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W List

Publications and source records attributed to W List.

At least 37 records · Page 2Linked to original sources
PubMed1986

Long-lasting EEG reactions in comatose patients after repetitive stimulation.

Twenty patients with severe head injury and a Glasgow Coma Scale of 4-6 were subjects of a multimodality EP study. After EEG recording during rest (control 1) 60 mechanical vibration stimuli and 60 visual stimuli (interstimulus interval 10 sec) were applied. Thereafter a second EEG (control 2) was measured. To quantify a long-lasting stimulated EEG alteration, control 2 was compared with control 1 on the basis of the spectral theta/beta ratio calculated from central derivations. In 50% of the patients the theta/beta ratio was changed in control 2 and therefore a long lasting stimulation effect can be assumed. Stimulus-induced cardiac alterations were also found.

Adolescent↗
PubMed1986

pi +d--> pi

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Journal Article↗
PubMed1986

Labile disulfide bonds and free thiol groups in human IgG. I. Assignment to IgG1 and IgG2 subclasses.

The content of free SH groups (about 0.24) and labile S-S bonds (about 0.64) per mole human IgG can be differentially determined by the reaction with 5,5'-dithio(2,2'-dinitro)benzoate (DTNB) for 30 min and 24 h, respectively. Highly significant linear correlations were found between the number of labile S-S and the percentage of IgG1, and the number of free SH and the percentage of IgG2 of the total IgG fraction. It is concluded that the IgG1 molecule contains one S-S bond which is opened during the 24 h interaction with DTNB by a disulfide exchange reaction. This was also confirmed by the investigation of pure monomeric IgG1. The splitting of this bond does not alter molecular weight, antigenic properties or antigen binding activity, but reduces significantly the complement binding activity of IgG. On the other hand, one free SH group could be found in the IgG2 molecule. Changes have been observed in SH and S-S levels of total IgG in patients with various malignant diseases that are to be explained by corresponding changes of the percentages of IgG1 and IgG2.

Disulfides↗
PubMed1986

Labile disulfide bonds and free thiol groups in human IgG. II. Characteristic changes in malignant diseases corresponding to shifts of IgG1 and IgG2 subclasses.

As recently shown, the measurement of labile disulfide bonds and free thiol groups of human IgG using 5,5'-dithio(2,2'-dinitro)benzoic acid (DTNB) provides direct information about the relative concentrations of IgG1 and IgG2, respectively. Furthermore, using this technique data have been obtained that show a decrease in labile S-S (corresponding to IgG1) and increase of free SH (corresponding to IgG2) in IgG from patients afflicted with various malignant diseases. In the present study a total of 280 sera from patients with malignancies of various tissue origin was investigated. Significantly reduced sigma S values, i.e. the sum of free SH and labile S-S, were obtained with IgG from cases of carcinoma of the mammary gland, urinary bladder, skin and prostate, as compared to cases with benign diseases of the respective organs. Most pronounced differences were observed between benign and malignant disorders of the prostate. It was confirmed with this group of patients that the reduction of sigma S was due to the decrease of S-S bonds, whereas the number of free SH groups remained unchanged or was increased. The cases of mammary gland carcinoma were grouped according to clinical stage. A clear correlation between reduction of sigma S and tumor size was observed. The possible theoretical and clinical implications of these results are discussed.

Breast Neoplasms↗
PubMed1985

Brain death and bioelectrical brain activity.

The effect of mechanical vibration and light stimulation on the ongoing and evoked bioelectrical activity was studied in two cases with clinically defined brain death and two other patients with severe head injury, one of them with an isoelectric EEG. The importance of such stimulation sequences for the definition of brain death is discussed, with particular emphasis on mechanical vibration.

Adult↗
PubMed1983

Quantification of spindles in comatose patients.

Quantification of spindles in comatose patients is easily possible by measurement of ERD (event-related desynchronization). ERD can either be positive (e.g., alpha blocking or alpha attenuation) or negative (spindle activity within the alpha band) or can be missing. Follow-up measurements in a comatose patient demonstrate the different time courses of VEP (visual evoked potential) and ERD during clinical recovery. That means that VEP and ERD are generated by different neuronal systems as reactions to the same external stimulus.

Brain↗
PubMed1983

[Computer assisted analysis of EEG, evoked potentials, EEG reactivity and heart rate variability in comatose patients].

A multifunctional system for combined evaluation of EEG, visual (VEP), somatosensory (SEP) and auditory brainstem evoked potentials (BAEP) is introduced. For the light stimulation an array of light emitting diodes are used for tactile stimulation a vibration stimulus is applied to he distal digit of one finger. Stimulus-synchronous EEG segments are used for EP averaging and also for quantification of either the blocking or the activation of rhythmic EEG activity. Using this technique, alpha spindles characteristic of certain comatose states can be quantified for the first time. An important parameter is the alpha frequency, which is slowed down when there is evidence of cortical lesions, but remains unchanged in primary brain stem lesions. Comparing SEP and VEP also allows for differentiation of brain stem lesions from lesions in other areas. VEP were found to be maintained in predominant brain stem disorders. The auditory brain stem potentials and the heart rate variability are of further diagnostic significance. The importance of the individual parameters such as alpha-frequency, VEP, SEP, BAEP and alpha-spindles is demonstrated by follow-up studies in comatose patients.

Alpha Rhythm↗