slightly slower and slightly less correctly than the s.c.w. group. 4. The individual relative accelerations of alpha frequency and shortening of reaction times were positively correlated with each other.
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